RU2792674C2 - Productive flowering watermelon plant - Google Patents

Abstract

FIELD: biochemistry.

SUBSTANCE: invention relates to the field of biochemistry, in particular to a method for selecting watermelon plants characterized by productive flowering. The method for identifying a watermelon plant containing three genetic determinants that are genetically or physically linked to 3 marker loci that segregate together with the feature being a productive flowering is also disclosed.

EFFECT: possibility to effectively identify watermelon plants characterized by productive flowering.

5 cl, 1 dwg, 3 tbl, 3 ex

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to new watermelon plants showing an increased number of male flowers. The present invention also relates to seeds and parts of these plants, such as fruits. The present invention further relates to methods for obtaining and using such seeds and plants. The present invention also relates to new genetic determinants associated with an increased number of male flowers, and to molecular markers linked to these new genetic determinants.

BACKGROUND OF THE INVENTION

Watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] is an important specialty crop believed to have originated in southern Africa near the Kalahari Desert (Dane & Liu, 2007). It is a traditional crop in all major areas of agricultural production, and in 2013 its world production was 109601914 tons (according to data provided by the Food and Agriculture Organization of the United Nations). The United States is the world's sixth largest producer of watermelons, with a production of about 1,771,734 tons in 2013, amounting to approximately US$483 million (USDA Vegetables 2015 Summary).

Most of the watermelon acreage in the United States is occupied by seedless watermelon. The triploid seedless watermelon produces a higher yield than the diploid watermelon. Significantly increased watermelon productivity and farm value, as well as reduced US production space since the mid-1990s, are the result of industrial use of triploid seedless watermelon varieties. Planted area of seedless watermelon is also increasing worldwide, as the production of seedless watermelon usually fetches a much better price than the average market price of seed watermelons.

The triploid seedless watermelon is a pure F1 hybrid between a tetraploid watermelon maternal and a diploid paternal watermelon (Kihara, 1951). The normal seeded diploid watermelon has 22 chromosomes (2N=2X=22), while the tetraploid watermelon has 44 chromosomes (2N=4X=44). When the female flowers of a tetraploid watermelon are pollinated by the male flowers of a diploid watermelon seed plant, the seeds produced in the fruits of the tetraploid plant are triploid hybrid seeds. Triploid hybrid plants grown from triploid seeds are self-infertile due to the inability of the triploid zygote to produce normal viable gametes (Fehr, 1987). Therefore, in order to produce seedless watermelon fruits, the triploid hybrid plants must be pollinated with pollen from diploid watermelon plants, called diploid pollinator plants, which, based on the foregoing, are planted together with the triploid hybrid plants in the same field.

To ensure proper pollination of seedless watermelon plants, it is common practice today to co-plant diploid pollinator plants on approximately 25-33% of the field area (eg WO 2003/075641, table 2). The rest of the field is planted with triploid plants. Thus, to maximize the value of the crop from the field, growers use high-yielding commercial varieties of diploid watermelons that end up competing with triploid seedless varieties for sun, nutrients, and space. Since the pollination of a triploid seedless watermelon is critical to producing seedless fruits, there is a need for an improved diploid watermelon pollinator plant that effectively pollinates a triploid seedless plant while maintaining or increasing the yield of said triploid seedless watermelon.

WO 2000/70933 discloses a pollinator for the triploid seedless watermelon that produces small and non-marketable fruits. However, the use of this pollinator reduced the overall yield of marketable seedless fruits compared to the use of a classic pollinator plant. In addition, the unharvested fruits of an open pollinator plant become hosts for diseases in the future, and their seeds will germinate and grow into weeds, further reducing yields.

WO 2003/075641 discloses an improved diploid watermelon pollinator plant that produces small disposable watermelon fruits. The pollinator plant also has small leaves, allowing the pollinator to grow in close proximity to triploid seedless watermelon plants without competing with them. US 6,759,576 describes SP-1 or Super Pollenizer 1 as one example of such an improved diploid pollinator plant.

Despite all efforts to provide improved diploid watermelon pollinator plants, stable pollination of triploid seedless watermelon plants is still a major limitation in fruit production of seedless watermelon, and there is a long and unmet need for further improved diploid watermelon pollinator plants.

BRIEF DESCRIPTION OF THE INVENTION

The present invention addresses the need for a more stable pollination of triploid seedless watermelon plants by incorporating and providing new watermelon plants with a productive flowering trait. In specific embodiments, the present invention discloses new watermelon plants capable of producing more open male flowers per unit area, optionally for a longer period of time, thereby improving the ability of the watermelon plant to pollinate a triploid seedless plant. Having more open male flowers per unit area increases the likelihood of a pollination event. Thus, by improving the pollination capacity of diploid watermelon, a more stable and more complete pollination of triploid female flowers can be achieved, which will have a positive impact on the yield potential of triploid fruits. In addition, in some embodiments, increasing the number of diploid male flowers in a watermelon plant will allow the grower to reduce the ratio of diploid to triploid plants in the field, thereby reducing the cost of production and increasing the efficiency of the use of acreage to produce triploid seedless watermelon.

In addition to being useful for pollinating a triploid seedless plant, the present invention is also useful for improving the efficiency of producing hybrid watermelon seeds by increasing the proportion of male flowers from a pollen donor compared to male flowers from a pollen acceptor. It is expected that this will lead to an increase in the share of hybrid seeds in uncontrolled production.

In general, the characteristics of the productive flowering watermelon plant disclosed in the present invention provide the watermelon grower with new solutions to increase economic and commercial efficiency when using a diploid watermelon pollinator plant to produce triploid seedless watermelon fruits or hybrid watermelon seeds.

The trait that is productive flowering is supported by three separate hereditary genetic determinants that cause an increase in the number of open male flowers and are located on chromosomes 1, 3 and 7, respectively. Together, these genetic determinants have been found to control/direct the trait that is productive flowering. The present invention further discloses specific molecular markers that are associated with these new genetic determinants and that allow the determinants to be identified and introgressed into any desired background plant genotype.

In a first embodiment, a productive flowering watermelon plant is provided comprising three genetic determinants that drive or control the expression of a productive flowering trait, wherein said productive flowering plant produces at least 40 open male flowers per square meter per the period of the most intensive flowering.

In a further embodiment, the watermelon plant according to any of the previous embodiments contains three genetic determinants that are genetically or physically linked to 3 marker loci that co-segregate with a productive flowering trait and are selected from the group consisting of marker loci IIH2119, IIH5250 and IIH4836, respectively.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said genetic determinants are genetically or physically linked to marker loci IIH2119, IIH5250, and IIH4836, respectively, and where:

a) marker locus IIH2119 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 1 and a reverse primer under SEQ ID NO: 2 and a probe under SEQ ID NO: 3,

b) marker locus IIH5250 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 4 and a reverse primer under SEQ ID NO: 5 and a probe under SEQ ID NO: 6,

c) marker locus IIH4836 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO: 8 and a probe under SEQ ID NO: 9.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said genetic determinants can be obtained from a donor plant that has the genetic background of an SP-7 watermelon plant whose representative seed is deposited under Accession No. No. PTA-123747 in ATCC, or its descendant or ancestor.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein the SP-7 watermelon plant, or a descendant or ancestor thereof, is the source of said genetic determinants of productive flowering, and wherein the representative seed of the SP-7 line deposited under the access number №РТА-123747 in АТСС.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said plant is obtained by crossing a watermelon plant line SP-7, the representative seed of which is deposited under ATCC Accession No. PTA-123747, or its descendant or ancestor with a watermelon plant that does not contain the genetic determinants of productive flowering.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said plant is an inbred, dihaploid, hybrid, triploid, or tetraploid plant.

In a further embodiment, a plant part, organ, or tissue is provided that can be obtained from a watermelon plant according to any of the previous embodiments, including, but not limited to, leaves, stems, roots, flowers or flower parts, fruits, shoots, gametophytes, sporophytes. , pollen, anthers, microspores, ovules, zygotes, embryos, meristem patches, callus tissue, seeds, cuttings, cell or tissue cultures, or any other part or product of a plant that still exhibits characteristics constituting a productive flowering, in accordance with this invention, in particular when grown to produce a plant that bears fruit.

In a further embodiment, a seed of a watermelon plant according to any of the previous embodiments is provided.

In another embodiment, the use of a watermelon plant, plant part, or seed according to any of the previous embodiments is contemplated for the production and harvesting of triploid seedless fruits.

In another embodiment, the present invention relates to the use of a watermelon plant, plant part, or seed according to any embodiments, wherein the plant, plant part, or watermelon seed refers to a watermelon plant line SP-7, the representative seed of which is deposited under Accession No. PTA- 123747 in ATCC, or its descendant or ancestor.

In another embodiment, the present invention relates to a method for providing a productive flowering watermelon plant, plant part, or plant seed, said method comprising the steps of:

a) crossing a 1st plant lacking the genetic determinants of productive flowering with a 2nd watermelon plant according to any embodiments,

b) producing offspring of a watermelon plant, and

c) optionally selecting a plant from said progeny, characterized in that said plant produces at least 40 open male flowers during its peak flowering period.

In a further embodiment, the present invention relates to the method of the previous embodiment, wherein the 2nd watermelon plant is an SP-7 watermelon plant whose exemplary seed is deposited under ATCC Accession No. PTA-123747, or a descendant or ancestor thereof.

In another embodiment, the present invention relates to a method for producing a productive flowering watermelon plant, comprising the following steps:

a) providing seeds of a watermelon plant according to any of the previous embodiments,

b) germinating said seed and growing from it into a mature fertile plant,

c) inducing self-pollination in said plant of a), growing fruits and extracting fertile seeds therefrom, and

d) growing plants from the seeds extracted in step c) and selecting a watermelon plant characterized by productive flowering.

In another embodiment, the present invention relates to a method for identifying a watermelon plant containing three genetic determinants that are genetically or physically linked to 3 marker loci that co-segregate with a productive flowering trait and are selected from the group consisting of marker loci IIH2119, IIH5250 and IIH4836, respectively, wherein said watermelon plant produces at least 40 open male flowers at its peak, and wherein said method comprises the steps of:

a) providing a population with segregation for a trait that is a productive bloom,

b) screening a segregating population for a representative having a productive flowering trait, where said trait can be identified by the presence of 3 marker loci that co-segregate with the productive flowering trait and are marker loci IIH2119, IIH5250 and IIH4836,

c) selecting one member of the segregating population, where said member is characterized by a trait that is a productive bloom.

In another embodiment, the present invention relates to a method for increasing the number of male flowers of a watermelon plant, comprising the steps of:

a) selecting a watermelon plant that is characterized by a productive flowering trait, wherein said productive flowering trait is associated with three genetic determinants capable of driving the expression of said productive flowering trait in the watermelon plant, where said trait can be identified by the presence of 3 marker loci that co-segregate with a productive flowering trait and are selected from the group consisting of marker loci IIH2119, IIH5250 and IIH4836, or by the presence of any contiguous marker locus that has a statistically significant correlation and therefore co-segregates with a trait representing a productive flowering;

b) crossing said plant from step a) which is characterized by the productive flowering trait with a watermelon plant, in particular a cultivated watermelon plant, which does not have the productive flowering trait and which exhibits fewer male flowers than with the plant from stage a), and

c) selection of progeny resulting from said cross that has an increased number of male flowers compared to the plant from stage b) and which shows the association of the trait, which is a productive flowering, with 3 marker loci IIH2119, IIH5250 and IIH4836 from stage a) .

BRIEF DESCRIPTION OF GRAPHICS

The figure 1 shows the number of open male flowers per square meter during the most intensive flowering for different genotypes, which were grown in Woodland, California.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments

In the 1st embodiment, the present invention relates to a watermelon plant, in particular a cultivated watermelon plant, more specifically to a diploid pollinator-type watermelon plant, where the specified plant contains three genetic determinants that jointly control the expression of a trait that is a productive flowering, or control it , and where the specified plant, characterized by productive flowering, produces at least 40 open male flowers per square meter during the period of the most intensive flowering. In a further embodiment, said productive flowering plant produces at least 45, more preferably at least 50 open male flowers per square meter during peak flowering.

In another embodiment, the present invention relates to a watermelon plant, in particular a cultivated watermelon plant, more specifically a diploid pollinator-type watermelon plant, wherein said plant contains three genetic determinants that direct or control the expression of a productive flowering trait, and wherein said a productive-flowering plant produces at least 30% more open male flowers per square meter during the peak flowering period compared to a watermelon plant that does not contain these three genetic determinants. In a further embodiment, said prolific flowering plant produces 50%, more preferably 70%, but even more preferably 100% more open male flowers per square meter at its peak, compared to a watermelon plant that lacks these genetic determinants.

In another embodiment, the present invention relates to a watermelon plant containing three genetic determinants that drive or control the expression of a productive flowering trait, wherein said three combined genetic determinants result in an increase in the number of open male flowers per square meter during the peak flowering period. compared with an isogenic watermelon plant line that does not contain the three indicated genetic determinants.

In an additional embodiment, the three genetic determinants of the present invention are located on chromosomes 1, 3 and 7, respectively.

In yet another embodiment, a further embodiment provides a watermelon plant according to any of the previous embodiments, wherein the three genetic determinants are genetically or physically linked to 3 marker loci that co-segregate with a productive flowering trait and are selected from the group consisting of marker loci IIH2119, IIH5250, and IIH4836, respectively.

In another embodiment, a watermelon plant is provided according to any of the previous embodiments, wherein said genetic determinants are genetically or physically linked to 3 marker loci, respectively, and wherein:

i. marker locus IIH2119 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 1 and a reverse primer under SEQ ID NO: 2 and a probe under SEQ ID NO: 3,

ii. marker locus IIH5250 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 4 and a reverse primer under SEQ ID NO: 5 and a probe under SEQ ID NO: 6,

iii. marker locus IIH4836 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO: 8 and a probe under SEQ ID NO: 9.

In another embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said plant comprises SEQ ID NO: 3, SEQ ID NO: 6, and SEQ ID NO: 9.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said genetic determinants can be obtained from a donor plant that has the genetic background of an SP-7 watermelon plant whose representative seed is deposited under Accession No. No. PTA-123747 in ATCC, or its descendant or ancestor.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said genetic determinants are themselves contained in a donor plant that has the genetic background of an SP-7 watermelon plant whose representative seed is deposited under Accession No. ATSS No. РТА-123747, or its descendant or ancestor.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein the SP-7 watermelon plant, or a descendant or ancestor thereof, is the source of said genetic determinants of productive flowering, and where the representative seed of the SP-7 line deposited under the access number №РТА-123747 in АТСС.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said plant is obtained by crossing a watermelon plant line SP-7, the representative seed of which is deposited under ATCC Accession No. PTA-123747, or its descendant or ancestor with a watermelon plant that does not contain the genetic determinants of productive flowering.

In a further embodiment, the watermelon plant of the present invention is a watermelon plant according to any of the previous embodiments, wherein said genetic determinants are introgressed from a donor plant that has the genetic background of an SP-7 watermelon plant, the representative seed of which is deposited under Accession No. PTA-123747 in ATCC, or its descendant or ancestor.

In a further embodiment, the present invention relates to a watermelon plant according to any of the previous embodiments, comprising three genetic determinants conferring a productive flowering trait in a watermelon plant, wherein said genetic determinants are identical to the corresponding alleles present in the SP-7 watermelon plant line. , the typical seed of which was deposited under accession number PTA-123747, in ATCC, or its descendant or ancestor, which are genetically or physically linked to 3 marker loci in the genome of the watermelon plant line SP-7, the typical seed of which was deposited under accession number PTA- 123747 in ATCC, or its descendant or ancestor, the marker loci of which segregate together with the productive flowering trait and can be identified in the genome of the SP-7 watermelon plant, the typical seed of which is deposited under accession number PTA-123747 in ATCC, or its descendant or ancestor, and at the same time its marker The first loci are marker loci IIH2119, IIH5250, and IIH4836.

In one embodiment of the present invention, the watermelon plant is a plant according to any of the previous embodiments, in particular a watermelon crop plant, in particular a haploid, dihaploid, inbred, hybrid, diploid, triploid or tetraploid watermelon crop plant.

In a further embodiment, a plant part, organ, or tissue is provided that can be obtained from a watermelon plant according to any of the previous embodiments, including, but not limited to, leaves, stems, roots, flowers or flower parts, fruits, shoots, gametophytes, sporophytes. , pollen, anthers, microspores, ovules, zygotes, embryos, meristem patches, callus tissue, seeds, cuttings, cell or tissue cultures, or any other part or product of a plant that still exhibits characteristics constituting a productive flowering, in accordance with this invention, in particular when grown to produce a plant that bears fruit.

In a further embodiment, a seed is provided that grows into a watermelon plant according to any of the previous embodiments.

In another embodiment, the present invention relates to the use of a watermelon plant, plant part or seed according to any of the previous embodiments for the purpose of obtaining and harvesting triploid seedless fruits.

In another embodiment, the present invention relates to the use of a watermelon plant, plant part, or seed according to any of the previous embodiments, wherein the watermelon plant, plant part, or seed refers to an SP-7 watermelon plant whose exemplary seed is deposited under Accession No. PTA -123747 in ATCC, or its descendant or ancestor.

In a further embodiment, the present invention relates to the use of a watermelon plant according to any of the previous embodiments for planting in a field, greenhouse, or film-covered greenhouse.

In a further embodiment, the present invention relates to the use of a watermelon plant according to any of the previous embodiments as a watermelon rootstock. In a further embodiment, the present invention relates to the use of the SP-7 watermelon plant, typical seed of which is deposited under ATCC Accession No. PTA-123747, or a descendant or ancestor thereof, as a watermelon rootstock.

In a further embodiment, the present invention relates to the use of genetic determinants that are genetically or physically linked to 3 marker loci that co-segregate with a productive flowering trait and are marker loci, respectively, IIH2119, IIH5250, and IIH4836, to confer a trait that is productive flowering, a watermelon plant that lacks the specified trait.

In another embodiment, the plant according to the present invention is a male sterile plant.

In another embodiment, the plant according to the present invention produces mature watermelon fruits wherein the inner flesh of said ripe fruits is yellow, red, green, orange or white.

In one embodiment, the present invention relates to a watermelon plant according to any of the previous embodiments, which is a hybrid watermelon plant, in particular a cultivated watermelon plant, containing genetic determinants of productive flowering.

In one embodiment, the present invention provides watermelon fruits derived from a watermelon plant according to any of the previous embodiments.

In a further embodiment, the genetic determinants are genetically linked to 3 marker loci that co-segregate with a productive flowering trait, where said genetic determinants can be obtained from a donor plant having the genetic background of the SP-7 watermelon plant, the typical seed of which is deposited under accession number No. PTA-123747 in ATCC, or a descendant or ancestor thereof, containing the indicated genetic determinants, and where 3 marker loci that co-segregate with a productive flowering trait are marker loci IIH2119, IIH5250 and IIH4836.

The present invention further relates to watermelon plant seed, in particular watermelon crop seed, which grows into a watermelon plant according to any of the previous embodiments.

In addition, the present invention relates to the use of a watermelon plant according to any of the previous embodiments to introgress a productive flowering trait into a watermelon plant that lacks said productive flowering trait.

The present invention further relates to the use of a watermelon plant according to any of the previous embodiments for sowing in a field, greenhouse or film-covered greenhouse.

In addition, the present invention relates to the use of a genetic determinant in accordance with any of the embodiments disclosed herein to increase the number of male flowers of a watermelon plant that lacks the specified characteristic, which is a productive flowering.

The present invention is further directed to a genetic determinant driving or controlling the expression of a productive flowering trait in a watermelon plant. In an additional embodiment, the genetic determinants of the present invention are located on chromosome 1, 3 and 7, respectively. In a further embodiment of the present invention, the genetic determinants can be obtained from a donor plant that has the genetic background of the watermelon plant line SP-7, the typical seed of which is deposited under accession number PTA-123747 in ATCC, or its descendant or ancestor, and containing the specified genetic determinants .

In a further embodiment, the genetic determinants of the present invention are genetically or physically linked to 3 marker loci that co-segregate with the productive flowering trait and are marker loci IIH2119, IIH5250 and IIH4836, or any adjacent marker that has a statistically significant correlation and , respectively, segregates together with the characteristic, which is a productive flowering.

In another embodiment, said genetic determinants of the present invention, or functional portions thereof, are genetically linked to 3 marker loci, respectively, where:

i. marker locus IIH2119 can be identified by NDP by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 1 and a reverse primer under SEQ ID NO: 2 and a probe under SEQ ID NO: 3,

ii. marker locus IIH5250 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: forward primer under SEQ ID NO: 4 and reverse primer under SEQ ID NO: 5 and probe under SEQ ID NO: 6, iii. marker locus IIH4836 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO: 8 and a probe under SEQ ID NO: 9.

The present invention provides a kit for detecting a locus of a trait that is a productive flowering in a watermelon plant, in particular in a cultivated watermelon plant, where the kit contains at least one pair of PCR oligonucleotide primers and a probe selected from the following:

a. a primer pair represented by a forward primer under SEQ ID NO 1 and a reverse primer under SEQ ID NO 2 and a probe under SEQ ID NO: 3, or

b. a primer pair represented by a forward primer under SEQ ID NO 4 and a reverse primer under SEQ ID NO 5 and a probe under SEQ ID NO: 6, or

c. a primer pair represented by a forward primer under SEQ ID NO 7 and a reverse primer under SEQ ID NO 8 and a probe under SEQ ID NO: 9, or

another primer pair, or a primer pair representing an adjacent marker that has a statistically significant correlation and, accordingly, co-segregates with the productive flowering trait.

The present invention also discloses the use of some or all of these DNA markers in accordance with the present invention for the precise selection and/or genotyping of a productive flowering trait locus in a watermelon plant, in particular a watermelon crop plant.

The present invention further discloses the use of some or all of these DNA markers to identify in a watermelon plant, in particular a cultivated watermelon plant, in particular a watermelon plant of the present invention, the presence of a trait locus that is a productive flowering, and/or to monitor locus introgression. a trait representing productive flowering in a watermelon plant, in particular a cultivated watermelon plant, in particular a watermelon plant in accordance with the present invention and described herein.

The present invention further discloses a polynucleotide (amplification product) that can be obtained in a PCR reaction using at least one oligonucleotide primer or a pair of oligonucleotide primers for PCR selected from the group consisting of SEQ ID NO 1 and SEQ ID NO 2; SEQ ID NO 4 and SEQ ID NO 5; SEQ ID NO 7 and SEQ ID NO 8; and reactions with probes selected from the group consisting of SEQ ID NO 3, SEQ ID NO 6, or SEQ ID NO 9, or another primer representing an adjacent marker that has a statistically significant correlation and, accordingly, co-segregates with a trait that is a productive flowering, or with one of the disclosed markers, the amplification product of which corresponds to the amplification product obtained from the watermelon plant line SP-7, the typical seed of which is deposited under accession number PTA-123747 in the ATCC, or its descendant or ancestor containing the indicated genetic determinants, in PCR reactions with identical primers or primer pairs, provided that the corresponding marker locus is still present in the specified watermelon plant and/or can be considered its allele.

Also contemplated herein is a polynucleotide that is characterized by at least 90%, in particular at least 95%, in particular at least 96%, in particular at least 97%, in particular at least 98%, in particular at least 99% sequence identity with the sequence of said amplification product and/or a polynucleotide having a nucleotide sequence that hybridizes with the nucleotide sequences of said amplification product, which can be obtained in the above PCR reaction.

The amplification product of the present invention and described herein above can then be used to generate or design new primers and/or probes that can be used to identify the locus of a trait that is a productive flowering.

Therefore, the present invention additionally relates in one embodiment to derived markers, in particular to derived primers or probes, designed from an amplification product in accordance with the present invention, and as described herein above, using methods known in the art. technique, and the resulting derived markers are genetically linked to the locus of the trait, which is a productive flowering.

In another embodiment, the present invention relates to a method for providing a productive flowering watermelon plant, plant part, or plant seed, said method comprising the steps of:

a) crossing a 1st plant lacking the genetic determinants of productive flowering with a 2nd watermelon plant according to any embodiments,

b) producing offspring of a watermelon plant, and

c) optionally selecting a plant from said progeny, characterized in that said plant produces at least 40 open male flowers per square meter during its peak flowering period.

In another embodiment, the present invention relates to the method of the previous embodiment, wherein said plant of step c) produces at least 45, more preferably at least 50 open male flowers per square meter during its peak flowering period.

In another embodiment, the present invention relates to a method for providing a productive flowering watermelon plant, plant part, or plant seed, said method comprising the steps of:

a) crossing a 1st plant lacking the genetic determinants of productive flowering with a 2nd watermelon plant according to any embodiments,

b) producing offspring of a watermelon plant, and

c) optionally selecting a plant from said progeny, characterized in that said plant produces 30% more open male flowers per square meter during the peak flowering period compared to the watermelon plant from step a) which lacks said three genetic determinants.

In another embodiment, the present invention relates to the method of the previous embodiment, wherein said plant from step c) produces 50%, more preferably 70%, but even more preferably 100% more open male flowers per square meter during the most intense period. flowering compared to the watermelon plant from stage a), which lacks these genetic determinants.

In a further embodiment, the method according to any of the previous embodiments is contemplated, wherein the 2nd watermelon plant from step a) is an SP-7 watermelon plant whose exemplary seed is deposited under ATCC Accession No. PTA-123747, or a descendant thereof, or ancestor.

In another embodiment, a process for producing a productive flowering watermelon plant is contemplated, comprising the steps of:

a) providing seeds of a watermelon plant according to any of the embodiments,

b) germinating said seed and growing from it into a mature fertile plant,

c) inducing self-pollination in said plant of a), growing fruits and extracting fertile seeds therefrom, and

d) growing plants from the seeds extracted in step c) and selecting a watermelon plant characterized by productive flowering.

In a further embodiment, the present invention relates to a method for producing a watermelon plant, in particular a cultivated watermelon plant, wherein said watermelon plant is characterized by a productive flowering trait, comprising the following steps:

a. selection of a watermelon plant that is characterized by a productive flowering trait, where said watermelon productive flowering trait is associated with three genetic determinants capable of directing or controlling the expression of a productive flowering trait in a watermelon plant, where said genetic determinants are genetically linked to 3 marker loci that co-segregate with the flowering trait and are IIH2119, IIH5250 and IIH4836 marker loci, or any adjacent marker that is statistically significantly correlated and therefore co-segregates with the trait productive flowering; or with any of the disclosed marker loci,

b. crossing said plant from step a) which is characterized by a productive flowering trait with a watermelon plant, in particular a cultivated watermelon plant, which is not characterized by a productive flowering trait, and

c. selecting a progeny of a watermelon plant resulting from said cross that is characterized by the productive flowering trait of watermelon and that shows association with said 3 marker loci from step a) and shows productive flowering.

The present invention further discloses methods for identifying a watermelon plant bearing a productive flowering trait, comprising the following steps:

a) providing a population with segregation for a trait that is a productive bloom,

b) screening the segregating population for a representative carrying the trait of productive flowering, where said trait can be identified by the presence of 3 marker loci IIH2119, IIH5250 and IIH4836,

c) selecting one member of the segregating population, where said member is characterized by a trait that is a productive bloom.

The present invention further discloses methods for identifying a watermelon plant bearing a productive flowering trait, comprising the following steps:

a) providing a population with segregation for a trait that is a productive bloom,

b) screening a segregating population for a representative carrying the trait of productive flowering, where said trait can be identified by the presence of 3 marker loci that are located on chromosomes 1, 3 and 7, respectively, and co-segregate with the trait of productive flowering, and can be identified using an oligonucleotide PCR primer or a pair of oligonucleotide PCR primers selected from the group of primer pairs represented by a forward primer under SEQ ID NO: 1 and a reverse primer under SEQ ID NO: 2, followed by probe detection under SEQ ID NO: 3 identifying marker locus IIH2119; primer pairs represented by a forward primer under SEQ ID NO: 4 and a reverse primer under SEQ ID NO: 5, followed by detection with a probe under SEQ ID NO: 6, identifying the IIH5250 marker locus; pairs of primers represented by a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO: 8, followed by detection with a probe under SEQ ID NO: 9 identifying the IIH4836 marker locus,

c) selecting one member of the segregating population, where said member is characterized by the characteristic that is a productive flowering.

In yet another embodiment, the present invention relates to a genetic determinant that provides productive flowering, or part of it that provides productive flowering, which is associated with at least 1 DNA marker represented by a 1 pair of oligonucleotide primers for NDP containing a forward primer under SEQ ID NO: 1, a reverse primer under SEQ ID NO: 2 and a probe under SEQ ID NO: 3, and/or with at least 2 DNA markers represented by a 2nd PCR primer pair containing a forward primer under SEQ ID NO: 4, a reverse primer under SEQ ID NO: 5 and a probe under SEQ ID NO: 6, and/or with at least a 3rd DNA marker represented by a 3rd pair of PCR primers containing a forward primer under SEQ ID NO: 7, the reverse primer under SEQ ID NO: 8 and the probe under SEQ ID NO: 9, while in particular, the specified genetic determinant or part thereof, providing productive flowering, is covered by the specified 1st, 2nd and 3rd DNA marker .

In yet another embodiment, the present invention relates to the use of a DNA marker amplified from the genome of a watermelon plant according to any of the previous embodiments, preferably from the genome of a watermelon plant line SP-7, the typical seed of which is deposited under Accession No. PTA-123747 in ATCC, or its descendant or ancestor, by PCR amplification using a pair of oligonucleotide primers: a forward primer under SEQ ID NO: 1 and a reverse primer under SEQ ID NO: 2 and a probe under SEQ ID NO: 3; or a forward primer under SEQ ID NO: 4 and a reverse primer under SEQ ID NO: 5 and a probe under SEQ ID NO: 6; or a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO: 8 and a probe under SEQ ID NO: 9; wherein said DNA fragment indicates the presence of a productive flowering trait in a watermelon plant, in order to identify a watermelon plant that exhibits the trait and exhibits the productive flowering trait.

The present invention also relates to the use of a productive flowering planting material obtained from a watermelon plant according to any of the previous embodiments for growing a watermelon plant to produce productive flowering watermelon plants, where said productive flowering can be assessed in a standard assay. , in particular, using the analysis described in example 2A below.

The present invention also relates to the use of a planting material characterized by productive flowering, which can be obtained from a watermelon plant in accordance with any of the previous embodiments, for the production of watermelon fruits.

The present invention also contemplates the use of the genetic determinants of productive flowering of the present invention in combination with genetic determinants associated with gynoeciums and/or increased female flowers.

In a further embodiment of the present invention, a method for increasing the number of male flowers of a watermelon plant is provided, comprising the steps of:

a) selecting a watermelon plant that is characterized by a productive flowering trait, wherein said productive flowering trait is associated with three genetic determinants capable of directing or controlling expression of the productive flowering trait in a watermelon plant, wherein said trait is can be identified by the presence of 3 marker loci that co-segregate with the productive flowering trait, which are marker loci IIH2119, IIH5250, and IIH4836, or by the presence of any adjacent marker that has a statistically significant correlation and therefore co-segregates with the trait , representing a productive flowering;

b) crossing said plant from step a) which has a productive flowering trait with a watermelon plant, in particular a cultivated watermelon plant, which does not have a productive flowering trait, and

c) selecting the progeny resulting from said cross that has an increased number of male flowers compared to the plant from stage b) and which shows an association of productive flowering with 3 marker loci IIH2119, IIH5250 and IIH4836 stage a).

In a further embodiment, the present invention provides a method for increasing the number of male flowers of a watermelon plant, comprising the following steps:

a) selecting a watermelon plant that is characterized by a productive flowering trait, wherein said productive flowering trait is associated with three genetic determinants capable of directing or controlling expression of the productive flowering trait in a watermelon plant, wherein said trait is can be identified by the presence of 3 marker loci or by the presence of any adjacent marker that has a statistically significant correlation and therefore co-segregates with the productive flowering trait;

b) crossing said plant from step a) which is characterized by the productive flowering trait with a watermelon plant, in particular a cultivated watermelon plant, which does not have the productive flowering trait and which exhibits fewer male flowers than with the plant from stage a), and

c) selecting a progeny resulting from said cross that has an increased number of male flowers compared to the plant from step b) and that shows a productive flowering association with the 3 marker loci from step a).

Genetic determinants of productive flowering can also be introduced by mutagenesis, eg by chemical mutagenesis, eg by EMS mutagenesis. Alternatively, the genetic determinants of productive flowering can also be identified and/or introduced using TILLING techniques.

In a further embodiment, the present invention relates to the use of the genetic determinants of the present invention to manipulate a phenotype with a productive flowering trait in a watermelon plant, where said manipulation is by genetic modification, and where said genetic modification is introduced by TILLING. Preferably, the genetic determinants of the present invention are characterized by the sequences disclosed herein, more preferably SEQ ID NOs: 3, 6 and 9 representing the target sequences.

Genetic determinants of productive flowering can also be introduced by targeted mutagenesis, e.g., homologous recombination, zinc finger nucleases, oligonucleotide-based mutation induction, transcription activator-like effector nucleases (TALEN), regularly arrayed short palindromic repeat systems (CRISPR) or any alternative genome editing technique.

Alternatively, the genetic determinants of productive flowering can also be introduced using transgenic or cis-gene methods through a nucleotide construct, which can be contained in the vector.

Based on the description of the present invention, a person skilled in the art having at his disposal a watermelon plant of the line SP-7, the typical seed of which is deposited under Accession No. PTA-123747 in the ATCC, or its descendant or ancestor, containing the indicated genetic determinants described herein , it will not be difficult to transfer said genetic determinants of the present invention to other watermelon plants of various types, using breeding techniques well known in the art, supporting the marker loci disclosed herein.

DEFINITIONS

Technical terms and expressions used within the scope of this application should generally have the meaning normally applied to them in the relevant field of plant breeding and cultivation, unless otherwise specified herein below.

Used in this description and the attached claims, the singular form includes references to the plural, unless the context clearly indicates otherwise. Thus, for example, reference to "plant" includes one or more plants, and reference to "cell" includes a combination of cells, tissues, and the like.

The term "cultivated watermelon plant" within the scope of the present invention means a plant that is no longer in its natural state, but has been developed and domesticated by human efforts and for agricultural use and/or human consumption, and excludes wild watermelon specimens such as Citrullus lanatus cultivar" Egun". As an example, in some embodiments, the implementation of the watermelon plant in accordance with the present invention is capable of producing yellow fruits. Alternatively or additionally, the watermelon crop according to the present invention contains a brittle skin (eg gene e in a homozygous state as found in the watermelon line SP-1 (WO 2003/075641)). In other embodiments, the watermelon crop plant is a diploid plant, a tetraploid plant, and/or a triploid plant.

"Genetic determinant that directs or controls expression" is herein understood to refer to an inherited genetic element that can contribute to the productive flowering of a plant by influencing the expression of a given trait, which is a productive flowering, at the level of the DNA itself, at the level of translation , transcription and/or activation of the final polypeptide product.

In one preferred embodiment, the genetic determinants that contribute to plant traits of the present invention are native to the genus Citrullus. The genetic determinants of the present invention do not include genetically modified transformants containing heterologous genetic material and/or genetic material foreign to the genus Citrullus.

The term "allele" within the scope of the present invention means alternative or variant forms of different genetic units associated with or identical to different forms of a gene, or any identifiable genetic determinant, which are alternative in inheritance because they are located at the same locus on homologous chromosomes. Such alternative or variant forms may result from single nucleotide polymorphisms, insertions, inversions, translocations, or deletions, or from gene regulation caused, for example, by chemical or structural modification, transcriptional regulation, or post-translational modification/regulation. In a diploid cell or organism, two alleles of a given gene or genetic element usually occupy corresponding loci on a pair of homologous chromosomes.

An allele associated with a trait may contain alternative or variant forms of various genetic units, including those associated with or identical to one or more genes or their products, or even a gene that is disrupted or controlled by a genetic determinant that contributes to the phenotype represented by the locus.

"Productive flowering watermelon plant" is defined herein as a watermelon plant having a productive flowering trait that produces an increased number of male flowers compared to a plant lacking said trait.

Roughly speaking, the term "increased number of male flowers" in this document is understood to mean that the plant in accordance with the present invention, that is, containing the genetic determinants of productive flowering, is capable of producing at least 40 male flowers per square meter during the period of the most intensive flowering.

"Blooming Period" is herein understood to mean the week when the most open male flowers were recorded in all plots.

The term "trait" refers to a characteristic or phenotype. In the context of the present invention, the trait that constitutes productive flowering is an increase in the number of male flowers. A trait may be inherited in a dominant or recessive manner, or in a partially or incompletely dominant manner. A trait may be monogenic or polygenic, or may result from the interaction of one or more genes with the environment. The watermelon plant may be heterozygous or heterozygous for a trait.

The expressions "hybrid", "hybrid plant", and "hybrid progeny" refer to individuals derived from genetically dissimilar parent forms (eg, a genetically heterozygous or predominantly heterozygous individual).

"Inbred lineage" refers to a genetically homozygous or nearly homozygous population. For example, an inbred line can be obtained through several cycles of sibling crosses or selfing or dihaploid production.

The term "dihaploid lineage" means stable inbred lines derived from an anther culture. Some pollen grains (haploid), cultivated on a certain medium and under certain conditions, can form seedlings containing n chromosomes. Then "doubling" occurs in the seedlings and they contain 2n chromosomes. The offspring of these seedlings are called "dihaploid" and they essentially no longer segregate (stably).

The term "cultivar" or "cultivar" refers to a variety obtained through horticulture, as opposed to a naturally occurring variety. In some embodiments of the present invention, cultivars or varieties have commercial value.

The term "genetically fixed" refers to a genetic element that is stably included in the genome of a plant that does not normally contain said genetic element. A genetically fixed genetic element can be transferred to other plants in a simple and predictable manner through sexual crosses.

The term "plant" or "plant part" hereinafter refers to a plant part, organ or tissue that can be obtained from a watermelon plant in accordance with the present invention, including, without limitation, leaves, stems, roots, flowers or parts flower, fruit, shoot, gametophyte, sporophyte, pollen, anther, microspore, egg, zygote, embryo, meristem patch, callus tissue, seed, cutting, cell or tissue culture, or any other plant part or product that still shows signs representing productive flowering, according to the present invention, in particular when grown to obtain a plant that bears fruit.

A "plant" is any plant at any stage of development.

A watermelon plant seed is a seed that grows into a watermelon plant according to any of the embodiments.

A "plant cell" is the structural and physiological unit of a plant containing a protoplast and a cell wall. The plant cell may be in the form of an isolated single cell or a cultured cell, or as part of a more highly organized unit such as, for example, a plant tissue, a plant organ or a whole plant.

"Plant cell culture" means cultures of plant units such as, for example, protoplasts, cells in cell culture, cells in plant tissues, pollen, pollen tubes, ovules, embryo sacs, zygotes, and embryos at various developmental stages.

A "plant organ" is a distinct and visually structured and differentiated part of a plant, such as a root, stem, leaf, flower bud, or embryo.

"Plant tissue" as used herein means a group of plant cells organized into a structural and functional unit. Any plant tissue in planta or in culture is included. The term includes, without limitation, whole plants, plant organs, plant seeds, tissue culture, and any group of plant cells organized into structural and/or functional units. The use of this term in conjunction with or without any specific type of plant tissue as defined above or otherwise covered by this definition is not intended to exclude any other type of plant tissue.

As used herein, the term "watermelon" means any variety, cultivar, or population of Citrullus lanutus.

The term "yield" of commercial fruits, as used in this document, refers to the number of harvested fruits (frt) obtained per unit area of production (frt/ha).

As used herein, the term "marker allele" refers to an alternative or variant form of a genetic unit as defined herein above, when used as a marker to locate genetic loci containing alleles on a chromosome that contribute to the variability of phenotypic traits.

As used herein, the term "reproduction" and its grammatical variants refer to any process by which an individual's offspring are produced. Reproduction can be sexual or asexual, or any combination of both. Representative non-limiting types of reproduction include crosses, selfing, double haploid derivatives, and combinations thereof.

As used herein, the expression "standard breeding population" refers to the collection of potential breeding partners that have been developed and/or used as parents in a breeding program; for example, a commercial breeding program. Members of a standard breeding population are usually well characterized genetically and/or phenotypically. For example, some phenotypic traits of interest could be assessed, for example, under different environmental conditions, in several places and/or at different times. Alternatively, or in addition, one or more genetic loci associated with the expression of phenotypic traits could be identified, and one or more members of the breeding population could be genotyped for one or more genetic loci, as well as for one or more genetic markers that are associated with one or more genetic loci.

As used herein, the phrase "diploid individual" refers to an individual that has two sets of chromosomes, usually one from each of its two parents. However, it is understood that in some embodiments, a diploid individual may derive its "maternal" and "father" sets of chromosomes from the same organism, such as when a plant self-pollinates to produce a subsequent generation of plants.

"Homozygous", as understood within the scope of the present invention, refers to the same alleles at one or more corresponding loci on homologous chromosomes.

"Heterozygous", as understood within the scope of the present invention, refers to different alleles at one or more corresponding loci on homologous chromosomes.

The term "backcrossing" is understood within the scope of the present invention to mean a method in which the hybrid progeny is repeatedly crossed with one of the parents. Various recurrent parental forms may be used in subsequent backcrosses.

Within the scope of the present invention, the term "locus" refers to a region on a chromosome that contains a gene or any other genetic element or factor that contributes to a trait.

As used herein, the term "marker locus" refers to a region on a chromosome that contains a nucleotide or polynucleotide sequence that is present in the genome of an individual and that is associated with one or more loci of interest, which may contain a gene or any other genetic determinant or factor conducive to symptom. "Marker locus" also refers to a region on a chromosome that contains a polynucleotide sequence complementary to a genomic sequence, such as a nucleic acid sequence used as probes.

"Genetic linkage" is understood within the scope of the present invention to refer to the association of traits in inheritance due to the proximity of genes on the same chromosome, as measured by the percentage of recombination between loci (centimorgans, cM).

For the purpose of the present invention, the term "co-segregation with" refers to the fact that an allele for a trait and an allele(s) for a marker(s) tend to be passed on together because they are physically located close to each other on the same chromosome (due to their physical proximity, reduced recombination is observed), which leads to a non-random association of such alleles as a result of their proximity on the same chromosome. "Segregated with" also refers to the presence of two or more traits in the same plant, of which at least one is genetic, and which cannot be explained by mere chance.

As used herein, the term "genetic architecture at a quantitative trait locus" refers to a genomic region that has a statistically significant correlation with a phenotypic trait of interest and represents the underlying genetic basis of the phenotypic trait of interest.

As used herein, the phrases "subjected to sexual interbreeding" and "sexual reproduction" in the context of the object of the present invention disclosed in this application refers to the fusion of gametes to produce offspring (for example, by fertilization, such as, for example, to obtain seeds using pollination in plants ). "Sexual crossing" or "cross-fertilization" is, in some embodiments, the fertilization of one individual by another (eg, cross-pollination in plants). "Selfing" refers in some embodiments to obtaining seeds by self-fertilization or self-pollination; those. pollen and ovule come from the same plant.

As used herein, the expression "genetic marker" refers to a feature of the genome in an individual (eg, a nucleotide or polynucleotide sequence that is present in the genome of an individual) that is associated with one or more loci of interest. In some embodiments, the genetic marker is polymorphic in the population of interest or at the locus occupied by the polymorphism, depending on the context. Genetic markers include, for example, single nucleotide polymorphisms (SNPs), insertion-deletion polymorphisms (i.e. insertions/deletions), simple sequence repeats (SSRs), restriction fragment length polymorphisms (RFLPs), random amplified DNA polymorphisms (RAPDs), markers amplified sequence restriction polymorphisms (CAPS), Diversity Arrays Technology (DArT) markers, and amplified fragment length polymorphisms (AFLP), among many other examples. Genetic markers can, for example, be used to locate genetic loci containing alleles on a chromosome that contribute to variation in phenotypic traits. The phrase "genetic marker" may also refer to a polynucleotide sequence complementary to a genomic sequence, such as a nucleic acid sequence used as probes.

A "genetic marker" may be physically located at a position on a chromosome that is within or outside the genetic locus with which it is associated (ie, intragenic or extragenic, respectively). In other words, although genetic markers are commonly used, if the location on the chromosome of a gene or functional mutation, for example, in a control element outside the gene that corresponds to the locus of interest, has not been identified and there is a non-zero rate of recombination between the genetic marker and the locus of interest , the subject matter disclosed herein may also use genetic markers that are physically located within a genetic locus (eg, within a genomic sequence that corresponds to such a gene, such as, without limitation, a polymorphism in the intron or exon of a gene). In some embodiments of the subject matter disclosed herein, one or more genetic markers provide from one to ten markers, and in some embodiments, one or more genetic markers provide more than ten genetic markers.

As used herein, the term "genotype" refers to the genetic structure of a cell or organism. The "genetic marker set genotype" of an individual includes specific alleles for one or more genetic marker loci present in the individual's haplotype. As is known in the art, a genotype may refer to a single locus or to multiple loci, whether the loci are related or unrelated and/or linked or unlinked. In some embodiments, an individual's genotype refers to one or more genes that are related in that one or more genes are involved in the expression of a phenotype of interest (eg, a trait defined herein). Thus, in some embodiments, a genotype is the sum of one or more alleles present in an individual at one or more genetic loci that define a quantitative trait. In some embodiments, the genotype is expressed as a haplotype (defined herein below).

As used herein, the term "germplasm" refers to the totality of the genotypes of a population or other group of individuals (eg, species). The term "germplasm" may also refer to plant material; for example, a group of plants that act as a repository for different alleles. The phrase "adapted germplasm" refers to plant materials with proven genetic superiority; for example, for a given habitat or geographic area, while the phrases "unadapted germplasm", "raw germplasm", and "exotic germplasm" refer to plant materials of unknown or unproven genetic value; for example, for a given habitat or geographic area; the phrase "unadapted germplasm" itself refers in some embodiments to plant materials that are not part of a standard breeding population and that have no known relationship to a member of the standard breeding population.

As used herein, the term "linkage" and its grammatical variants refers to the tendency of alleles at different loci on the same chromosome to segregate together more often than would be expected randomly if their transmission were independent, in some embodiments as a result of their physical proximity.

As used herein, the expression "nucleic acid" refers to any physical stretch of monomeric units that can correspond to a stretch of nucleotides, including a polymer of nucleotides (for example, a typical polymer of DNA, cDNA or RNA), modified oligonucleotides (for example, oligonucleotides containing bases, which are not typical of biological RNA or DNA, such as 2'-O-methylated oligonucleotides) and the like. In some embodiments, the nucleic acid may be single-stranded, double-stranded, multi-stranded, or a combination thereof. Unless otherwise indicated, a particular nucleic acid sequence of the subject matter disclosed herein does not necessarily contain or encode complementary sequences in addition to any clearly specified sequence.

As used herein, the term "set" refers to more than one entity. Thus, "multiple individuals" refers to at least two individuals. In some embodiments, the term "multiple" refers to more than half of the whole. For example, in some embodiments, "many of a population" refers to more than half of the members of a given population.

As used herein, the term "offspring" refers to the offspring(s) resulting from a particular cross. As a rule, offspring are the result of crossing two individuals, although some species (especially some plants and hermaphroditic animals) may undergo selfing (i.e. one plant acts as a donor of both male and female gametes). The descendant(s) may be, for example, from F ₁ , F ₂ or any subsequent generation.

As used herein, the expression "quantitative trait" refers to a phenotypic trait that can be represented numerically (ie, quantified or counted). A quantitative trait tends to show persistent differences between individuals in a population; that is, the differences in the numerical value of the phenotypic trait are insignificant and differ from each other. Often the distribution of frequencies in a population of a quantitative phenotypic trait has a bell-shaped curve (i.e. shows a normal distribution between the ranges of values).

A "quantitative trait" is usually the result of the interaction of a genetic locus with the environment, or multiple genetic loci interacting with each other and/or with the environment. Examples of quantitative traits include plant height and yield.

For the purpose of the present invention, the term "co-segregation with" refers to the fact that an allele for a trait and an allele(s) for a marker(s) tend to be passed on together because they are physically located close to each other on the same chromosome (due to their physical proximity, reduced recombination is observed), which leads to a non-random association of such alleles as a result of their proximity on the same chromosome. "Segregated with" also refers to the presence of two or more traits in the same plant, of which at least one is genetic, and which cannot be explained by mere chance.

As used herein, the terms "quantitative trait locus" (QTL) and "marker-trait association" refer to the association between a genetic marker and a chromosomal region and/or gene that influences the phenotype of a trait of interest. As a rule, this is determined statistically; for example, based on one or more methods published in the literature. The QTL may be a chromosomal region and/or a genetic locus with at least two alleles that affect a phenotypic trait (either a quantitative trait or a qualitative trait) differently.

As used herein, the expression "qualitative trait" refers to a phenotypic trait that is controlled by one or more genes that exhibit major phenotypic effects. In view of this, qualitative traits, as a rule, are simply inherited. Examples in plants include, but are not limited to, flower color and several known types of disease resistance, such as, for example, fungus blotch resistance or tomato mosaic virus resistance.

"Marker-based selection" within the scope of the present invention refers, for example, to the use of genetic markers to identify one or more nucleic acids in a plant, where the nucleic acid is associated with a desired trait, to identify plants carrying genes for desirable (or undesirable) traits, such Thus, these plants can be used (or avoided) in a breeding program.

The term "microsatellite or SSR (single sequence repeat) markers" within the scope of the present invention refers to a type of genetic marker that consists of multiple repeats of short DNA base sequences that are found at loci throughout the plant genome and are likely to be highly polymorphic.

Single nucleotide polymorphism (SNP), a variation at a single site in DNA, is the most common type of variation in the genome. The term "single nucleotide polymorphism (SNP)" is a DNA sequence variation that occurs when one nucleotide - A, T, C or G - in the genome (or other common sequence) differs between members of the same species or between paired chromosomes in an individual . For example, two sequenced DNA fragments from different individuals, AAGCCTA and AAGCTTA, contain a single nucleotide difference. In this case, there are two alleles: C and T. The basic principles of the SNP matrix are the same as those of the DNA microarray. This is a fusion of DNA hybridization, fluorescence microscopy and DNA capture. The three components of the SNP templates are a template that contains nucleic acid sequences (ie, amplified sequences or targets), one or more labeled allele-specific oligonucleotide probes, and a detection system that detects and interprets the hybridization signal.

The presence or absence of the desired allele can be determined by real-time PCR using double-stranded DNA dyes or the fluorescent reporter probe method.

"PCR (Polymerase Chain Reaction)" within the scope of the present invention is intended to refer to a method for obtaining relatively large amounts of certain DNA regions or group(s) of genome regions, thereby allowing various analyzes to be carried out using these regions.

By "PCR primer" is meant within the scope of the present invention relatively short single-stranded DNA fragments used in the PCR amplification of specific DNA regions.

"Phenotype" is understood within the scope of the present invention to refer to distinguishable characteristic(s) genetically

controlled sign.

As used herein, the expression "phenotypic trait" refers to the appearance or other detectable characteristic of an individual resulting from the interaction of its genome, proteome and/or metabolome with the environment.

"Polymorphism" is understood within the scope of the present invention to refer to the presence in a population of two or more different forms of a gene, a genetic marker, or an inherited trait, or a gene product, obtained, for example, by alternative splicing, DNA methylation, etc.

"Selective propagation" is understood within the scope of the present invention to refer to a breeding program in which plants are used as parent plants that have or exhibit desirable traits.

The term "test plant" within the scope of the present invention refers to a plant of the genus Capsicum used to genetically characterize a plant trait to be tested. Typically, the plant to be tested is crossed with a "test" plant and the ratio of trait segregation in the progeny resulting from the cross is calculated.

The term "probe" as used herein refers to a group of atoms or molecules that is capable of recognizing and binding to a particular target molecule or cellular structure and therefore allowing the target molecule or structure to be detected. In particular, "probe" refers to a labeled DNA or RNA sequence that can be used to detect and quantify a complementary sequence by molecular hybridization.

As used herein, the term "hybridizes" refers to conventional hybridization conditions, preferably hybridization conditions in which 5xSSPE, 1% SDS, 1x Denhardt's solution is used as the working solution, and/or hybridization temperatures are in the range of 35°C to 70 °C, preferably 65°C. After hybridization, washing is preferably carried out first with 2xSSC, 1% SDS, and then with 0.2xSSC at temperatures from 35°C to 75°C, in particular from 45°C to 65°C, but especially at 59°C ( for the determination of SSPE, SSC and Denhardt's solution, see Sambrook et al. loc. cit). High stringency hybridization conditions, such as those described in Sambrook et al. above, are particularly preferred. Particularly preferred stringent hybridization conditions are present, for example, if hybridization and washing are carried out at 65° C. as indicated above. Hybridization conditions other than stringent, for example with hybridization and washing carried out at 45° C., are less preferred, and at 35° C. even less preferred.

The terms "sequence homology or sequence identity" are used interchangeably. The terms "identical" or percent "identity" in the context of two or more nucleic acid or protein sequences refer to two or more sequences or subsequences that are the same or have a certain percentage of amino acid residues or nucleotides that are the same when compared and aligned for maximum match. measured using one of the following sequence comparison algorithms or by visual inspection. If the two sequences to be compared with each other differ in length, sequence identity preferably refers to the percentage of nucleotide residues of the shorter sequence that are identical to the nucleotide residues of the longer sequence. As used herein, the percent identity/homology between two sequences is a function of the number of identical positions shared by the sequences (i.e., % identity = number of identical positions/total positions x 100), taking into account the number of gaps and the length of each gap that must be administered to optimally align the two sequences. Comparing sequences and determining the percent identity of two sequences can be performed using the mathematical algorithm described herein below. For example, sequence identity can be determined conventionally using computer programs such as Bestfit (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, 575 Science Drive, Madison, Wisconsin 53711). Bestfit uses the local homology algorithm of Smith and Waterman, Advances in Applied Mathematics 2 (1981), 482-489, to identify the segment having the highest sequence identity between two sequences. When using Bestfit or another program to align sequences to determine if a particular sequence is, for example, 95% identical to a reference sequence in accordance with the present invention, the parameters are preferably set such that percent identity is calculated over the entire length of the reference sequence, and that homology gaps of up to 5% of the total number of nucleotides in the reference sequence are allowed. During the application of Bestfit, the so-called optional parameters are preferably left at their preset ("default") values. Deviations that occur when comparing this sequence and the above sequences of the present invention may be due to, for example, addition, deletion, substitution, insertion or recombination. Such sequence comparison can preferably also be performed using the "fasta20u66" program (version 2.0u66, September 1998, by William R. Pearson and the University of Virginia; see also W. R. Pearson (1990), Methods in Enzymology 183, 63-98 , appended examples and http://workbench.sdsc.edu/). You can use the "default" parameter settings for this purpose.

Another indication that two nucleic acid sequences are substantially identical is that the two molecules hybridize to each other under stringent conditions. The phrase "hybridizes specifically with" refers to the binding, duplexing, or hybridization of a molecule to only a particular nucleotide sequence under stringent conditions, when such sequence is present in a complex mixture of (eg, common cellular) DNA or RNA. "Significantly binds(binds)" refers to complementary hybridization between a probe nucleic acid and a target nucleic acid, and covers minor mismatches that can be corrected by reducing the stringency of the hybridization media to achieve the necessary detection of the target nucleic acid sequence.

"Stringent hybridization conditions" and "stringent hybridization wash conditions" in the context of nucleic acid hybridization experiments such as Southern and Northern hybridizations are sequence dependent and differ under different environmental conditions. Longer sequences hybridize specifically at higher temperatures. Detailed guidance on nucleic acid hybridization can be found in Tijssen (1993) Laboratory Techniques in Biochemistry and Molecular Biology-Hybridization with Nucleic Acid Probes part I chapter 2 "Overview of principles of hybridization and the strategy of nucleic acid probe assays" Elsevier, New York. Typically, hybridization and high stringency wash conditions are chosen such that the temperature is approximately 5° C. below the melting point for a particular sequence at a particular ionic strength and pH. Typically, under "stringent conditions", a probe will hybridize to its target sequence but not to any other sequences.

"Melting point" is the temperature (at a given ionic strength and pH) at which 50% of the target sequence hybridizes to an exact match probe. For very severe conditions choose a temperature equal to the melting temperature (T _m ) for a particular probe. An example of stringent hybridization conditions for hybridizing complementary nucleic acids that have more than 100 complementary filter residues in a Southern or Northern blot is 50% formamide with 1 mg heparin at 42°C, with hybridization carried out overnight. An example of high stringency wash conditions is the use of 0.15 M NaCl at 72° C. for approximately 15 minutes. An example of stringent wash conditions is a wash using 0.2×SSC at 65° C. for 15 minutes (see Sambrook below for a description of SSC buffer). Often, in order to eliminate the background signal of the probe, a wash under conditions of high hardness is preceded by a wash under conditions of low hardness. An example of washing under medium stringency conditions for a duplex having, for example, more than 100 nucleotides, is the use of 1×SSC at 45°C for 15 minutes. An example of low stringency wash conditions for a duplex having, for example, more than 100 nucleotides is 4-6×SSC at 40°C for 15 minutes. For short probes (eg, about 10 to 50 nucleotides in length), stringent conditions typically include salt concentrations of less than about 1.0 M Na ions, typically concentrations of about 0.01-1.0 M ions Na (or other salts) at pH 7.0-8.3, as well as a temperature typically at least about 30°C. Stringent conditions can also be achieved by adding destabilizing agents such as formamide. In general, a signal-to-noise ratio that is 2× (or greater) times that observed for an unrelated probe in a particular hybridization assay indicates the detection of specific hybridization. Nucleic acids that do not hybridize to each other under stringent conditions are still essentially identical if the proteins they encode are essentially identical. For example, this occurs when a copy of the nucleic acid is created using the maximum codon degeneracy allowed by the genetic code.

DETAILS REGARDING SEED DEPOSIT

The Applicant deposited 2,500 seeds of watermelon (diploid Citrullus lanatus) line SP-7 under the Budapest Treaty with the ATCC, Manassas, Virginia, USA on 14 December 2016 under the number PTA-123747 with the ATCC. The applicant opted for the expert's decision.

BIBLIOGRAPHY

Dane F. and Liu J., 2007, Diversity and origin of cultivated and citron type watermelon (Citrullus lanatus), Genetic Resources and Crop Evolution, Volume 54, Issue 6, pp 1255-1265.

Food and Agriculture Organization of the United Nations, Statistics Division, FAOSTAT, http://faostat3.fao.org/browse/Q/*/E.

United States Department of Agriculture, National Agricultural Statistics Service, Vegetables 2015 Summary, http://usda.mannlib.cornell.edu/usda/current/VegeSumm/VegeSumm-02-04-2016.pdf.

Kihara H., 1951, Triploid watermelons, Proc. amer. soc. Hort. Sc., 58:217-230.

Fehr W.R., 1987, Principles of cultivar development, theory and technique, Vol. 1, Macmillian Publishing Company.

GRAPHIC MATERIALS

The figure 1 shows the number of open male flowers in the period of the most intensive flowering for different genotypes, which were grown in Woodland, California.

SEQUENCES

EXAMPLES

EXAMPLE 1 GEMPLASMA AND POPULATION DEVELOPMENT

A recombinant inbred line (RIL) genetic population was created by hybridizing wild watermelon accessions, PI595203, [Citrullus lanatus cultivar "Egun"] with a modern cultivar, PI635731, [Citrullus lanatus cultivar "Dixielee"], self-hybridized using a single seed generation, until until all of the observed phenotypic traits were captured and each line showed uniform characteristics. The population (also referred to as the ED-RIL population) was cultured in open field trials and subjected to phenotyping for various traits. The result of this was the observation of an extreme phenotype (called "productive flowering"), which showed a significant increase in the number of male flowers. The line designated ED268 was the most preferred line for increasing the number of male flowers. Some ED-RILs expressed the trait of productive flowering and some did not, indicating discrete genetic control of the phenotype. Follow-up observation of the population showed that productive flowering was a hereditary trait. Productive flowering was not observed in either parent, indicating that a specific combination of both Egun and Dixielee alleles controls the expression of the phenotype. Further research showed that at least three genetic determinants, one from Egun and two from Dixielee, are involved in the control of productive flowering.

Plants of line ED268 were selected and crossed with plants of line SP-6 to develop new watermelon plants with the trait of productive flowering. The resulting F1 plants were self-hybridizing and subsequently fixed and the resulting lines were again phenotyped for productive flowering. Some lines expressed a productive flowering trait (eg line SP-7) and some did not (eg non-productive sister line SP-7) suggesting discrete genetic control of the phenotype. It also confirmed that the productive flowering trait can be introgressed into different genetic backgrounds.

The line designated SP-7 was identified as the most preferred line selected to increase the number of male flowers and was retained and deposited with ATCC under ATCC Accession No. PTA-123747 on December 14, 2016. Line SP-7 was found to have a trait representing productive flowering, i.e. line SP-7 contains three favorable genetic determinants in the homozygous state.

Example 2 PHENOTYPING

Example 2A. A way to measure productive flowering: the number of male flowers

Plots with each genotype were cultivated in open field conditions with a spacing of 24 inches (61 cm) between plants. All data are derived from a field study performed using a randomized block design with three repeats considered as blocks. The number of male flowers was estimated by counting the number of open male flowers per square meter. For each site, two measurements were taken weekly. The period of the most intense flowering was defined as the week when the most open male flowers were recorded in all plots.

Example 2 B Phenotyping Results

The figure 1 shows the results of phenotyping in relation to productive flowering of the following genotypes: (i) deposited line SP-7 and its ancestors: line SP-6 and line ED268; (ii) ancestors of the ED268 line: Egun and Dixielee; (iii) non-producing sister line SP-7; and (iv) unrelated non-producing line: Estrella.

During the most intensive flowering period, parental ED268, Dixielee and Egun presented only 12.44% and 34.74%, respectively, of the number of open male flowers presented by ED268. The non-productive parent lines SP-7, SP-6 accounted for approximately 32.57% of the number of male flowers that SP-7 presented during the period of the most intensive flowering. It was also shown that SP-7 showed a much higher number of male flowers than its non-productive sister line, ED268/SP-6 non-productive line, which accounted for only 43.96% of the number of male flowers that fell on line SP-7 during the most intensive flowering. This demonstrates that the productive flowering trait is a discrete genetic trait that can be selected as either positive or negative during the breeding process.

Table 1 below demonstrates how SP-7 differs from other non-productive varieties. Statistical analysis shows that SP-7 differs significantly in the number of male flowers per unit area, presented during the period of the most intensive flowering, compared with all other varieties included in these experiments. In addition, using the Fisher LSD method, the watermelon genotypes with the productive flowering trait included in these experiments (SP-7 and ED268) have a significantly higher number of male flowers per unit area than watermelon genotypes that do not have the trait , which is a productive flowering.

For statistical purposes, the average number of male flowers at peak flowering per square meter was used. One-way analysis of variance showed significant differences between list items (F=128.083, Df=6, P<0.05). Multiple comparison of means for each list item (Fischer's LSD method) showed significant differences between different list items (shown with different letters).

EXAMPLE 3 GENOTYPING AND QTL DETECTION

Example 3A. A method for identifying the genetic determinants underlying a trait that is a productive flowering

For QTL detection, 166 recombinant inbred lines (RILs) from the "ED-RIL" population were genotyped with 260 genome-spanning genetic markers and genetically mapped. These lines were grown in an open field in Woodland, California using standard growing methods and phenotyped for productive flowering.

QTL detection was performed using the R/qt1 package in the R statistical framework. First, the "calc.genoprob" function was used to calculate genotype probabilities (1 cM step). Haley-Knott regression was performed to provide an approximation of the results of standard interval mapping. We then used the stepwiseqtl function, which provides a fully automated forward/reverse algorithm model selection algorithm. The LOD threshold for the main effect was determined using 10,000 permutations. Such an algorithm takes into account various possible interactions (for example, epistasis). The "refineqtl" function was used to refine the QTL locations in the context of the multiple QTL (maximum likelihood estimator) model. The "fitqtl" function was used to fit a specific QTL model and obtain estimates of QTL effects. Three QTLs were identified based on productive flowering phenotypes (Table 2).

Example 3B. Effect of QTLs located on chromosomes 1, 3 and 7 on productive flowering

Table 2 shows chromosomal location, QTL influence, LOD scores, percentage of variation explained by each QTL on chromosome 1, 3 and 7 in terms of productive flowering and favorable genotype.

df=degrees of freedom, "LOD"=log likelihood score, "% var"=percentage of phenotypic variance explained by the QTL, "P-value (Chi2)"=probability of each QTL found by probability chance by chi-square analysis.

Example 3C. QTL sequence information

Table 3 shows the nucleotide sequences associated with marker loci IIH2119, IIH5250 and IIH4836, respectively. For each marker locus, the table shows the location in the chromosome, primers (forward and reverse) that provide amplification of the DNA fragment of the marker and the target sequence. For each target sequence, the favorable SNP allele is shown in bold.

--->

SEQUENCE LIST

<110> SINGENTA PARTICIPATIONS AG

<120> PRODUCTIVE FLOWERING WATERMELON PLANT

<130> 81212-WO-REG-ORG-P-1

<150> US 62/437187

<151> 2016-12-21

<160> 9

<170> PatentIn version 3.5

<210> 1

<211> 20

<212> DNA

<213> Artificial sequence

<220>

<223> Primer

<400> 1

cgttgagacg ttcgctgttc 20

<210> 2

<211> 21

<212> DNA

<213> Artificial sequence

<220>

<223> Primer

<400> 2

gacggagacc catgataagg a 21

<210> 3

<211> 201

<212> DNA

<213> Citrullus lanatus

<400> 3

gctcgtagcc gtcgttggtc tctacgccat gtccgctcgc cgccacgtcg agatgccrtc 60

gttttcgtcg tcgttgagac gttcgctgtt cgtccctttt ggttcctcga ccaccagcgt 120

ctccttatca tgggtctccg tcgtttgcag tcgccgccgg ttctcatcct cacacctgct 180

gccgtcaacc aacgaccctc c 201

<210> 4

<211> 22

<212> DNA

<213> Artificial sequence

<220>

<223> Primer

<400> 4

ggtcggcaat gactagacga at 22

<210> 5

<211> 20

<212> DNA

<213> Artificial sequence

2

<220>

<223> Primer

<400> 5

tcctccatcg ctccaaacct 20

<210> 6

<211> 201

<212> DNA

<213> Citrullus lanatus

<400> 6

cgttaaaata aaaaaataaa aaaaataaaa aaagccttta gcagcgacaa atgatagagg 60

gtggtcggca atgactagac gaatggaagc accatgagag aaaaggaggt ttggagcgat 120

ggaggagatc agagatgagg agagggatca aatttgggga ccacgaactc gtggaccccc 180

tccmcgagtt acctgctaag t 201

<210> 7

<211> 24

<212> DNA

<213> Artificial sequence

<220>

<223> Primer

<400> 7

tcgacaaatg gagaaggttc aact 24

<210> 8

<211> 21

<212> DNA

<213> Artificial sequence

<220>

<223> Primer

<400> 8

acctttgtgt ccttcccaga a 21

<210> 9

<211> 201

<212> DNA

<213> Citrullus lanatus

<400> 9

gattgataaa atccacaaca aattcgacaa atggagaagg ttcaacttat ctagaagtgg 60

gagggccact ttatataagt ctattctttc caatcttcca ccatattata tgtctctatt 120

tctaatgcct gaaaaggttg tctctatatt gaaaaagaat aatgcggaac ttcttctggg 180

aaggacacaa aggtagcata a 201

<---

Claims (32)

1. A method for selecting watermelon plants characterized by productive flowering, where this method includes the following steps: a) crossing a 1st plant lacking the productive flowering genetic determinants with a 2nd productive flowering watermelon plant containing three genetic determinants associated with a productive flowering trait, wherein said productive flowering plant produces at least 40 open male flowers per square meter at the peak of flowering, with these three genetic determinants genetically or physically linked to 3 marker loci that co-segregate with the productive flowering trait and are selected from the group consisting of marker loci IIH2119, IIH5250 and IIH4836, respectively, and where i) marker locus IIH2119 contains the G nucleotide corresponding to position 101 in SEQ ID NO:3; And ii) marker locus IIH5250 contains nucleotide A corresponding to position 101 in SEQ ID NO:6; And iii) marker locus IIH4836 contains nucleotide C corresponding to position 101 in SEQ ID NO:9, b) obtaining offspring of a watermelon plant, c) genotyping the resulting watermelon plant by PCR amplification using a pair of oligonucleotide primers: a forward primer under SEQ ID: 1 and a reverse primer under SEQ ID NO: 2 to identify the marker locus with SEQ ID NO: 3; a forward primer under SEQ ID NO: 4 and a reverse primer under SEQ ID NO; 5 to identify the marker locus with SEQ ID NO: 6; a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO 8 to identify the marker locus of SEQ ID NO: 9, and d) selecting a plant from said progeny, characterized in that said plant produces at least 40 open male flowers per square meter during the period of most intensive flowering and contains marker loci with SEQ ID NO: 3, c SEQ ID NO: 6, c SEQ ID NO: 9 identified in step (c). 2. The method of claim 1, wherein said 2nd watermelon plant is an SP-7 watermelon plant whose exemplary seed is deposited under ATCC Accession No. PTA-123747, or a descendant or ancestor thereof. 3. A method for selecting a watermelon plant characterized by productive flowering, comprising the following steps: a) providing seeds of a productive flowering watermelon plant containing three genetic determinants associated with a productive flowering trait, wherein said productive flowering plant produces at least 40 open male flowers per square meter during its peak flowering period, wherein said three the genetic determinants are genetically or physically linked to 3 marker loci that co-segregate with a productive flowering trait and are selected from the group consisting of marker loci IIH2119, IIH5250 and IIH4836, respectively, and where i) marker locus IIH2119 contains the G nucleotide corresponding to position 101 in SEQ ID NO:3; And ii) marker locus IIH5250 contains nucleotide A corresponding to position 101 in SEQ ID NO:6; And iii) marker locus IIH4836 contains nucleotide C corresponding to position 101 in SEQ ID NO:9, b) germinating said seed and growing from it a mature fertile plant, c) inducing self-pollination in said plant from a) growing fruits and extracting fertile seeds from them, d) growing plants from the seeds extracted in step c), e) genotyping the resulting watermelon plant by PCR amplification using a pair of oligonucleotide primers: forward primer under SEQ ID: 1 and reverse primer under SEQ ID NO: 2 to identify the marker locus with SEQ ID NO: 3; forward primer under SEQ ID NO: 4 and reverse primer under SEQ ID NO: 5 to identify the marker locus with SEQ ID NO: 6; a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO 8 to identify the marker locus of SEQ ID NO: 9, and f) selecting a watermelon plant characterized by productive flowering and containing marker loci of SEQ ID NO: 3, c SEQ ID NO: 6, c SEQ ID NO: 9 identified in step (e). 4. A method for identifying a watermelon plant containing three genetic determinants that are genetically or physically linked to 3 marker loci that co-segregate with a productive flowering trait and are marker loci IIH2119 characterized by SEQ ID NO: 3, IIH5250 characterized by SEQ ID NO: 6, and IIH4836, characterized by SEQ ID NO: 9, respectively, wherein said watermelon plant produces at least 40 open male flowers per square meter during its peak flowering period, and wherein said method comprises the following steps: a) providing a population with segregation for a trait that is a productive bloom, b) screening a segregating population for a representative with a productive flowering trait, where said trait can be identified by the presence of 3 marker loci that co-segregate with the productive flowering trait and are marker loci IIH2119, IIH5250 and IIH4836, And c) selecting one representative of the segregating population, where the specified representative is characterized by a trait that is a productive flowering; and i) marker locus IIH2119 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: forward primer SEQ ID NO: 1 and reverse primer SEQ ID NO: 2 and probe SEQ ID NO: 3, ii) marker locus IIH5250 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: forward primer SEQ ID NO: 4 and reverse primer SEQ ID NO: 5 and probe SEQ ID NO: 6, iii) marker locus IIH4836 can be identified by PCR by amplifying a DNA fragment using a pair of oligonucleotide primers: forward primer SEQ ID NO: 7 and reverse primer SEQ ID NO: 8 and probe SEQ ID NO: 9. 5. A method for selecting a watermelon plant, comprising the following steps: a) selecting a watermelon plant that is characterized by a productive flowering trait, wherein said productive flowering trait is associated with three genetic determinants capable of directing or controlling expression of the productive flowering trait in a watermelon plant, wherein said trait is can be identified by the presence of 3 marker loci that co-segregate with the productive flowering trait and are marker loci IIH2119 characterized by SEQ ID NO: 3, IIH5250 characterized by SEQ ID NO: 6, and IIH4836 characterized by SEQ ID NO: 9, or by the presence of any contiguous marker locus that has a statistically significant correlation and therefore co-segregates with a productive flowering trait; b) crossing said plant from step a) which is characterized by the productive flowering trait with a watermelon plant, in particular a cultivated watermelon plant, which does not have the productive flowering trait and which has fewer male flowers than with a plant from stage a), c) genotyping the resulting watermelon plant by PCR amplification using a pair of oligonucleotide primers: a forward primer under SEQ ID: 1 and a reverse primer under SEQ ID NO: 2 to identify the marker locus with SEQ ID NO: 3; forward primer under SEQ ID NO: 4 and reverse primer under SEQ ID NO: 5 to identify the marker locus with SEQ ID NO: 6; a forward primer under SEQ ID NO: 7 and a reverse primer under SEQ ID NO 8 to identify the marker locus of SEQ ID NO: 9, and d) selecting a progeny resulting from said cross that has an increased number of male flowers compared to the plant from stage b) and that shows an association of the productive flowering trait with 3 marker loci selected from the group consisting of marker loci IIH2119 , IIH5250 and IIH4836 from step a).

Images