OA19902A - Method for enhancing plant characteristics and method for producing seedless fruit. - Google Patents
Method for enhancing plant characteristics and method for producing seedless fruit. Download PDFInfo
- Publication number
- OA19902A OA19902A OA1201900412 OA19902A OA 19902 A OA19902 A OA 19902A OA 1201900412 OA1201900412 OA 1201900412 OA 19902 A OA19902 A OA 19902A
- Authority
- OA
- OAPI
- Prior art keywords
- plant
- freezing
- thawing
- tissue
- treatment
- Prior art date
Links
- 230000002708 enhancing Effects 0.000 title claims abstract description 31
- 238000004519 manufacturing process Methods 0.000 title claims description 22
- 235000013399 edible fruits Nutrition 0.000 title description 80
- 238000007710 freezing Methods 0.000 claims abstract description 105
- 210000001519 tissues Anatomy 0.000 claims abstract description 75
- 238000010257 thawing Methods 0.000 claims abstract description 73
- 229920000160 (ribonucleotides)n+m Polymers 0.000 claims description 20
- 239000000126 substance Substances 0.000 claims description 17
- 150000001720 carbohydrates Chemical class 0.000 claims description 8
- 230000003247 decreasing Effects 0.000 claims description 7
- HDTRYLNUVZCQOY-LIZSDCNHSA-N Trehalose Chemical compound O[C@@H]1[C@@H](O)[C@H](O)[C@@H](CO)O[C@@H]1O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 HDTRYLNUVZCQOY-LIZSDCNHSA-N 0.000 claims description 6
- HDTRYLNUVZCQOY-WSWWMNSNSA-N Trehalose Natural products O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@@H]1O[C@@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 HDTRYLNUVZCQOY-WSWWMNSNSA-N 0.000 claims description 6
- 238000000034 method Methods 0.000 abstract description 17
- 238000005215 recombination Methods 0.000 abstract description 6
- 241000196324 Embryophyta Species 0.000 description 229
- 241000219173 Carica Species 0.000 description 51
- 235000009467 Carica papaya Nutrition 0.000 description 48
- 235000002354 carica papaya Nutrition 0.000 description 48
- 241000234295 Musa Species 0.000 description 21
- 235000018290 Musa x paradisiaca Nutrition 0.000 description 20
- 230000006308 pollination Effects 0.000 description 12
- 240000002254 Ananas comosus Species 0.000 description 10
- 235000007119 Ananas comosus Nutrition 0.000 description 9
- 241000219172 Caricaceae Species 0.000 description 8
- 241000238631 Hexapoda Species 0.000 description 8
- 230000001939 inductive effect Effects 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- 240000007154 Coffea arabica Species 0.000 description 7
- 230000034303 cell budding Effects 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 6
- 201000010099 disease Diseases 0.000 description 6
- 235000007460 Coffea arabica Nutrition 0.000 description 5
- 206010033157 Ovarian enlargement Diseases 0.000 description 5
- 241000607479 Yersinia pestis Species 0.000 description 5
- 230000001488 breeding Effects 0.000 description 5
- 230000035784 germination Effects 0.000 description 5
- 230000004083 survival Effects 0.000 description 5
- 240000002922 Armillaria mellea Species 0.000 description 4
- 210000001161 Embryo, Mammalian Anatomy 0.000 description 4
- 210000004027 cells Anatomy 0.000 description 4
- 239000003448 gibberellin Substances 0.000 description 4
- IXORZMNAPKEEDV-OBDJNFEBSA-N gibberellin A3 Chemical compound C([C@@]1(O)C(=C)C[C@@]2(C1)[C@H]1C(O)=O)C[C@H]2[C@]2(C=C[C@@H]3O)[C@H]1[C@]3(C)C(=O)O2 IXORZMNAPKEEDV-OBDJNFEBSA-N 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 4
- 230000004301 light adaptation Effects 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 235000014649 Carica monoica Nutrition 0.000 description 3
- 108020004999 Messenger RNA Proteins 0.000 description 3
- 241000508269 Psidium Species 0.000 description 3
- 239000003905 agrochemical Substances 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 3
- 230000035558 fertility Effects 0.000 description 3
- 229920002106 messenger RNA Polymers 0.000 description 3
- 230000035772 mutation Effects 0.000 description 3
- 239000002689 soil Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 240000006432 Carica papaya Species 0.000 description 2
- 240000000712 Casimiroa edulis Species 0.000 description 2
- 235000003936 Casimiroa edulis Nutrition 0.000 description 2
- 241000233866 Fungi Species 0.000 description 2
- 241000282412 Homo Species 0.000 description 2
- 241000282414 Homo sapiens Species 0.000 description 2
- 206010020649 Hyperkeratosis Diseases 0.000 description 2
- 244000183278 Nephelium litchi Species 0.000 description 2
- 241000845082 Panama Species 0.000 description 2
- 235000000370 Passiflora edulis Nutrition 0.000 description 2
- 240000008915 Passiflora edulis Species 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 238000004113 cell culture Methods 0.000 description 2
- 239000002577 cryoprotective agent Substances 0.000 description 2
- 201000009910 diseases by infectious agent Diseases 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229940093476 ethylene glycol Drugs 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 238000003306 harvesting Methods 0.000 description 2
- 210000000056 organs Anatomy 0.000 description 2
- 210000001938 protoplasts Anatomy 0.000 description 2
- 230000014639 sexual reproduction Effects 0.000 description 2
- 244000144725 Amygdalus communis Species 0.000 description 1
- 235000011437 Amygdalus communis Nutrition 0.000 description 1
- 235000007755 Annona Nutrition 0.000 description 1
- 235000011518 Annona purpurea Nutrition 0.000 description 1
- 240000006199 Annona purpurea Species 0.000 description 1
- 240000002398 Annona squamosa Species 0.000 description 1
- 235000005274 Annona squamosa Nutrition 0.000 description 1
- 241001081440 Annonaceae Species 0.000 description 1
- 241000233788 Arecaceae Species 0.000 description 1
- 235000014417 Averrhoa Nutrition 0.000 description 1
- 241001072280 Averrhoa Species 0.000 description 1
- 235000010082 Averrhoa carambola Nutrition 0.000 description 1
- 240000006063 Averrhoa carambola Species 0.000 description 1
- 241000234670 Bromeliaceae Species 0.000 description 1
- 241000219357 Cactaceae Species 0.000 description 1
- 235000005902 Casimiroa Nutrition 0.000 description 1
- 210000000349 Chromosomes Anatomy 0.000 description 1
- 241000723347 Cinnamomum Species 0.000 description 1
- 244000223760 Cinnamomum zeylanicum Species 0.000 description 1
- 235000004310 Cinnamomum zeylanicum Nutrition 0.000 description 1
- 241000546193 Clusiaceae Species 0.000 description 1
- 241000723377 Coffea Species 0.000 description 1
- 241000219104 Cucurbitaceae Species 0.000 description 1
- 241000339364 Cylicomorpha Species 0.000 description 1
- 235000011511 Diospyros Nutrition 0.000 description 1
- 241000723267 Diospyros Species 0.000 description 1
- 235000015031 Diospyros digyna Nutrition 0.000 description 1
- 240000002655 Diospyros digyna Species 0.000 description 1
- 241000792913 Ebenaceae Species 0.000 description 1
- 241000218218 Ficus <angiosperm> Species 0.000 description 1
- 241000879841 Fusarium oxysporum f. cubense Species 0.000 description 1
- 235000017048 Garcinia mangostana Nutrition 0.000 description 1
- 240000006053 Garcinia mangostana Species 0.000 description 1
- 235000000885 Garcinia xanthochymus Nutrition 0.000 description 1
- 240000000773 Garcinia xanthochymus Species 0.000 description 1
- 241001652155 Horovitzia Species 0.000 description 1
- 241001677302 Hylocereus Species 0.000 description 1
- 235000018481 Hylocereus undatus Nutrition 0.000 description 1
- 240000001501 Hylocereus undatus Species 0.000 description 1
- 241000339360 Jacaratia Species 0.000 description 1
- 241000339384 Jarilla Species 0.000 description 1
- 241000218922 Magnoliophyta Species 0.000 description 1
- 241000219071 Malvaceae Species 0.000 description 1
- 241000218231 Moraceae Species 0.000 description 1
- 241000234615 Musaceae Species 0.000 description 1
- 241000219926 Myrtaceae Species 0.000 description 1
- 238000000636 Northern blotting Methods 0.000 description 1
- 241000208165 Oxalidaceae Species 0.000 description 1
- 241000218996 Passiflora Species 0.000 description 1
- 241000218995 Passifloraceae Species 0.000 description 1
- 241000233805 Phoenix Species 0.000 description 1
- 235000010659 Phoenix dactylifera Nutrition 0.000 description 1
- 240000001732 Phoenix dactylifera Species 0.000 description 1
- 235000004789 Rosa xanthina Nutrition 0.000 description 1
- 241000220222 Rosaceae Species 0.000 description 1
- 241001107098 Rubiaceae Species 0.000 description 1
- 241001093501 Rutaceae Species 0.000 description 1
- 241001093760 Sapindaceae Species 0.000 description 1
- 241001409305 Siraitia Species 0.000 description 1
- 235000002423 Theobroma angustifolium Nutrition 0.000 description 1
- 235000002425 Theobroma bicolor Nutrition 0.000 description 1
- 240000006474 Theobroma bicolor Species 0.000 description 1
- 240000000280 Theobroma cacao Species 0.000 description 1
- 235000002424 Theobroma grandiflorum Nutrition 0.000 description 1
- 235000002323 Theobroma simiarum Nutrition 0.000 description 1
- 241000050660 Vasconcellea Species 0.000 description 1
- 235000020224 almond Nutrition 0.000 description 1
- 235000005764 cacao Nutrition 0.000 description 1
- 235000005767 cacao Nutrition 0.000 description 1
- 235000001046 cacaotero Nutrition 0.000 description 1
- 235000017803 cinnamon Nutrition 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 210000002257 embryonic structures Anatomy 0.000 description 1
- 238000003958 fumigation Methods 0.000 description 1
- 238000002493 microarray Methods 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N oxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 230000001717 pathogenic Effects 0.000 description 1
- 244000052769 pathogens Species 0.000 description 1
- 238000003752 polymerase chain reaction Methods 0.000 description 1
- 238000003753 real-time PCR Methods 0.000 description 1
- 238000003559 rna-seq method Methods 0.000 description 1
- 238000009331 sowing Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 230000035897 transcription Effects 0.000 description 1
- 230000017260 vegetative to reproductive phase transition of meristem Effects 0.000 description 1
Abstract
To provide a novel technique for enhancing characteristics of a plant without using a gene recombination technique. A plant is treated with a freezing step of freezing a plant tissue, a thawing step of thawing the frozen plant tissue, and a generating step of generating a plant from the thawed plant tissue.
Description
Technical Field
The présent invention relates to a method for enhancing characteristics of a plant without using gene manipulation.
Further, the présent invention relates to a technique for obtaining a seedless fruit without using gene manipulation or Chemical treatment.
Background Art
Since ancient times, human beings hâve produced a plant having advantageous properties by a breeding technique. The conventional breeding method requires a long time to fix the certain characteristics, however, with the advent of a génération accélération technique, the time required for fixing the certain characteristics can be shortened. However, even with the génération accélération technique, there has been a problem that it takes several years to fix the certain characteristics. Therefore, biotechnology such as anther culture that does not require any fixing work has been developed.
Further, as the method for producing a plant having advantageous characteristics, a gene recombination technique is known. By the gene recombination technique, herbicide-tolerant crops, pest-resistant crops, disease-resistant crops, and crops with increased préservation hâve been produced.
On the other hand, there has been proposed a method for inducing mutation and enhancing characteristics of a plant by performing a certain treatment. For example, in Patent Literature 1, a breeding method for imparting cold tolérance, including a step of performing gamma irradiation and chromosome doubling treatment has been disclosed.
Further, a method for controlling characteristics of a plant without changing the gene sequence has been devised. For example, in Patent Literature 2, a method for controlling the flowering time in the next génération of a plant by applying a stress treatment of sait stress, poor sunshine stress, strong light stress, drought stress, over-humidity stress, high-temperature stress, low-temperature stress, nutrient stress, heavy métal stress, disease stress, oxygen deficiency stress, ozone stress, C02 stress, strong wind stress, or the like due to the cultivation environment in the végétative growth time of a plant has been disclosed.
By the way, most of the areas in Japan belong to the temperate zone, and Hokkaido and Tohoku région belong to the subarctic zone (cool-temperate zone). Therefore, crops that are not suitable for the cultivation in a climate in Japan, such as those cultivated in from the subtropical zone area to the tropical zone area, are in a situation of being dépendent on the import.
Further, the expression fruit is generally referred to as a fruit having a structure containing seeds inside thereof in angiosperms. Therefore, normally, seeds are contained in a fruit, and it is required to remove the seeds when the fruit is eaten by humans because the seeds cannot be eaten by humans . However, the work of removing the seeds is complicated.
In view of such a problem, a method for producing a fruit with no seeds (seedless fruit) has been devised. As the typical method for obtaining a seedless fruit (anucleated), a gibberellin treatment method can be mentioned (Patent Literature 3).
Further, as in the case of the banana that has been generally distributed, production increase by a method in which a strain having a property of bearing a fruit with no seeds by mutation is multiplied by division has also been performed.
Depending on the kind of a plant, no pollination occurs, and there are some cases where a plant naturally bears a seedless fruit.
A papaya species, which has male trees and female trees, is an example of these cases, and if the pollination does not occur, parthenogenesis may occur. However, the efficiency is extremely low (around 5 to 10%).
Note that in papaya that is a species having male and female trees, a male flower and a female flower altemately corne out and the self-pollination occurs, and therefore, the parthenogenesis hardly occurs.
Further, a papaya species obtained by breed improvement, in which parthenogenesis occurs, is known (Variety registration No. 16161).
Citation List
Patent Literature
Patent Literature 1: JP 2006-25632 A
Patent Literature 2: JP 2016-182094 A
Patent Literature 3: Re-publication of PCT International Publication No. 97/031536
Summary of Invention Technical Problem
As described above, as to the crops that are cultivated in from the subtropical zone area to the tropical zone area, most of the crops are not suitable for cultivation in from the temperate zone to the arctic zone, and it is required to import such crops in from the temperate zone area to the arctic zone area. However, as to the imported crops, there are some cases where a large amount of agricultural Chemicals is used in order to realize the large-scale cultivation, or a Chemical treatment such as fumigation treatment is performed for the importation, and many of the cases are harmful to the human body. Further, the imported crops to which such a Chemical treatment has not been performed are expensive, and often not readily available.
In view of such a situation, a technique in which crops being cultivated in from the subtropical zone area to the tropical zone area can be cultivated in from the temperate zone to the arctic zone has been desired.
On the other hand, there are many cases where several years are required from the sowing to the harvesting depending on the plant species, and there may be a problem in the return on the investment for the cultivation of such a plant species.
In view of such a problem, a technique for accelerating the growth rate of a plant has been desired.
As described above, a technique for enhancing the growth rate and cold tolérance of a plant has been desired. There is a problem that it takes a long time to achieve the adoption of a breeding technique as the solution means. Further, the problem with an anther culture technique is that there is difficulty in the culture between plant species. In addition, with respect to a gene recombination technique, there is a problem of contamination in the gene pool, and in the method for inducing mutation, there is a problem that the degree of uncertainty in achieving the objective is high.
Further, a technique for enhancing the growth rate and environmental adaptation characteristics of a plant without changing the gene sequence has not been known.
In view of such a problem, the first problem to be solved by the présent invention is to provide a novel technique for enhancing characteristics of a plant without using gene recombination.
Further, as described above, in a case where pollination is not performed, although the parthenogenesis can occur in papaya, the efficiency is extremely poor.
As the method for obtaining a papaya that bears a seedless fruit, breed improvement can be mentioned, however, it takes an extremely long period of time, and further the certainty is low.
On the other hand, there is a method of performing a Chemical treatment such as gibberellin treatment, however, the method is not preferred because there is a problem of residual Chemical substances or the like.
In view of such a problem, the second problem to be solved by the présent invention is to provide a novel technique for obtaining a seedless fruit of papaya.
Solution to Problem
The présent invention to solve the above-described first problem is a method for enhancing characteristics of a plant, including: a freezing step of freezing a plant tissue; a thawing step of thawing the frozen plant tissue; and a step of generating a plant from the thawed plant tissue.
According to the characteristic enhancement method of the présent invention, in particular, the growth characteristics and/or cold tolérance of a plant can be enhanced.
Further, in a preferred mode of the présent invention, the lowest température during freezing in the freezing step is -20°C or less .
By setting the lowest température during freezing to -20°C or less, the characteristics of a plant can be further enhanced.
In a preferred mode of the présent invention, in the freezing step, the plant tissue is frozen while decreasing the température at a rate of 0.5°C/day or less.
By slowly decreasing the température in this way, the survival rate of the plant tissue after the thawing step can be improved, and the efficiency of the method according to the présent invention can be improved.
In a preferred mode of the présent invention, the period of the freezing step is 180 days or more.
By freezing the plant tissue over the above period, the effect of enhancing characteristics of a plant can be improved.
In a preferred mode of the présent invention, in the freezing step, the plant tissue is frozen in a state of being immersed in an aqueous saccharide solution.
By setting the mode in such an embodiment, the survival rate of the plant tissue after the thawing step can be improved, and the efficiency of the method according to the présent invention can be improved.
In a preferred mode of the présent invention, the saccharides are trehalose.
By using trehalose, the survival rate of the plant tissue after the thawing step can be further improved.
The présent invention to solve the second problem is a method for producing a seedless fruit of a plant belonging to the Caricaceae, characterized by including: a freezing step of freezing a plant tissue of a plant belonging to the Caricaceae; a thawing step of thawing the frozen plant tissue; a generating step of generating a plant from the thawed plant tissue, and a first growing step of growing the plant obtained by the generating step.
According to the production method of the présent invention, a seedless fruit of a plant belonging to the Caricaceae can be obtained with high efficiency in a shorter period of time than that of breed improvement and without performing a Chemical treatment such as gibberellin treatment.
In a preferred mode of the présent invention, the first growing step is performed under an environment without pollination by a living organism. Since the pollination by an insect or the like does not occur, a seedless fruit can be obtained with extremely high efficiency.
In a preferred mode of the présent invention, a culturing step of collecting a plant tissue of the plant grown by the first growing step and culturing the plant tissue; and a second growing step of growing the plant obtained by the culturing step are included.
The plant obtained by the first growing step also bears a seedless fruit, and the plant obtained by the second growing step through the culturing step has a unique property with which ovarian enlargement is observed at the budding stage, and occurrence of a seedless fruit can be confirmed. Further, buds in each of which the occurrence of a seedless fruit has been confirmed account for around 90% of the total buds. That is, the seedless fruit can be obtained with extremely high efficiency.
In a preferred mode of the présent invention, the second growing step is open-field cultivation.
The plant obtained by the second growing step bears a seedless fruit with high efficiency even in open-field cultivation in which pollination by an insect normally may occur.
In a preferred mode of the présent invention, a sorting step of observing a bud occurred in the course of the second growing step, and removing a bud in which the occurrence of a fruit has not been confirmed is included.
By removing the bud in which the occurrence of a fruit has not been confirmed in the sorting step, and leaving only the bud in which the occurrence of a fruit has been confirmed at the budding stage, fruits to be borne can be ail made into seedless fruits.
The présent invention also relates to a seedless fruit produced by the production method described above. Such a seedless fruit is different from a fruit that has been made seedless by Chemicals such as gibberellin, and can be eaten at ease without worrying about residual substances.
Further, the présent invention also relates to a plant bearing a seedless fruit obtained by the first growing step in the method for producing the seedless fruit described above. Such a plant bears a seedless fruit with high efficiency.
Further, the présent invention also relates to a plant bearing a seedless fruit obtained by the second growing step in the method for producing the seedless fruit described above. Such a plant has a unique property with which ovarian enlargement is observed at the budding stage, and occurrence of a seedless fruit can be confirmed, as described above.
Further, by using the method described above, the présent invention also relates to a plant in which the characteristics are enhanced, a plant tissue used as a scion for grafting, obtained from the plant, a plant obtained by grafting the plant tissue as a scion, and a plant tissue (except for a seed) obtained from each of the plants, and capable of generating a plant individual independent of the plant.
Further, the présent invention also relates to a method for searching a gene for enhancing characteristics of a plant, characterized by including: a step of treating a plant by the method described above; and a step of identifying an RNA showing a higher expression level in the plant that has been subjected to the treatment as compared with an expression level in a plant that has not been subjected to the treatment.
Further, the présent invention also relates to a method for screening a factor for enhancing characteristics of a plant, characterized by including screening a test substance as a factor for enhancing characteristics of a plant when an expression level of an RNA in a plant to which the test substance has applied is higher than an expression level of an RNA in a plant to which the test substance has not applied, by using as an indicator an RNA showing a higher expression level in a plant that has been subjected to the treatment described above as compared with an expression level in a plant that has not been subjected to the treatment.
According to the présent invention, a factor for enhancing characteristics of a plant can be easily screened.
Advantageous Effects of Invention
According to the présent invention to solve the first problem, a plant of which the characteristics hâve been enhanced can be obtained without using a breeding method over several years or a gene recombination method. In particular, according to the présent invention, the growth characteristics and/or cold tolérance of a plant can be enhanced.
According to the présent invention to solve the second problem, a seedless fruit of a plant belonging to the Caricaceae can be obtained with high efficiency.
Brief Description of Drawings
Fig. 1 is a scheme of a method for producing a seedless fruit.
Fig. 2 is a photograph 30 days after germination of a papaya to which freezing and thawing treatment has been performed and a papaya to which the freezing and thawing treatment has not been performed.
Fig. 3 is a photograph 45 days after germination of a papaya to which freezing and thawing treatment has been performed and a papaya to which the freezing and thawing treatment has not been performed.
Fig. 4 is a photograph 60 days after germination of a papaya to which freezing and thawing treatment has been performed and a papaya to which the freezing and thawing treatment has not been performed.
Fig. 5 is a photograph three months after germination of a papaya to which freezing and thawing treatment has been performed and a papaya to which the freezing and thawing treatment has not been performed.
Fig. 6 is a photograph at harvest time of a papaya to which freezing and thawing treatment has been performed and a papaya to which the freezing and thawing treatment has not been performed.
Fig. 7 is a comparison photograph of a bud of a normal papaya and a bud of a papaya that has borne a fruit in the course of the second growing step.
Fig. 8 is a comparison photograph of cross sections of buds of a normal papaya and a papaya that has borne a fruit in the course of the second growing step.
Fig. 9 is photographs showing the cultivated States observed over time of a pineapple to which freezing and thawing treatment has been performed and a pineapple to which the freezing and thawing treatment has not been performed. The photograph in the lowest part shows the pineapples one year after germination.
Fig . 10 is a photograph of a cultivated banana to which freezing and thawing treatment has been performed.
Fig. 11 is photographs of cultivated coffee trees to which freezing and thawing treatment has been performed.
Description of Embodiments
[Characteristic enhancement method]
The characteristic enhancement method according to the présent invention can be applied to ail of plant species without particular limitation, and application of the method to a plant belonging to, for example, the Caricaceae, the Bromeliaceae, the Musaceae, the Cucurbitaceae, the Myrtaceae, the Oxalidaceae, the Moraceae, the Malvaceae, the Rubiaceae, the Laureaceae, the Passifloraceae, the Sapindaceae, the Clusiaceae, the Ebenaceae, the Rutaceae, the Annonaceae, the Arecaceae, the Cactaceae, or the Rosaceae can be mentioned.
More specifically, application to a plant belonging to the Carica, the Ananas, the Musa, the Siraitia, the Psidium, the Averrhoa, the Ficus, the Theobroma, the Coffea, the Cinnamomum, the Passiflora, the Litchi, the Garcinia, the Diospyros, the Casimiroa, the Annona, the Phoenix, the Hylocereus, or the Cerasus, or the like can be mentioned.
The characteristic enhancement method according to the présent invention includes a freezing step of freezing a plant tissue.
As the plant tissue subjected to the freezing step, a plant tissue that is obtained from a plant and can generate a plant individual independent of the plant can be preferably mentioned.
Since a plant is totipotent, any part of a plant corresponds to a plant tissue that is obtained from a plant and can generate a plant individual independent of the plant, and as the part, specifically, a seed, a root, a sprout, a stem, a leaf, a petal, or the like of a plant can be mentioned, and preferably a seed, a root, or a sprout can be mentioned.
When the plant tissue is subjected to a freezing step, such a tissue may be frozen as it is, or a part of the tissue may be excised and frozen in a form of a section.
In the freezing step, it is preferred to freeze the plant tissue in a state of being immersed in a liquid. As a liquid to immense the plant tissue, a cryoprotective agent including an aqueous solution of dimethyl sulfoxide (DMSO), glycerin, ethylene glycol, saccharides, or the like is preferably used. Among them, it is preferred to use an aqueous saccharide solution, or in particular, an aqueous trehalose solution.
The upper limit of the lowest température during freezing in the freezing step is preferably -20°C or less, more preferably -30°C or less, furthermore preferably -40°C or less, still more preferably -50°C or less, and still furthermore preferably -55°C or less.
Further, the lower limit of the lowest température during freezing is preferably -200°C or more, more preferably -150°C or more, furthermore preferably -100°C or more, still more preferably -80°C or more, still furthermore preferably -70°C or more, and even still more preferably -65°C or more.
In the freezing step, it is preferred to slowly decrease the température rather than rapidly decrease the température to the lowest température during freezing. From the viewpoint of the survival rate after thawing, the rate of température decrease is preferably 0.8°C/day or less, more preferably 0.6°C/day or less, furthermore preferably 0.5°C/day or less, still more preferably 0.3°C/day or less, still furthermore preferably 0.2°C/day, and even still more preferably 0.1°C/day.
In a case where the température is slowly decreased as described above, it is preferred to use a program freezer in the freezing step.
The lower limit of the period of the freezing step is preferably 100 days or more, more preferably 120 days or more, furthermore preferably 150 days or more, still more preferably 160 days or more, and still furthermore preferably 180 days or more.
In this regard, the expression period of the freezing step is referred to as a period of time from the time point when the température of a plant tissue is started to decrease until the time point when a thawing step is started.
The thawing method in the thawing step is not particularly limited. The plant tissue in the frozen State may be naturally thawed by leaving the plant tissue at room température, or the plant tissue in the frozen state may be thawed while rinsing the plant tissue under running water.
The characteristic enhancement method according to the présent invention includes a generating step of generating a plant from the plant tissue thawed as described above.
In a case where the plant tissue subjected to the freezing step and the thawing step is a seed of a plant, the seed is sown in accordance with a conventional method, and a plant individual can be generated.
In a case where the plant tissue subjected to the freezing step and the thawing step is a plant part other than the seed, the plant part may be transferred to soil or a medium as it is to allow to germinate, or by finely chopping the plant tissue, subjecting the chopped plant tissue to cell culture in accordance with a conventional method, and performing callus induction, adventitious embryo induction, or adventitious shoot induction on the cultured chopped plant tissue, a plant individual can be generated.
In the plant generated through the freezing step, thawing step, and generating step described above, the characteristics are enhanced.
More specifically, the growth rate and cold tolérance of a plant can be remarkably enhanced according to the characteristic enhancement method of the présent invention.
That is, even if the plant is a plant that can be cultivated only in from the tropical zone area to the subtropical zone area, by applying the characteristic enhancement method according to the présent invention to the plant, the plant can be cultivated in from the temperate zone area to the arctic zone area.
By the way, new Panama disease, which is an infection of banana caused by Fusarium oxysporum f. sp. cubense being one kind of fungi as a pathogen, gives damage to the banana cultivation in Malaysia, the Philippines, Taiwan, and African countries, and in recent years, the damage to the banana cultivation has been spread also in China, Indonesia, Australia, Jordan, Mozambique, and Central American countries.
This mold fungus causes damages of infection in from a subtropical zone area to a tropical zone area, however, does not spread in from the temperate zone area to the arctic zone area because the température deviates from the optimum température.
Therefore, if the cold tolérance of banana is enhanced by the characteristic enhancement method according to the présent invention, and the banana with the enhanced cold tolérance is cultivated in from a temperate zone to an arctic zone, the banana can be supplied stably without being exposed to the threat of new Panama disease.
In addition, according to a preferred mode of the characteristic enhancement method of the présent invention, environmental adaptation characteristics such as heat tolérance, a high altitude adaptation characteristic, and a low altitude adaptation characteristic can be enhanced. That is, according to the characteristic enhancement method of the présent invention, even if the plant is a plant that can be cultivated only in from the temperate zone area to the arctic zone area, the plant can be made adaptable to the cultivation in from the tropical zone area to the subtropical zone area, and a plant that is cultivated in highlands can be made adaptable to the cultivation in lowlands, and vice versa.
Further, according to a preferred mode of the characteristic enhancement method of the présent invention, the fertility, pest résistance, and root rot résistance of a plant can also be enhanced.
The characteristic enhancement method according to the présent invention may include more preferably a screening step.
That is, in a case of using a seed as the plant tissue, multiple seeds are subjected to a freezing step, a thawing step, and a generating step, and each of the seeds is germinated and cultivated, and a strain having excellent characteristics may be screened among the résultant strains.
Further, in a case of using ones other than the seed as the plant tissue, a plant individual is generated from multiple buds, calli, adventitious embryos, or adventitious shoots, which hâve been generated after being subjected to a freezing step, a thawing step, and a generating step, and a strain having excellent characteristics may be screened among the résultant strains.
The next-generation plant obtained by a method other than sexual reproduction from the plant to which the characteristic enhancement method according to the présent invention has been applied takes over the enhanced characteristics. Therefore, if a plant in which the characteristics hâve been enhanced by the characteristic enhancement method according to the présent invention can be obtained, the progeny in the next and future générations generated from a plant tissue (child strain or the like) other than the seed, which is obtained from a plant and can generate a plant individual independent of the plant, also hâve the enhanced characteristics.
Further, even in a case where a plant to which the characteristic enhancement method according to the présent invention has been applied is used as a scion for grafting, the progeny exhibit the enhanced characteristics.
In a plant that has been subjected to a treatment by the characteristic enhancement method according to the présent invention, the level of the RNA expressed in a cell of the plant is significantly increased as compared with that of a plant that has not been subjected to the treatment. It can be said that this remarkable increase in the level of RNA is a factor for enhancing the characteristics. That is, it can be said that the gene encoding an RNA whose expression level increases in a plant cell by applying the characteristic enhancement method according to the présent invention is a gene for enhancing the characteristics of the plant.
Therefore, by analyzing and identifying the RNA whose expression level increases in a plant cell by applying the characteristic enhancement method according to the présent invention, a gene for enhancing the characteristics of the plant can be searched.
That is, the présent invention also relates to a method for searching a gene for enhancing characteristics of a plant, including a step of treating a plant by the characteristic enhancement method described above, and a step of identifying an RNA showing a higher expression level in a plant that has been subjected to the treatment as compared with that in a plant that has not been subjected to the treatment.
The step of identifying the RNA in the searching method according to the présent invention can be performed in the conventional method. For example, by transcriptome analysis such as microarray or RNA sequencing, the RNA showing a high expression level in a plant that has been subjected to the treatment by the characteristic enhancement method according to the présent invention can be identified.
Further, as described above, since the RNA whose expression level increases in a plant to which the characteristic enhancement method according to the présent invention has applied is a factor for enhancing the characteristics, if the RNA is used as an indicator, the factor for enhancing the characteristics of a plant can be screened.
That is, the présent invention also relates to a method for screening a test substance as the factor for enhancing the characteristics of a plant when an expression level of the RNA in a plant to which the test substance has applied is higher than that of the RNA in a plant to which the test substance has not applied.
The expression level of the RNA, which is a factor for enhancing the characteristics of a plant, can be confirmed by a conventional method such as Northern blotting or real-time polymerase chain reaction (PCR).
[Method for producing seedless fruit]
Hereinafter, an embodiment of the présent invention will be described in detail with reference to Fig. 1.
The method for producing a seedless fruit according to the présent invention can be applied to a plant belonging to the Caricaceae, such as the Cylicomorpha, the Carica, the Horovitzia, the Jarilla, the Jacaratia, and the Vasconcellea. Specifically, the method can be applied to a plant belonging to the Carica, and more specifically, to a papaya (Carica papaya L).
The method for producing a seedless fruit according to the présent invention includes a freezing step SU of freezing a plant tissue.
As the plant tissue to be subjected to the freezing step SU, a plant tissue that is obtained from a plant and can generate a plant individual independent of the plant can be preferably mentioned.
Since a plant is totipotent, any part of a plant corresponds to a plant tissue that is obtained from a plant and can generate a plant individual independent of the plant, and as the part, specifically, a seed, a root, a sprout, a stem, a leaf, a petal, or the like of a plant can be mentioned, and preferably a seed, a root, or a sprout, and more preferably a seed can be mentioned.
When the plant tissue is subjected to a freezing step SU, such a tissue may be frozen as it is, or a part of the tissue may be excised and frozen in a form of a section.
In the freezing step SU, it is preferred to freeze the plant tissue in a state of being immersed in a liquid. As a liquid to immense the plant tissue, a cryoprotective agent including an aqueous solution ofdimethylsulfoxide (DMSO), glycerin, ethyleneglycol, saccharides, or the like is preferably used. Among them, it is preferred to use an aqueous saccharide solution, or in particular, an aqueous trehalose solution.
The upper limit of the lowest température during freezing in the freezing step SU is preferably -20°C or less, more preferably -30°C or less, furthermore preferably -40°C or less, still more preferably -50°C or less, and still furthermore preferably -55°C or less.
Further, the lower limit of the lowest température during freezing is preferably -200°C or more, more preferably -150°C or more, furthermore preferably -100°C or more, still more preferably -80°C or more, still furthermore preferably -70°C or more, and even still more preferably -65°C or more.
In the freezing step SU, it is preferred to slowly decrease the température rather than rapidly decrease the température to the lowest température during freezing. From the viewpoint of the survival rate after thawing, the rate of température decrease is preferably 0.8°C/day or less, more preferably 0.6°C/day or less, furthermore preferably 0.5°C/day or less, still more preferably 0.3°C/day or less, still furthermore preferably 0.2°C/day, and even still more preferably 0.1°C/day.
In a case where the température is slowly decreased as described above, it is preferred to use a program freezer in the freezing step SU .
The lower lirait of the period of the freezing step SU is preferably 100 days or more, more preferably 120 days or more, furthermore preferably 150 days or more, still more preferably 160 days or more, and still furthermore preferably 180 days or more.
In this regard, the expression period of the freezing step SU is referred to as a period of time from the time point when the température of a plant tissue is started to decrease until the time point when a thawing step S12 is started.
The thawing method in the thawing step S12 is not particularly limited. The plant tissue in the frozen State may be naturally thawed by leaving the plant tissue at room température, or the plant tissue in the frozen state may be thawed while rinsing the plant tissue under running water.
The method for producing a seedless fruit according to the présent invention includes a generating step S13 of generating a plant from the plant tissue thawed as described above.
In a case where the plant tissue subjected to the freezing step SU and the thawing step S12 is a seed of a plant, the seed is sown in accordance with a conventional method, and a plant individual can be generated.
In a case where the plant tissue subjected to the freezing step SU and the thawing step S12 is a plant part other than the seed, the plant part may be transferred to soil or a medium as it is to allow to germinate, or by finely chopping the plant tissue, subjecting the chopped plant tissue to cell culture in accordance with a conventional method, and performing callus induction, adventitious embryo induction, or adventitious shoot induction on the cultured chopped plant tissue, a plant individual can be generated.
The plant individual generated by the generating step S13 is grown in a first growing step S14. The first growing step S14 may be performed by any method, and a known plant cultivation method such as open-field cultivation, greenhouse cultivation, or closed-door cultivation can be applied.
If natural pollination by an insect occurs, a plant 41 to be grown by the first growing step S14 bears a fruit containing seeds. Therefore, in the first growing step S14, in order to further improve the efficiency of parthenogenesis, it is preferred to perform the step by closed-door cultivation or the like under an environment without pollination by a living organism such as an insect.
In view of the optimum température in the cultivation of a plant belonging to the Caricaceae, the first growing step S14 may be performed in from the tropical zone area to the subtropical zone area, or in a room where the température is controlled so as to be équivalent to the climates in these areas.
In this regard, in the plant 41 that has gone through the freezing step SU, the thawing step S12, and the generating step S13, the cold tolérance is dramatically improved, and therefore, the plant 41 can also be cultivated in from the temperate zone area to the arctic zone area, where the température is lower than that in from the tropical zone area to the subtropical zone area, or in a room where the température is controlled so as to be équivalent to the climates in these areas.
If natural or artificial pollination is not performed, the plant 41 grown in the first growing step S14 bears a seedless fruit 31 with high efficiency.
In also a plant belonging to the Caricaceae, which has cultivated by an ordinary cultivate method, parthenogenesis occurs unless pollination is performed, however, the efficiency is extremely low. On the other hand, in the plant 41 grown in the first growing step S14, the parthenogenesis occurs with extremely high efficiency, and therefore, the plant 41 is particularly excellent in the productivity of a seedless fruit.
In a preferred embodiment of the présent invention, a plant tissue of the plant grown by the first growing step S14 is collected, and cultured (culturing step S21). As the method for culturing a tissue, it is not particularly limited, and organ culture for culturing an organ such as a leaf, mericlone culture (shoot tip culture) for culturing a shoot apex, embryo culture for culturing an immature embryo, anther culture for culturing an anther, protoplast culture for culturing a protoplast, or the like can be mentioned.
Needless to say, the culturing step S21 is not required to wait until the plant 41 bears a fruit in the first growing step S14. Even if the plant is a plant 41 at any growth stage, the plant can be subjected to the culturing step S21.
A plant individual is newly generated by the culturing step S21, and then a second growing step S22 for growing the obtained plant is performed.
With respect to the conditions in the second growing step S22, the above-described content of the first growing step S14 can be applied. However, a plant 42 that has gone through the culturing step S21 has a unique property with which ovarian enlargement is observed at the budding stage, and occurrence of a seedless fruit can be confirmed. Further, buds in each of which the occurrence of a seedless fruit has been confirmed account for around 90% of the total buds. In this way, since buds in each of which the occurrence of parthenogenesis has been confirmed at the budding stage account for almost ali the buds, there is no problem that the natural pollination by an insect is generated by performing open-field cultivation and the efficiency of parthenogenesis is decreased. Therefore, the second growing step S22 may be performed by open-field cultivation. It is extremely advantageous to perform the second growing step S22 by open-field cultivation also in terms of réduction in the production cost.
As described above, in the plant 42 that has gone through the culturing step S21, the parthenogenesis can be confirmed in a State of a bud. Therefore, it is preferred to perform a sorting step S23 of removing a bud in which occurrence of a fruit has not been confirmed (it is possible to bear a fruit having seeds by pollination) . If the sorting step S23 is performed, the proportion of the seedless fruits in the total fruits that hâve each borne a fruit can be improved. If ail of the buds in each of which occurrence of a fruit has not been confirmed are removed by the sorting step S23, ail of the fruits that hâve each borne a fruit can be made into seedless fruits 32.
As described above, the plants 41 and 42 each hâve a property of bearing a seedless fruit with high efficiency. The next-generation plant obtained by a method other than sexual reproduction from each of the plants 41 and 42 takes over the characteristic of parthenogenesis with high efficiency. Therefore, the progeny in the next and future générations generated from a plant tissue (child strain or the like) other than a seed, which is obtained from the plants 41 and 42 and can generate a plant individual independent of the plants, also hâve the characteristic of parthenogenesis with high efficiency.
Further, even in a case where the plants 41 and 42 are each used as a scion for grafting, the characteristic of parthenogenesis can be exhibited with high efficiency.
Examples <Test Example 1> Enhancement of characteristics and production of seedless fruit of papaya
A seed of papaya was left to stand in a program freezer and frozen in a State of being immersed in an aqueous trehalose solution (freezing step). The freezing was performed slowly over 180 days at a température decrease rate of 0.5°C/day so that the lowest température during freezing was -60°C.
The frozen seed of papaya was thawed while rinsing the frozen seed under running water (thawing step) , and the thawed seed was sown and cultivated (generating step, first growing step). Further, the cultivation area is Okayama Préfecture in Japan.
In Figs. 2 to 6, the results of observation over time of the growth of each of the seed that had been subjected to freezing and thawing treatment and the seed that had not been subjected to the freezing and thawing treatment are shown.
As shown in Figs. 2 to 6, it was able to be confirmed that the growth rate of the papaya that had been subjected to the freezing and thawing treatment described above was significantly improved as compared with that of the papaya that had not been subjected to the freezing and thawing treatment. This resuit shows that the growth characteristics of a plant can be enhanced according to the characteristic enhancement method of the présent invention.
Further, papaya is a plant that is native of from Southern Mexico to the West Indies and is cultivated in tropical countries, and the papaya has a property of poor cold tolérance. However, the papaya that had been subjected to freezing and thawing treatment grew without having any problems as shown in Figs. 2 to 6, in spite of the fact that the cultivation area was Okayama Préfecture in Japan belonging to the temperate zone. This resuit shows that the cold tolérance of a plant can be enhanced according to the characteristic enhancement method of the présent invention.
In addition, as shown in Fig. 6, the papaya that had been subjected to the freezing and thawing treatment bore more fruits than those of the papaya that had not been subjected to the freezing and thawing treatment bore. This resuit shows that the fertility of a plant can be enhanced according to the characteristic enhancement method of the présent invention.
In the présent Test Example, although agricultural Chemicals were not used, papaya was able to be cultivated without being damaged by disease and insect pests. Further, even in a case where the papaya to which the freezing and thawing treatment had been performed in a similar manner as in the présent Test Examples was cultivated on a large scale without using any agricultural Chemicals, the papaya was able to be cultivated without being damaged by disease and insect pests. This resuit shows that the pest résistance of a plant can be enhanced according to the characteristic enhancement method of the présent invention.
Further, in the papaya that had been subjected to the freezing and thawing treatment, résistance to root rot was observed. This resuit shows that the root rot résistance of a plant can be enhanced according to the characteristic enhancement method of the présent invention.
Borne fruits of papaya were harvested, and when the content of each of the fruits was checked, around 95% of the total fruits were seedless fruits.
When the results described above are summarized, it has been found that by subjecting a papaya to a freezing step, a thawing step, a generating step, and a first growing step, a seedless fruit of the papaya can be obtained with high efficiency. Further, the papaya cultivated by the présent method was extremely excellent in the fertility. That is, it has been found that by the method according to the présent invention, a seedless fruit can be obtained with extremely high productivity.
In addition, a papaya cultivated by the présent method is excellent in the cold tolérance, the insect résistance, and the root rot résistance, and therefore, the first growing step can be performed even in the temperate zone, and agrochemical-free cultivation can also be performed.
<Test Example 2> Production of seedless fruit of papaya (2)
A shoot apex of a papaya obtained by the freezing step, thawing step, generating step, and first growing step in Test Example 1 was collected, and the collected shoot apex was mericlone cultured (culturing step). A seedling of the papaya individual generated through the culturing step was subjected to open-field cultivation (second growing step).
In Figs. 7 and 8, comparison photographs of a bud budded in the course of the second growing step and a bud of a normal papaya are shown, and the différence between the buds is obvious at a glance. As shown in Fig. 7, in the bud budded in the course of the second growing step, ovarian enlargement was observed. Further, as shown in Fig. 8, it can be understood that the bud budded in the course of the second growing step has already borne a fruit when the cross section of the bud is observed. Since the fruit that has been borne at this budding stage is not pollinated, the fruit is naturally a seedless fruit.
The proportion of the buds in which parthenogenesis had been confirmed to the total buds that had budded in the course of the second growing step was around 90%.
A bud in which ovarian enlargement had not been confirmed (around 10%) as shown in Fig. 7 was sorted, and removed (sorting step) .
After the sorting step, eventually, ail of the fruits obtained from the papaya that had grown in the second growing step were seedless fruits.
<Test Example 3> Characteristic enhancement of pineapple
A seed of a pineapple was subjected to freezing and thawing treatment in a similar manner as in Test Example 1, and the treated seed was sown and cultivated. In Fig. 9, photographs are shown, which hâve recorded over time the growth of the pineapple that had been subjected to the freezing and thawing treatment and the growth of the pineapple that had not been subjected to the freezing and thawing treatment, seeds of both pineapples were sown and cultivated at the same time.
As shown in Fig. 9, as is the case with the papaya in Test Example 1, also in a pineapple, enhancement of the growth characteristics and cold tolérance by the freezing and thawing treatment was able to be confirmed.
<Test Example 4> Characteristic enhancement of banana (1)
A root of a child strain of a banana was sliced into rings, and each of the rings was frozen and thawed in a similar manner as in Test Example 1. The root of the child strain after the freezing and thawing was finely chopped, and this finely-chopped growth cell cluster was cultured on a medium and allowed to germinate. The seedling grown to some extent was transferred to soil and cultivated. Further, the cultivation was performed in Okayama Préfecture in Japan.
As a resuit, the seedling has grown to be in a state that the fruit can be harvested, in around 9 months after the seedling was planted (Fig. 10) . In general, it takes at least one year for a banana to be in a state that the fruit can be harvested from the time when a seedling of the banana was planted, however, this resuit shows that the growth rate of the banana can be remarkably improved by the freezing and thawing treatment.
Further, as in the case of a papaya, a banana is also native of from the subtropical zone to the tropical zone, and in general, does not bear a fruit in the temperate zone, however, in the présent Test Example, the banana was cultivated also in Okayama Préfecture in Japan belonging to the temperate zone, and the fruit was able to be harvested (Fig. 10).
This resuit shows that the cold tolérance of the banana can be enhanced by the freezing and thawing treatment.
<Test Example 5> Characteristic enhancement of banana (2)
A side bud generated from the plant foot of a banana was eut out, the leaves and root were eut off, and the side bud was processed to hâve a bamboo-shoot shape. The processed side bud was frozen and thawed in a similar manner as in Test Example 1. The side bud after the thawing was planted in a pot. After that, the stem rotted and disappeared, however, it was confirmed that a bud newly germinated. When this newly germinated bud was cultivated, a banana in which the growth rate and cold tolérance had been enhanced was able to be obtained in a similar manner as in Test Example 4.
CTest Example 6> Characteristic enhancement of coffee
A seed of a coffee free, which has been cultivated in Tainan city in Taiwan, was subjected to freezing and thawing treatment and germinated in a similar manner as in Test Example 1, and the germinated seed was cultivated in Okayama Préfecture in Japan (Fig. 11). As a resuit, in the coffee tree that had been subjected to the freezing and thawing treatment, accélération at a growth rate of 3 to 40% was observed as compared with that of the same body of the coffee tree cultivated in Tainan city, which had not been subjected to the freezing and thawing treatment.
This resuit shows that the growth rate of the coffee tree can be improved by the freezing and thawing treatment.
Further, the grown was observed without having any problems in Okayama Préfecture in Japan where the température is lower than that in Tainan city in Taiwan, and therefore, it shows that the cold tolérance of the coffee tree can be improved by the freezing and thawing treatment.
CTest Example 7> Characteristic enhancement of other plant species A seed of each of the plants listed below was subjected to freezing and thawing treatment in a similar manner as in Test Example 1, and a plant individual was generated from a plant tissue after the treatment, and cultivated.
The plants are listed as follows: Lo Han Kuo, guava, star fruit, fig, cacao, Ceylon cinnamon, passionfruit, litchi, mangosteen, black sapote, white sapote, spine sugar apple, date palm, red dragon fruit, and almond.
As a resuit, also in any one of the plant species listed above, enhancement of the growth characteristics and cold tolérance by the freezing and thawing treatment was able to be confirmed.
This resuit shows that the characteristic enhancement method according to the présent invention is effective to ail of the plant species.
<Test Example 8> Molecular biological analysis
Papaya, banana, passionfruit, and guava fruit, in each of which the characteristics had been enhanced by the freezing and thawing treatment in the above Test Example, were subjected to transcriptome analysis by using a plant that had not been subjected to the freezing and thawing treatment as a comparison object. As a resuit, it has been found that in any one of the plants, the expression level of mRNA is improved by around 32 to 38 times by being subjected to the freezing and thawing treatment.
This resuit shows that the expression of a gene for enhancing the growth characteristics and cold tolérance is remarkably improved by the freezing and thawing treatment.
That is, it is shown that by analyzing the mRNA improved by the freezing and thawing treatment, a gene for enhancing the characteristics of a plant, such as growth characteristics and cold tolérance can be identified.
Further, this resuit shows that by using the mRNA that is a transcription product of the above-described enhancing gene as an indicator, a factor for enhancing the characteristics of a plant, such as growth characteristics and cold tolérance can be screened.
Industrial Applicability
The présent invention can be applied to a production technigue for crops.
Further, the présent invention can be applied to production of a seedless fruit of papaya.
Claims (8)
1. A method for enhancing growth characteristics and/or cold tolérance of a plant, comprising:
a freezing step of freezing a plant tissue;
a thawing step of thawing the frozen plant tissue; and a generating step of generating a plant from the thawed plant tissue, wherein a lowest température during freezing In the freezing step is -20°C or less, in the freezing step, the plant tissue is frozen while decreasing the température at a rate of 0.8°C/day or less, and a period of the freezing step is 100 days or more.
2 . The method according to claim 1, wherein the lowest température during freezing in the freezing step is -55°C or less, in the freezing step, the plant tissue is frozen while decreasing the température at a rate of 0.6°C/day or less, and a period of the freezing step is 160 days or more.
3. The method for enhancing characteristics of a plant according to claim 1 or 2, wherein in the freezing step, the plant tissue is frozen in a State of being immersed in an aqueous saccharide solution.
4. The method for enhancing characteristics of a plant according to claim 3, wherein the saccharides are trehalose.
5. A method for producing a plant, wherein growth characteristics and/or cold tolérance of the plant was enhanced by applying the method according to any one of claims 1 to 4.
6. A method for producing a plant tissue (except for a seed), comprising a step of growing the plant produced by the production method according to claim 5, wherein the plant tissue is capable of 33 generating a plant individual independent from the plant.
7 . A method for detecting a gene for enhancing characteristics of a plant, comprising:
a step of treating a plant by the method according to any one 5 of daims 1 to 4; and a step of identifying an RNA showing a higher expression level in the plant subjected to the treatment as compared with an expression level in a plant not subjected to the treatment.
8. A method for screening a factor for enhancing characteristics
10 of a plant, comprising:
screening a test substance as a factor for enhancing characteristics of a plant when an expression level of an RNA in a plant to which the test substance has been applied is higher than an expression level of the RNA in a plant to which the test substance
15 has not been applied, by using as an indicator an RNA showing a higher expression level in a plant subjected to the treatment by the method according to any one of daims 1 to 4 as compared with an expression level in a plant not subjected to the treatment.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017-088327 | 2017-04-27 | ||
JP2018-086221 | 2018-04-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
OA19902A true OA19902A (en) | 2021-07-14 |
Family
ID=
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3617310A1 (en) | Method for enhancing plant characteristics and method for producing seedless fruit | |
CN101884294B (en) | Method for reducing juvenile period of hybrid tangerine | |
US11350583B2 (en) | Method for enhancing plant characteristics and method for producing seedless fruit | |
JP6864304B1 (en) | How to enhance plant properties | |
WO2015010562A1 (en) | Breeding method of plant induced mutation of breeding target plant | |
OA19902A (en) | Method for enhancing plant characteristics and method for producing seedless fruit. | |
JP6830591B1 (en) | How to enhance the properties of plants | |
JP6716140B6 (en) | How to enhance the properties of plants | |
O'Brien et al. | Cryopreservation for tree species with recalcitrant seeds: The avocado case | |
Liu et al. | Production and research of longan in China | |
US20230127872A1 (en) | Method for enhancing characteristics of plant | |
Hannachi et al. | Effects of tegument, endosperm, cold treatment and harvest date on germination of wild olive. | |
Sharma et al. | Seedling growth pattern of guava (Psidium guajava L.) as influenced by different seed scarification treatments | |
Jutamanee et al. | Pollination and fruit set in durian'Monthong'at various times and with various methods of pollination | |
Kolev | Investigation of the cold resistance of promising plum cultivars during the winter period. | |
Lavee | Adaption of commercial olive cultivation to new production zones and environments including in the Southern hemisphere-possibilities, considerations and the problems involved | |
Balaj et al. | The effect of rootstock on vegetative development and flower production in modern garden roses (Rosa canina L.). | |
Emuh et al. | The phenology of flowering in Citrullus lanatus (Thumb.) Mansf. in southwestern Nigeria | |
Dulay et al. | Seed germination of selected economically important indigenous fruit trees | |
Mahmoudzadeh | Clonal selection and superior cultivar selection of Iranian grape germplasm to cold hardiness | |
Peşteanu et al. | The Influence of Abiotic Factors on the Development and Productivity of Apricot Plantations in the Republic of Moldova | |
Ion et al. | INFLUENCE OF TREATMENTS WITH FUNGICIDES ON THE PHYSIOLOGICAL PROCESSES IN Persica vulgaris MILLER ATTACKED BY Taphrina deformans (BERK.) TUL. | |
Stambouli-Essassi et al. | Sexual Propagation of the tunisian spinescent opuntia ficus-indica (L.) Mill., morphogenetic deployment and polymorphism | |
JP2017195823A (en) | Method for cultivation of compositae plants | |
Cioloca et al. | In vitro selection of true potato seed genotypes tolerant to drought stress |