CN107041299A - A kind of method of the Rapid deactivation torrid zone/Subtropical Corn Germplasms light sensitivity - Google Patents

Abstract

The invention relates to breeding technology, and specifically discloses a method for quickly inactivating the photosensitivity of tropical/subtropical maize germplasm. Combining DH breeding technology, DNA molecular marker technology and other biological breeding technologies, a method for rapidly inactivating the photosensitivity of tropical/subtropical maize germplasm was proposed. A completely homozygous excellent maize inbred line (DH line) is obtained, so that the tropical/subtropical maize germplasm can be quickly introduced into the temperate germplasm, the breeding efficiency is improved, and the stable and sustainable development of the breeding work is guaranteed.

Description

A rapid passivation method for photosensitivity of tropical/subtropical maize germplasm

technical field

The invention relates to breeding technology, in particular to a method for quickly inactivating the photosensitivity of tropical/subtropical maize germplasm.

Background technique

Tropical/subtropical maize germplasm is a unique maize germplasm group with good lodging resistance, drought tolerance, disease and insect resistance, etc. It can be used as an excellent material to broaden the temperate maize germplasm base and further improve temperate maize germplasm agronomy traits, enhanced disease resistance and adaptability. However, tropical/subtropical maize germplasm has strong light sensitivity when planted in temperate regions, which will cause delays in growth and flowering stages, and even fail to reproduce, making it difficult to use directly. It is necessary to passivate its photosensitivity by introduction, domestication and genetic improvement.

At present, the commonly used tropical/subtropical maize germplasm domestication methods are mainly through mixed selection in different regions, gradual domestication, or direct selection and domestication in temperate regions, or through multiple methods such as single cross, three cross, backcross and compound hybridization. /Transfer of subtropical germplasm to temperate germplasm. However, these methods all need 5-6 years or more, the domestication process is slow, and the residual germplasm of the donor system cannot be completely eliminated, and the efficiency is low. Therefore, there is an urgent need to propose a method for quickly inactivating the photosensitivity of tropical/subtropical maize germplasm, aiming at introducing tropical/subtropical germplasm into temperate germplasm in 2 years and 4 generations, and obtaining completely homozygous maize germplasm that can be used in temperate regions. new maize germplasm.

Contents of the invention

In order to solve the problems existing in the prior art, the technical scheme of the present invention is as follows:

A method for quickly inactivating the photosensitivity of tropical/subtropical maize germplasm, comprising the following steps:

(1) In the first season, select temperate maize backbone inbred line A as the recipient based on the heterogeneous group, and select tropical/subtropical maize germplasm that has synergy with temperate maize germplasm and has excellent traits such as pest resistance, drought tolerance, and lodging resistance. Germplasm B is the donor, planted in tropical/subtropical regions, after flowering, the temperate maize inbred line A is used as the female parent, and the tropical germplasm B is used as the male parent for hybridization. After maturity, the hybrid seed C is harvested;

(2) In the second season, the hybrid seed C was planted in Beijing, Inner Mongolia, Shanxi, Liaoning, Heilongjiang, Gansu and other temperate regions, and the maize haploid induction line D was planted at the same time; The female parent and the maize haploid induction line D are used as the male parent for hybridization. After maturity, the hybrid ears are harvested; and according to the purple markings on the top of the grain embryo and endosperm, the purple grain at the top of the grain and the colorless embryo are selected as the haploid grain. Obtain more than 10,000 haploid grains E;

(3) In the third season, haploid seed E is planted in tropical/subtropical areas such as Hainan, Guangxi, and Yunnan, or in temperate areas such as Beijing, Inner Mongolia, Shanxi, Liaoning, Heilongjiang, and Gansu. The flowering period depends on the loose powder of haploid plants Carry out selfing, after maturing, harvest selfing fruit ears, which is the DH pure line F (DH0 generation);

(4) In the fourth season, the pure line F (DH0 generation) was planted in the temperate zone for selfing, and the pure lines with serious lodging, sex imbalance, delayed flowering and non-selfing of photosensitivity reactions were eliminated.

After maturity, the pure lines with serious diseases and less than 50 grains will be eliminated, and the pure line G (DH1 generation) with more than 50 self-seeds will be harvested;

(5) Plant pure line G in tropical/subtropical areas such as Hainan, Guangxi, and Yunnan, or in temperate areas such as Beijing, Inner Mongolia, Shanxi, Liaoning, Heilongjiang, and Gansu, and use DNA molecular marker technology to identify homozygosity at the seedling stage and establish DNA fingerprints Atlas, analyze the genetic distance and heterotopic groups between the pure line G and the existing inbred lines commonly used in different groups;

According to the classification results, the hybrid combination H is combined with the backbone inbred lines of the corresponding heterogeneous group;

(6) Plant the hybrid combination H in more than 10 different ecological zones for identification, select the hybrid combination with strong adaptability, high quality, and high yield as the selected hybrid variety K, and its corresponding DH pure line G is the elite variety quality.

Further, the strong adaptability described in the step (6) is manifested in that the main diseases in the ecological zone reach the level of resistance above medium resistance, the lodging rate is lower than 10%, and the empty rod rate is less than 3%; Protein content ≥ 8%, crude starch content ≥ 72%, crude fat content ≥ 3%, bulk density ≥ 690g/L; the high yield means that the yield is higher than that of the control.

The control is a commonly used local hybrid variety.

Preferably, the maize haploid-inducing line D in step (2) is derived from an improved line of maize haploid-inducing germplasm Stock6.

More preferably, the maize haploid induction line D is selected from Jingkeyu 044, Jingkeyu 045 or Jingkeyu 046.

Further, the serious diseases described in step (4) mainly refer to leaf spot, stem rot, ear rot and the like.

Preferably, the backbone inbred line described in step (5) is selected from Jing 2416, Zheng 58, Jing MC01 or Jing 92.

Further, the technical solution of the present invention is in the research and development stage, and the tropical/subtropical regions are selected as Hainan, Guangxi and Yunnan. The temperate regions are selected as Beijing, Gansu, Shanxi, Liaoning and Heilongjiang.

The invention also provides the application of the method for quickly inactivating the photosensitivity of tropical and subtropical maize germplasms into temperate maize germplasms in maize breeding.

The beneficial effects of the present invention are:

Aiming at the deficiencies of commonly used breeding methods, the present invention combines biological breeding technologies such as DH breeding technology and DNA molecular marker technology, and proposes a method for rapidly inactivating the photosensitivity of tropical/subtropical maize germplasm. The subtropical germplasm is introduced into the temperate germplasm, and a completely homozygous excellent maize inbred line (DH line) is obtained, so that the tropical and subtropical maize germplasm can be quickly introduced into the temperate germplasm, which improves the breeding efficiency and excellent effect, and ensures the smoothness of the breeding work. Continuous innovation and stable and sustainable development are an efficient and practical breeding method for quickly introducing tropical and subtropical maize germplasm into temperate zone germplasm.

detailed description

Preferred embodiments of the present invention will be described in detail below in conjunction with examples. It should be understood that the following examples are given for the purpose of illustration only, and are not intended to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

Example 1

(1) Select the temperate maize backbone inbred lines Jing 2416 and Zheng 58 as the recipient basic materials based on the heterogeneous groups, select the tropical germplasm SUWAN 1 as the donor, and plant them in Hainan. After flowering, the temperate maize lines Jing 2416 and Zheng 58 was the female parent, and the tropical/subtropical material SUWAN 1 was used as the male parent to cross the two. After maturity, hybrid seeds Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1 were harvested.

(2) The hybrid seeds Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1 were planted in temperate regions such as Beijing, Shanxi, Liaoning, Heilongjiang, etc., and at the same time, they were planted with improved haploid-induced germplasm Stock6 from maize, which had obvious grain markers The maize haploid induction line Jingkeyu 044, which has the advantages of strong growth potential, good pollination, and sufficient pollen amount, etc.

(3) At the flowering stage, the hybrid seeds of Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1 were used as the female parent, and the maize haploid induction line Jingkeyu 044 was used as the male parent. After maturity, the hybrid ears are harvested. According to the purple markers on the top of the embryo and endosperm, the haploid kernels were selected as the purple kernels and colorless embryos. Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1 obtained 4000 haploid kernels respectively.

(4) In Hainan, the haploid seeds from Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1 were planted separately, and the haploid plants were self-crossed according to the pollination of the haploid plants at the flowering stage. After maturity, self-fertilization and fruit ears were harvested, which were DH pure lines. Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1 obtained DH pure lines (Jing 2416×SUWAN 1)DH01, (Jing 2416×SUWAN 1)DH02, ( Beijing 2416 × SUWAN 1) DH03, etc., (Zheng 58 × SUWAN 1) DH01, (Zheng 58 × SUWAN 1) DH02, (Zheng 58 × SUWAN 1) DH03, etc. 120.

(5) Plant pure lines in Beijing (Jing 2416×SUWAN 1)DH01, (Jing 2416×SUWAN 1)DH02, (Jing 2416×SUWAN 1)DH03, etc., (Zheng 58×SUWAN 1)DH01, (Zheng 58×SUWAN 1)DH01, (Zheng 58×SUWAN 1) 1) DH02, (Zheng 58×SUWAN 1) DH03, etc., for self-propagation. Eliminate the pure lines with serious lodging, male and female imbalance, delayed flowering and inability to self-fertilize with photosensitivity. After maturity, the pure lines with serious diseases such as large spot, small spot, stem rot, and ear rot and extremely poor fruiting (less than 50 grains) were eliminated, and the pure lines with more than 50 self-seeds were harvested ( Beijing 2416 x SUWAN 1) DH11, (Jing 2416 x SUWAN 1) DH12, (Jing 2416 x SUWAN 1) DH13, etc., (Zheng 58 x SUWAN 1) DH11, (Zheng 58 x SUWAN 1) DH12, (Zheng 58 x SUWAN 1) ) DH13 and so on 80.

(6) 80 pure lines of DH11, DH12, DH13, and DH14, which were harvested from Jing 2416×SUWAN 1 and Zheng 58×SUWAN 1, were planted in Hainan, and the homozygosity was identified by DNA molecular marker technology at the seedling stage to establish DNA fingerprints were used to analyze the genetic distance and heterotopic groups between the 80 pure lines and the existing inbred lines commonly used in different groups.

According to the classification results, the combination with the backbone inbred lines corresponding to the heterogeneous group, for example, the DH line derived from Jing 2416×SUWAN 1 is combined with Zheng 58, Jing MC01 and other backbone inbred lines (Jing 2416×SUWAN 1) DH11×Zheng 58, (Beijing 2416×SUWAN 1) DH12×Zheng 58, (Beijing 2416×SUWAN 1) DH13×Zheng 58, (Beijing 2416×SUWAN 1) DH11×Beijing MC01, (Beijing 2416×SUWAN 1) DH12× There are 80 hybrid combinations of Jing MC01, (Jing 2416×SUWAN 1)DH13×Jing MC01, etc., derived from the combination of Zheng 58×SUWAN 1DH line and the backbone line Jing 2416, Chang 7-2 (Zheng 58×SUWAN 1)DH11×Jing 2416, (Zheng 58×SUWAN 1) DH12×Jing 2416, (Zheng 58×SUWAN 1)DH13×Jing 2416, (Zheng 58×SUWAN 1)DH11×Chang 7-2, (Zheng 58×SUWAN 1)DH12×Chang 7-2, (Zheng 58×SUWAN 1)DH13×Chang 7-2 and other hybrid combinations 80.

(7) The 160 hybrid combinations were planted in more than 10 different ecological regions such as Heilongjiang, Liaoning, Jilin, Inner Mongolia, Beijing, Shanxi, Hebei, Henan, Shandong, Shaanxi, and Xinjiang for identification.

Select the main diseases such as stem rot, ear and grain rot, large spot disease, small spot disease and other major diseases to reach the level of resistance above medium resistance, the lodging rate is less than 10%, the empty stem rate is less than 3%, and the crude protein content is ≥ 8%. , crude starch content ≥ 72%, crude fat content ≥ 3%, bulk density ≥ 690g/L, yield higher than the control and other comprehensive agronomic traits (Zheng 58×SUWAN 1) DH11×Jing 2416, (Zheng 58×SUWAN 1) DH12×Jing 2416, (Zheng 58×SUWAN 1) DH11×Chang 7-2, (Zheng 58×SUWAN 1)DH12×Chang 7-2, (Jing 2416×SUWAN 1)DH13×Zheng 58, (Jing 2416×SUWAN 1) The DH13×Jing MC01 hybrid combination is a selected hybrid variety, and its corresponding (Zheng 58×SUWAN 1)DH11, (Zheng 58×SUWAN 1)DH12, (Jing 2416×SUWAN 1)DH13 pure lines contain tropical The germplasm does not have the good germplasm of photosensitivity reaction.

Example 2

The inbred line Beijing SV19.

1. Source of parents

The inbred line Beijing SV19 is a self-selected line of the Maize Research Center of Beijing Academy of Agriculture and Forestry Sciences. It is bred by DH breeding technology with Suwan1×PH4CV as the basic material. This inbred line can be released to the public.

2. Breeding process

In October 2009, 20 tropical germplasm Suwan1 were screened and identified in Hainan, and the hybridization of Suwan1 and PH4CV was completed. After the hybrid F1 is mature, it is mixed and threshed, and used as the basic material for line selection.

In May 2010, 100 F1 plants were planted in Beijing at a density of 4000 plants/mu, and 20 corn haploid induction lines Jingkeyu 045 were planted at the same time. During the flowering period, the two are crossed. After maturity, 80 hybrid fruit ears were harvested. And according to the purple mark on the top of the grain embryo and endosperm, 1100 haploid grains were selected with purple grain top and colorless embryo.

In October 2010, all 1000 haploid seeds were sown in a single seed in Hainan, and self-crossing was carried out according to the pollination of the haploid plants during the flowering stage, and 112 DH pure lines were obtained.

In May 2011, 112 DH pure lines will be planted in Beijing. The pure lines that lodg more than 10%, and produce photosensitivity, flowering delay, anomyny, and self-fertilization are eliminated. After maturity, the pure lines with serious diseases such as large spot, small spot, stem rot, and ear rot and extremely poor fruiting (less than 50 seeds) are eliminated, and DH pure lines with more than 50 self-seeds are harvested 20 plants.

In October 2011, 20 DH pure lines were planted in Hainan. At the seedling stage, the DNA molecular marker-assisted breeding technology was used to identify the homozygosity, and the DNA fingerprint was established to analyze the genetic distance and heterozygosity between the 20 DH pure lines and the existing backbone inbred lines. The superior taxa were multiplied and combined with the existing commonly used inbred line PH6WC at the same time.

In May 2012, the combined hybrid combinations were planted in more than 10 different ecological areas such as Heilongjiang, Liaoning, Jilin, Inner Mongolia, Beijing, Shanxi, Hebei, Henan, Shandong, Shaanxi, and Xinjiang for identification. Select the main diseases such as stem rot, ear and grain rot, large spot disease, small spot disease and other major diseases to reach the level of resistance above medium resistance, the lodging rate is less than 10%, the empty stem rate is less than 3%, and the crude protein content is ≥ 8%. PH6WC × Jing SV19 hybrid combination with excellent comprehensive agronomic traits such as crude starch content ≥ 72%, crude fat content ≥ 3%, bulk density ≥ 690g/L, and yield higher than that of the control is a selected hybrid variety, and its corresponding pure line Jing SV19 is an excellent germplasm.

3. Characteristics

The seedlings have purplish red leaf sheaths, lavender anthers, green leaves, semi-compact plant type, plant height 176cm, ear position 98cm, tassel branches 5-7, filaments light red, ear length 17.2cm, ear diameter 4.9cm, ear row 16 rows, tube-shaped ears, red cobs, light yellow grains, semi-hard grains. The inbred line is highly resistant to large leaf spot, small leaf spot, and Curvularia leaf spot, and has good lodging resistance. Large amount of pollen, long pollen time, suitable for male parent.

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (9)

1. a method for fast passivation tropical/subtropical maize germplasm photosensitivity, is characterized in that, comprises the following steps: (1) In the first season, select temperate maize backbone inbred line A as the recipient based on the heterogeneous group, and select tropical/subtropical species that have synergies with temperate maize germplasm and have excellent traits of pest resistance, drought tolerance, and lodging resistance Germplasm B is the donor, planted in tropical/subtropical regions, and after flowering, the temperate maize inbred line A is used as the female parent, and the tropical germplasm B is used as the male parent for hybridization. After maturity, the hybrid seed C is harvested; (2) In the second season, the hybrid seed C is planted in multiple different temperate regions, and the maize haploid induction line D is planted at the same time; at the flowering stage, the hybrid seed C is used as the female parent, and the maize haploid induction line D is the parent Hybridization is carried out, and after maturity, the hybrid ear is harvested; and according to the purple marking on the top of the grain embryo and endosperm, the purple grain at the top of the grain and the colorless embryo are selected as haploid grains, and more than 10,000 haploid grains E are obtained; (3) In the third season, the haploid grain E is planted in the tropics/subtropics, self-crossing is carried out according to the pollination of the haploid plants during the flowering period, and after maturity, the self-crossing fruit ears are harvested, which is the DH pure line F (DH0 generation); (4) In the fourth season, plant the pure line F (DH0 generation) in the temperate zone for selfing, and eliminate the pure lines that have serious lodging, male and female imbalance, delayed flowering and non-selfing due to photosensitivity reactions. Eliminate the pure lines with serious diseases and less than 50 grains, and harvest the pure line G (DH1 generation) with more than 50 self-seeds; (5) Plant pure line G in tropical/subtropical regions or temperate regions, use DNA molecular marker technology to identify homozygosity at the seedling stage, establish DNA fingerprints, and analyze the genetic distance between pure line G and existing inbred lines commonly used in different groups and heterotic groups; According to the classification results, the hybrid combination H was combined with the backbone inbred lines; (6) Plant the hybrid combination H in more than 10 different ecological zones for identification, select the hybrid combination with strong adaptability, high quality, and high yield as the selected hybrid variety K, and its corresponding DH pure line G is the elite variety quality. 2. The method according to claim 1, characterized in that, the strong adaptability described in step (6) is manifested in that the main diseases in the ecological zone reach the level of resistance above medium resistance, the lodging rate is lower than 10%, and the empty bar rate is less than 10%. 3% or less; the high quality is represented by crude protein content ≥ 8%, crude starch content ≥ 72%, crude fat content ≥ 3%, bulk density ≥ 710g/L; the high yield is represented by a higher yield than the control. 3. The method according to claim 2, characterized in that the control is a local commonly used hybrid variety. 4. The method according to any one of claims 1-3, characterized in that the maize haploid-inducing line D in step (2) is derived from an improved line of maize haploid-inducing germplasm Stock6. 5. The method according to claim 4, characterized in that the maize haploid induction line D is selected from Jingkeyu 044, Jingkeyu 045 or Jingkeyu 046. 6. The method according to any one of claims 1-3, characterized in that the serious diseases described in step (4) are mainly large leaf spot, small leaf spot, stem rot or ear rot. 7. The method according to claim 3, characterized in that the backbone inbred line described in step (5) is selected from Jing 2416, Zheng 58, Jing MC01 or Jing 92. 8. The method according to any one of claims 1-3, characterized in that the tropical/subtropical region is selected from Hainan, Guangxi and Yunnan. 9. The method according to any one of claims 1-3, characterized in that the temperate region is selected from Beijing, Inner Mongolia, Shanxi, Liaoning, Heilongjiang and Gansu.