CN103875462B - Triple cross wheat breeding technical method - Google Patents

Abstract

The invention discloses a three-line hybrid wheat breeding method, which is a hybrid wheat breeding method which closely combines conventional hybrid breeding and heterosis breeding. Specifically, the technical method is composed of six modules, including: germplasm resources and parent nursery module, hybrid parent breeding module, heterosis detection and selection module, hybrid breeding module, conventional hybrid breeding module, production performance comparison test module , the relationship between the modules and the working procedures within the modules is clear. The invention solves the problem that breeding resources and information cannot be effectively shared between the two breeding methods, resulting in low efficiency of heterosis breeding.

Description

A kind of three-line hybrid wheat breeding method

technical field

The invention relates to the technical field of wheat breeding, in particular to a three-line hybrid wheat breeding method.

Background technique

Wheat is the food crop with the largest total output and high nutritional value in the world. With the further increase of the population, the per capita arable land area is decreasing year by year, and the food problem is one of the most important problems we are currently facing. Heterosis is a common phenomenon in the biological world. At present, using wheat heterosis is one of the main measures to increase wheat yield. There are three main ways for wheat to utilize heterosis: both "three-line method", "two-line method" and "chemical male killing method". The present invention is only aimed at the first two methods.

The three-line method refers to the three-line matching of the sterile line, the maintainer line and the restorer line. The sterile line is the female parent, and the maintainer line is the male parent. The offspring of the sterile line is still male sterile. The sterile line continues to reproduce or is used to prepare hybrids; the sterile line is used as the female parent, the restorer line is used as the male parent, and they are planted alternately, and the pollen of the sterile line is given to the sterile line through the restorer line, and the seeds produced on the sterile line plants are hybrids kind.

The two-line method means that only the photothermosensitive male sterile line and the restorer line are matched. Photothermosensitive male sterility is controlled by a recessive major gene, and its fertility expression is affected by the external temperature and light conditions. In the sensitive period, when the ambient temperature is within the critical temperature range of sterility, it is completely sterile, and the sterile line can be used to produce seeds with the restorer line; when the ambient temperature is within the critical temperature range of fertility, the sterile line will recover Normal fertile, self-fertile reproduction.

In wheat breeding, conventional hybrid breeding and heterosis breeding are two research directions, generally carried out by two breeding teams respectively. Due to different breeding directions, different breeding methods, different breeding procedures, and different selection priorities, they are integrated and rarely combined. The parents of heterosis breeding are sterile lines and restorer lines. The key to the utilization of hybrid wheat is the selection of strong dominant combinations. The advantages and disadvantages of combinations mainly depend on the comprehensive performance of individual plants, lines and multiple generations of families selected for segregation generations (F2～Fn). Generally, F1 combinations are not selected. Heterosis breeding is limited by parental characteristics (parents must be stable sterile lines and restorer lines). The number of hybrid wheat combinations is small every year, and the probability of strong dominant combinations is very low. The conventional crossbreeding of wheat is not limited by the fertility of the parents, and hundreds or even thousands of hybrid combinations can be configured every year, but the breeding information of the strong dominant combinations among them is lost due to the non-selection of the F1 generation.

In addition, when selecting hybrid combinations for three-line wheat breeding, it is necessary to manually cover the sterile lines with parchment paper bags after earing, and then manually grant pollen to the restorer lines. Large, a large number of bagging and pollination manual operations in the field are time-consuming and labor-intensive and inefficient. The efficiency of mass seed production of hybrid wheat dominant combinations is limited.

Contents of the invention

The purpose of the present invention is to propose a three-line hybrid wheat breeding method to solve the problem that parental resources and information cannot be effectively shared between the two breeding methods, resulting in low efficiency of heterosis breeding.

In order to solve the above technical problems, the present invention adopts a technical method composed of six modules, including: germplasm resources and parent nursery module, hybrid parent breeding module, heterosis detection and selection module, hybrid breeding module, conventional hybrid breeding module The module, the production performance comparison test module, the relationship between the modules and the relationship between the working procedures in the modules are clear.

Germplasm Resources and Parental Nursery Module. The parent nursery collects a wealth of variety materials at home and abroad and characteristic strain materials in comparative tests of production performance. Some materials can be used as backbone parents in conventional breeding and entered into the module of conventional cross-breeding. Some materials can be used as parents for heterosis breeding, enter the hybrid parent selection module, and be backcrossed to produce a sterile line (female parent) or a restorer line (male parent).

Conventional crossbreeding module. The heterosis yield test was carried out on the single-cross F1 generation of conventional hybrid breeding, and the strong dominant combination female parent and strong dominant combination male parent were detected; the strong dominant combination female parent and male parent were respectively entered into the hybrid parent selection module as heterosis breeding parents Candidate parent for selection. The remaining combinations entered the conventional breeding program for offspring selection.

Hybrid parent selection module. There are three sources for parental breeding of hybrids: the female parent of strong dominant combination and the male parent of strong dominant combination obtained by conventional hybridization; the excellent lines produced in the comparative test of production performance; characteristics, and determine the scheme of sterile lines and restorer lines.

The heterosis detection and selection module. The excellent and stable sterile lines and the excellent and stable restorer lines from hybrid parent selection are planted between each male parent and multiple female parents under isolation conditions to form n units with one parent and multiple mothers (n = number of male parents ), the heterosis combination was identified in the next year, and the yield of the identified strong hybrid combination was compared in one year, and the upgraded combination was determined to enter the production performance comparison test module; at the same time, the parent male sterile line of the strong dominant hybrid combination And the restorer line enters the hybrid breeding module for seed propagation.

Hybrid breeding module. CMS breeders propagate by using bagged seed panicle row circulation method, bagging 2 panicles per panicle row and artificially awarding maintainer line pollen to collect separately, and harvesting other mixed lines; CMS original seed propagation, CMS: maintain The lines are planted at a row ratio of 5:1, and the maintainer line is cut off in advance after pollination is completed, and then the sterile line is harvested; the restorer line is propagated by the breeder, and the panicle row cycle method is adopted, and 1-2 ears are selected for each panicle row to harvest separately, and the rest of the mixed lines are harvested In the following year, the original seed of the restorer line is propagated by mixed seeds; the original seed of the CMS line is propagated by hybrids: the original seed of the restorer line is planted at a row ratio of 5:1, and the restorer line is cut off in advance after pollination is completed, and then the hybrid is harvested.

Production performance comparison test module. In turn, it includes family comparison, strain comparison, variety comparison and regional variety comparison.

In the above-mentioned three-line hybrid wheat breeding method, further, the identified strong hybrid combination is compared with the yield of the strong hybrid combination for one year, and the upgraded combination is directly entered into the variety comparison test in the production performance comparison test.

The three-line hybrid wheat breeding method described above, further, hybrid parent selection includes male sterile line selection and restorer line selection; in the process of restorer line selection, SSR molecular markers Xgwm95 and Barc61 gene-assisted selection techniques are used in Early generations select for the target trait. Wheat fertility recovery is controlled by two pairs of major genes, which are located on chromosome 2A and chromosome 1B, respectively, and are linked to SSR molecular markers Xgwm95 and Barc61, respectively.

In the three-line hybrid wheat breeding method described above, further, in the breeding of the sterile line, the bagging self-pollination seed setting rate of the stable sterile line is ≤0.5%. In the breeding of restorer lines, the bagging self-pollination seed setting rate of stable restorer lines is more than 90%; compared with the prior art, the beneficial effects of the present invention are:

1. The present invention consists of six modules: germplasm resource and parent nursery; conventional hybrid breeding; hybrid parent selection; heterosis selection; relationship is clear. Among them, the close combination of conventional hybrid breeding and heterosis breeding (heterosis selection, hybrid breeding) is a prominent innovation point. In the existing wheat breeding work, conventional hybrid breeding and heterosis breeding are two research directions, which are generally carried out by two breeding teams separately, with little relationship.

2. Combination of conventional hybrid breeding and heterosis breeding. Conventional cross breeding usually does not select the first generation of single-cross (F1), and selects after the field evaluation and the second generation of offspring (F2). In the method of the present invention, the yield of heterosis is measured in the single-cross F1 generation of conventional breeding. The female parent and the male parent of the strong dominant combination are respectively used as candidate parents for the selection of heterosis breeding parents (sterile line and restorer line). Through the analysis of F1 data, rich information of strong dominant combination is provided, and the source of strong dominant combination is expanded. . In addition, through the identification of production performance comparison tests, other excellent offspring of conventional breeding entered germplasm resources and parental nurseries to be used.

3. The restorer line was selected by molecular marker-assisted selection technique. Wheat fertility recovery is controlled by two pairs of major genes, which are located on chromosome 2A and chromosome 1B, respectively, and are linked to SSR molecular markers Xgwm95 and Barc61, respectively. In the process of restoring line selection, the molecular marker-assisted selection technology is used to select the target traits in the early generation, which greatly shortens the breeding cycle and improves the breeding efficiency. Preferably, the excellent restorer lines are also included in the production performance comparison test, and those that are particularly outstanding can participate in the new variety approval.

4. Testing and selection of strong dominant hybrid combinations. The present invention takes one father and multiple mothers (one restorer line and multiple sterile lines) as a unit, the male restorer lines are pollinated freely in the seed production isolation enclosure, and the seeds harvested from the female sterile lines are hybrids. In this way, multiple one-parent and multiple-parent units can be set up in the field. With this method, each hybrid combination can produce batches of hybrid seeds, which can be used for comparative identification of strong vigor in hybrid combinations and research on heterosis genetics, greatly improving the batch seed production efficiency of hybrid wheat dominant combinations.

Description of drawings

Fig. 1 is the flowchart of the three-line hybrid wheat breeding method of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples, but not as a limitation of the present invention.

As shown in Figure 1, it is a three-line hybrid wheat breeding method according to an embodiment of the present invention. Including: germplasm resources and parent nursery; conventional hybrid breeding; hybrid parent selection; heterosis testing and selection; hybrid breeding and production performance comparison test;

(1) Germplasm resources and parent nursery: The parent nursery includes abundant wheat variety materials collected from home and abroad; germplasm resources and parent nursery provide raw materials for conventional hybrid breeding and hybrid parent selection;

(2) Conventional cross-breeding: The single-cross F1 generation of conventional cross-breeding enters the production performance comparison test for heterosis yield measurement, selects the female parent of the strong dominant combination and the male parent of the strong dominant combination, and the female parent of the strong dominant combination and the male parent of the strong dominant combination are respectively Enter hybrid parent selection as a candidate parent for heterosis breeding parent selection;

(3) Hybrid parent selection: There are three sources of parents for hybrid parent selection: the strong dominant combination female parent and strong dominant combination male parent obtained by conventional hybrid breeding; the excellent lines produced in the production performance comparison test; The materials of wheat varieties were collected from home and abroad; parental selection of hybrids included male sterile line selection and restorer line selection; in the process of restorer line selection, SSR molecular markers Xgwm95 and Barc61 gene-assisted selection techniques were used to select the target in the early generation. Traits are selected. Wheat fertility recovery is controlled by two pairs of major genes, which are located on chromosome 2A and chromosome 1B, respectively, and are linked to SSR molecular markers Xgwm95 and Barc61, respectively.

(4) Heterosis testing and selection: the excellent and stable sterile lines and the excellent and stable restorer lines selected from the hybrid parents are planted in isolation between each male parent and multiple female parents to form multiple male and multiple females. For the mother unit, the strong dominant hybrid combination identified will be compared with the yield of the strong dominant hybrid combination for one year, and the upgraded combination will enter the production performance comparison test; at the same time, the parent sterile line and restorer line of the strong dominant hybrid combination will start to enter the hybrid breeding Propagate by seed;

(5) Hybrid breeding: breeding by CMS breeders, using bagged seed panicle row cycle method, bagging 2 panicles per panicle row, artificially awarding maintainer line pollen to collect separately, and harvesting other mixed lines; original seed of sterile line Propagation, CMS: the maintainer line is planted at a row ratio of 5:1, and the maintainer line is cut off in advance after pollination is completed, and then the sterile line is harvested; the restorer breeder breeds, adopts the panicle row cycle method, and selects 1-2 ears per panicle row Harvest separately, harvest the rest of the mixed lines, and reproduce the original seed of the restorer line in the next year; breed the original seed of the sterile line: plant the original seed of the restorer line at a row ratio of 5:1, cut off and restore in advance after pollination line, and then harvest the hybrids.

(6) The production performance comparison test includes family comparison, strain comparison, variety comparison and regional variety comparison in sequence.

Specific applications of the above breeding methods

1. Conventional hybrid breeding. According to the breeding goal, the male parent and female parent of wheat with ecological or geographical or blood ancestry are selected from the parent nursery, and the female parent is artificially detasselled for 3 to 5 ears and bagged, and pollen is given to the male parent. . In this way, hundreds of single-cross combinations can be configured every year, and the seeds can be harvested according to the combination after maturity.

2. Hybrid combination planting and harvesting. Each combination is a 5-row area, the middle 3 rows are planted with hybrid F1, and the two sides are planted with male and female parents respectively. The row length is 1.5m, the row spacing is 20cm, and 30 seeds are sown on demand in each row. For every 20 combinations, 3 rows were planted to promote the control varieties. During the growth period, the growth performance of the F1 combination was observed and recorded. At the mature stage, harvest 10-15 plants for each F1 combination, and harvest 10 plants for each of the parent and control varieties.

3. Determination of hybrid vigor. Investigate the plant height and yield traits (number of ears, thousand-grain weight, and grain yield of 10 plants) of each combination of F1, parents and controls indoors, calculate the yield exceeding standard (control) advantage of each combination, and sort from high to low, and select the superiority of exceeding the standard ≥ 45%. combination.

4. Select the parents of the hybrid and determine the technical plan for the sterile line and the restorer line. Further analysis of the growth traits (plant height, heading date, stress resistance, etc.) A male parent of a strong dominant combination that was transformed into a restorer line.

Backcrossing to transfer excellent sterile line (female parent) should be saturated backcrossing, bagging self-crossing is 100% sterile, stable sterility, plant height ≤ 85cm, large open angle of glumes at flowering stage, and time for pistil to be exposed longer. Excellent restorer line (male parent) transfer, limited backcrossing based on sterile cytoplasm, combined with molecular marker-assisted selection, the selection is very similar to the recurrent parent, bagging recovery rate and recovery degree> 85%, plant height between 85-95cm , an inbred stable line with high exposure of anthers, large amount of pollen and good loose pollen characteristics during flowering stage.

5. Testing and selection of heterosis. Several stable sterile lines (female parent) and restorer lines (male parent) with excellent traits were selected for planting, and the field planting methods of male and female parents were as follows. According to the needs of seed production, the male parent: female parent can be planted in rows at a row ratio of 1:1, 1:2 or 1:3. That is to plant 1 row of restorer lines and 1 to 3 rows of sterile lines. The row length is 1.5-1.8m, the row spacing is 20cm, and 30 seeds are sown in each row.

During the wheat earing stage, each male parent and the female parent interplanted with the male parent are covered with a seed-making isolation cover with the male parent as a unit to form a multi-female unit of one father; The number of fathers is the same. During the earing stage of wheat, the one-father and multiple-mother units are respectively covered with seed production isolation covers to form multiple one-father and multiple-mother seed production units.

The seed production isolation cover used in the above steps comprises: isolation cover support, nylon cloth, zipper, pocket cover; isolation cover support constitutes the frame of the wheat seed production isolation cover; nylon cloth is covered on the isolation cover support; On the front and the back side; the outer cover of the pocket is positioned at the top of the zipper; the wheat plant is positioned at the inside of the isolation cover; 2 zippers are installed on the front and back of the isolation cover, the zippers are U-shaped, the zipper length is 0.95m, the U-shaped height is 0.2m, the bottom of the zipper is 0.6m from the ground, 0.2m from the frame, and the distance between the two zippers is 0.2m.

The planting method of male parent and female parent is, male parent: female parent according to seed production quantity needs, by 1:1, 1:2 or 1:3 row ratio interrow planting, the width of seed production isolation cover is constant 1.8m, And the length of isolation cover is preferably 4.5m (determined according to the number of rows planted by isolation unit), it will be convenient to make seed isolation cover on the wheat heading stage cover.

6. The flowering period of the male parent and the female parent is adjusted. The earing of the sterile line was 2-3 days earlier than the restorer line or the same period was the best. CMS lines are heading 1 to 2 days later than restorer lines, and gibberellin can be sprayed on both parents after the heading of the male parent, which can promote heading and prolong the vitality of anthers. Artificially assisted pollination. During the flowering and pollination period of the restorer line (male parent), artificial bamboo poles were used to catch powder twice a day through the operation hole of the isolation cover for 5 to 7 consecutive days to increase the outcross seed setting rate of the sterile line (female parent).

7. Seed harvest. At maturity, remove the isolation cover. The sterile line (female parent) of each unit is harvested separately, and the seeds produced by the sterile line are hybrids. The restorer line (male parent) can be mixed to harvest, which increases the seed quantity of the restorer line.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present invention within the spirit and protection scope of the present invention, and such modifications or equivalent replacements should also be deemed to fall within the protection scope of the present invention.

Claims (5)

1. a triple crossing method for breeding wheat, it is characterized in that, described method is by six module Organic structure, comprise: germ plasm resource and parent garden module, hybrid parents seed selection module, hybrid vigour survey modeling block, crossbreed breeding module, conventional cross-breeding module, productivity comparative test module, in the contact between module and module, the relation of working procedure is as follows;

Germ plasm resource and parent garden module; Collect distinctive product based material in abundant kind material and productivity comparative test both at home and abroad in parent garden, the backbone parent that some material can be used as in conventional breeding utilizes, and enters conventional cross-breeding module; Some material can be used as the parent of heterosis breeding, enters hybrid parents seed selection module, and backcross transformation becomes male sterile line (female parent) or restorer (male parent);

Conventional cross-breeding module; Carry out hybrid vigour to conventional cross-breeding single cross F1 generation and survey product, mirror measures influential point set female parent and influential point set male parent; Influential point set female parent and male parent enter the candidate parent of hybrid parents seed selection module as heterosis breeding parent seed selection respectively; All the other are combined into conventional breeding programmes and carry out progeny selection;

Hybrid parents seed selection module; Hybrid parents seed selection has three sources: the influential point set female parent that conventional cross-breeding obtains and influential point set male parent; The outstanding strain produced in productivity comparative test; Collect from wheat breed material both domestic and external in parent garden; According to parent's feature, determine the scheme of transformation male sterile line and restorer;

Hybrid vigour surveys modeling block; From the outstanding stable male sterile line of hybrid parents seed selection and outstanding stable restorer under isolation condition between each male parent and multiple female parent row plant, form the many female unit of a multiple father, next year carries out the qualification of hybrid combination advantage, 1 year strong advantage hybrid combination Yield compari@is carried out in the strong advantage hybrid combination identified again, and that determines upgrading is combined into productivity comparative test module; Meanwhile, parent's male sterile line of strong advantage hybrid combination and restorer enter crossbreed breeding module and carry out seminal propagation;

Crossbreed breeding module; Male sterile line breeding man breeds, and adopt bagging seed head progeny row round-robin method, every head progeny row bagging 2 fringe manually authorizes maintainer pollen point receipts separately, all the other mixed system results; Male sterile line breeder's stock is bred, male sterile line: it is capable of plantation that maintainer presses 5:1, cuts off maintainer in advance, then gather in the crops male sterile line after having pollinated; Restorer breeding man breeds, and adopt head progeny row round-robin method, every head progeny row selects 1-2 fringe to gather in the crops separately, all the other mixed system results, next year composite variety breeding restorer breeder's stock; Crossbreed breeds, male sterile line breeder's stock: it is capable of plantation that restorer breeder's stock presses 5:1, cuts off restorer in advance, then gather in the crops crossbreed after having pollinated;

Productivity comparative test module; Comprise that family compares, strain compares successively, variety protection and region variety protection.

2. triple crossing method for breeding wheat according to claim 1, it is characterized in that, carry out hybrid vigour to conventional cross-breeding single cross F1 generation to survey and produce, the candidate parent of the maternal and influential point set male parent of influential point set as heterosis breeding parent seed selection measured by mirror.

3. triple crossing method for breeding wheat according to claim 1, it is characterized in that, to sow in isolation condition from the outstanding stable male sterile line of hybrid parents seed selection and outstanding stable restorer and plant the many female unit of a multiple father, carry out strong advantage hybrid combination Yield compari@, determine that the combination of upgrading directly enters the varietal yield test in productivity comparative test.

4. triple crossing method for breeding wheat according to claim 1, is characterized in that, hybrid parents seed selection module comprises sterile line breeding and Breeding for restoration lines; In Breeding for restoration lines process, SSR molecular marker Restore gene assisted Selection technology is adopted to select objective trait in generation morning.

5. triple crossing method for breeding wheat according to claim 1, is characterized in that, in sterile line breeding, and stable sterile line bagging self-pollination ripening rate≤0.5%; In Breeding for restoration lines, stablize restorer bagging self-pollination ripening rate >=90%.