A method for creating a new germplasm of large spike and large grain wheat

Abstract

This invention discloses a method for creating new germplasm of large-spike, large-grain wheat. The method involves hybridizing dwarf wheat, large-spike wheat varieties or lines, and large-grain wheat varieties or lines as parents to obtain dwarf hybrid seeds. Half of the dwarf hybrid seeds are planted, and superior fertile plants with large spikes or large grains are selected. The other half of the dwarf hybrid seeds are then planted and hybridized with the selected superior fertile plants with large spikes or large grains to obtain a dwarf wheat selection population. Superior fertile plants with large spikes and large grains are obtained from this selection population, and through continuous self-pollination, these superior plants are selected to obtain new large-spike, large-grain wheat lines. This invention clarifies the construction method and selection criteria for large-spike, large-grain wheat selection populations, significantly improving the breeding efficiency of large-spike, large-grain wheat. The newly bred large-spike, large-grain wheat lines increase the number of grains per spike and the thousand-grain weight, enhancing the yield potential of wheat and providing important germplasm support for high-yield wheat breeding and yield improvement.

Description

I. Technical Field:

[0001] This invention belongs to the field of wheat breeding technology, specifically relating to a method for creating new germplasm of large-eared, large-grained wheat. II. Background Technology:

[0002] Wheat is one of my country's three staple grains, with an annual planting area of ​​approximately 350 million mu (16.7 million hectares) and a total output exceeding 130 million tons for eight consecutive years, holding a vital strategic position in ensuring national food security. Improving wheat yield per unit area plays a decisive role in total output. Wheat yield per mu is determined by the number of ears per mu, the number of grains per ear, and the grain weight, while genetic improvement of varieties determines the potential for increasing wheat yield per unit area. Continuous improvement of wheat varieties has brought the potential for wheat yield per unit area to a high level, but the relatively narrow genetic base has created a bottleneck in yield improvement. The three factors of yield have become mutually restrictive, resulting in a phenomenon of "large ears but small grains, large grains but small ears," making it difficult to achieve coordinated increases.

[0003] With the accelerating pace of wheat industrialization, breeding units are pursuing faster variety development and increased profits. This has led to the development of new varieties often employing single crosses or backcrosses with varieties exhibiting similar agronomical traits. This results in problems such as a narrow genetic base, high varietal similarity, and slow yield increases. New germplasm of large-eared, large-grained wheat will help alleviate these problems. Therefore, how to create new wheat germplasm that is both large-eared and large-grained has become an urgent issue to be addressed.

[0004] Currently, there are few literature reports on breeding methods for new germplasm of large-spike, large-grain wheat. For example, patent application CN201410051898.5 discloses a breeding method for new germplasm of multi-spike, large-spike, and large-grain wheat. The steps are: 1) breeding of the new large-spike wheat line DaSui 1; 2) breeding of the new large-spike wheat line R11-2; 3) breeding of new germplasm of multi-spike, large-spike, and large-grain wheat. This invention has bred 16 new germplasm of multi-spike, large-spike, and large-grain wheat, with an average of 13.03 spikes per plant; spike length of over 10 cm, belonging to the long-spike type; spikelet number between 18.91 and 20.87; average thousand-grain weight of 42.05 g; and the total variation of the four traits (spike number per plant, spike length, spikelet number, and thousand-grain weight) Σ(±CK)% (super control Shi 4185) is 59.13-189.88%. III. Summary of the Invention:

[0005] The technical problem this invention aims to solve is: addressing the urgent need in the field for creating new wheat germplasm with both large spikelets and large grains, this invention provides a method for creating new wheat germplasm with large spikelets and large grains. The new wheat lines with large spikelets and large grains created using the technical solution of this invention have advantages such as multiple spikelets, multiple grains, and high thousand-grain weight, providing important germplasm resources for high-yield wheat breeding and increasing wheat yield per unit area.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for creating a new germplasm of large-eared, large-grained wheat, the method comprising the following steps:

[0008] 1) Combined configuration:

[0009] A hybrid was formed by crossing the dwarf and sterile Yumai 158 as the female parent and the large-eared wheat variety Luoxin 001 as the male parent to obtain dwarf and sterile F1; then, the dwarf and sterile F1 was crossed with the large-grained wheat variety Luomai 76 as the male parent to obtain dwarf hybrid seeds.

[0010] 2) Selecting a group to build:

[0011] a) Sow half of the dwarf hybrid seeds obtained in step 1) and select large spikes or large grains of excellent fertile single plants for threshing to obtain seeds of excellent single plants.

[0012] b) Sow the other half of the dwarf hybrid seeds obtained in step 1) by dividing the superior single plant with large spikes or large grains into lines; select the dwarf sterile single plant with large spikes as the female parent and the superior single plant with large spikes or large grains as the male parent for hybridization to obtain dwarf wheat selection population hybrid seeds.

[0013] 3) Offspring selection and breeding:

[0014] All the hybrid seeds of the dwarf wheat selection population obtained in step 2) were sown and planted. Excellent fertile single plants with large ears and large grains were selected. Then, the obtained excellent fertile single plants with large ears and large grains were self-pollinated. Excellent single plants with large ears and large grains were selected. This self-pollination and selection was carried out for 4 generations or more to obtain a new wheat line with large ears and large grains.

[0015] According to the above-mentioned method for creating new germplasm of large-eared and large-grained wheat, the dwarf Yumai 158 mentioned in step 1) is obtained by backcrossing dwarf wheat as the female parent and Yumai 158 as the male parent for more than 4 consecutive times (the resulting dwarf Yumai 158 has the main agronomic traits of Yumai 158).

[0016] Based on the above-mentioned method for creating new germplasm of large-eared, large-grained wheat, the approval number of Yumai 158 is Guoshenmai 2014004.

[0017] According to the above-mentioned method for creating new germplasm of large-spike, large-grain wheat, the plant variety application number of the large-spike type wheat line Luoxin 001 mentioned in step 1) is 20241005605, with 25 to 30 spikelets and 74 to 126 grains per spike.

[0018] According to the above-mentioned method for creating new germplasm of large-eared and large-grained wheat, the approval number of the large-grained wheat variety Luomai 76 mentioned in step 1) is Yu Shenmai 20220031, and its thousand-grain weight is 52.44 grams.

[0019] According to the above method for creating new germplasm of large-eared and large-grained wheat, the number of dwarf hybrid seeds obtained in step 1) shall not be less than 2,000.

[0020] According to the above-mentioned method for creating new germplasm of large-eared and large-grained wheat, the selection criteria for the superior fertile single plant with large ears in step 2) are as follows: when selecting in the field, the number of spikelets on the main stem of the selected single plant is ≥27, and after indoor threshing and seed testing, the number of grains on the main stem of the selected single plant is ≥100.

[0021] The selection criteria for large-grained, superior fertile single plants are: the thousand-grain weight of the selected single plant is ≥55 grams;

[0022] The selection criteria for the large-eared, short-stemmed sterile single plants are: the number of spikelets on the main stem of the selected sterile single plant is ≥27.

[0023] According to the above method for creating new germplasm of large-eared and large-grained wheat, the number of hybrid seeds of the dwarf wheat selection population obtained in step 2) shall not be less than 4,000.

[0024] According to the above-mentioned method for creating new germplasm of large-eared and large-grained wheat, the selection criteria for the superior fertile single plants with large-eared and large-grained wheat and the superior single plants with large-eared and large-grained wheat in step 3) are as follows: when selecting in the field, the number of spikelets on the main stem of a single plant is ≥27, and after indoor threshing and seed testing, the number of grains on the main stem of a single plant is ≥100, and the thousand-grain weight of a single plant is ≥55 grams.

[0025] The positive and beneficial effects of this invention are:

[0026] 1. This invention aims to create a new variety with large spikes and large grains. It combines the advantages of wide adaptability (Yumai 158), large spikes (Luoxin 001), and large grains (Luomai 76). At the same time, it introduces the superior genes of triticale and artificially synthesized wheat into ordinary wheat, enriching the genetic base and forming super-parental advantages. It integrates the characteristics of multiple spikelets, multiple grains per spike, and high thousand-grain weight into one. The average values ​​of spikelet number, spikelet number, and thousand-grain weight obtained by this invention are 28.86, 103.29, and 59.89 grams, respectively. These represent increases of 37.41%, 84.44%, and 11.79% compared to Yumai 158, 6.88%, 3.29%, and 18.59% compared to Luoxin 001, and 25.47%, 98.63%, and -6.76% compared to Luomai 76. In contrast, the highest spikelet number and thousand-grain weight among wheat varieties approved by the state in 2024 were 45.7 and 51.9 grams, respectively. Therefore, this invention solves the problems of large spikelets with small grains and large grains with small spikelets, providing new germplasm resources for high-yield wheat breeding and yield improvement.

[0027] 2. This invention innovates a method for constructing a selective population of dwarf wheat, forming a "finite germplasm infinite hybridization" method. Unfavorable traits in wheat (springiness, red grains, awnlessness, etc.) are mostly dominant traits. Traditional multi-parent recurrent dwarf wheat populations easily introduce unfavorable traits into new wheat lines. This invention uses only three parents, combining "directed parental pollination" with "selection-while-hybridizing," i.e., combining "directed improvement" with "selection-while-breeding," gradually reducing unfavorable traits while aggregating target traits. It also fully leverages the advantages of dwarf wheat—"labor-saving and suitable for large-scale hybridization"—to fully recombine excellent agronomic traits such as large ears and large grains. Compared to traditional recurrent selection breeding of dwarf wheat, this invention is more targeted in selecting breeding objectives, minimizing the elimination of unfavorable traits and improving breeding efficiency.

[0028] 3. This invention clarifies the selection criteria for creating large-eared, large-grained wheat, including selection indicators such as the number of spikelets, the number of grains per spike, and the thousand-grain weight. It is simple and clear, and greatly improves the breeding efficiency of large-eared, large-grained wheat. IV. Description of the attached drawings:

[0029] Figure 1 A flowchart illustrating the method for breeding new large-eared, large-grained wheat varieties according to the present invention;

[0030] Figure 2 A comparison of the spikelet morphology of the new large-ear, large-grain cultivar bred in this invention with its parent;

[0031] Depend on Figure 2 It can be seen that the spike shape and size of the seven new wheat varieties with large spikes and large grains obtained by this invention are significantly better than those of the three parents.

[0032] Figure 3 A comparison diagram of spikelet number between the new large-ear, large-grained variety bred in this invention and its parents;

[0033] Depend on Figure 3 It can be seen that the number of spikelets in the seven new wheat varieties with large spikelets and large grains obtained by this invention is significantly more than that in the three parents.

[0034] Figure 4 A comparison diagram of the number of grains per ear of the new large-ear, large-grain cultivar bred in this invention and its parents.

[0035] Depend on Figure 4 It can be seen that the number of grains per spike in the seven new wheat varieties with large spikes and large grains obtained by this invention is significantly greater than that of the three parents. V. Detailed Implementation Methods:

[0036] The present invention will be further illustrated below with reference to the embodiments, but this does not limit the scope of protection of the technical solution of the present invention.

[0037] In the following examples, the breeding method of dwarf wheat 158 ​​is as follows: dwarf wheat is used as the female parent and wheat 158 ​​is used as the male parent for hybridization. Then, wheat 158 ​​is backcrossed 3 times to obtain dwarf wheat 158. After 4 hybridizations, dwarf wheat 158 ​​is obtained. The obtained dwarf wheat 158 ​​has most of the main agronomic traits of wheat 158.

[0038] The wheat variety used, Yumai 158, was bred by the Luohe Academy of Agricultural Sciences and approved by the state in 2014 (approval number: Guoshenmai 2014004). It has 364,000 ears per mu, 34.4 grains per ear, and a thousand-grain weight of 45.1 grams. It is characterized by wide adaptability, high yield, and stable yield.

[0039] The adopted variety, Luoxin 001, is a new large-spike wheat line bred by Luohe Academy of Agricultural Sciences through hybridization of triticale and common wheat. Plant variety rights application number: 20241005605. The number of spikelets is 25-30, and the number of grains per spike is 74-126. For details of its large spike agronomic traits, please refer to: Yuan Qian et al., Genetic effect analysis of spike traits of new large-spike wheat germplasm [J], Jiangsu Agricultural Sciences, 2022, 50(16):86-91.

[0040] The variety used, Luomai 76, is a new large-grain wheat variety bred by Luohe Academy of Agricultural Sciences through hybridization of synthetic wheat and common wheat. It was approved by Henan Province in 2022, with the approval number: Yu Shen Mai 20220031. The average thousand-grain weight is 52.44 grams. For details of its grain traits, please refer to: Yuan Qian et al., Analysis of the genetic effects of wheat grain traits and its breeding strategies [J]. Journal of Triticeae Crops, 2023, Vol. 43 (4): 434-441.

[0041] Example 1:

[0042] The method for creating new germplasm of large-eared, large-grained wheat according to the present invention comprises the following detailed steps:

[0043] 1) Combined configuration:

[0044] In April 2015, a hybrid F1 was obtained by using the dwarf sterile plant of the dwarf Yumai 158 as the female parent and the large-spike type wheat line Luoxin 001 as the male parent. The hybrid F1 seeds were sown in the autumn of the same year.

[0045] In April 2016, a hybridization was carried out using the dwarf sterile F1 hybrid as the female parent and the large-grained wheat variety Luomai 76 as the male parent, resulting in 2,460 dwarf hybrid seeds.

[0046] 2) Selecting a group to build:

[0047] a. In the autumn of 2016, 1230 dwarf hybrid seeds obtained in step 1) were sown by spot planting (the remaining 1230 hybrid seeds were stored in a 4℃ refrigerator for later use). In May 2017, 15 superior fertile single plants with large spikelets and ≥27 spikelets on the main stem were selected, and 36 superior fertile single plants with outstanding grain filling and yellowing were selected. After indoor seed testing, 5 superior fertile single plants with large spikelets and ≥100 grains per spike were obtained. After indoor seed testing, 10 superior fertile single plants with large grains and ≥55 grams per thousand grains were obtained.

[0048] b. In the autumn of 2017, the remaining 1230 seeds of the dwarf hybrid obtained in step 1) were sown by spot planting. At the same time, 5 superior single plants with large spikes and 10 superior single plants with large grains were sown by spot planting in different lines, with 3 rows planted in each line.

[0049] In April 2018, 17 large-spike sterile plants with ≥27 spikelets on the main stem were selected from the dwarf hybrid population. All spikelets of the sterile plants were clipped and bagged, totaling about 100 spikelets. Each group of 3-5 spikelets was randomly hybridized with large-spike or large-grain lines. Finally, the plants were mixed, harvested, and threshed to obtain 5436 hybrid seeds from the dwarf wheat selection population.

[0050] 3) Offspring selection and breeding:

[0051] In the autumn of 2018, all 5436 hybrid seeds from the dwarf wheat selection population were sown individually. In May 2019, 72 fertile plants with ≥27 spikelets on the main stem were selected. After indoor seed testing, 12 superior single plants with ≥100 grains per spike and a thousand-grain weight ≥55 grams were obtained. In the autumn of the same year, the plants were sown individually, with 3 rows planted for each line.

[0052] In May 2020, a total of 157 superior single plants with ≥27 spikelets on the main stem were selected in the field, with no less than 10 plants selected from each line. After indoor seed testing, 25 superior single plants with large spikelets and large grains with ≥100 grains per spike and ≥55 grams per thousand grains were obtained. In the autumn of the same year, the lines were sown and planted in 3 rows for each line.

[0053] In May 2021, a total of 397 superior single plants with ≥27 spikelets on the main stem were selected in the field. No less than 6 plants were selected from each line. After indoor seed testing, 58 superior single plants with large spikelets and large grains with ≥100 grains per spike and ≥55 grams per thousand grains were obtained. In the autumn of the same year, the lines were sown and planted in 3 rows for each line.

[0054] In May 2022, a total of 768 superior single plants with ≥27 spikelets on the main stem were selected in the field, with no less than 6 plants selected from each line. After indoor seed testing, 138 superior single plants with large spikelets and large grains with ≥100 grains per spike and ≥55 grams per thousand grains were obtained. In the autumn of the same year, the lines were sown and planted in 3 rows for each line.

[0055] In May 2023, 72 wheat lines with consistent agronomic traits were observed in the field. At the same time, considering agronomic traits such as winter and spring characteristics, plant height, maturity, and disease resistance, 7 new wheat lines with large ears and large grains that are suitable for field production were selected.

[0056] Based on field observations and indoor testing, the average number of spikelets per spike on the main stem of the new large-ear, large-grain wheat variety was 28.86, the average number of grains per spike was 103.29, and the average thousand-grain weight was 59.89 grams. These three figures represent increases of 37.41%, 84.44%, and 11.79% respectively compared to Yumai 158; 6.88%, 3.29%, and 18.59% respectively compared to Luoxin 001; and 25.47%, 98.63%, and -6.76% respectively compared to Luomai 76 (see details). Figure 2 , Figure 3 and Figure 4 ).

[0057] The agronomic trait data of the new large-eared, large-grained wheat varieties obtained by the technical solution of this invention are detailed in Table 1.

[0058] Table 1. Agronomic trait data of the new large-eared, large-grained wheat lines obtained in this invention.

[0059] strain Number of spikelets per main stem spike number of grains per ear 1000 grains / gram Yumai 158 21 56 53.57 Luoxin001 27 100 50.50 Luomai 76 23 52 64.23 New Product Series 1 28 102 62.94 New Product Series 2 29 101 66.14 New Product Series 3 30 100 55.80 New Product Series 4 30 103 57.57 New Product Series 5 29 105 60.10 New product series 6 29 104 57.69 New product series 7 27 108 58.98 New product lines average 28.86 103.29 59.89 .

Claims

1. A method for creating a new germplasm of large-eared, large-grained wheat, characterized in that, The creation method includes the following steps: 1) Combined configuration: A hybrid was formed by crossing the dwarf and sterile Yumai 158 as the female parent and the large-eared wheat variety Luoxin 001 as the male parent to obtain dwarf and sterile F1; then, the dwarf and sterile F1 was crossed with the large-grained wheat variety Luomai 76 as the male parent to obtain dwarf hybrid seeds. 2) Selecting a group to build: a) Sow half of the dwarf hybrid seeds obtained in step 1) and select large-eared or large-grained superior fertile single plants for threshing to obtain superior single plant seeds. b) Sow the other half of the dwarf hybrid seeds obtained in step 1) by planting the superior single plant with large ears or large grains by planting the lineage; select the dwarf sterile single plant with large ears as the female parent and the superior single plant with large ears or large grains as the male parent to carry out hybridization to obtain dwarf wheat selection population hybrid seeds. The selection criteria for the large-ear superior fertile single plant are as follows: during field selection, the number of spikelets on the main stem of the selected single plant is ≥27, and after indoor threshing and seed testing, the number of grains on the main stem of the selected single plant is ≥100. The selection criteria for large-grained, superior fertile single plants are: the thousand-grain weight of the selected single plant is ≥55 grams; The selection criteria for the large-eared, short-stemmed sterile single plant is: the number of spikelets on the main stem of the selected sterile single plant is ≥27; 3) Offspring selection and breeding: All the hybrid seeds of the dwarf wheat selection population obtained in step 2) were sown and planted. Large-eared and large-grained superior fertile single plants were selected. Then, the obtained large-eared and large-grained superior fertile single plants were self-pollinated. Large-eared and large-grained superior single plants were selected. This self-pollination and selection was carried out for 4 generations or more to obtain a new large-eared and large-grained wheat line. The selection criteria for the large-ear, large-grain superior fertile single plants and the large-ear, large-grain superior single plants are as follows: when selected in the field, the number of spikelets on the main stem of a single plant is ≥27, and after indoor threshing and seed testing, the number of grains on the main stem of a single plant is ≥100, and the thousand-grain weight of a single plant is ≥55 grams.

2. The method for creating new germplasm of large-eared, large-grained wheat according to claim 1, characterized in that: The plant variety application number of the large-spike type wheat line Luoxin 001 mentioned in step 1) is 20241005605. It has 25 to 30 spikelets and 74 to 126 grains per spike.

3. The method for creating new germplasm of large-eared, large-grained wheat according to claim 1, characterized in that: The number of dwarf hybrid seeds obtained in step 1) shall not be less than 2000.

4. The method for creating new germplasm of large-eared, large-grained wheat according to claim 1, characterized in that: The number of hybrid seeds obtained from the dwarf wheat selection population in step 2) shall not be less than 4,000.

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