A method for breeding lodging-resistant oat germplasm

Abstract

This invention provides a method for breeding lodging-resistant oat germplasm, belonging to the field of oat breeding technology. The method utilizes selected oat varieties with lodging resistance traits as parents, performs hybridization followed by backcrossing for one generation, and then continuous self-pollination. During both backcrossing and continuous self-pollination, lodging resistance is tested in each generation. Those varieties exhibiting lodging resistance are then self-pollinated in the next generation to breed highly lodging-resistant varieties. In one embodiment of this invention, three lodging-resistant lines were screened, with lodging indices between 0.136 and 0.139, classifying them as extremely lodging-resistant lines.

Description

Technical Field

[0001] This invention belongs to the field of oat breeding technology, specifically relating to a method for breeding lodging-resistant oat germplasm. Background Technology

[0002] Oats are an annual herbaceous crop belonging to the genus *Avena* of the family Poaceae. Based on whether the grains have husks or not, they can be divided into hulled oats and naked oats. Currently, 90% of the oats grown in my country are naked oats, while hulled oats are mainly used for forage. In contrast, oats grown abroad as a staple food are mostly hulled oats, with only a small portion being naked oats, primarily used for forage. Oats are considered a food and medicine crop with extremely high nutritional and health benefits, making them an indispensable complete nutritional and health food for improving people's health. Oat protein, fat, and β-glucan are its main nutritional and functional components. Oat protein content ranks first among cereal crops, reaching 14.00%–16.00%. Oat fat content is relatively high among grains, with about 80% being unsaturated fatty acids, and linoleic acid accounting for about 33.00%–49.00% of the fatty acid content. Oat β-glucan content is relatively high among cereal crops, ranging from 2.00% to 7.00% in oat germplasm resources. Currently, β-glucan is considered one of the most promising functional factors in oats, possessing the ability to lower serum cholesterol and prevent cardiovascular diseases. With increasing awareness of the health benefits of oats, consumer demand has grown rapidly in recent years, leading to a continuous expansion of planting areas and higher demands for high-yield, high-quality, and specialized new varieties.

[0003] my country is one of the origins of naked oats and has abundant naked oat germplasm resources. However, oat cultivation generally suffers from lodging problems. Investigations have revealed that due to the tall, spreading plants in the later stages of oat growth, the canopy becomes increasingly dense, weakening stem support and reducing canopy carbon assimilation and leaf light retention efficiency. This makes oats highly susceptible to lodging during rainfall and strong winds from the grain-filling to maturity stages. Lodging has become a significant factor limiting stable, high-quality, and efficient oat yields, and is a common and pressing problem in current oat production. To address the lodging problem in oats, one approach is to update oat cultivation techniques, but more importantly, it is crucial to develop lodging-resistant oat varieties. Summary of the Invention

[0004] The purpose of this invention is to provide a method for breeding lodging-resistant oat germplasm, which can quickly breed lodging-resistant oat germplasm.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for breeding lodging-resistant oat germplasm, comprising the following steps: hybridizing parents with lodging resistance traits to obtain F1 generation, performing backcrossing on the obtained F1 generation to obtain F2 generation, and then performing continuous self-pollination on the F2 generation to screen for extremely lodging-resistant oat germplasm.

[0006] Lodging resistance was tested on the F2 generation and all self-pollinated offspring, and those with moderate lodging resistance were selected for the next generation of self-pollination.

[0007] The lodging resistance trait is measured by the lodging index, wherein the lodging index corresponding to lodging resistance is not higher than 0.18, the lodging index corresponding to moderate lodging resistance is in the range (0.180, 0.595), and the lodging index corresponding to extremely lodging resistance is in the range (0.136, 0.139).

[0008] In one embodiment of the present invention, the parent lines include Mengyan Youwu No. 5 and Mengyan No. 1.

[0009] In one embodiment of the present invention, Mengyan Youwu is used as the female parent and Mengyan 1 is used as the male parent.

[0010] In one embodiment of the present invention, during the backcross, F1 is used as the female parent and the male parent is used as the male parent.

[0011] In one embodiment of the present invention, the number of generations of self-crossing is not less than 5.

[0012] In one embodiment of the present invention, the lodging resistance test includes detecting the lodging index of the second internode at the base.

[0013] In one embodiment of the present invention, the method for calculating the stem lodging index includes:

[0014] Stem lodging index = main stem fresh weight × stem center of gravity height / stem mechanical strength.

[0015] In one embodiment of the present invention, the fresh weight of the main stem is measured by taking a sample close to the ground surface and weighing it using a 0.1% analytical balance, with the unit expressed in g.

[0016] In one embodiment of the present invention, the height of the stem's center of gravity is measured by measuring the distance from the base of the plant stem to the balance point of the main stem, expressed in centimeters (cm).

[0017] In one embodiment of the present invention, the mechanical strength of the stem is measured as follows: the second internode at the base with the leaf sheath removed is placed on a support frame, and the stem is pressed with a steady force using a stem strength tester. The force that causes the stem to break instantly is multiplied by 100g / N, which is the mechanical strength of the stem.

[0018] Beneficial effects: This invention provides a method for breeding lodging-resistant oat germplasm. Using selected oat varieties with lodging resistance traits as parents, the mixture is hybridized and backcrossed for one generation, followed by continuous self-pollination. During the backcrossing and continuous self-pollination periods, lodging resistance is tested in each generation. The selected varieties with lodging resistance traits are then self-pollinated for the next generation, thereby breeding highly lodging-resistant varieties.

[0019] In one embodiment of the present invention, Mengyan You 5 was used as the female parent and Mengyan 1 as the male parent to obtain F1 generation seeds through hybridization; F2 generation seeds were obtained by backcrossing the F1 generation line as the female parent and Mengyan 1 as the male parent; F2 generation seeds were obtained by continuous self-pollination and lodging resistance screening of each generation, thus obtaining a total of 64 materials. The traits of the 64 materials were identified, and 3 lodging-resistant lines were screened out with lodging index between 0.136 and 0.139, which belong to extremely lodging-resistant lines. Attached Figure Description

[0020] Figure 1 This is a complete flowchart of the breeding process for lodging-resistant oat varieties according to the present invention. Detailed Implementation

[0021] This invention provides a method for breeding lodging-resistant oat germplasm, comprising the following steps: hybridizing parents with lodging resistance traits to obtain F1 generation, performing a first-generation backcross on the obtained F1 generation to obtain F2 generation, performing continuous self-pollination on the F2 generation, and screening to obtain extremely lodging-resistant oat germplasm.

[0022] Lodging resistance was tested on the F2 generation and all self-pollinated offspring, and those with moderate lodging resistance were selected for the next generation of self-pollination.

[0023] The lodging resistance trait is measured by the lodging index, wherein the lodging index corresponding to lodging resistance is not higher than 0.18, the lodging index corresponding to moderate lodging resistance is in the range (0.180, 0.595), and the lodging index corresponding to extremely lodging resistance is in the range (0.136, 0.139).

[0024] This invention does not impose any special restrictions on the selection of the parent plants, as long as they have lodging resistance. For example, in one embodiment, Mengyan Youwu and Mengyan 1 are used as the parents, specifically, Mengyan Youwu is the female parent and Mengyan 1 is the male parent. Mengyan Youwu is a hybrid of 5-1-3 as the female parent and Magna as the male parent, bred in 1986 and stabilized in 1993. Mengyan 1 is bred using the French-introduced naked oat variety "Yong 492" as the female parent and the Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences' self-bred resource material "80-13" as the male parent, through interspecific distant hybridization of naked oats, and its registration number is Guopinjianza 2010026. Mengyan Youwu has been disclosed in the literature (Fu Xiaofeng, Liu Junqing, Liu Jianguo, et al. Application of foreign-introduced oat germplasm resources in the breeding of new naked oat varieties [J]. Inner Mongolia Agricultural Science and Technology, 1999, (02): 18-19.).

[0025] This invention utilizes the aforementioned parents for hybridization, and the hybridization methods are well known in the art and will not be described in detail here. For example, refer to the hybridization methods involved in Chinese Invention Patent CN116349600A (A method and application of oat hull hybridization without pruning).

[0026] This invention uses the F1 generation of hybrid offspring as the female parent and the male parent from the parental line as the male parent for backcrossing. For example, in the embodiment, Mengyan 1 was used as the male parent. After one generation of backcrossing, the F2 generation was obtained. This invention does not specifically limit the backcrossing method; conventional techniques in the art can be used, such as the backcrossing method described in Chinese Invention Patent CN116349600A (A Method and Application of Oat Unpruned Hybridization). The resulting backcross offspring can be tested for lodging resistance. For example, in the embodiment, the lodging index of the second internode at the base is tested. Those with moderate lodging resistance are selected for self-pollination in the next generation.

[0027] When performing self-pollination in this invention, sowing can be done indoors, in Hainan, in open fields, or even through southern breeding. By harvesting three generations in one year, the breeding cycle is shortened, and individual plants are harvested. Of course, multiple methods can be used in combination, and the number of generations of self-pollination is generally not less than five. For example, in the embodiment, F2 generation seeds are taken and sown indoors to obtain F3 generation seeds; F3 generation seeds are taken and sown in Hainan to harvest F4 generation seeds; F4 generation seeds are sown in paddy fields, and through self-pollination, F5 generation seeds are harvested; F5 generation seeds are obtained by potting F5 generation seeds; F6 generation seeds are obtained by southern breeding of F6 generation seeds to obtain F7 generation seeds, which are then planted in paddy fields.

[0028] In this invention, the lodging index of the second internode at the base is also tested during each generation of self-pollination, and strains with moderate lodging resistance are selected. After the above hybridization-backcrossing-multiple generations of self-pollination and screening, extremely lodging-resistant strains with lodging indices in the range of (0.136, 0.139) can be screened.

[0029] The lodging calculation method referred to in this invention is as follows: Stem lodging resistance index = main stem fresh weight × stem center of gravity height / stem mechanical strength.

[0030] The method for measuring the fresh weight of the main stem is as follows: after taking a sample close to the ground surface, the sample is weighed using a 0.1 g analytical balance.

[0031] The method for measuring the height of the stem's center of gravity is as follows: measure the distance from the base of the plant stem to the balance point of the main stem, expressed in centimeters (cm).

[0032] The method for measuring the mechanical strength of the stem is as follows: place the second internode at the base (with the leaf sheath removed) on a support frame, and use a stem strength tester to apply a steady force to the stem. The force that causes the stem to break instantly is multiplied by 100g / N, which is the mechanical strength of the stem.

[0033] To further illustrate the present invention, the following detailed description of a method for breeding lodging-resistant oat germplasm provided by the present invention is provided in conjunction with embodiments, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0034] In this embodiment of the invention, the hybridization, backcrossing, and self-pollination methods used in each generation are all conventional techniques in the art. At sowing, the seed quality should meet the requirements of GB 4404.4, and the seeds should be dried for 2-3 days before sowing. Fertilizer should meet the following requirements: N: 3.5-4.5 kg / 667 m³. 2 P2O5: 2.5~3.5kg / 667m 2 K2O: 2.5~3.5kg / 667m 2 Fertilizer application should comply with NY / T496 and be applied together with the seeds. Depending on soil moisture and rainfall, sprinkler irrigation should be applied 2 to 4 times after sowing, during the jointing stage, heading stage, and grain-filling stage, with each irrigation providing 15 cubic meters of water. 3 / 667m 2 ~30m 3 / 667m 2 Irrigation water quality should comply with GB 5084. Manual weeding should be carried out promptly during the seedling and jointing stages. When the aphid population density reaches 500 aphids per 100 ears, control should be achieved with 2.5% deltamethrin emulsion or 10% imidacloprid wettable powder. The dosage and number of applications should follow DB15 / T 2444, and pesticide use should comply with NY / T1276.

[0035] Example 1

[0036] according to Figure 1 The breeding process is as follows: Using Mengyan Youwu No. 5 as the female parent and Mengyan No. 1 as the male parent, hybridization is carried out to obtain F1 generation seeds; using the F1 generation line as the female parent and Mengyan No. 1 as the male parent, backcrossing is carried out to obtain F2 generation seeds; F2 generation seeds are taken and sown indoors to obtain F3 generation seeds; F3 generation seeds are taken and sown in Hainan to harvest F4 generation seeds; F4 seeds are sown in paddy fields and self-pollinated to harvest F5 seeds; F5 seeds are potted to obtain F6 seeds; F6 seeds are propagated in the south to obtain F7 seeds, which are planted in paddy fields. Using Mengyan No. 1 as a control, line materials with low lodging index at the second internode at the base are selected. The experiment is carried out for 2 consecutive years to screen out lodging-resistant varieties. A 3-year regional trial is carried out, followed by a 2-year production trial to breed lodging-resistant varieties.

[0037] Among them, lodging resistance trait testing is required for each generation after backcrossing.

[0038] The results are shown in Table 1. A total of 64 materials were obtained. The properties of the 64 materials were identified, and three lodging-resistant strains were selected, with lodging indices ranging from 0.136 to 0.139, which are considered to be extremely lodging-resistant strains.

[0039] Table 164 Clustering Table of Lodging Resistance Coefficients of Hybrid Progeny

[0040]

[0041] Based on the grading results, continuous trials were conducted, and three new lodging resistance varieties with lodging resistance coefficients between 0.136 and 0.139 were selected:

[0042] 1. Variety number 18-29 naked oats: plant height 87.4cm, spike length 15.3cm, spike weight 2.22g, center of gravity height 42.39cm, total tillers 4.6 / plant, effective tillers 3.6 / plant, fresh weight of the second basal node stem 0.49g, stem diameter 3.82mm, stem length 5.16cm, stem mechanical strength 1754.3kPa, stem puncture strength 2057.89kPa, lodging index 0.136, actual lodging rate in the field 0%.

[0043] 2. Variety number 16-36 naked oats: plant height 81cm, spike length 18.2cm, spike weight 3.66g, center of gravity height 39.2cm, total tillers 4 / plant, effective tillers 2.8 / plant, fresh weight of the second basal node stem 0.67g, stem diameter 3.97mm, stem length 5.79cm, stem mechanical strength 2310.68kPa, stem puncture strength 1860.88kPa, lodging index 0.139, actual lodging rate in the field 0%.

[0044] 3. Variety No. 15-9 naked oats: plant height 100.2cm, spike length 18.26cm, spike weight 3.45g, center of gravity height 49.06cm, total tillers 5.2 / plant, effective tillers 3.2 / plant, fresh weight of the second basal stem node 1.25g, stem diameter 4.59mm, stem length 8.59cm, stem mechanical strength 2938.85kPa, stem puncture strength 2076.15kPa, lodging index 0.137, actual lodging rate in the field 0%.

[0045] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for breeding lodging-resistant oat germplasm, characterized in that, The process includes the following steps: crossing parents with lodging resistance traits to obtain the F1 generation; performing a first-generation backcross on the F1 generation to obtain the F2 generation; continuously self-pollinating the F2 generation to select highly lodging-resistant oat germplasm; the parents include Mengyan Youwu No. 5 and Mengyan No. 1, with Mengyan Youwu No. 5 as the female parent and Mengyan No. 1 as the male parent; during the backcross, the F1 generation is used as the female parent and the male parent from the parent series is used as the male parent. Lodging resistance was tested on the F2 generation and all self-pollinated offspring. Those with moderate lodging resistance were selected for the next generation of self-pollination; the number of generations of self-pollination should not be less than 5. The lodging resistance trait is measured by the lodging index, wherein the lodging index corresponding to lodging resistance is not higher than 0.18, the lodging index corresponding to moderate lodging resistance is in the range (0.180, 0.595], and the lodging index corresponding to extremely lodging resistance is in the range (0.136, 0.139]. The lodging resistance test includes detecting the stem lodging index, and the method for calculating the stem lodging index includes: Stem lodging index = main stem fresh weight × stem center of gravity height / stem mechanical strength; The method for measuring the fresh weight of the main stem is as follows: the plant is sampled close to the ground surface and weighed using a 0.1% analytical balance, with the unit expressed in g; The method for measuring the height of the stem's center of gravity is as follows: measure the distance from the base of the plant stem to the balance point of the main stem, expressed in centimeters; The method for measuring the mechanical strength of the stem is as follows: place the second internode at the base (with the leaf sheath removed) on a support frame, and use a stem strength tester to apply a steady force to the stem. Multiply the force at which the stem breaks instantly by 100 g / N, which is the mechanical strength of the stem.

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