Wheat powdery mildew resistance breeding method and application

Abstract

The invention discloses a wheat powdery mildew resistance breeding method and application. Belongs to the technical field of crop breeding. The method comprises the following steps: treating wheat seeds by adopting a mixed bacterial solution of different powdery mildew physiological races, observing the morbidity in the tillering stage, screening out plants with high resistance to the mixed bacterial solution of the physiological races in the tillering stage as parents, hybridizing to obtain first-generation grain seeds, and screening resistant plants from the first-generation grain seeds by adopting the same treatment measures to obtain the high-resistance wheat seeds. And backcrossing the resistant plant with the female parent, harvesting second-generation grains and seeds, and treating the second-generation grains and seeds with an antioxidant solution to finally obtain the powdery mildew resistant wheat strain. In the method, through resistance screening of different powdery mildew physiological races and multi-generation hybridization and selfing, genes are effectively accumulated in vertical resistance and horizontal resistance, and the maintenance time and effectiveness of variety resistance are improved.

Description

Technical Field

[0001] The invention relates to the technical field of crop breeding, and more particularly to a wheat powdery mildew resistance breeding method and application. Background Art

[0002] Wheat powdery mildew is a fungal disease caused by Blumeria graminis (DC.) Speer of the Poaceae family. It mainly harms leaves. In severe cases, leaf sheaths, stems, and ears are all infected. In the early stage of the disease, small yellow spots can be seen on the diseased parts. As the disease worsens, the diseased spots gradually develop into lesions, which are oval or round in shape, with a layer of powdery mold on the surface. In the middle stage, they are white-gray, and in the later stage, they are light brown, and closed thecae are produced. When the disease is mild, the mildew spots are scattered. As the disease worsens, the mildew spots gradually expand into pieces, eventually covering the entire leaf, causing the whole plant to fall over, the plant to be short and weak, the ears to be small and the grains to be few, and the thousand-grain weight to drop significantly, seriously affecting wheat yields. There are many physiological species of wheat powdery mildew fungi that cause this disease. Currently, there are more than 70 known physiological species of powdery mildew fungi, including low-virulence, medium-virulence and high-virulence. The diversity of physiological species of wheat powdery mildew fungi has further increased the difficulty of prevention and control of wheat powdery mildew, and also directly affects the effectiveness of resistance of wheat production varieties. Therefore, it is urgent to cultivate wheat powdery mildew-resistant varieties with long resistance time and good resistance.

[0003] At present, the breeding method for wheat resistance to powdery mildew mainly adopts traditional disease-resistant breeding methods, such as using conventional breeding methods such as introduction, selective breeding, and hybrid breeding to select a group of excellent varieties and strains with good vertical resistance. However, the varieties selected by conventional breeding often have short-lasting resistance. Some new varieties resistant to powdery mildew can only maintain resistance for a few years. They will lose resistance due to environmental changes, mutations of pathogens, etc., resulting in a resistance maintenance time shorter than the breeding time and low economic value.

[0004] Therefore, how to provide a breeding method with long-term resistance maintenance and good powdery mildew resistance effect is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of this, the present invention provides a wheat powdery mildew resistance breeding method and application. The method is used to select wheat powdery mildew resistance varieties, thereby improving the maintenance time of wheat powdery mildew resistance. After breeding, the wheat has good powdery mildew resistance and low morbidity, thereby achieving the technical effect of increasing efficiency and improving quality.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0008] (1) Seed pretreatment: Take wheat seeds, place them in a mixed bacterial solution of powdery mildew physiological species, soak them at 15-20°C for 1-2 days, wash them, drain the water and set aside;

[0009] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants according to the incidence of the plants, using the selected disease-resistant plants as parents for parent hybridization; and harvesting first-generation grains;

[0010] (3) Treatment of first-generation seeds: Place the first-generation seeds in a mixed bacterial solution of powdery mildew species at 15-20°C for 1-2 days, wash, drain and set aside;

[0011] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence of the plants, and backcrossing the selected disease-resistant plants with the parents selected in step (2) as parents to harvest the second generation grains;

[0012] (5) Second-generation grain treatment: The second-generation grains are placed in an antioxidant solution at 18-25°C for 2-3 days, washed, drained, self-pollinated after sowing, and the grains are harvested to obtain a powdery mildew-resistant wheat variety.

[0013] Preferably, the powdery mildew physiological species in step (1) is obtained by collecting fresh powdery mildew diseased leaves from wheat fields in different regions during the peak period of wheat powdery mildew, shaking them off and inoculating them into living test tube wheat seedlings for preservation.

[0014] Preferably, the number of powdery mildew species in the mixed bacterial solution of powdery mildew species in step (1) is ≥5-10; and the powdery mildew species in the mixed bacterial solution are mixed in equal proportions.

[0015] Preferably, the disease incidence of the plant in step (2) refers to the disease incidence during the tillering stage; and the disease incidence during the screening of disease-resistant plants needs to be ≤5-10%.

[0016] Preferably, the number of powdery mildew species in the mixed bacterial solution of powdery mildew species in step (3) is ≥5-10; and the powdery mildew species in the mixed bacterial solution are mixed in equal proportions.

[0017] Preferably, the disease incidence of the plants in step (4) refers to the disease incidence during the tillering stage; and the disease incidence during the screening of disease-resistant plants needs to be ≤5-8%.

[0018] Preferably, the antioxidant solution in step (5) is composed of vitamin C, vitamin E and / or polyphenol compounds.

[0019] Another object of the present invention is to provide application of the above method in wheat powdery mildew resistance breeding.

[0020] Another object of the present invention is to provide a powdery mildew resistant wheat line bred by the above method.

[0021] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses a mixed bacterial solution of different powdery mildew physiological races to treat wheat seeds, observes the morbidity during the tillering stage, screens out plants with high resistance to the mixed bacterial solution of physiological races during the tillering stage as parents for hybridization, obtains first-generation grain seeds, and simultaneously uses the same treatment measures to screen resistant plants for the first-generation grain seeds, backcrosses the resistant plants with the female parent, harvests the second-generation grain seeds, and treats the second-generation grain seeds with an antioxidant solution to finally obtain a powdery mildew resistant wheat variety. In the method of the present invention, through resistance screening of different powdery mildew physiological races, as well as multi-generation hybridization and selfing, genes are effectively accumulated in vertical resistance and horizontal resistance, thereby improving the maintenance time and effectiveness of variety resistance. At the same time, the present invention selects the morbidity during the tillering stage for resistance screening, and the resistance screening has high accuracy, so that the screening results are more accurate, and it also helps to screen varieties with long resistance maintenance time. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Acquisition of wheat powdery mildew physiological races used in the embodiments of the present invention:

[0025] During the peak period of powdery mildew of wheat (early to mid-June), fresh powdery mildew diseased leaves were collected from wheat production fields in Xiping County of Zhumadian City, Fugou County of Zhoukou City, Baofeng County of Pingdingshan City, Huixian City of Xinxiang City and Suiyang District of Shangqiu City, and inoculated onto living test tube wheat seedlings by shaking-off method under isolation conditions. The leaves were cultured at 18-20°C and 8000lx light for 10h / day for one week. When white colonies appeared on the leaves, the single colonies were inoculated onto new sterile wheat seedlings by smearing method. After the colonies grew out, the separation, purification and propagation were repeated, and each single spore pile was numbered and preserved alive.

[0026] Nine differential hosts, namely Afu, Ulka / Cc8, Era, Caucasus, CI12632, Maris Huntsman, Kenguia, Baimian 3 and Xiaobaidongmai, proposed by the National Wheat Powdery Mildew Collaboration Group in 1984, were used. The isolated monospore piles were inoculated and identified by the detached leaf segment culture method. The reaction type of the lesions on the detached leaf segments of each differential host was recorded, and it was graded as 0, 0, 12.3, and 4, where 0-1 was resistant (R), 2 was moderately resistant (MR), 3 was moderately susceptible (MS), and 4 was susceptible (S). The recorded reaction types were coded according to the octal system of J. Gilmour. The physiological races of wheat powdery mildew collected were counted, and the physiological races were as follows: 1, 2, 4, 5, 7, 11, 15, 17, 21, 31, 111, 115, 311 and 401.

[0027] Example 1

[0028] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0029] (1) Seed pretreatment: Take 10 kg of Fengshuo 94 wheat seeds and set aside. Select powdery mildew species 1, 5, 7, 11 and 15 and mix them in equal proportions to prepare a powdery mildew species mixed bacterial solution. Place the wheat seeds in the powdery mildew species mixed bacterial solution at 15°C for 2 days, wash them, drain the water and set aside.

[0030] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants with an incidence rate of ≤10% based on the disease incidence rate of the plants during the tillering stage, using the selected disease-resistant plants as parents, and performing parent hybridization; harvesting first-generation grains;

[0031] (3) Treatment of first-generation seeds: Place the first-generation seeds in a mixed bacterial solution of powdery mildew species 1, 5, 7, 11 and 15 in equal proportions, soak at 15°C for 2 days, wash, drain and set aside;

[0032] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence rate during the tillering stage of the plants, screening disease-resistant plants with a disease incidence rate of ≤8% as parents, backcrossing with the parents screened in step (2), and harvesting the second generation grains;

[0033] (5) Second-generation grain treatment: The second-generation grains were placed in an antioxidant solution composed of vitamin C, vitamin E and catechins at 18°C ​​for 3 days, washed, drained, self-pollinated after sowing, and the grains were harvested to obtain a powdery mildew resistant wheat line.

[0034] Example 2

[0035] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0036] (1) Seed pretreatment: Take 10 kg of Fengshuo 94 wheat seeds, select powdery mildew physiological species 1, 5, 15, 31, 111 and 311 in equal proportions to prepare a powdery mildew physiological species mixed bacterial solution, place the wheat seeds in the powdery mildew physiological species mixed bacterial solution, soak at 20°C for 1 day, wash, drain and set aside;

[0037] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants with an incidence rate of ≤5% according to the disease incidence rate of the plants at the tillering stage, using the selected disease-resistant plants as parents, and performing parent hybridization; harvesting first-generation grains;

[0038] (3) Treatment of first-generation seeds: Place the first-generation seeds in a mixed bacterial solution of powdery mildew species 1, 5, 15, 31, 111 and 311 in equal proportions at 20°C for 1 day, wash, drain and set aside;

[0039] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence rate during the tillering stage of the plants, screening disease-resistant plants with a disease incidence rate of ≤5% as parents, backcrossing with the parents screened in step (2), and harvesting the second generation grains;

[0040] (5) Second-generation grain treatment: The second-generation grains were placed in an antioxidant solution composed of vitamin C and catechins at 25°C for 2 days, washed, drained, self-pollinated after sowing, and harvested to obtain a powdery mildew-resistant wheat line.

[0041] Example 3

[0042] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0043] (1) Seed pretreatment: Take 10 kg of Fengshuo 94 wheat seeds, select powdery mildew physiological species 1, 2, 4, 5, 7, 11, 15, 17, 21 and 31, mix them in equal proportions to prepare a powdery mildew physiological species mixed bacterial solution, place the wheat seeds in the powdery mildew physiological species mixed bacterial solution, soak at 18°C ​​for 1 day, wash, drain and set aside;

[0044] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants with an incidence rate of ≤8% according to the incidence rate of the plants at the tillering stage, using the selected disease-resistant plants as parents, and performing parent hybridization; harvesting first-generation grains;

[0045] (3) Treatment of first-generation grains: Place the first-generation grains in a mixed bacterial solution of powdery mildew species 1, 2, 4, 5, 7, 11, 15, 17, 21 and 31 in equal proportions, soak at 15°C for 1 day, wash, drain and set aside;

[0046] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence rate during the tillering stage of the plants, screening disease-resistant plants with a disease incidence rate of ≤6% as parents, backcrossing with the parents screened in step (2), and harvesting the second generation grains;

[0047] (5) Second-generation grain treatment: The second-generation grains were placed in an antioxidant solution composed of catechins at 20°C for 2 days, washed, drained, self-pollinated after sowing, and the grains were harvested to obtain a powdery mildew resistant wheat line.

[0048] Comparative Example 1

[0049] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0050] (1) Seed pretreatment: Take 10 kg of Fengshuo 94 wheat seeds, select powdery mildew physiological species 1, 2, 4, 5, 7, 11, 15, 17, 21 and 31, mix them in equal proportions to prepare a powdery mildew physiological species mixed bacterial solution, place the wheat seeds in the powdery mildew physiological species mixed bacterial solution, soak at 18°C ​​for 1 day, wash, drain and set aside;

[0051] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants with an incidence rate of ≤8% based on the disease incidence rate of the plants at the seedling stage, using the selected disease-resistant plants as parents, and performing parent hybridization; harvesting first-generation grains;

[0052] (3) Treatment of first-generation grains: Place the first-generation grains in a mixed bacterial solution of powdery mildew species 1, 2, 4, 5, 7, 11, 15, 17, 21 and 31 in equal proportions, soak at 15°C for 1 day, wash, drain and set aside;

[0053] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence rate of the plants at the seedling stage, screening disease-resistant plants with a disease incidence rate of ≤6% as parents, backcrossing with the parents screened in step (2), and harvesting the second generation grains;

[0054] (5) Second-generation grain treatment: The second-generation grains were placed in an antioxidant solution composed of catechins at 20°C for 2 days, washed, drained, self-pollinated after sowing, and the grains were harvested to obtain a powdery mildew resistant wheat line.

[0055] Comparative Example 2

[0056] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0057] (1) Seed pretreatment: Take 10 kg of Fengshuo 94 wheat seeds, select powdery mildew species No. 15 to prepare powdery mildew species solution, place the wheat seeds in the powdery mildew species No. 15 solution, soak at 18°C ​​for 1 day, wash, drain and set aside;

[0058] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants with an incidence rate of ≤8% according to the incidence rate of the plants at the tillering stage, using the selected disease-resistant plants as parents, and performing parent hybridization; harvesting first-generation grains;

[0059] (3) Treatment of first-generation seeds: Place the first-generation seeds in a solution of powdery mildew species No. 15 at 15°C for 1 day, wash, drain and set aside;

[0060] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence rate during the tillering stage of the plants, screening disease-resistant plants with a disease incidence rate of ≤6% as parents, backcrossing with the parents screened in step (2), and harvesting the second generation grains;

[0061] (5) Second-generation grain treatment: The second-generation grains were placed in an antioxidant solution composed of catechins at 20°C for 2 days, washed, drained, self-pollinated after sowing, and the grains were harvested to obtain a powdery mildew resistant wheat line.

[0062] Comparative Example 3

[0063] A method for breeding wheat for resistance to powdery mildew comprises the following steps:

[0064] (1) Seed pretreatment: Take 10 kg of Fengshuo 94 wheat seeds, select powdery mildew physiological species 1, 2, 4, 5, 7, 11, 15, 17, 21 and 31, mix them in equal proportions to prepare a powdery mildew physiological species mixed bacterial solution, place the wheat seeds in the powdery mildew physiological species mixed bacterial solution, soak at 18°C ​​for 1 day, wash, drain and set aside;

[0065] (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants with an incidence rate of ≤8% according to the incidence rate of the plants at the tillering stage, using the selected disease-resistant plants as parents, and performing parent hybridization; harvesting first-generation grains;

[0066] (3) Treatment of first-generation grains: Place the first-generation grains in a mixed bacterial solution of powdery mildew species 1, 2, 4, 5, 7, 11, 15, 17, 21 and 31 in equal proportions, soak at 15°C for 1 day, wash, drain and set aside;

[0067] (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence rate during the tillering stage of the plants, screening disease-resistant plants with a disease incidence rate of ≤6% as parents, backcrossing with the parents screened in step (2), and harvesting the second generation grains;

[0068] (5) Second-generation grain treatment: The second-generation grains are sown and then self-pollinated, and the grains are harvested to obtain a powdery mildew-resistant wheat line.

[0069] Breeding effect verification

[0070] The wheat lines obtained by the breeding methods of Examples 1-3 and Comparative Examples 1-3 were sown in the open air, and the powdery mildew resistance rate of the wheat lines obtained in each group was counted. 2,000 seeds were sown in each group. The resistance rate = (total number of test plants - number of diseased plants) / total number of test plants × 100%. The experimental results are shown in Table 1:

[0071] Table 1 Resistance rate of wheat lines from different groups to powdery mildew

[0072]

[0073]

[0074] Results analysis: According to the data in Table 1, the wheat strains screened in Examples 1-3 have a resistance rate to powdery mildew of more than 99%, indicating that the wheat strains screened by the method of the present invention have high resistance to powdery mildew. The seedling stage was selected for disease resistance screening in Comparative Example 1, and the resistance rate of the wheat strains screened therein to powdery mildew was 78.85%, which was significantly lower than that in Examples 1-3. It can be seen that the resistance screening period has a direct relationship with the accuracy of powdery mildew resistance screening.

[0075] At the same time, in order to verify the resistance maintenance time of wheat lines screened from different groups, wheat lines obtained from different groups were divided into different areas for greenhouse cultivation and planting. During the planting process, the light intensity was supplemented to ensure the maturity of the wheat. Through multiple generations of pollination and planting (2,000 seeds were planted per generation), the resistance maintenance generations of each wheat line were determined and the average value was taken. The experimental results are shown in Table 2:

[0076] Table 2 The number of generations of resistance to powdery mildew maintained by wheat lines obtained from different groups

[0077] Group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Maintenance time (generation) 20 21.2 22.4 15.2 16.7 17.8

[0078] Result analysis: From the table data, it can be seen that the resistance maintenance generations of the wheat lines cultivated in Examples 1-3 are around 20-22 generations, while the resistance maintenance generations of Comparative Examples 1-3 are all lower than those of Examples 1-3. Moreover, by comparison, it can be seen that the selection of the tillering stage for resistance screening and the selection of mixed bacterial liquid of multiple powdery mildew species and antioxidant solution for seed treatment all have a certain effect on improving the resistance maintenance generations of wheat varieties, which provides a direction for the later wheat powdery mildew resistance breeding.

[0079] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0080] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for breeding wheat for resistance to powdery mildew, characterized in that: The steps include: (1) Seed pretreatment: Take wheat seeds, place them in a mixed bacterial solution of powdery mildew physiological species, soak them at 15-20°C for 1-2 days, wash them, drain the water and set aside; (2) Screening and hybridization of parents: sowing the seeds treated in step (1), screening disease-resistant plants according to the incidence of the plants, using the selected disease-resistant plants as parents for parent hybridization; and harvesting first-generation grains; (3) Treatment of first-generation seeds: Place the first-generation seeds in a mixed bacterial solution of powdery mildew species at 15-20°C for 1-2 days, wash, drain and set aside; (4) backcrossing: sowing the first generation grains treated in step (3), screening disease-resistant plants according to the disease incidence of the plants, and backcrossing the selected disease-resistant plants with the parents selected in step (2) as parents to harvest the second generation grains; (5) Second-generation grain treatment: The second-generation grains are placed in an antioxidant solution at 18-25°C for 2-3 days, washed, drained, self-pollinated after sowing, and the grains are harvested to obtain a powdery mildew-resistant wheat variety.

2. The method for breeding wheat for resistance to powdery mildew according to claim 1, characterized in that: The powdery mildew physiological species in step (1) is obtained by collecting fresh powdery mildew diseased leaves from wheat fields in different regions during the peak period of wheat powdery mildew, shaking them off and inoculating them into living test tube wheat seedlings for preservation.

3. The method for breeding wheat for resistance to powdery mildew according to claim 1, characterized in that: In step (1), the number of powdery mildew physiological races in the powdery mildew physiological race mixed bacterial solution is ≥5-10; and the powdery mildew physiological races in the powdery mildew physiological race mixed bacterial solution are mixed in equal proportions.

4. The method for breeding wheat for resistance to powdery mildew according to claim 1, characterized in that: The disease incidence of the plants in step (2) refers to the disease incidence during the tillering stage; the disease incidence during the screening of disease-resistant plants needs to be ≤5-10%.

5. The method for breeding wheat for resistance to powdery mildew according to claim 1, characterized in that: In step (3), the number of powdery mildew physiological races in the powdery mildew physiological race mixed bacterial solution is ≥5-10; and the powdery mildew physiological races in the powdery mildew physiological race mixed bacterial solution are mixed in equal proportions.

6. The method for breeding wheat for resistance to powdery mildew according to claim 1, characterized in that: The disease incidence of the plants in step (4) refers to the disease incidence during the tillering stage; the disease incidence during the screening of disease-resistant plants needs to be ≤5-8%.

7. The method for breeding wheat for resistance to powdery mildew according to claim 1, characterized in that: The antioxidant solution described in step (5) is composed of vitamin C, vitamin E and / or polyphenol compounds.

8. Use of the method according to any one of claims 1 to 7 in wheat powdery mildew resistance breeding.

9. A powdery mildew resistant wheat line bred by the method according to any one of claims 1 to 7.

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