Breeding method of rice capable of resisting southern rice black-streaked dwarf virus

Abstract

The invention relates to a breeding method of plant varieties, in particular to a breeding method of southern rice black-streaked dwarf virus resistant rice. The method comprises the following steps: hybridizing a Hinning rice No.7 material and a material of which the resistance of southern rice black-streaked dwarf needs to be improved to obtain an F1-generation material, and obtaining rice resisting southern rice black-streaked dwarf; wherein the Haireclamation rice No.7 material is a material with the announcement number of CNA080658E on New Agricultural Plant variety Protection Business, and according to the method disclosed by the invention, the incidence rate of the black-streaked dwarf disease is reduced to 3.4%-6.7% by 100%.

Description

Technical Field

[0001] The present invention relates to a breeding method for plant varieties, and particularly to a breeding method for rice resistant to Southern rice black-streaked dwarf virus (SRBSDV). Background Art

[0002] Southern rice black-streaked dwarf disease is a rice disease caused by Southern rice black-streaked dwarf virus. The main symptoms of this disease are plant dwarfing, increased tillering, short and broad and stiff leaves, dark green leaf color, initially wax-white and then brown short strip tumor-like bulges on the veins on the back of the leaves and the stem, no heading or small panicles, poor seed setting, incomplete heading at the heading stage, and wrinkling at the base of the flag leaf. The symptoms after infection at different growth stages are slightly different. Its incidence characteristics include strong explosiveness, fast spread, and hidden harm. Once it breaks out, it will lead to a reduction in rice yield or even a complete crop failure.

[0003] Southern rice black-streaked dwarf disease is mainly caused by white-backed planthoppers carrying the virus, and there is no specific medicine to control it. In production, prevention is the main measure. In view of the past bad situation of farmers "emphasizing pesticide application and neglecting prevention" in controlling Southern rice black-streaked dwarf disease, agricultural scientific and technical personnel have put forward a comprehensive prevention and control plan of replacing "drug treatment" with "production repellency" in actual production. The severity of the occurrence of Southern rice black-streaked dwarf disease is closely related to the resistance of rice varieties, the population density and virus-carrying rate of white-backed planthoppers, the farming system, and the coincidence degree between the immigration period of white-backed planthoppers and the sensitive period of rice. Generally, when all the above conditions conducive to the occurrence of the disease are met, the disease will occur severely. The disease incidence rate is basically equal to the loss rate. Once it breaks out on a large scale, the yield will be reduced by more than 90%, or even a complete crop failure. Due to the lack of resistant sources with stable resistance in the existing technology, most of them avoid the spread of harm by controlling the insect source. The incidence rate of the existing excellent materials resistant to Southern rice black-streaked dwarf disease is 6.25% - 28.51%. Although they have resistance to Southern rice black-streaked dwarf disease, their incidence rate is still relatively high, and it is unknown whether the resistance genes of the disease-resistant materials can be stably inherited to the offspring when used in breeding. Therefore, a breeding method for rice that reduces the loss rate of Southern rice black-streaked dwarf disease from the breeding technology is needed. Summary of the Invention

[0004] In order to reduce the loss rate of Southern rice black-streaked dwarf disease, the present invention provides a breeding method for rice resistant to Southern rice black-streaked dwarf disease.

[0005] A breeding method for rice resistant to Southern rice black-streaked dwarf disease, which hybridizes the Haiken rice No. 7 material with the material that needs to improve the resistance to Southern rice black-streaked dwarf disease to obtain the F1 generation material, thus obtaining the rice resistant to Southern rice black-streaked dwarf disease; Among them, the Haiken rice No. 7 material is the material with the announcement number CNA080658E in the "Bulletin of the Protection of New Varieties of Agricultural Plants"; Directional generation acceleration selection is performed on the F1 generation materials to obtain rice with stable inheritance of resistance to southern rice black-streaked dwarf disease; When performing the directional generation acceleration selection, selection is carried out with the yield traits of the F1 generation materials as the goal.

[0006] Preferably, the yield traits refer to tillering ability and seed setting rate of grains.

[0007] Preferably, when performing the directional generation acceleration selection, plants with a tillering ability better than the average tillering ability of the F1 generation materials are selected in terms of plant type performance.

[0008] Preferably, when performing the directional generation acceleration selection, plants with a seed setting situation where the seed setting rate of grains is higher than the average seed setting rate of the F1 generation materials are selected.

[0009] Preferably, when performing the directional generation acceleration selection, plants that do not show disease in the field in terms of resistance to pests and diseases are selected from the F1 generation materials.

[0010] Preferably, the rice with stable resistance to southern rice black-streaked dwarf disease simultaneously meets the conditions of the above-mentioned plant type performance, the above-mentioned seed setting situation, and the above-mentioned resistance to pests and diseases performance.

[0011] Preferably, when performing the directional generation acceleration selection, plants infected with southern rice black-streaked dwarf disease rice stumps are planted in the same area as the F1 generation materials to provide the pathogen source.

[0012] Preferably, the material that needs to improve the resistance to southern rice black-streaked dwarf disease is 19 Xiang.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a resistant source with stable resistance, namely Haiken Rice No. 7. On the basis of the provided resistant source with stable resistance, the present invention provides a breeding method for rice resistant to southern rice black-streaked dwarf disease, breaking through the method in the prior art that can only avoid harm by controlling pests, that is, using Haiken Rice No. 7 resistant to southern black-streaked dwarf disease as the resistant source material. The incidence rate of southern rice black-streaked dwarf disease of Haiken Rice No. 7 is 0%. By crossing the resistant source material with the material that needs to improve the resistance to southern rice black-streaked dwarf disease, resistant plants to black-streaked dwarf disease are separated in the offspring, proving that its characteristics of resistance to southern rice black-streaked dwarf disease can be stably inherited. After directional generation acceleration selection, rice with stable inheritance of resistance to southern rice black-streaked dwarf disease is obtained, reducing the 100% incidence rate of black-streaked dwarf disease to 3.4% - 6.7%, providing a method that can stably resist southern rice black-streaked dwarf disease.

[0014] The method of the present invention can improve the technical level of resistance breeding, avoid the production losses caused by the large-scale outbreak of southern rice black-streaked dwarf disease again, and also reduce the amount of pesticides used for controlling planthoppers. Description of the Drawings

[0015] Figure 1 Flow chart for the breeding of rice resistant to Southern rice black-streaked dwarf virus

[0016] Figure 2 Comparison between 19Xiang and Haiken Rice No. 7, where A is 19Xiang and B is Haiken Rice No. 7

[0017] Figure 3 Comparison between Haiken Rice No. 7 and the diseased materials of the same batch, where A is Haiken Rice No. 7 and B is the diseased materials of the same batch

[0018] Figure 4 F1 generation seeds and rice resistant to Southern rice black-streaked dwarf virus, where A is the F1 generation seeds obtained by cutting the glumes for hybridization, and B is the selection of resistant single plants by screening the plants in the field for black-streaked dwarf virus infection

[0019] Figure 5 Performance of the F1 generation materials in the later stage of planting, where A is the performance of 19Xiang, basically in the diseased state, severely dwarfed, unable to head normally, and B is the offspring of the hybrid of 19Xiang and Haiken Rice No. 7, with normal growth, normal plant height, and no dwarfing phenomenon Detailed implementation manners

[0020] The following is a detailed description of the specific implementation manners of the present invention. However, it should be understood that the protection scope of the present invention is not limited by the specific implementation manners. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified

[0021] 19Xiang in the present invention is the naming of rice

[0022] Example 1 Breeding method of Haiken Rice No. 7, including the following steps Starting from 2009, Zhongzhonghui 629 was subjected to recurrent hybridization with BL122 and Cbb23 until 2012 for 6 cycles, respectively obtaining Zhongzhonghui 629-1 and 2 materials containing Pi2 gene and Xa23. Specifically: Zhongzhonghui 629 was hybridized with the bacterial blight-resistant material CBB23 and then recurrently hybridized with Zhongzhonghui 629 to obtain 629-1 Zhongzhonghui 629 was hybridized with the blast-resistant material BL122 and then recurrently hybridized with Zhongzhonghui 629 to obtain 629-2 In 2013, through pyramiding hybridization, the single plants with successful pyramiding were tentatively named R6294

[0023] In 2019, the early rice was hybridized using Longhui 1031 as the female parent and the selected R6294 as the male parent. After that, the generation was continuously increased through directional selection. By 2022, the generation material had reached F8. The offspring showed good plant and leaf morphology, strong tillering, and good resistance. The stable and consistent single plant C135-7 was selected for variety comparison. In the 2023 late production comparison, the performance was 8% higher than the control special indica 25, and the field resistance performance was also significantly improved, so a trial planting was arranged and named Haiken Rice No. 7.

[0024] In late-season planting in Sanya, Hainan, Haiken Rice No. 7 has a full growth period of 110 days, an average yield of 508.3 kg per mu, an increase of 8.0% over the control special indica 25, a plant height of 112 cm, a coordinated panicle-grain structure, 155,000 effective panicles per mu, a panicle length of 27.4 cm, a total number of grains per panicle of 152.7 grains, a fruit setting rate of 88.1%, and a thousand-grain weight of 20.3 grams. No rice blast was found in field planting, and white leaf blight was mild. The combination has a uniform population, moderate plant type, strong stems, good toughness, medium tillering rate, upright leaves, light green leaf sheaths, and yellow lemma tips. The combination has good yield, good appearance, and is resistant to rice blast. It is proposed to be recommended to participate in the late-season regional trial in Hainan Province in 2024.

[0025] Among them, the full growth period of Haiken Rice No. 7 is 110 days, which is equivalent to the growth period of Texianzhan 25. The average yield of Haiken Rice No. 7 is 508.3 kilograms per mu, which is 8.0% higher than the control Texianzhan 25, and the incidence rate of southern rice black-streaked dwarf disease is 0%.

[0026] The announcement number of Haiken Rice No. 7 in the "Bulletin of Protection of New Varieties of Agricultural Plants" is CNA080658E.

[0027] Example 2 A method for breeding rice resistant to southern rice black streaked dwarf disease, the flow chart is as follows Figure 1 As shown, the following steps are included: The Haiken Rice No. 7 material is hybridized with materials that need to be improved and have no resistance to southern rice black-streaked dwarf disease to obtain F1 generation materials and hybrid combinations. The F1 generation materials are identified or multiplied and targetedly screened to obtain new rice materials and new combinations resistant to southern rice black-streaked dwarf disease.

[0028] In this embodiment, the material that needs to be improved and has no resistance to southern rice black-streaked dwarf disease is 19Xiang. Haikendao No. 7 material is hybridized with 19Xiang to obtain the F1 generation material 19Xiang×Haikendao No. 7, that is, rice resistant to southern rice black-streaked dwarf disease.

[0029] Example 3 The F1 generation material obtained in Example 2 was subjected to directional additional generation selection to obtain rice with stable resistance to southern rice black-streaked dwarf disease.

[0030] When performing directional backcross selection, plants infected with southern rice black-streaked dwarf virus (SRBSDV) are planted in the same area as the F1 generation materials to provide the pathogen source. Among the F1 generation materials, plants are selected with tillering ability better than the average tillering ability of the F1 generation materials, seed setting rate higher than the average seed setting rate of the F1 generation materials, and resistance to pests and diseases manifested as no disease occurrence in the field.

[0031] Effect verification 1. Test the F1 generation materials obtained in Example 2 for resistance to black-streaked dwarf disease as follows: (1) Create an area suitable for the occurrence of southern rice black-streaked dwarf disease Utilize the natural basin terrain of the outpost base of Nanbin Farm, Yazhou District, Sanya City, and the environment with a high incidence of white-backed planthoppers and thrips in the fruits, vegetables, and surrounding areas of the terrain, and select it as the test site.

[0032] Collect plants infected with southern rice black-streaked dwarf virus and transplant and preserve them. Utilize the characteristic that rice can still grow normally in winter in Sanya, Hainan. Divide and plant the diseased plants around the test site to maintain a stable supply of the pathogen source. The pathogen rice stumps are only controlled for stem borers and not for planthoppers.

[0033] (2) Transplant the 19Xiang × Haiken Dao 7 obtained in Example 2 together with its parents, that is, transplant 19Xiang × Haiken Dao 7, 19Xiang, and Haiken Dao 7. Transplant 60 plants of each material and start the investigation after the dwarf disease of each material has fully occurred at the early heading stage, i.e., in early July, to obtain the proportion of diseased plants in the population.

[0034] Results According to the field investigation results of the hybrid offspring obtained in July 2024, as Figures 2 to 5 , the resistance of the F1 generation materials of 19Xiang × Haiken Dao 7 has been significantly improved, with an incidence rate of 6.7%. The incidence rate of 19Xiang sown in the same plot in the same season was 100%.

[0035] 2. After verifying the effect of southern rice black-streaked dwarf disease resistance in the known variety 19Xiang, the inventor also verified it in the materials without southern rice black-streaked dwarf disease resistance preserved in the laboratory.

[0036] The materials without southern rice black-streaked dwarf disease resistance are Haixiang 319, 201A, and Jia 201A.

[0037] Haixiang 319 is a conventional rice variety bred by pedigree method from the cross of Hanxiang-S × F309. Hanxiang-S is a two-line sterile line selected by Hainan Nongle South Subtropical Seed Industry Co., Ltd. The parental variety source: mutant strain of Jiuxiang. F309 is an intermediate progeny material of Hainan University using 93-11 / CBB23.

[0038] 201A was obtained by crossing 9311 with Intermediate Material 1, and Intermediate Material 1 was obtained by crossing HD9802S with R6. Among them, R6 is a rice blast resistance gene resource containing Pigm.

[0039] Jia 201A was obtained by crossing Guang 8B with Intermediate Material 2, and Intermediate Material 2 was obtained by crossing Yun 9S with Luojia 9. Among them, Luojia 9 is a material with Bph9 in the background of 9311.

[0040] The material of Haiken Rice 7 was crossed with Haixiang 319 to obtain the F1 generation material Haixiang 319 × Haiken Rice 7.

[0041] The material of Haiken Rice 7 was crossed with 201A to obtain the F1 generation material 201A × Haiken Rice 7.

[0042] The material of Haiken Rice 7 was crossed with Jia 201A to obtain the F1 generation material Jia 201A × Haiken Rice 7.

[0043] The resistance to black-streaked dwarf disease of Haixiang 319 × Haiken Rice 7, 201A × Haiken Rice 7 and Jia 201A × Haiken Rice 7 was tested respectively, and the tests are as follows: (1)Create an area suitable for the occurrence of southern rice black-streaked dwarf disease Using the natural basin terrain of the outpost base of Nanbin Farm, Yazhou District, Sanya City, and the environment with a high incidence of white-backed planthoppers and thrips in the fruits, vegetables and surrounding terrain, it was selected as the test site.

[0044] Collect the plants infected with southern rice black-streaked dwarf disease rice stumps for transplanting and preservation. Utilizing the characteristic that rice can still grow normally in winter in Sanya, Hainan, the diseased plants were planted in clusters around the test site to maintain a stable supply of the pathogen. The pathogen rice stumps were only controlled for stem borers and not for planthoppers.

[0045] (2)Haixiang 319 × Haiken Rice 7, 201A × Haiken Rice 7 and Jia 201A × Haiken Rice 7 were transplanted together with their parents, that is, Haixiang 319 × Haiken Rice 7, Haixiang 319, Jia 201A × Haiken Rice 7, Jia 201A, 201A × Haiken Rice 7, 201A and Haiken Rice 7 were transplanted. 60 plants of each material were transplanted. The investigation started after the dwarf disease of each material fully occurred at the early heading stage, that is, in early July, and the proportion of diseased plants in the population was obtained.

[0046] Results According to the field investigation results of the hybrid offspring obtained in July 2024, the incidence of dwarf disease in the field of Jia 201A was 100%, and the incidence of field investigation of Jia 201A × Haiken Rice 7 was 3.4%. The incidence of dwarf disease in the field of 201A was also 100%, and the incidence of field investigation of 201A × Haiken Rice 7 was 5.0%. The resistance of the hybrid offspring has been significantly improved.

[0047] The dwarf disease incidence rate of the combinations of Jia201A×Haixiang319 and 201A×19xiang sown at the same time reached 100%, which also shows that Jia201A, Haixiang319, 201A, and 19xiang are all materials without resistance to southern rice black-streaked dwarf disease.

[0048] In summary, the present invention utilizes the phenomenon of continued high incidence and recurrence of southern rice black-streaked dwarf disease in recent years at the outpost base of Nanbin Farm in Yazhou District, Sanya City. In 2023 and 2024, for two consecutive years, almost all varieties were completely lost due to dwarf disease. In this detection area, the disease resistance of various rice varieties to southern black-streaked dwarf disease was investigated, and a variety resistant to dwarf disease was found, named Haiken Rice No. 7. After two years of planting, rice has outstanding resistance to southern black-streaked dwarf disease. Other rice varieties are infected with southern black-streaked dwarf disease, with an incidence rate of 100%, reaching the level of total loss. Haiken Rice No. 7 can still head normally and set fruit normally.

[0049] After a year of hybridization and breeding, it was found that the offspring had separated out plants that were resistant to southern black-streaked dwarf disease, proving that its trait of resistance to southern black-streaked dwarf disease can be stably inherited. This provides a stable and reliable traditional breeding method for further solving the problem of rice resistance to southern black-streaked dwarf disease.

[0050] First, the bred Haiken rice No. 7 material is hybridized with the material that needs to improve the resistance to dwarf disease. In the process of additional generation selection, according to the occurrence characteristics of white-backed planthoppers every year, the occurrence time of intensive damage in Yacheng area starts from March 20, and the density of white-backed planthoppers is relatively large when sowing at this time. If the terrain environment is suitable, such as the low-lying terrain selected in the current experiment, it is very easy to cause a large number of white-backed planthoppers to reproduce. If the planthopper group carries viruses, it will cause a large number of southern rice black-striped dwarf disease. The present invention meets the terrain characteristics, the occurrence characteristics of the insect group and the characteristics of rice susceptibility, that is, it meets the climate and season suitable for the large-scale reproduction of white-backed planthoppers, the presence of virus-carrying plants in the field, and the rice growth period is a period that is more susceptible to the disease. At the same time, these three conditions are met, and an area suitable for the occurrence of southern rice black-striped dwarf disease is created, which is used for field identification of whether the additional generation of offspring can resist dwarf disease. Screening for resistance to dwarfing disease is carried out from March to July each year, which is the peak period of the disease. Targeted selection is carried out on yield traits at other times. Among the high-generation materials, rice quality testing is then used to select excellent varieties with strong resistance, high yield and good rice quality.

[0051] So far, although the incidence of Southern rice black-streaked dwarf disease has been increasing year by year, there is no representative area or scope where this disease can occur repeatedly every year. To meet the condition of continuous disease occurrence, in addition to finding the suitable terrain for pest occurrence, a rich source of pests is also needed. The test plot selected for the experiment is somewhat like a basin with poor air circulation. There are large banana plantations, and thrips and white-backed planthoppers are severely damaged in the surrounding melon and vegetable fields such as cowpea and eggplant fields, meeting the conditions of rich pest sources and easy reproduction and spread of virus-carrying pests. Since the incidence reached the peak this year, Southern rice black-streaked dwarf disease has basically occurred in the entire base. The present invention preserves and plants the virus-infected rice stumps with severe disease, maintaining the occurrence conditions of the pathogen and also ensuring the reliability of the selection of resistant materials.

[0052] Regarding the resistant materials for Southern rice black-streaked dwarf disease, the resistance performances of the publicly released resistant materials are not ideal at present. That is to say, there is no resistant source material with good resistance performance. However, the incidence of Haiken Rice No. 7 resistant to Southern rice black-streaked dwarf disease in the present invention is 0%, obtaining a stable resistant material and truly achieving a breakthrough in the breeding technology for resistance to Southern rice black-streaked dwarf disease.

[0053] It should be noted that when the claims of the present invention involve numerical ranges, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. To avoid unnecessary repetition, the preferred embodiments of the present invention are described.

[0054] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for breeding rice resistant to southern rice black-streaked dwarf disease, characterized in that: Crossing Haiken Rice No. 7 with materials that need to be improved in resistance to southern rice black-streaked dwarf disease to obtain F1 generation materials, that is, rice resistant to southern rice black-streaked dwarf disease; Directed selection of F1 generation materials was conducted to obtain rice with stable inheritance resistance to southern rice black-streaked dwarf disease; During the directional additional generation selection, the yield traits of the F1 generation material are selected as the target.

2. The breeding method according to claim 1, characterized in that: The yield traits refer to tillering and grain setting rate.

3. The breeding method according to claim 2, characterized in that: During the directional additional generation selection, plants are selected whose plant type shows tillering properties better than the average tillering properties of the F1 generation materials.

4. The breeding method according to claim 3, characterized in that: During the directional additional generation selection, plants with a grain setting rate higher than the average value of the grain setting rate of the F1 generation materials are selected.

5. The breeding method according to claim 4, characterized in that: During the directional additional generation selection, the F1 generation materials are selected for plants that are resistant to pests and diseases and are free of disease in the field.

6. The breeding method according to claim 5, characterized in that: The stable rice resistant to southern rice black-streaked dwarf disease satisfies the conditions of plant type performance, grain setting and disease and insect pest resistance performance at the same time.

7. The breeding method according to claim 1, characterized in that: During the directional additional generation selection, the plants infected with southern rice black-streaked dwarf disease and the F1 generation materials are planted in the same area to provide a source of disease.

8. The breeding method according to claim 1, characterized in that: The material for improving resistance to southern rice black-streaked dwarf disease is 19 Xiang.

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