Breeding method of new rice variety resistant to rice false smut and atomization inoculator

Abstract

The application discloses a new rice variety breeding method for resisting rice smut and a misting inoculator, relates to the technical field of rice breeding, and comprises the following steps: (1) hybrid breeding of rice smut-resistant rice varieties; (2) single-plant selection of resistant varieties in a disease nursery; (3) rice smut resistance identification through misting inoculation; and (4) quality trait analysis to obtain a new rice variety resistant to rice smut and having high quality. The application screens rice varieties resistant to rice smut through multi-generation hybrid breeding and single-plant selection under natural disease infection conditions. The misting inoculation method is adopted to uniformly distribute rice smut chlamydospores in the air, and then the rice is contacted with the air, and the disease resistance is evaluated through moisture and heat preservation treatment. The application can efficiently obtain a new rice variety resistant to rice smut and having high quality, can realize improvement of inoculation controllability, cost saving, uniform inoculation, stable effect, enhancement of the anti-infection capacity of the new variety, and can breed a new rice variety with early maturity and high yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of breeding rice varieties, more particularly, it relates to a method for breeding a new rice variety resistant to false smut of rice and a misting inoculator. BACKGROUND

[0002] False smut of rice (FSR) is a fungal disease of the spike of rice caused by the anamorphic fungus Ustilaginoidea virens (Cooke) Tak, which is widely distributed in more than 40 countries in Asia, Africa, South America, Europe and other major rice-producing regions. False smut of rice leads to an increase in empty rate, a decrease in thousand-grain weight, and a reduction in rice yield. Seed treatment with diseased grains can reduce the germination rate of rice seeds to varying degrees. In addition, Ustiloxins, a secondary metabolite of the pathogen of false smut of rice, is a type of active substance that blocks mitosis in eukaryotic cells, has strong cytotoxicity, and is toxic to humans, animals, and plants.

[0003] Patent No. CN114041419B discloses a method for breeding a new rice variety resistant to false smut of rice and having high quality. In the method, chlamydospores are artificially inoculated and light is blocked to screen for a false smut of rice resistant source. The resistant source material is crossed with a variety having excellent quality traits by hybridization breeding. Through recombination and separation of offspring, an excellent new rice variety is bred. In the method for breeding a new rice variety resistant to false smut of rice and having high quality, artificial inoculation of conidia is mainly used, that is, natural infection is supplemented by artificial spraying of chlamydospore suspension of false smut of rice, and light is blocked after inoculation to screen for a rice variety resistant to false smut of rice. However, this method cannot improve the controllability of inoculation, is not conducive to enhancing the anti-infection ability of the new variety, and the inoculation effect is easily affected by the environment and crops, and is unstable.

[0004] Therefore, it is necessary to provide a new method for breeding a new rice variety resistant to false smut of rice, which can efficiently and stably obtain a new rice variety resistant to false smut of rice and having high quality, and is of great significance for solving the threat of false smut of rice and improving rice yield and high-quality rice supply. SUMMARY

[0005] To solve the problem of artificial inoculation in breeding a new rice variety resistant to false smut of rice, the first object of the present application is to provide a method for breeding a new rice variety resistant to false smut of rice and a misting inoculator. The method uses a misting inoculator to screen for a false smut of rice resistant source and improve the controllability of inoculation. The second object of the present application is to provide a method for breeding a new rice variety resistant to false smut of rice. In the method, the use of nitrogen fertilizer is increased during hybridization breeding to improve the infection rate of false smut of rice and enhance the anti-infection ability of the new variety. A high-yield early-maturing variety is crossed with a false smut of rice resistant variety by hybridization breeding. Through recombination and separation, a new rice variety resistant to false smut of rice, early maturing, and high yielding is bred.

[0006] To achieve the above object, the present application provides the following technical solutions.

[0007] In the first aspect, the present application provides a breeding method of a new rice variety resistant to rice blast, which specifically comprises the following steps.

[0008] (1) Hybrid breeding of rice varieties resistant to rice blast;

[0009] (2) Single plant selection of resistant varieties in a disease nursery;

[0010] (3) Identification of resistance to rice blast by atomization inoculation;

[0011] (4) Analysis of quality traits to obtain a new rice variety resistant to rice blast and of high quality.

[0012] As a further scheme of the present application, the hybrid breeding of rice varieties resistant to rice blast comprises:

[0013] Selecting a female parent and a male parent: selecting parent rice varieties with resistance to rice blast for hybridization; wherein a high-yield early-maturing rice variety is selected as the female parent, and a variety resistant to rice blast is selected as the male parent, the variety resistant to rice blast is screened by natural infection and atomization inoculation of Magnaporthe oryzae using an atomization inoculator, and a rice variety with a gene resistant to rice blast is selected as the male parent, wherein the atomization inoculator is used to uniformly spray the thick-walled spore suspension of Magnaporthe oryzae on the rice plant to simulate the process of natural infection, for screening rice varieties resistant in the natural environment, the rice varieties resistant in the natural environment carry the gene resistant to rice blast and are used as the male parent;

[0014] Group hybridization: removing the stamens of the female parent flowers, pollinating the anthers of the male parent on the stigma of the female parent, performing artificial hybridization, and obtaining hybrid offspring;

[0015] Single plant selection: selecting single plants with resistance to rice blast, early maturity, and high yield from the hybrid offspring, and performing single plant selection for continuous multiple generations to obtain a breeding variety resistant to disease, early-maturing, and high-yielding.

[0016] As a further scheme of the present application, when the atomization inoculator is used to atomize Magnaporthe oryzae to screen a rice variety with a gene resistant to rice blast as the male parent, a molecular marker technique is used for screening, PCR (polymerase chain reaction) is used to identify the rice variety, and the following steps are included.

[0017] Step 1. DNA extraction: extracting total DNA from the rice variety.

[0018] Step 2. Design primers: When identifying genes associated with rice blast resistance, specific primers are designed to guide the PCR amplification of DNA fragments. The primers are designed based on the DNA sequences of known rice blast resistance genes, which can be obtained from existing literature and databases.

[0019] Step 3. PCR amplification: Using the designed primers, PCR amplification is performed to amplify the target DNA fragments. In the PCR reaction, the template DNA will bind to the primers, and DNA polymerase will synthesize new DNA strands at high temperature. If the sample contains DNA with rice blast resistance, it will be amplified during PCR.

[0020] Step 4. Electrophoresis analysis: The PCR product is analyzed and visualized by agarose gel electrophoresis.

[0021] Step 5. Comparison and verification: The PCR product is compared with the DNA sequence of the known rice blast resistance gene to determine whether the gene or related DNA sequence is found in the sample. Sequencing technology is used to verify the sequence of the PCR product.

[0022] Step 6. Result interpretation: Based on the PCR results and comparison information, it is determined whether the gene or DNA sequence associated with rice blast resistance is detected in the rice variety.

[0023] Step 7. Verification and in-depth study: The identified candidate gene or DNA sequence is further verified to ensure its association with rice blast resistance.

[0024] Among them, any one of the rice genes Pi-ta, Pi-ta2, Pi-ta-2, Pi-b, and Pi9 is used as a rice blast resistance gene for screening at the gene level, and finally a rice variety with rice blast resistance gene is selected as the male parent.

[0025] As a further scheme of the present application, resistant varieties are selected in a disease nursery, including:

[0026] Seedling nursery preparation: Simulate natural disease conditions and set up a seedling nursery;

[0027] Pseudo-hybrid removal: Remove pseudo-hybrids from F1 generation in the seedling nursery;

[0028] Resistant variety selection: From F2 generation, select single plants without disease and with excellent comprehensive traits in the seedling nursery, and perform self-crossing propagation, gradually increasing the stress of rice blast and the amount of nitrogen fertilizer to screen out rice blast resistance varieties without disease and with excellent comprehensive traits as candidate varieties.

[0029] As a further scheme of the present application, the rice sheath blight resistance identification is performed by atomization inoculation, and the atomization inoculation device is used for the rice sheath blight resistance identification of the candidate variety, including: the thick-walled spore suspension of the rice sheath blight fungus is diluted with sterile water and poured into the atomization inoculation device for atomization; the atomization inoculation device includes an atomization inoculation device and a protective cover, and the protective cover is used for covering the rice and limiting the atomized water vapor sprayed by the atomization inoculation device within the protective cover; wherein the atomization inoculation device is used for the rice sheath blight resistance identification, including:

[0030] Pathogen culture: culture the thick-walled spore suspension of the rice sheath blight fungus to ensure that there are enough spores for inoculation;

[0031] Atomization inoculation: the thick-walled spore suspension of the rice sheath blight fungus is uniformly sprayed on the leaves of the candidate variety using the specially designed atomization inoculation device to simulate the natural infection process;

[0032] Post-inoculation treatment: after inoculation, the moisture and temperature are maintained to promote the infection of the pathogen, the leaves of the candidate variety are monitored, and the disease resistance is evaluated.

[0033] As a further scheme of the present application, the quality traits are analyzed to obtain a new variety of high-quality rice resistant to rice sheath blight, including:

[0034] The quality traits of the candidate variety that does not appear disease symptoms after atomization inoculation are analyzed, and the final new variety of high-quality rice resistant to rice sheath blight is determined through comprehensive evaluation.

[0035] The new variety of high-quality rice resistant to rice sheath blight of the present application is bred by using the atomization inoculation device for inoculation, which can more accurately simulate the infection process of the pathogen, improve the screening efficiency and accuracy of the rice sheath blight resistance traits, and also help to obtain a new variety of high-quality rice. This method can significantly accelerate the breeding process of the rice sheath blight-resistant rice variety, and provide more disease-resistant high-quality rice resources for agricultural production.

[0036] As a further scheme of the present application, in the hybrid breeding of the rice sheath blight-resistant rice variety, a single plant selection method is used to select a parent rice variety with rice sheath blight resistance traits, including the following steps:

[0037] A disease nursery is set up in a stable plot where rice sheath blight occurs seriously every year, and rice plant lines that have been infected with rice sheath blight under natural conditions are planted in the disease nursery; in the second or third year of planting rice, a single plant selection method is used to select a single plant with very light or no disease every year, and the seeds are collected separately; the seeds of the selected single plant in each year are planted again in the next year, and the single plant selection method is continued to select a single plant with very light or no disease from it to obtain a parent rice variety with rice sheath blight resistance traits.

[0038] As a further scheme of the present application, when selecting the resistant variety, a single plant without disease and with excellent comprehensive traits is selected in the F2 generation, the seeds are harvested, and self-reproduction is carried out for 6-7 generations, and a single plant is selected under the stress of rice smut in each generation, and the amount of nitrogen fertilizer is gradually increased every 2 generations until a rice smut resistant variety with stable and consistent phenotype, excellent comprehensive traits and no occurrence of rice smut is obtained.

[0039] As a further scheme of the present application, the amount of nitrogen fertilizer is gradually increased every 2 generations, specifically: no nitrogen fertilizer is applied in the F1 generation, the amount of nitrogen fertilizer is 80 kg / hm 2 in the F2 and F3 generations, the amount of nitrogen fertilizer is 160 kg / hm 2 in the F4 and F5 generations, and the amount of nitrogen fertilizer is 240 kg / hm 2 in the F6 generation.

[0040] As a further scheme of the present application, in step S3, the rice smut resistance identification is carried out by atomization inoculation, and the steps of atomization inoculation are as follows:

[0041] Culturing the thick-walled spore suspension of the rice smut fungus: 2 g of rice smut balls are cultured in 150 ml of PBS medium for 2 days to obtain the thick-walled spore suspension of the rice smut fungus, and the thick-walled spore suspension is placed in a spore storage box;

[0042] Inoculating the rice smut thick-walled spores into the rice with atomized water vapor: when inoculating, the thick-walled spore suspension of the rice smut in the spore storage box is diluted with 2000 ml of sterile water and poured into the spore storage box of the atomization inoculator, and the atomized water vapor is sprayed through the atomization nozzle to carry the air in the protective cover range for atomization;

[0043] Moisturizing by atomization until the end: the atomization inoculation is carried out after the sun sets during the heading period of the rice, so that the rice smut thick-walled spores are uniformly distributed in the air on the same horizontal plane in the protective cover with the atomized water vapor, and continuous atomization and water spraying are carried out for moisturizing and heat preservation;

[0044] Among them, after inoculation, continuous atomization and water spraying are carried out for moisturizing and heat preservation, and the atomization liquid only contains sterile water to promote spore germination and infection of the rice.

[0045] As a further scheme of the present application, in step S3, when the rice smut resistance identification is carried out by atomization inoculation, the atomization inoculation is carried out on the freeze-dried powder of the rice smut thick-walled spores, which is obtained by freeze-drying the thick-walled spore suspension of the rice smut, and the freeze-dried powder is contacted with the atomized water vapor during inoculation and is carried by the atomized water vapor for inoculation on the rice; after inoculation, sterile water is continuously sprayed at a rate of 0.2 ml / min for atomization, and atomization is carried out for 15 min every 30 min to maintain the wet state of the rice smut thick-walled spores;

[0046] Among them, the preparation method of the thick-walled spore freeze-dried powder is as follows: first, 2 g of rice smut balls are cultured in 150 ml of PBS medium, and then the thick-walled spore suspension of the rice smut is freeze-dried.

[0047] As a further scheme of the present application, when the quality traits of the milled rice rate, chalkiness, eating quality, imperfect grain content, moisture content, and amylose content of the rice varieties resistant to rice sheath blight obtained in the identification of the rice sheath blight resistance are analyzed, the standards in the quality trait analysis are: according to the National Standard of the People's Republic of China - High-quality Rice GB / 17891-2017, the rice varieties meeting the national second-class and above standards of high-quality japonica rice are selected, that is, the milled rice rate is ≧61.0%, the chalkiness is ≦4.0%, the eating quality is ≧80 points, the imperfect grain content is ≦3.0%, the moisture content is ≦14.5%, the amylose content is 14.0% to 20.0%, and the diseased spike rate is ≦3%, so as to obtain a new high-quality rice variety resistant to rice sheath blight.

[0048] In a second aspect, the present application further provides an atomization inoculator for breeding a new rice variety resistant to rice sheath blight, which is used to realize the breeding method of the new rice variety resistant to rice sheath blight. The atomization inoculator comprises an atomization inoculation device and a protective cover. The protective cover comprises an upper cover and a lower cover. The upper cover is a cuboid. The interior of the upper cover is hollow, the lower end is open, and the upper end is closed. The lower cover is also a cuboid. The interior of the lower cover is hollow, the upper and lower ends are open, and through holes are formed around the height direction. The through holes are used for ventilation inside the protective cover. The protective cover is made of transparent material.

[0049] As a further scheme of the present application, one side of the atomization inoculation device is further provided with a detachable spore storage box for storing spore suspension. The spore storage box is fixed at the top of the upper cover. The inner bottom of the spore storage box is filled with spore lyophilized powder. Through grooves are formed on both sides of the inner bottom of the spore storage box.

[0050] As a further scheme of the present application, the atomization inoculation device of the atomization inoculator further comprises an atomization water tank, a mist guide pipe, and a mist atomization nozzle. The atomization water tank is connected to the mist atomization nozzle through the mist guide pipe. The mist atomization nozzle is fixed at the top of the upper cover. The mist outlet end of the mist guide pipe is communicated with the mist atomization nozzle. The mist inlet end of the mist guide pipe is located above the liquid level in the atomization water tank.

[0051] As a further scheme of the present application, an elastic film is fixed at the top of the upper cover. The elastic film is pulled by a roller to make the atomized water vapor uniformly adsorbed on the surface and back of the rice, so as to enhance the inoculation effect.

[0052] The elastic film is an arc-shaped rubber film, which comprises an opening and a convex surface. The opening of the elastic film is airtightly fixed in the upper cover. The convex surface of the elastic film is away from the top of the upper cover. The elastic film is located in front of the spore storage box.

[0053] The roller is fixed outside the upper cover. The roller is wound by a thin rope. The other end of the thin rope is fixed at the top end of the convex surface of the elastic film.

[0054] Compared with the prior art, the beneficial effects of the present application are:

[0055] 1. Efficient breeding of rice varieties resistant to rice sheath blight: Through the combination of hybrid breeding, single plant selection in disease nursery, mist inoculation resistance identification, and quality trait analysis, this method can efficiently breed new rice varieties with resistance to rice sheath blight. Not only can it increase rice yield, but also can reduce the impact of diseases on crop yield.

[0056] 2. Comprehensive consideration of resistance and quality: The breeding method of new rice varieties resistant to rice sheath blight in this application not only focuses on the resistance to rice sheath blight, but also emphasizes the analysis of the quality traits of rice. By comprehensively considering the two key factors of resistance and quality, it ensures that the bred rice varieties not only have advantages in disease resistance, but also can meet the market and consumer demand for high-quality food.

[0057] 3. Utilizing natural disease environment to enhance selection effect: In the single plant selection step in the disease nursery, the screening of hybrid offspring under natural disease conditions more realistically simulates the actual disease environment, thereby enhancing the selection effect of resistance to rice sheath blight. This helps to ensure that the bred varieties have stable disease resistance in actual production environment.

[0058] 4. Improved mist inoculation method to improve identification accuracy: Through the improved mist inoculation method, the infection process of the pathogen can be more accurately simulated during the identification of rice sheath blight resistance, improving the accuracy and reliability of resistance identification. This helps to screen out rice varieties that truly have resistance to rice sheath blight.

[0059] 5. Comprehensive consideration of nutrition and resistance: By gradually increasing the amount of nitrogen fertilizer every 2 generations, rice grows under different nutritional conditions, better simulating the actual planting environment, and strengthening the resistance of rice to rice sheath blight. This comprehensive consideration can produce rice varieties that are adapted to different growing environments.

[0060] In summary, the breeding method of new rice varieties resistant to rice sheath blight provided by the present application not only improves disease resistance, but also focuses on quality traits, uses improved mist inoculation method and comprehensive selection strategy, and can obtain new rice varieties with disease resistance and quality traits, providing a beneficial solution for agricultural production.

[0061] These aspects or other aspects of the present application will be more apparent in the following description of the embodiments. It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative effort based on these drawings.

[0063] In the drawings:

[0064] Figure 1 The breeding flow chart of the breeding method of the new rice variety resistant to rice sheath blight of the present application.

[0065] Figure 2 The structure schematic diagram of the atomization inoculation device for breeding the new rice variety resistant to rice sheath blight of the embodiment 2 of the present application.

[0066] Figure 3 The structure schematic diagram of the atomization inoculation device for breeding the new rice variety resistant to rice sheath blight of the embodiment 3 of the present application.

[0067] Figure 4 The structure schematic diagram of the atomization inoculation device for breeding the new rice variety resistant to rice sheath blight of the embodiment 4 of the present application.

[0068] Figure 5 The structure schematic diagram of the initial state of the roller in the atomization inoculation device for breeding the new rice variety resistant to rice sheath blight of the embodiment 4 of the present application.

[0069] Figure 6 The structure schematic diagram of the working state of the roller in the atomization inoculation device for breeding the new rice variety resistant to rice sheath blight of the embodiment 4 of the present application.

[0070] Figure 7 The schematic diagram of the movement of the atomized water vapor droplets in the atomization inoculation device for breeding the new rice variety resistant to rice sheath blight of the present application. DETAILED DESCRIPTION

[0071] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the related drawings; the preferred embodiments of the present application are shown in the drawings, but the present application can be realized in many different forms and is not limited to the embodiments described herein; on the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application; the use herein of the terms "and / or" includes a set of one or more associated listed items.

[0073] In order to solve the problem of artificial inoculation in breeding of new rice varieties resistant to rice sheath blight, the application provides a method for breeding new rice varieties resistant to rice sheath blight, which uses an atomization inoculator to screen rice sheath blight resistance, improves the controllability of inoculation, increases the use of nitrogen fertilizer during hybrid breeding to improve the infection rate of rice sheath blight, thereby enhancing the anti-infection ability of new varieties, and using hybrid breeding to cross high-yield and early-maturing varieties with rice sheath blight-resistant varieties, and through recombination and separation, a new rice variety resistant to rice sheath blight, early maturing and high yield is bred.

[0074] The technical solutions of the application will be further described in detail in combination with Examples 1 to 4 of the specific embodiments.

[0075] Example 1

[0076] Referring to Figure 1 , Figure 2 , Figure 7 As shown in the accompanying drawings, the embodiments of the application provide a method for breeding new rice varieties resistant to rice sheath blight, which is bred by the following steps:

[0077] 1. Hybrid breeding of rice varieties resistant to rice sheath blight: a disease nursery is set up in a stable plot where rice sheath blight has been seriously prevalent for many years, and a rice sheath blight-resistant variety "Wuyoudao No. 1" is planted in the disease nursery. During the heading period of the variety, an atomization inoculator is used for inoculation. From the second year of rice planting, a single plant selection method is used. Every year, single plants with very light or no disease are selected from the planting population, and the seeds are collected and numbered. The selected single plants are planted again the next year, and the single plant selection method is continued, and single plants with very light or no disease are selected again to screen out rice varieties with rice sheath blight resistance.

[0078] According to the breeding target, an early-maturing and high-yield rice variety "Xiangzao No. 6" with good agronomic traits is selected as the female parent, and a rice sheath blight-resistant variety is selected as the male parent for group crossing, which includes removing the stamens of the female parent flowers, and then pollinating the stigma of the female parent with the pollen of the male parent.

[0079] 2. In the disease nursery, select resistant varieties: the selection nursery is set in the disease nursery, using natural infection, F1 generation removes pseudo-hybrid, in F2 generation, select single plant without disease and good comprehensive traits, harvest seeds, self-propagation for 6 generations, each generation is selected under the stress of rice smut, and the amount of nitrogen fertilizer is increased by 2 generations, specifically, F1 generation without nitrogen fertilizer, F2 and F3 generations with 80 kg / hm 2 , F4 and F5 generations with 160 kg / hm 2 , F6 generation with 240 kg / hm 2 , until the variety with stable phenotype, consistent, good comprehensive traits and no occurrence of rice smut is selected.

[0080] 3. Rice smut resistance identification: through natural infection assisted by artificial atomization inoculation of rice smut chlamydospore suspension, and taking the method of shading treatment after inoculation, the rice variety is identified for disease resistance, and the rice variety resistant to rice smut is obtained.

[0081] The preparation method of the chlamydospore suspension of rice smut is as follows: 2 g of rice smut ball is cultured in 150 ml PBS for 2 days.

[0082] Further, the method steps of the atomization inoculation are as follows:

[0083] (1) Prepare the chlamydospore suspension of rice smut.

[0084] (2) Referring to Figure 2 , pour the chlamydospore suspension into the spore storage box 200 of the atomization inoculator, the spore storage box 200 is located on one side of the atomization water tank, and the atomization inoculation is carried out after the sun sets at the heading stage of the rice 300 by adding a spraying amount of sterile water to the atomization water tank.

[0085] (3) After inoculation, atomize and moisturize at 0.2 ml / min from 8:00 to 18:00 every day, atomize for 15 min every 30 min, and investigate the number of diseased spikes after 3 weeks to calculate the diseased spike rate, and screen the variety without occurrence of rice smut.

[0086] During inoculation, the atomization inoculator atomizes sterile water and adds chlamydospore suspension, and the chlamydospore suspension floats to the panicle 320 or leaf of the rice 300 with the atomized water vapor, and then the inoculation is completed. After inoculation, continue to atomize, and the atomized liquid is only sterile water, which is used for moisturizing and promoting spore germination.

[0087] The application embodiment of the present application provides a new rice variety breeding method for resisting smut, and the method adopts a misting inoculator to screen smut antigens, and improves the controllability of inoculation. Compared with a new rice variety breeding method for resisting smut by manually spraying thick-walled spore suspensions, the utilization rate of the misting inoculator and the manual spraying of the suspensions is compared as shown in Table 1, and the comparison of the disease incidence of the rice by using the misting inoculator and the manual spraying is shown in Table 2.

[0088] Table 1 comparison table of utilization rate of suspensions by using a misting inoculator and manual spraying

[0089]

[0090] The comparison of the disease incidence of the rice by using the misting inoculator and the manual spraying is shown in Table 2.

[0091] Table 2 comparison table of disease incidence of rice by using a misting inoculator and manual spraying

[0092]

[0093]

[0094] Note: The average number of diseased grains is the average number of diseased grain in 320 rice ears.

[0095] 4. The quality traits are analyzed to obtain a new rice variety for resisting smut and having high quality: The quality traits such as the head rice yield, chalkiness, eating quality, and amylose content (dry basis) of the rice variety for resisting smut obtained in step 3 are analyzed. The results are shown in Table 3.

[0096] Table 3 quality trait analysis table of the rice variety for resisting smut

[0097]

[0098] Example 2

[0099] Since the misting water vapor generated by the misting inoculator in Example 1 is easily affected by air flow and drifts, the inoculation effect is affected, and therefore, a protective cover 700 is added within the range of action of the misting inoculator, which can prevent the misting water vapor from drifting.

[0100] Referring to Figure 2 The application embodiment of the present application provides a new rice variety breeding method for resisting smut, and the method adopts a misting inoculator to screen smut antigens, and improves the controllability of inoculation. Compared with a new rice variety breeding method for resisting smut by manually spraying thick-walled spore suspensions, the utilization rate of the misting inoculator and the manual spraying of the suspensions is compared as shown in Table 1, and the comparison of the disease incidence of the rice by using the misting inoculator and the manual spraying is shown in Table 2. Figure 2As shown, the thick-walled spore suspension is stored in the spore storage box 200, mixed with sterile water in the atomizing inoculation device 600 at the time of inoculation, atomized, and enters the inside of the protective cover 700 through the mist guide pipe 400 and the atomizing nozzle 100, and then falls on the rice 300 to complete inoculation. The upper cover 500 is transparent, and can provide light and maintain a certain temperature to promote spore germination. The lower cover 800 has holes to contact air for ventilation.

[0101] In the present embodiment, the utilization rate of the atomizing inoculator for inoculating the suspension is shown in Table 4 as follows:

[0102] Table 4 Utilization rate of atomizing inoculator for inoculating suspension

[0103]

[0104] In the present embodiment, the atomizing inoculator for inoculating rice has a disease incidence as shown in Table 5 as follows:

[0105] Table 5 Disease incidence of rice inoculated by atomizing inoculator

[0106]

[0107] In the present embodiment, the utilization rate of the atomizing inoculator for inoculating the suspension is shown in Table 4 as follows:

[0108] Table 6 Comparison of space utilization of atomizing inoculator for rice and current greenhouse culture

[0109]

[0110] Example 3

[0111] In Example 2, because the thick-walled spore suspension is not a uniform solution, and the thick-walled spores do not have a certain shape and size, and cannot completely move to the rice 300 with the mist generated by the atomizing inoculator, affecting the inoculation effect and the utilization rate is not high. Therefore, on the basis of this improvement, the present embodiment provides an atomizing inoculator for breeding new varieties of rice resistant to rice scald. In the implementation of the method for breeding new varieties of rice resistant to rice scald, the steps for breeding new varieties of rice resistant to rice scald are the same as in Example 1. In the present embodiment, referring to Figure 3 As shown, the thick-walled spore freeze-dried powder 900 is stored at the outlet of the mist pipeline.

[0112] As shown in Figure 3As shown, the thick-walled spore freeze-dried powder 900 is placed in the spore storage box 200, when the atomization starts, the atomized water vapor enters the spore storage box 200 through the mist guide pipe 400, and contacts and carries the thick-walled spore freeze-dried powder 900 during the distribution process, so that the thick-walled spore freeze-dried powder 900 moves with the thick-walled spore freeze-dried powder 900 and enters the inside of the protective cover 700, and then falls on the rice 300 to complete inoculation.

[0113] In this embodiment, the utilization rate of the atomization inoculator inoculation suspension of the embodiment of the application is shown in Table 7 as follows:

[0114] Table 7 Atomization inoculator inoculation suspension utilization rate table

[0115]

[0116] In this embodiment, the rice disease incidence of the atomization inoculator inoculation of the embodiment of the application is shown in Table 8 as follows:

[0117] Table 8 Atomization inoculator inoculation rice disease incidence table

[0118]

[0119] Example 4

[0120] In Example 3, the diameter of the atomized water vapor droplets is 1-5 μm, which is in a mixed state of irregular motion and sedimentation in the protective cover 700, and under the action of gravity, it moves from top to bottom, and cannot completely cover the back of the rice leaf 310 and the rice ear 320, which affects the inoculation effect and the utilization rate is not high, so improvement is made on this basis.

[0121] The embodiment of the application provides an atomization inoculator for breeding new varieties of rice resistant to smut, and the steps for breeding new varieties of rice resistant to smut are the same as those in Example 1, and in this embodiment, referring to Figures 4 to 6 As shown, the atomization inoculator is provided with an elastic film 1000 at the top of the protective cover 700, and the roller 1100 pulls the string to change the volume of the film, changes the air pressure in the protective cover 700, and makes the air move upward, and then the atomized water vapor moves upward to contact the back of the rice leaf 310 and the rice ear 320.

[0122] When the atomization inoculator is in the initial state (as shown in Figure 5 As shown, the atomized water vapor droplets are at positions A and B (as shown in Figure 7 As shown, the atomized water vapor droplets are at positions A and B (as shown in Figure 6 As shown, the atomized water vapor droplets are at positions A and B (as shown in

[0123] In this embodiment, the atomization inoculator inoculates the suspension utilization rate of the present embodiment is shown in Table 9 as follows:

[0124] Table 9 atomization inoculator inoculation suspension utilization rate table

[0125]

[0126] In this embodiment, the atomization inoculator inoculates the rice disease rate of the present embodiment is shown in Table 10 as follows:

[0127] Table 10 atomization inoculator inoculation rice disease rate table

[0128]

[0129] In summary, the anti-smut rice new variety breeding method provided by the present application, by setting up the disease garden in the stable plot where the smut occurs seriously every year, using single plant selection method to screen out resistant varieties, and under the natural disease conditions, screening and selfing the offspring, gradually increasing the amount of nitrogen fertilizer, to obtain stable traits of new rice varieties. In addition, by atomization inoculation assisted by natural disease, resistance identification is carried out, and comprehensive analysis of quality traits is carried out, to ensure that the new rice variety with resistance to smut and good quality is bred. The method has important application value in rice industry, and provides an innovative and effective method for solving the problem of smut and improving the quality level of rice.

[0130] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A neotype of rice variety of resistance to rice blast developed by neotype breeding of a rice plant, characterized by, The atomization inoculator comprises an atomization inoculation device and a protective cover, the protective cover comprises an upper cover and a lower cover, the upper cover is a cuboid, the inside of the upper cover is hollow, the lower end is open, and the upper end is closed; the lower cover is a cuboid, the inside of the lower cover is hollow, the upper and lower ends are open, and a through hole is formed around the height direction, the through hole is used for ventilation inside the protective cover; the protective cover is made of transparent material; One side of the atomization inoculation device is further provided with a detachable spore storage box, the spore storage box is used for storing spore suspension; the spore storage box is fixed at the top of the upper cover, the inside bottom of the spore storage box is filled with spore freeze-dried powder, and through grooves are formed on the two sides of the inside bottom of the spore storage box; The top of the upper cover of the atomization inoculator is fixed with an elastic film, and the elastic film is pulled by a roller, so that the atomized water vapor is uniformly adsorbed on the front and back surfaces of the rice.

2. The atomizing inoculator of claim 1, wherein The atomization inoculation device of the atomization inoculator further comprises an atomization water tank, a mist guide pipe and an atomization nozzle, the atomization water tank is connected with the atomization nozzle through the mist guide pipe, the atomization nozzle is fixed at the top of the upper cover, the mist outlet end of the mist guide pipe is communicated with the atomization nozzle, and the mist inlet end of the mist guide pipe is located above the liquid level in the atomization water tank.

3. The atomizing inoculator of claim 2, wherein, The elastic film is an arc-shaped rubber film, comprising an opening and a convex surface; the opening of the elastic film is airtightly fixed in the upper cover; the convex surface of the elastic film is away from the top of the upper cover; the elastic film is located in front of the spore storage box; the roller is fixed outside the upper cover, the roller is wound by a thin rope, and the other end of the thin rope is fixed at the top end of the convex surface of the elastic film.

4. A method for breeding a new variety of rice resistant to rice blast, characterized by, Comprise the following steps: S1, hybrid breeding of rice blast resistance rice varieties Selecting female and male parents: selecting parent rice varieties with rice blast resistance traits for hybridization; wherein, selecting high-yield early-maturing rice varieties as female parents, and selecting rice varieties resistant to rice blast, screening by natural infection and using atomization inoculator to inoculate rice blast fungus, and selecting rice varieties with rice blast resistance genes as male parents, wherein, the atomization inoculator is used to uniformly spray the thick-walled spore suspension of rice blast fungus on the rice plants, simulating the process of natural infection, for screening rice varieties resistant in natural environment, the selected rice varieties resistant in natural environment carry rice blast resistance genes, and are used as male parents; Grouping and hybridization: remove the stamens of the female flowers, pollinate the anthers of the male flowers on the stigma of the female parent, and perform artificial hybridization to obtain hybrid offspring; Single plant selection: selecting single plants with rice blast resistance, early maturity and high yield traits from the hybrid offspring, and continuously selecting single plants for multiple generations to obtain disease-resistant, early-maturing and high-yielding breeding varieties; Step 2: single plant selection of resistant varieties in disease nursery Preparation of seed plot: simulate natural infection conditions and set up seed plot; Pseudo hybrid removal: removing pseudo hybrids from F1 generation in the seed plot; Resistant variety selection: selecting single plants without disease and with excellent comprehensive traits from F2 generation in the seed plot, and performing self-reproduction, increasing the stress of rice blast and the amount of nitrogen fertilizer with each generation to screen out rice blast resistance varieties without disease and with excellent comprehensive traits as candidate varieties; Step 3: rice blast resistance identification by atomization inoculation The method for identifying the resistance of a candidate rice variety to rice sheath blight by using the atomizing inoculator according to any one of claims 1 to 3 comprises: diluting a thick-walled spore suspension of the rice sheath blight fungus with sterile water and pouring the diluted thick-walled spore suspension into the atomizing inoculator for atomization; the atomizing inoculator comprises an atomizing inoculation device and a protective cover, the protective cover is used for covering the rice and limiting the atomized water vapor sprayed by the atomizing inoculation device within the protective cover; wherein the method for identifying the resistance of the candidate rice variety to the rice sheath blight comprises: pathogen culture: culturing the thick-walled spore suspension of the rice sheath blight fungus, the spores in the thick-walled spore suspension are used for inoculation; atomizing inoculation: using the designed atomizing inoculator to uniformly spray the thick-walled spore suspension of the rice sheath blight fungus on the leaves of the candidate variety, simulating the natural infection process; post-inoculation treatment: after inoculation, the treatment of moisturizing and keeping warm is carried out to promote the infection of the pathogen, the leaves of the candidate variety are monitored, and the disease resistance is evaluated; Step 4: analyzing the quality traits to obtain a new rice variety with resistance to rice sheath blight and high quality The candidate variety without disease symptoms after atomizing inoculation is analyzed for quality traits, and the final new rice variety with resistance to rice sheath blight and high quality is determined through comprehensive evaluation.

5. The method of claim 4, wherein the new variety of rice resistant to rice blast is selected from the group consisting of the varieties of rice listed in Table 1. In the cross breeding of rice varieties with resistance to rice sheath blight, a single plant selection method is used to select parent rice varieties with resistance to rice sheath blight, comprising the following steps: A disease nursery is set up in a stable plot where the rice sheath blight occurs seriously every year, and rice plantings that have been infected by the rice sheath blight under natural conditions are planted in the disease nursery; In the second or third year of planting rice, a single plant selection method is used to select single plants with very light or no disease every year, and the seeds of the selected single plants are collected; The seeds of the selected single plants in each year are planted again in the next year, and the single plant selection method is continued to select single plants with very light or no disease from the selected single plants to obtain parent rice varieties with resistance to rice sheath blight.

6. The method of breeding a new variety of rice resistant to rice scab according to claim 5, wherein In the selection of resistant varieties, single plants without disease and with excellent comprehensive traits are selected in the F2 generation, the seeds are harvested, and self-reproduction is carried out for 6-7 generations, single plants are selected under the stress of rice sheath blight in each generation, and the amount of nitrogen fertilizer is gradually increased every 2 generations until a rice sheath blight resistant variety with stable and consistent phenotype, excellent comprehensive traits and no occurrence of rice sheath blight is obtained.

7. The method of claim 6, wherein the new variety of rice resistant to rice blast is selected from the group consisting of the varieties of rice listed in Table 1. The amount of nitrogen fertilizer is gradually increased every 2 generations, specifically: no nitrogen fertilizer is applied in F1 generation, 80 kg / hm of nitrogen is applied in F2 and F3 generations 2 , 160 kg / hm of nitrogen is applied in F4 and F5 generations 2 , and 240 kg / hm of nitrogen is applied in F6 generation 2 .

8. The method of claim 4, wherein the new variety of rice resistant to rice blast is selected from the group consisting of the varieties of rice listed in Table 1. In step S3, the resistance to rice sheath blight is identified by atomizing inoculation, and the steps of atomizing inoculation are as follows: Culturing the thick-walled spore suspension of the rice sheath blight fungus: 2g of rice sheath balls are cultured in 150ml of PBS medium for 2 days to obtain the thick-walled spore suspension of the rice sheath blight fungus, and the thick-walled spore suspension is placed in a spore storage box; Inoculating the rice sheath blight thick-walled spores with atomized water vapor to rice: when inoculating, the thick-walled spore suspension of the rice sheath blight fungus in the spore storage box is diluted with 2000ml of sterile water and poured into the spore storage box of the atomizing inoculator, and the atomized water vapor is sprayed through the atomizing nozzle to carry the air in the protective cover for atomization; Moisturizing by atomization until the end: in the heading stage of rice, atomizing inoculation is carried out after sunset, so that the rice sheath blight thick-walled spores are uniformly distributed in the air at the same horizontal plane in the protective cover with atomized water vapor, and the atomized water is continuously sprayed for moisturizing and keeping warm. The misting water is used to keep the moisture and temperature after inoculation, and the misting liquid only contains sterile water to promote the germination of spores and infection of rice.

9. The method for breeding a new variety of rice resistant to rice scab according to claim 4, wherein In step S3, the rice smut resistance identification is performed by misting inoculation. The misting inoculation is the freeze-dried powder of the rice smut chlamydospore, which is obtained after freeze-drying of the rice smut chlamydospore suspension. The water vapor is contacted with the freeze-dried powder during inoculation and is carried to inoculate on the rice. After inoculation, the sterile water is continuously misted at a rate of 0.2 ml / min, and the misting is performed every 30 min for 15 min to keep the moisture of the rice smut chlamydospore. The preparation method of the chlamydospore freeze-dried powder is as follows: 2 g of rice smut balls are first cultured in 150 ml of PBS medium, and then the chlamydospore suspension of the rice smut is freeze-dried.

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