| As one of the three major grains,wheat is an important source of human nutrition,and its high and stable yield is of great significance to national life,economic development and national food security.The pathogen mainly infects living wheat in the form of summer spores,which can be cyclically infected with air flow throughout the year,and occurs in all growth periods of wheat.In order to meet the increasing food demand caused by the global population growth,people value excellent yield traits,resulting in a decrease in the genetic diversity of wheat,resulting in the continuous outbreak of rust under selection pressure,which has a very negative impact on wheat yield and quality.In view of the threat of stripe rust to national food security,the prevention and control of this disease has gradually become one of the priorities of the wheat production.The promotion of the green revolution has eased the pressure on food demand to a certain extent,but the unreasonable use of pesticides and fertilizers has also increased production costs and aggravated farmland environmental pollution.With the implementation of the concept of sustainable development,the breeding of diseaseresistant materials has become the most cost-effective strategy for preventing wheat stripe rust.In addition,the co-evolution between the host and stripe rust has caused the disease-resistant varieties bred in the past to lose their resistance to the current popular races.Reasons such as the unreasonable use and distribution of disease-resistant genes and disease-resistant varieties,and the long breeding cycle are also accelerate the loss of wheat resistance,which has led to the severe situation of production reduction or even no harvest caused by the pandemic of stripe rust.Therefore,screening materials with good resistance to the current popular physiological races in our country,digging the disease resistance potential and applying them to the front line of wheat breeding are the keys to preventing wheat stripe rust and ensuring national food production security.With the development and maturity of molecular marker technology,the use of molecular markers to identify and screen specific loci or genes has become a routine method.Through specific molecular markers closely linked to disease resistance genes or loci,materials carrying target genes or loci can be quickly screened,while eliminating the influence of environment and experimental errors,and improving the efficiency and accuracy of breeding work.This study mainly used 188 wheat high-generation lines or varieties collected from12 regions in our country and participated in the regional test.The seedling stage identification test was carried out in the laboratory and incubator,and the following conclusions were drawn based on the detection results of 13 specific molecular markers of major disease resistance genes:1.The results of race identification at the seedling stage showed that among the candidate varieties,9(5%)were immune to physiological race CYR32,22(12%)were highly resistant,49(26%)were moderately resistant,and 49 were moderately resistant.42 samples(22%),66 samples(35%)with high sensitivity;5 samples(3%)showed immunity to physiological race CYR34,43 samples(23%)with high resistance,and 19samples(10%)with medium resistance.,70 samples(37%)of medium-sensitivity,50samples(27%)of high-sensitivity;32 samples(17%)showed resistance to both races at the same time,and 46 samples(24%)showed resistance to CYR32 only,only 35samples(19%)showed resistance to CYR34.2.The adult-plant stage test combined with the seedling stage identification results showed that 16(9%)materials showed stable adult-stage resistance under different environments and flora structures,and 18(10%)showed stable full-growth stage resistance materials,14(7%)materials were susceptible to disease under all experimental conditions and environments,and the rest of the materials showed different resistant phenotypes under different environments and bacterial structures.3.In the molecular marker detection of disease resistance genes of candidate varieties,9 samples carry Yrsp,33 samples carry Yr2,3 samples carry Yr5,4 samples carry Yr15,27 samples carry Yr7,60 samples carry Yr9,20 documents carry Yr10,22 samples carry Yr15,3 samples carry Yr18,1 samples carry Yr26,37 samples carry Yr29,103 samples carry Yr30,40 samples carry Yr78,and 2 samples carry Yr80.Based on the screening results and origin of the disease resistance genes of the tested materials,preliminary statistics on the distribution of disease resistance genes in each region and province were made;Yr7,Yr9,Yr29,and Yr30 were distributed in almost every region or province,and Yr7 Yr9 and Yr9 are two race-specific resistance genes.Although they have lost their resistance to the current popular races,they can still play a certain role through the use of disease resistance genes.However,if they exist independently in the form of single genes,the material needs to be cautious Use;Yr18 is one of the earliest non-race specialized genes located,and its distribution frequency is gradually decreasing.Currently,it is only distributed in Shandong and other places.The use of such disease resistance genes should be strengthened in the future to prevent the loss of resistance gene resources.Yr29 and Yr30 are two multi-resistance loci,which have certain resistance to a variety of common diseases in a specific period.Through the level of resistance provided by them and the aggregation of other resistance genes,they can provide lasting resistance to the distribution area.disease effect.A total of 27 test materials did not contain any detected genes,but some materials still showed different types of resistance in the inoculation test at the adult stage and seedling stage;51 test materials only carried a single detected gene;3 only carried Among the materials with the resistance gene Yr10 in the whole growth period,Wankenmai and Hengmai showed resistance to the physiological race strip Zhong34 in the seedling identification test,indicating that these two materials carry the resistance against the virulence spectrum of CYR34.1 material only carried Yr29;19 only carried Yr30;5 materials carrying Yr78 showed relatively stable disease resistance at the adult stage in various environments,which also reflected the gene’s effect on the current popular physiological races It can be used as a core gene for disease resistance breeding and diversified use to achieve the purpose of preventing and controlling wheat stripe rust.4.As far as the disease resistance genes used in this study are concerned,a total of110 materials in the form of polygene aggregation were detected,accounting for 58.5%of the total materials;a total of 54 samples were detected in the materials in the form of aggregation of two disease resistance genes;A total of 13 materials were found in the aggregated form of disease resistance genes;a total of 18 materials were detected in the aggregated form of 4 disease resistance genes;Yr9+Yr10+Yr29+Yr30+Yr78 5disease resistance genes aggregated materials at the seedling stage Susceptible to CYR34,but showed stable adult resistance in all environments.The material with Yr2+Yr7+Yr9+Yr29+Yr30 five disease resistance genes aggregated resistance to the inoculated race at the seedling stage,and showed stable resistance throughout the growth period in five environments.At the same time,it also showed that with the increase of the aggregation number and type of stripe rust resistance genes,the level of plant disease resistance also increased significantly,and there was a positive correlation between the two. |
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