Resistance Spectrum Analysis And Breeding Application Of Resistance Gene HvPDIL5-1 For Barley Yellow Mosaic Disease

Barley,one of the most important cereal crops in the world,was mainly used as livestock feed,brewing-use raw material and grain ration.Barley yellow mosaic disease,known as a soil-borne virus disease,was characterized by wide range of disease attack,rapid transmission speed and high infection rate.Barley yellow mosaic disease has caused serious damage to barley production in China.Therefore,it was necessary to tap resistance resources and use resistance genes to prevent and control the threat of barley yellow mosaic disease.In this study,HvPDIL5-1 gene loss-of-function mutant(10253-1-5)obtained by EMS mutagenesis,sister line(10253-1-6)and original parent material(Barke)were used as the study subjects to explore the resistance difference and breeding utilization potential of HvPDIL5-1gene loss-of-function mutant to different virus strains in China.The preliminary results were as follows:1.Identification of disease resistance of tested materials in the disease nursery showed that all the tested materials were infected by Ba YMV in the disease nursery,the mutant 10252-1-5 was moderately resistant to the virus strains in the disease nursery,and the parent Barke and 10253-1-6 were highly susceptible to the virus strains in the disease nursery.Secondly,7 virus strains were collected from 5epidemic areas of barley yellow mosaic disease,the tested materials were performed with mechanical inoculation with the 7 virus strains.Resistance and susceptibility of HvPDIL5-1 gene to different virus strains were detected with the combination of phenotype observation and molecular identification(M-RT-PCR).The results showed that HvPDIL5-1 gene was resistant to 1 Ba YMV strain(Dazhong)and 3 Ba MMV strains(Yancheng,Yangzhou,Linhai),but was susceptible to the other 3 Ba YMV strains(Yancheng,Yangzhou,Xinyang).The above-mentioned results suggested that HvPDIL5-1 gene was immune to Chinese Ba MMV strains,but had race-specific resistance to Chinese Ba YMV strains.It was speculated that the introduction of HvPDIL5-1 gene into cultivated varieties would make the disease resistance changed from high susceptibility to moderate resistance.2.Through the investigation of the main agronomic trains of the tested materials in five environments for two years,and the results showed that there were significant differences in plant traits among the tested materials in the disease nursery,where in the 5 agronomic traits,including plant height,spike length,the length of internode,the number of grains per spike and the thousand-grain weight,of mutant 10253-1-5were significantly higher than those of parent Barke and 10253-1-6.In addition,the analysis of variance(ANOVA)regarding the main agronomic traits under different environments found that there were extremely significant differences in the plant height,the spike length,the length of internode,the number of grains per spike and the thousand-grain weight between different genotypes in the disease nursery;and extremely significant differences were observed with respect to grain traits,including grain length,grain width,grain area and grain circumference,between different environments in the disease nursery.Similarly,there were extremely significant differences in the plant traits(plant height,spike length,the number of grains per spike and the length of internode)and the grain traits(grain length,grain width,grain area and grain circumference)between different environments in the non-disease nursery.3.In the mutant 10253-1-5,there was a G-A nucleotide mutation(G183A)of the coding sequence of HvPDIL5-1 gene.By using the mutation site,a KASP functional molecular marker was developed to be used to accurately detect the 10253-1-5 and select resistance variation of the mutation site of HvPDIL5-1.