玉米DH群体及抗南方锈病的BSR-seq定位分析

Southern corn rust has gradually become one of the main diseases that seriously endanger China\'s corn production, causing serious yield and economic losses to China\'s corn producing areas, and its efficient prevention and control is an urgent problem to be solved. In this study, the disease phenotypes of maize inbred lines R99 and Nongxi 110 were observed at the seedling and adult stages before and after inoculation, and it was found that R99 was resistant to southern rust (TI 3), while Nongxi 110 was highly susceptible (TI 9). They were crossed as susceptible parents, combined with F1 as the basic material, and then 210 DH population families were obtained by CAU5 (C5) induction method. Furthermore, BSR-seq was used to locate the genes of southern rust resistance in maize, and the high-density genetic linkage map was constructed, and the main results of the study were as follows: (1) The structure of the disease-resistant parent R99 and the susceptible parent Nongxi 110 were observed after being infected by pathogenic bacteria by reactive oxygen species (ROS), WGA-PI staining and saffron-solid green staining technology. The results showed that the accumulation of reactive oxygen species in R99 was significantly higher than that of the susceptible parent 110 after 24 h of inoculation. After 7 days of inoculation, the symptoms of spores appeared on the surface of the leaves of Nongxi 110, while there were no obvious spores produced in the leaves of R99. These results showed that R99 was more resistant to southern maize rust than Nongxi 110. (2) A total of 210 DH populations were constructed using R99 and Nongxi 110, and the resistance identification at the adult plant stage was carried out combined with the phenotypic identification in the field at 2 years. According to the phenotype, 30 homozygous resistant families and 30 susceptible families were selected to construct a mixed susceptibility pool. Through in-depth analysis by BSR-seq technology, the following conclusions were reached: 88.57% of the variants were mapped to the maize reference genome, and 1061 and 556 trait-related variants were found to be located on the Chr1 and Chr7 chromosomes, respectively, and it was thought that there were candidate variant loci that might be related to this trait.