Genetic dissection of the powdery mildew resistance in wheat breeding line LS5082 using BSR-Seq

Powdery mildew of wheat is a destructive disease seriously threatening yield and quality worldwide. Comprehensive dissection of new resistance-related loci/genes is necessary to control this disease. LS5082 is a Chinese wheat breeding line with resistance to powdery mildew. Genetic analysis, using the populations of LS5082 and three susceptible parents (Shannong 29, Shimai 22 and Huixianhong), indicated that a single dominant gene, tentatively designated PmLS5082, conferred seedling resistance to different Blumeria graminis f. sp. tritici (Bgt) isolates. Bulked segregant RNA-Seq was carried out to map PmLS5082 and to profile differentially expressed genes associated with PmLS5082. PmLS5082 was mapped to a 0.7 cM genetic interval on chromosome arm 2BL, which was aligned to a 0.7 Mb physical interval of 710.3-711.0 Mb. PmLS5082 differs from the known powdery mildew (Pm) resistance genes on chromosome arm 2BL based on their origin, chromosome positions and/or resistance spectrum, sug-gesting PmLS5082 is most likely a new Pm gene/allele. Through clusters of orthologous groups and kyoto encyclopedia of genes and genomes analyses, differentially expressed genes (DEGs) associated with PmLS5082 were profiled. Six DEGs in the PmLS5082 interval were confirmed to be associated with PmLS5082 via qPCR analysis, using an additional set of wheat samples and time-course analysis post -inoculation with Bgt isolate E09. Ten closely linked markers, including two kompetitive allele-specific PCR markers, were confirmed to be suitable for marker-assisted selection of PmLS5082 in different genetic backgrounds, thus can be used to detect PmLS5082 and pyramid it with other genes in breeding programs.(c) 2022 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study identified a new resistance gene PmLS5082 against powdery mildew in wheat through genetic analysis and RNA-Seq technology. By mapping and validating associated genes, important information for marker-assisted selection was provided.