Characterization of the powdery mildew resistance locus in wheat breeding line Jimai 809 and its breeding application.

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Powdery mildew, caused by f. sp. (), is a severe disease that affects the yield and quality of wheat. Popularization of resistant cultivars in production is the preferred strategy to control this disease. In the present study, the Chinese wheat breeding line Jimai 809 showed excellent agronomic performance and high resistance to powdery mildew at the whole growth stage. To dissect the genetic basis for this resistance, Jimai 809 was crossed with the susceptible wheat cultivar Junda 159 to produce segregation populations. Genetic analysis showed that a single dominant gene, temporarily designated , conferred the resistance to different isolates. was then mapped on the chromosome arm 2BL and flanked by the markers and with genetic distances 0.4 and 0.8 cM, respectively, corresponding to a physical interval of 704.12-708.24 Mb. differed from the reported genes on chromosome arm 2BL in origin, resistance spectrum, physical position and/or genetic diversity of the mapping interval, also suggesting was located on a complex interval with multiple resistance genes. To analyze and screen the candidate gene(s) of , six genes related to disease resistance in the candidate interval were evaluated their expression patterns using an additional set of wheat samples and time-course analysis post-inoculation of the isolate E09. As a result, four genes were speculated as the key candidate or regulatory genes. Considering its comprehensive agronomic traits and resistance findings, was expected to be a valuable gene resource in wheat disease resistance breeding. To efficiently transfer into different genetic backgrounds, 13 of 19 closely linked markers were confirmed to be suitable for marker-assisted selection. Using these markers, a series of wheat breeding lines with harmonious disease resistance and agronomic performance were selected from the crosses of Jimai 809 and several susceptible cultivars.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11032-024-01467-8.