Crop Journal (Apr 2024)

Mapping of powdery mildew resistance genes transferred to common wheat from wild emmer wheat revealed three functional Pm60 haplotypes

  • Wenxin Wei,
  • Nannan Liu,
  • Shengnan Zhang,
  • Jing Zhang,
  • Wei Pan,
  • Xiaoming Xie,
  • Zuhuan Yang,
  • Junna Sun,
  • Jun Ma,
  • Zhaorong Hu,
  • Weilong Guo,
  • Qiaoling Luo,
  • Jingzhong Xie,
  • Fei He,
  • Yinghui Li,
  • Chaojie Xie,
  • Qixin Sun

Journal volume & issue
Vol. 12, no. 2
pp. 540 – 548

Abstract

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Powdery mildew (PM), caused by Blumeria graminis f. sp. tritici (Bgt), is one of the destructive wheat diseases worldwide. Wild emmer wheat (Triticum turgidum ssp. dicoccoides, WEW), a tetraploid progenitor of common wheat, is a valuable genetic resource for wheat disease resistance breeding programs. We developed three hexaploid pre-breeding lines with PM resistance genes derived from three WEW accessions. These resistant pre-breeding lines were crossed with susceptible common wheat accessions. Segregations in the F2 populations were 3 resistant : 1 susceptible, suggesting a single dominant allele in each resistant parent. Mapping of the resistance gene in each line indicated a single locus on the long arm of chromosome 7A, at the approximate location of previously cloned Pm60 from T. urartu. Sanger sequencing revealed three different Pm60 haplotypes (Hap 3, Hap 5, and Hap 6). Co-segregating diagnostic markers were developed for identification and selection of each haplotype. The resistance function of each haplotype was verified by the virus-induced gene silencing (VIGS). Common wheat lines carrying each of these Pm60 haplotypes were resistant to most Bgt isolates and differences in the response arrays suggested allelic variation in response.

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