Wheat leaf rust resistance gene Lr13 is a specific Ne2 allele for hybrid necrosis

• 作者: Timothy Hewitt Jianping Zhang Li Huang Narayana Upadhyaya Jianbo Li Robert Park Sami Hoxha Robert Mclntosh Evans Lagudah Peng Zhang
• 来源期刊: 分子植物（英文版）
• 年，卷（期）: 2021,（7）
• 所属期刊栏目: Correspondences
• 页码范围: 1025-1028
• 页数: 4页
• 语种: 英文

摘要

Dear Editor, Wheat leaf rust,caused by Puccinia triticina (Pt),is a destructive fungal disease of wheat globally.Host resistance (R) genes are widely studied as a means to combat disease.Lr13 is regarded as one of the most widely distributed leaf rust R genes in wheat(Mclntosh et al.,1995).Researchers observed that lines carrying Lr13 consistently gave hybrid necrosis in specific crosses.Hybrid necrosis (henceforth,HN) in wheat,ascribed to NE loci (Hermsen,1963),is a genetic incompatibility disorder encountered in inter-and intra-specific hybrids caused by com-plementary alleles Ne1 on chromosome arm 5BL and Ne2 on chromosome arm 2BS (Nishikawa et al.,1974).A range of necrosis symptoms is caused by multiple alleles at both loci,varying from complete lethality of F1 hybrids (strong "s" alleles)to near-normal hybrids that segregate in F2 (weak "w" alleles).The allele in Lr13-possessing genotypes that is consistently associated with HN is described as Ne2m (medium) (Hermsen,1963).Recombination between Lr13 and Ne2m was never proven in genetic studies extending over more than 40 years,leading to the hypothesis that Lr13 and Ne2m are the same gene.The single exception was cv.Kalyansona,which does not express an Lr13-resistant phenotype but produces HN symptoms similar to those produced by genotypes carrying Lr13 (Zhang et al.,2016).This raised the possibility that Kalyansona had a rare recombination between Lr13 and Ne2 m or that it carried a different,albeit indistinguishable,NE2 allele.