Molecular mapping of the hybrid necrosis gene NetJingY176 in Aegilops tauschii using microsatellite markers

The rich genetic variation preserved in collections of Aegilops tauschii can be readily exploited to improve common wheat using synthetic hexaploid wheat lines. However, hybrid necrosis, which is characterized by progressive death of leaves or plants, has been observed in certain interspecific crosses between tetraploid wheat and Ae. tauschii. The aim of this study was to construct a fine genetic map of a gene (temporarily named NetJingY176) conferring hybrid necrosis in Ae. tauschii accession Jing Y176. A triploid F1 population derived from distant hybridization between Ae. tauschii and tetraploid wheat was used to map the gene with microsatellite markers. The newly developed markers XsdauK539 and XsdauK561 co-segregated with NetJingY176 on chromosome arm 2DS. The tightly linked markers developed in this study were used to genotype 91 Ae. tauschii accessions. The marker genotype analysis suggested that 49.45% of the Ae. tauschii accessions carry NetJingY176. Interestingly, hybrid necrosis genotypes tended to appear more commonly in Ae. tauschii ssp. tauschii than in Ae. tauschii ssp. strangulata