Molecular cytogenetic characterization of two partial wheat Elytrigia elongata amphiploids resistant to powdery mildew

摘要

Two new partial amphiploids SN20 and SN122, derived from crosses between Elytrigia elongata and common wheat Yannong15 and Shannongfu63, were found resistant to powdery mildew, a serious fungal wheat disease. Cytogenetic observations showed that each SN20 and SN122 plant had 56 chromosomes. The chromosomes in most pollen mother cells formed approximately 28 bivalents, thereby showing a high degree of cytogenetic stability. Genomic in situ hybridization using St-genomic DNA from Pseudoroegneria strigosa as a probe and ABD-genomic DNA from Chinese Spring wheat as a blocker demonstrated that the genomic formulas for the alien chromosomes in SN20 and SN122 were 2 St+10 J(S)+2J and 2 St+8 J(S)+4J, respectively. These wheat E.elongata partial amphiploids represent a potential novel source of resistance to powdery mildew for wheat breeding.