Alien Chromosome-Specific PCR Markers for Selection of Powdery Mildew Resistance Introgressed from Haynaldia villosa in Wheat

In the introgression of the distinguished powdery mildew resistance from Haynaldia villosa to wheat, a focus task is to develop applicable molecular markers for tracing alien genetic substances and breeding selection. In an attempt to breed wheat breeding lines combining powdery Mildew resistance of wheat stock 010714 conferred by alien 6V chromosome from H. villosa with thermo-photo-sensitive genic male sterility (TGMS) from wheat line C050S, a molecular marker RM874 was identified in PCR amplification using RAPD primer S2018. Batched sequencing indicated that the band contained large amounts of equal-length homologues amplified from TY3-gypsy retro-transposon-like repetitive regions. Based on comparative cloning and bioinformatic analysis, it was converted into a more reproducible sequence characterized amplified region (SCAR) marker SM142. In wheat genetic background, the marker is 6V-specific and linked to powdery Mildew resistance. The linkage of the marker is further verified in F5 generation. The approach of transforming repetitive regions-derived RAPD band into a specific SCAR marker can be referred for SCAR marker development of other genes. GISH (Genome in situ hybridization) analysis of 010714 and F-7 translocation lines indicated that the resistance gene is conferred by the short arm of 6V.