Mapping powdery mildew resistance gene in V 97‐3000 soybean

V97‐3000 is a maturity group ( MG ) V soybean breeding line derived from SS 516 × V90‐2592 (Vance × V81‐1325) with high stachyose, small seed and powdery mildew resistance. A total of 53 F 2:3 families were derived from a cross between V97‐3000 and a powdery mildew susceptible line V99‐5089. The 53 F 2:3 families, each with 30 plants, were grown in the greenhouse for powdery mildew evaluation, and the corresponding 53 F 2 plants were genotyped using simple sequence repeat ( SSR ) markers. Results showed that the 53 F 2:3 families segregated in ratio of one resistant : two segregating : one susceptible (13 : 26 : 14) and the 26 segregating F 2:3 families each exhibited a good fit to three resistant : one susceptible, indicating that resistance to powdery mildew is conditioned by a single dominant gene. The gene for powdery mildew resistance in V97‐3000 was mapped on chromosome 16 [linkage group ( LG ) J] flanked by Satt547 and Sat_396 on one side and Sat_393 on the other side with 3.8 cM and 3.9 cM distance, respectively. This study provides a new source of powdery mildew resistance and information of genetic location of the resistance gene and linked markers, which is useful for breeders selecting powdery mildew resistance through marker‐assisted selection ( MAS ) in soybean breeding programmes.