Inheritance and Gene Mapping of Resistance to Powdery Mildew in Soybean.

Inheritance and Gene Mapping of Resistance to Powdery Mildew in Soybean Yueqiang Wang1,2, Pengyin Chen1©~, and Bo Zhang1 1 Dept. of Crop, Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701. 2 Jilin Academy of Agricultural Science, Soybean Research Center. Changchun, China 130124 ABSTRACT Powdery mildew is an important fugal disease in soybean. Research information on inheritance of resistance and molecular mapping is very limited. The objectives of this study were to investigate the mode of inheritance of powdery mildew resistance in a soybean breeding line V97-3000 and to tag the resistance gene with simple sequence repeats (SSR) markers. A total of 53 F2:3 lines were derived from a cross between V97-3000 and a powdery mildew susceptible line V99-5089. The 53 F2:3 lines each with 30 plants were grown in the greenhouse for powdery mildew rating. A total of 750 SSR markers were screened in the parents, and 135 polymorphic markers were screened in the F2:3 lines. Results showed that 53 F2:3 lines segregated in ratio of 1 resistant: 2 segregating: 1 susceptible (13:26:14) and that 26 segregating lines exhibited a good fit to 3 resistant: 1 susceptible, indicating that resistance to powdery mildew is conditioned by a single dominant gene. Molecular data showed that this gene is linked to Satt 547 on molecular linkage group J at 67.79 cM. This gene and the linked marker will be useful to breeders in breeding for cultivars with powdery mildew resistance. Key words: Glycine max, Powdery mildew, Resistance, Inheritance, Molecular markers.