Abstract:

Soybean mosaic virus (SMV) is one of the most serious diseases to soybean yield and quality in Chi?na. In this study, the soybean resistant (R) cultivar Wandou 33 was crossed respectively with a susceptible (S) culti?var (Nannong 1138-2 or Williams 82) or a resistant cultivar (Kefeng 1, Dabaima or Qihuang 1) to determine the in?heritance of Wandou 33 and test the allelism of the resistance genes when inoculated with the SMV prevalent strain SC3. The results showed that all F1 plants were resistant to SC3, the F2 plants and F2:3 progenies derived from the crosses (Williams 82×Wandou 33 and Wandou 33×Nannong 1138-2) segregated in a 3∶1(R∶S) and 1∶2∶1 ratio re? spectively when inoculated with SC3. This suggested that the resistance of Wandou 33 was controlled by a dominant resistance gene (named as RSC3(w)). The test of the allelism (Kefeng 1, Qihuang 1 and Dabaima×Wandou 33) of the re? sistance genes to SC3 indicated that the resistance genes between Kefeng 1 and Wandou 33 were alleles at a com? mon locus or very closely linked. The resistance genes between Qihuang 1 and Wandou 33，between Dabaima and Wandou 33 were at different locus for SC3. The resistance gene RSC3(w) was located betweenBARCSOYSSR_02_0610 and ZL-52 SSR markers on chromosome 2 by using 392 F2 individuals of Wandou 33×Nannong 1138-2, with
a physical distance of about 175 kb. This study broadened the resources of SMV resistance genes and laid the foun? dation for resistance breeding.

Key words: soybean, soybean mosaic virus, inheritance of resistance, gene mapping