New genes for resistance to Xanthomonas campestris pv. glycines in soybean[Glycine max (L.) Merr.] and their inheritance

Bacterial leaf pustule (BLP) caused by Xanthomonas campestris pv. glycines is an important disease of soybean. A new resistant source, P-4-2, showing an immune reaction in controlled conditions to BLP was crossed with the sus ceptible cultivar Monetta to study the inheritance of resistance. All F-1 p lants were susceptible. The F-2 population segregated 15 susceptible: 1 res istant plants indicating the presence of duplicate recessive genes controll ing resistance. This was further confirmed in the F-3 generation. Two reces sive genes conferring high levels of resistance in soybean to Xanthomonas c ampestris pv. glycines under controlled conditions are being reported here for the first time.