Identification of new sources of resistance in Rajmash (Phaseolus vulgaris L.) against powdery mildew (Erysiphe polygoni) and stem rot (Sclerotinia sclerotiorum) diseases

Abstract

Rajmash (Phaseolus vulgaris L.) is one of the important legume crops of North and Central India. This crop is commonly affected by most devastating diseases like powdery mildew and stem rot. Therefore, identification of new resistance source is urgently needed to achieve potential yield. In present investigation fifty-two genotypes of rajmash comprising landraces, cultivars and exotic genotypes were screened against powdery mildew and stem rot diseases under natural field conditions during rabi 2014-15 and 2015-16. The results revealed that, out of 52 genotypes screened against powdery mildew disease, four genotypes/cultivars were free from powdery mildew disease, 16 were found resistant, 12 were moderately resistant, 4 were moderately susceptible, 10 were susceptible and 6 lines were highly susceptible. In case of Sclerotinia stem rot disease, out of 52 genotypes 20 genotypes exhibited resistance, 12 moderately resistance, 7 found susceptible and 5 genotypes were highly susceptible. Furthermore, only four genotypes viz., EC150250, BLF101, EC 565673A and GPR 203 demonstrated resistance reaction against both powdery mildew and stem rot disease. Thus, these genotypes could be used in breeding programme as donor for development of disease resistant varieties against powdery mildew and stem rot disease in future.