Screening of Withania somnifera L. Germplasm for Resistance against Leaf Spot Caused by Alternaria alternata (Fr.) Keissler

Ashwagandha (Withania somnifera L. Dunal), commonly called as ‘winter cherry. The roots, leaves and fruits of this medicinal plant possess tremendous medicinal value. In recent years the demand of Ashwagandha in the international market increases by many folds. Plant diseases are the major constraints in the production of Ashwagandha. In this study seven Ashwagandha genotypes were screened against Alternaria leaf spot under pot condition on the basis of disease severity and percent reduction in yield. Among seven genotypes RAS-10 Showed consistently resistant reaction. IC-310620(A) and IC-283942 were tolerant and moderately tolerant, while remaining genotypes were found to be susceptible to highly susceptible. During the estimation of reduction in chlorophyll and carotenoid content of the 7 genotypes, the reduction in chlorophyll content was maximum in genotype RAS-10 and minimum in IC-283942. The reduction in carotenoid content was maximum in genotype RAS-98 and minimum in RAS-7.