Phenotypic classes of leaf curl virus disease severity for nursery screening in chilli pepper

Chilli leaf curl virus disease is an important disease caused by begomovirus transmitted by vector whitefly (Bemisia tabaci). The current experiment was carried out to develop a phenotypic scale to assess disease severity at the nursery stage by screening chilli genotypes using mass inoculation method by using viruliferous whiteflies. For this purpose a new disease rating scale was developed based on number of leaves infected/plant as it is not appropriate to grade plants having only 4–6 leaves, on the basis of per cent portion of plant infected. By using this scale out of 13 chilli lines screened, three lines viz., S-343, SL 475 and SL 476 were found resistant and five lines viz., JL 282, PE 415, SR 477, SL 468 and VR 521 showed a moderate resistant reaction. These three lines viz., S-343, SL 475 and SL 476 can be used for the development of disease resistant hybrids with better horticultural traits in future chilli breeding programmes. The new scale developed to assess disease severity at nursery stage was found quite efficient in classifying chilli genotype for disease reaction.