1Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110012, India.
2D.M.J.B. Senanayake, Field Crop Research and Development Institute, Maha Illuppallama, Sri Lanka.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
Chilli leaf curl disease has emerged as a serious constraint in cultivation of chilli in Jodhpure, which is the major chilli growing area in Rajasthan. The characteristic field symptoms were curling, rolling and smalling of leaves. Severely affected plants were stunted and unproductive. An isolate designated as Chilli Leaf curl virus –[Narwan] (ChiLCuV-[Nar]) was selected for biological and molecular characterization. The host range of ChiLCuV-[Nar] was restricted in Solanaceae (Nicotiana tabacum, N. benthamiana, Lycopersicon esculentum) and Caricaceae (Carica papaya). A single whitefly could transmit the disease and a group of 8 or more whiteflies per plant resulted 100% transmission. The minimum acquisition access period and inoculation access period required by whitefly to transmit the disease were 180 min and 60 min, respectively. The persistence of virus in whitefly was 5 days indicating a persistent mode of transmission. Molecular cloning and sequencing of total DNA A and DNA b were achieved. The DNA-A genome (2756 nucleotides) containing six open reading frames, was typical to Old world begomoviruses. The sequence comparison with 28 begomoviruses showed that ChilLCuV-[Nar] shared the greatest identity of 96.1% with ChiLCuV-[Multan] reported from Pakistan. The sequence of DNA b (1380 nt) was closely related with a DNA b isolated from tomato leaf curl from Rajasthan. The DNA probe developed over the intergenic region successfully detected the virus in 30% - 100% of the field samples. Although, several begomovirus species have been reported to be associated with chilli leaf curl disease, the present study for the first time demonstrated association of ChiLCuV with the chilli in India.
