Division of Plant Pathology, Indian Institute of Horticultural Research, Hessaraghatta Lake PO, Bangalore-560089, India.
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 (Capsicum annuum) is an important spice and vegetable crop cultivated throughout India. In India, chilli is known to be infected by several viruses, among these leaf curl disease of chilli has emerged as a serious problem in the chilli growing tracts of Delhi, Haryana, Punjab, Rajasthan, West Bengal and Uttar Pradesh states. Surveys conducted in 2005 and 2006 showed very high disease incidence of leaf curl disease (40–95%) in farmers’ fields. The typical leaf curl affected plants showed symptoms of upward curling, puckering, crinkling and reduced leaf size, shortened internodes and stunted growth. Such plants produced either less number or no fruits. The selected leaf curl samples of chilli were collected in Delhi, Haryana, Rajasthan, West Bengal and Uttar Pradesh states were experimentally transmitted from infected to healthy chilli and tobacco seedlings by whitefly (Bemisia tabaci), where as by mechanical inoculation failed to transmit the virus. Inoculated chilli and tobacco plants showed typical symptoms of leaf curl similar to natural infection. To test the presence of begomovirus with the disease, PCR was performed using the total DNA isolated from naturally affected and whitefly transmitted chilli plants using two sets of begomovirus specific primers. Cloning and sequencing of DNA-A from different samples has indicated that chilli is affected by three different begomoviruses. Of the 12 isolates PCR amplified, one isolate from Kalyani of West Bengal was cloned, sequenced and compared with sequences available for other begomoviruses using clustal alignment method. The highest nucleotide identity was with Pepper leaf curl Bangladesh virus (96.3%). The three isolates from Rajasthan showed nucleotide identity of 88.9 to 91.1% identity with Chilli leaf curl virus –Multan and eight isolates two each from Dehli, Haryana, Punjab and Uttar Pradesh showed nucleotide identity of 92.4 to 98.5% with Tomato leaf curl New Delhi virus.
