Prevalence of begomoviruses associated with tomato leaf curl disease in the sub-Himalayan plains of West Bengal

Abstract

Tomato is a solanaceous crop and one of the most economically important vegetables in the world. India ranks second in total production of tomato in the world. It has been referred to as a “functional food”, a food that goes beyond providing just basic nutrient. To LCD is one of the major constraints to tomato production in India. To study the disease incidence of tomato, a survey was made in the tomato crop growing fields of Darjeeling, Jalpaiguri, Coochbehar and Uttar Dinajpur districts of sub-Himalayan West Bengal during December 2015 to February 2016 and several infected and healthy leaf samples were collected based on the morphological symptoms like-vein cleaning, leaf curling, leaf deformations and stunted growth of plants. Disease incidence ranged from 70% to 86.66% of the collected samples from different districts. All the samples collected from the present study area were tested by PCR with DengA and DengB primer and expected amplicon of ̴ 530bp was found. Two randomly selected PCR positive samples were sequence and analyzed (Acc. Nos KX108859 and KX108860). The SLG-1 isolate (Acc. No. KX108859) showed 95 % nt identity with ToLCKV (Acc. No. KP178730) and the ISL-1 isolate (Acc. No. KX108860) showed 96% nt identity with ToLCNDV (Acc. No. KC513822). The threat of begomoviral spread to the north-eastern part of India has been taken into consideration.