1Mahyco Research Center, Jalna-Aurangabad Road, Dawalwadi, Jalna 431203, Maharashtra.
2Department of virology, Sri Venkateswara University, Tirupati-517502, Andhra Pradesh.
Tospoviruses is an emerging group of viruses causing devastating diseases in crops worldwide. Groundnut bud necrosis virus (GBNV), Watermelon bud necrosis virus (WBNV), peanut yellow spot virus (PYSV) and Iris yellow spot virus are four distinct tospoviruses reported from India. Surveys revealed that diseases caused by topsoviruses were widely prevalent in tomato, peanut, chilli, brinjal, soybean and watermelon. Characteristic symptoms produced are chlorotic or necrotic rings on leaves and wilting of plants. Spotted wilt in tomato was endemic in Nasik and Pune regions of Maharashtra and Coimbatore and Hosur regions of Tamil Nadu. Host range studies revealed that the tomato virus isolate infected 30 out of 33 plant species belonging to six families. The watermelon bud necrosis isolate infected ten out of sixteen plant species. In a molecular study, NP gene sequences from 47 tospovirus isolates collected from nine different crops shared 94 to 99% homology at nucleotide level with the reference GBNV peanut isolate. Watermelon bud necrosis and peanut yellow spot isolates shared 93.5% and 96.8% nucleotide homology with the reference WBNV and PYSV NP gene sequences respectively. The GBNV-N protein was over expressed, purified and produced recombinant polyclonal antibodies. Developed an ELISA based diagnostics for the detection of virus. In a conventional resistance evaluation, observed varied levels of virus tolerance among tomato genotypes. In a second approach, the NP gene construct was transformed into tomato using Agrobacterium mediated trasnfromation. Twenty five independent T0 transgenic events were generated and characterization of T1 progenies are under progress.
