TOMATO SPOTTED WILT VIRUS IN SRI LANKA: EMERGING PROBLEMS OF TOSPOVIRUSES

Tomato spotted wilt virus (TSWV), the type species of the genus Tospovirus has long been reported infecting economically important horticultural crops such as tomato, groundnut, pepper, potato and soybean, all over the world. In Sri Lanka, characteristic tospovirus symptoms such as bud necrosis, axillary shoot proliferation and ring spots were observed on leaves of groundnut in Angunakolapalassa, and concentric rings on leaves and fruits of tomato, in Ambalantota and Gannoruwa. Sap extracted from both tomato and groundnut plants was serologically positive for TSWV infection in a double antibody sandwich enzyme-linked immunosorbentassay (DASELISA), but not for Groundnut bud necrosis virus (GBNV). Nucleocapsid (N) genes of both isolates were amplified in Reverse Transcription Polymerase Chain Reactions (RT-PCR) using primers specific for TSWV and GBNV. The sequences obtained showed 98% amino acid sequence identity to the N gene of the Brazilian isolate of TSWV-BR-01. This study confirms the presence of TSWV infecting groundnut and tomato in Sri Lanka.