WATERMELON BUD NECROSIS TOSPOVIRUS IS A DISTINCT VIRUS SPECIES BELONGING TO SEROGROUP-IV

The nucleocapsid protein gene of a tospovirus infecting watermelon in India was cloned and sequenced. Sequence analyses showed that the gene was most closely related to those of watermelon silver mottle tospovi rus (WSMV) from Taiwan and peanut bud necrosis tospovirus (PBNV) from India, the two definitive species of serogroup IV. Amino acid sequence similarity was 84% and 82% with WSMV and PBNV. respectively. On the b asis of the sequence divergence and the previously determined host ran ge differences, the watermelon tospovirus, designated as watermelon bu d necrosis tospovirus, should be considered as a distinct species belo nging to serogroup IV.