Increase of tospoviral diversity in Brazil with the identification of two new tospovirus species, one from chrysanthemum and one from zucchini

During a survey conducted in several different regions of Brazil, two uniqu e tospoviruses were isolated and characterized, one from chrysanthemum and the other from zucchini. The chrysanthemum virus displayed a broad host ran ge, whereas the virus from zucchini was restricted mainly to the family Cuc urbitaceae. Double-antibody sandwich-enzyme-linked immunosorbent assay and western immunoblot analyses demonstrated that both viruses were serological ly distinct from all reported tospovirus species including the recently pro posed peanut yellow spot virus and iris yellow spot virus (IYSV) species. T he nucleotide sequences of the nucleocapsid (N) genes of both viruses conta in 780 nucleotides encoding for deduced proteins of 260 amino acids. The N proteins of these two viruses displayed amino acid sequence similarities wi th the previously described tospovirus species ranging from 20 to 75%, but they were more closely related to each other (80%). Based on the biological and molecular features, these viruses are proposed as two new tospovirus s pecies, designated chrysanthemum stem necrosis virus (CSNV) and zucchini le thal chlorosis virus (ZLCV). With the identification of CSNV and ZLCV in ad dition to tomato spotted wilt virus, groundnut ring spot virus, tomato chlo rotic spot virus, and IYSV, Brazil harbors the broadest spectrum of tospovi rus species reported.