Isolation and characterization of an attenuated strain of an Orthotospovirus, melon yellow spot virus

Abstract

An attenuated mutant strain of melon yellow spot virus (MYSV), an Orthotospovirus, designated as SA08-8, was obtained from a pathogenic isolate, C95S, via high temperature treatment, single local lesion isolation, and serial mechanical inoculation. Under greenhouse conditions, the SA08-8 strain conferred the cross-protection against wild-type MYSV but it was not transmissible by its known natural vector melon thrips. In SA08-8 genome, a total of 16 amino acid substitutions were found in the genes encoding RNA-dependent RNA polymerase, glycoprotein precursor, and nonstructural S protein. This attenuated mutant strain is a potential biocontrol agent for MYSV-induced crop diseases in the field.