Molecular evidence for natural occurrence of Pepper veinal mottle virus (PVMV) on hot pepper (Capsicum Annuum L.) in Himachal Pradesh

An isolate of Pepper veinal mottle virus (PVMV) infecting hot pepper (Capsicum annuum L.) under natural conditions in Himachal Pradesh, India has been characterized and identified on the basis of symptomatology, transmission, host range, biophysical properties, serology and electron microscopy besides sequence analysis of partial CP gene. Mottling, mild mosaic along with stunted growth of plants were the characteristic symptoms exhibited by the infected plants. The causal virus was transmissible through sap and aphid (Myzus persicae) but not through seed and soil. Host range of the virus was restricted to a few hosts namely Datura metel, D. metel var. festuosa, D. stramonium, Nicotiana tabacum var. White Burley, N. debneyii and Physalis floridana belonging to Solanaceae and Chenopodium amaranticolor of Chenopodiaceae family. Virus isolate had a thermal inactivation point (TIP) of 65–70°C, dilution end point (DEP) of 10⁻⁴-10⁻⁵ and longevity in vitro (LIV) of 6 days under room temperatue (25±1°C) and 8 days under refrigeration (4°±1C). Serologically, present isolate was found closely related to PVMV in DAS-ELISA and ISEM studies. Virus particles were flexuous filamentous measuring 730 x 11 nm in dimension. The virus produced inclusion bodies such as scrolls, curved plates and pinwheels typical of potyviruses. PCR detection of the virus by applying a primer pair (P9502/CPUP) designed elsewhere for detection of potyviruses resulted in obtaining a desired amplicon of about 800 bp. Sequence analysis of partial coat protein gene showed 88% homology with PVMV sequences FJ617225 (Chinese isolate) and AB126177 (South Korean isolate) of the GenBank database of NCBI. Based on these findings, the virus under report was confirmed to be PVMV of genus Potyvirus, family Potyviridae. Genotype DKC-8 was found to be highly resistant to this isolate upon sap inoculation under glass house conditions.