Identification of weed hosts of major legume viruses in Niger State, Southern Guinea Savanna of Nigeria.

Abstract

Field survey was conducted during the 2015 cropping season to identify and determine the distribution of legume viruses in Niger State Southern Guinea Savanna of Nigeria. A total of 27 locations were visited. Leaves were collected from weed plants showing virus and virus-like symptoms in fields of cowpeas, groundnuts and soybean. Samples were also collected from asymptomatic plants within the vicinity of infected plants. The antigen coated plate - enzyme linked immunosorbent assay (ACP –ELISA) method was employed for virus detection in the leaf samples. Blackeye cowpea mosaic virus (BICMV), Cowpea mild mottle virus (CPMMV) and Cowpea mottle virus (CPMoV). Aeschynomene indica, Amaranthus caudatum and Centrosema pubescen were positive to BICMV, Aspilia africana, Cleome viscera, Euphorbia hirta and Heterotis rotundifolliai were host of CPMoV while CPMMV was detected in Chenopodium amaranticolor, Desmodium scorpiurus, and Vicia faba. The detection of these viruses in weed species indicates their importance in the ecology, survival and the significant role they play in the epidemiology of the various virus diseases. The occurrence of BICMV, CPMoV and CPMMV in these weed species is believed to be the first report in the study area. Fields should be kept free of these weed species in order to control the spread of these viruses to avoid overwintering.