Occurrence and distribution of viruses infecting groundnuts (Arachis hypogaea L) in Kenya

As well as providing food, animal feed and cash, groundnuts are important components of farming systems as they improve soil fertility. In Kenya, the current yields are well below potential and important constraints include the devastating impact of high levels of pests and diseases particularly viruses spread by insect vectors which cause approximately 80% of damage. About 31 viruses from 14 genera have been found infecting groundnuts naturally worldwide. Among these, Groundnut rosette assistor virus (GRAV), Groundnut rosette virus (GRV), satellite RNA associated with GRV and/or GRAV (rosette complex), Peanut mottle virus (PeMoV) and Cuncumber mosaic virus (CMV) are economically important in Sub-Saharan Africa. Recent diagnostic surveys in Kenya have not elucidated much about the viruses infecting the crop. Accordingly, this study identified virus diseases of groundnut in the main producing areas of Kenya. In October 2016 and May 2017, two diagnostic surveys were conducted in six major groundnut growing counties of Western Kenya. Leaf samples showing virus-like symptoms were collected and analysed either by serology and /or next generation sequencing (NGS). I n total, 103 groundnut farms were visited and 315 samples, collected. Of these, 261 were ELISA positive for one or more viruses tested. Fourteen viruses (CAB YV, CABMV, CMV, CPMMV, BYMV, GRSV, CCYV, BCMNV, BGMV, PeMoV, SPCFV, BCMV, CPMV and MCMV) were detected by ELISA while nine (GRAV, satellite RRA associated with GRV and/or GRAV, CPPV1, CPPV2, CpCSV, PBMYV, SPCFV, BCMNV and PeMoV) were detected by NGS. Most plants had mixed infections of more than one virus. The most common viruses detected by EL1SA were CABY V, PeMoV, CMV, CPMM V, BCMNV and BYMV. Of all the viruses detected in Kenyan groundnut fields only Cowpea aphid-borne mosaic virus (CABM V), CMV, PeMoV, and CPMMV are transmitted through groundnut seed. Therefore, fun her studies are needed to determine how In any more viruses are transmitted through this route.