First Report of Peanut Stripe Virus Infecting Groundnut (<i>Arachis hypogaea</i> L.) in Western Kenya

Abstract

Peanut (Arachis hypogaea) is a leguminous food crop in Kenya, whose yields are probably affected by Peanut stripe virus (PStV) belonging to the genus Potyvirus and family Potyviridae, that causes Peanut stripe disease (PSD), also referred to as groundnut stripe disease (GSD). PSD/GSD is rapidly spread through seed and mechanically transmitted in a nonpersistent manner by aphid vectors causing 30-100% decrease in production. Different isolates of PStV induce different symptoms in groundnut ranging from striping, ring spots, vein banding and oakleaf mosaic. PStV occurrence in Kenya has neither been reported nor its resistance identified in commercial cultivars of groundnut in research stations. This informs the need for resistance breeding programmes of wild genotypes to be explored as the only practical solution. This study reports the first occurrence, distribution and molecular detection of PStV infecting groundnut in western Kenya, which is crucial in developing appropriate crop protection and plant health management strategies for this new disease. A survey of PSD was conducted in western Kenya among the four counties of Bungoma, Busia, Kisumu and Kisii during the short rains season of 2019. A total of 14 symptomatic leaf samples were selected from the collected samples and preserved until use. Total RNA was extracted from the symptomatic leaf samples using GeneJET Plant RNA Purification Mini Kit according to the manufacturers' protocol. Two-step RT-PCR detection of PStV was done using specific primers that yielded the expected 454 bp. DNA libraries were prepared and sequenced using the Sanger sequencing platform, but produced poor quality sequences after performing sequence quality check using BioEdit workbench that based on the low quality peaks of the electropherograms generated, therefore recommend for further research. To our knowledge, this is the first report of the occurrence, distribution and molecular diagnostics of PStV in Kenya. Further studies are needed to assess the molecular and biological diversity of PStV strains, the spatial distribution and the incidence of this emerging groundnut disease in Kenya.