Current Status Of Rice Yellow Mottle Disease In Mottle Disease In Western Kenya

Abstract

Rice yields in Kenya remain very low due to several constraints with Rice Yellow Mottle Disease (RYMD) caused by Rice Yellow Mottle Virus (RYMV) being the greatest challenge. However, information on pattern of distribution and diversity still remain scanty and hence a hindrance in designing most suitable control measures. A research study was carried out determine the occurrence and distribution of RYMV in rice growing areas of Western Kenya. A survey was conducted in rice growing schemes and farms in five Counties in July 2015 and June 2016 and symptomatic and some asymptomatic leaf samples were collected. Visual RYMD incidence ranged between 2-100%. Serological detection of RYMV in the leaf samples was done by DAS-ELISA. Results showed that 54% and 96% of the 2015 and 2016 samples, respectively were RYMV positive. Selected ELISA positive samples were subjected to molecular analysis. Extraction of total RNA was done using GeneJET Plant RNA Purification Mini Kit. PCR was done using RYMV specific primers and a product of approximately 1000 bp obtained. The coat protein gene was sequenced and sequences (720 bp) were established which identified strain S4 of RYMV. This is useful in monitoring diversity of RYMV in Western Kenya and to assist plant breeders develop resistant rice varieties.