Identification of Resistant Germplasm to Rice Blast under Silicon Amendment in Uganda

Abstract

Rice blast caused by Magnaporthe grisea is one of the most serious diseases of rice, causing yield losses of 50 -100% in susceptible varieties worldwide. Durable host resistance has been hard to achieve given large pathogen diversity and capacity of pathogen to mutate. It has been suggested that silicon enhances durable resistance in partially resistant genotypes. A study was conducted to evaluate rice genotypes for their reaction to M. grisea under silicon amendments and to detect genotypes with high silicon uptake. Sixty-seven genotypes were evaluated for their reaction to Magnaporthe grisea under silicon amendments in a CRD in three replications in a screen house. Seeds were planted in soil amended with silica gel at the rate of 0, 29, and 58 g per 180 g of soil.Genotypes were inoculated with a virulent strain of Magnaporthe grisea (Namulonge isolate) 21 days after planting. Seven plants were inoculated per genotype. Data were taken on lesion size induced by blast one week after inoculation and, interpreted from 9 to 0. Data were also taken on leaf blast severity and used to compute area under disease progress curve (AUDPC). Twenty-four Case Study