Identification of Quantitative Trait Loci (QTLs) for sheath blight resistance in cultivated rice, Oryza sativa L.

Abstract

One of the two major rice diseases is sheath blight, which is caused by the fungus Rhizoctonia solani. To date, only partial resistance to rice sheath blight has been identified. In this experiment, 58 Recombinant Inbred Lines from the BC2F6 progenies of 'IR64' x 'Binam' were studied for polymorphism using 176 Simple Sequence Repeats (SSR) Markers. Five Quantitative Trait Loci (QTLs) for sheath blight were identified, three of which are located on chromosome 2; these are QTL1 which was linked to RM324, QTL2 and QTL3 which were both linked to RM262. The two other QTLs, which are QTL4 and QTL5, were located on chromosomes 9 and 11, respectively. The QTL4 was linked to RM242 while QTL5 was linked to RM209. Identification of Quantitative Trait Loci (QTL) for sheath blight resistance can be used to identify major genes conferring to sheath blight resistance fbr production of rice varieties with nearly complete or complete resistance.