Quantitative Trait Loci for Resistance to Banded Leaf and Sheath Blight in Maize

ABSTRACT Banded leaf and sheath blight (BLSB) caused by Rhizoctonia solani Kühn in maize (Zea mays L.) is an important disease in China as well as South and Southeast Asia. The identification of quantitative trait loci (QTL) for resistance to this disease would facilitate the development of disease resistant maize hybrids. A mapping population consisting of 229 F2 individuals derived from the cross of inbreds R15 (resistant) and 478 (susceptible) was used in this study. A genetic linkage map was constructed containing 146 single sequence repeat (SSR) markers, which covered 1666 cM of the maize genome, with an average distance of 11.4 cM. All F2:4 population individual plants were artificially inoculated by anastomosis groups AG1‐IA of R. solani at two locations for disease evaluations. Composite interval mapping (CIM) identified 11 QTL for resistance to BLSB located on chromosomes 1, 2, 3, 4, 5, 6, and 10, but only four QTL located on chromosomes 2, 6, and 10, were identified across both locations. The range of phenotypic variation explained by the QTL was 3.72 to 10.35%. The information gained from mapping resistance can be used in a marker‐assisted selection (MAS) program for the development of BLSB resistant germplasm.