Dissection of the genetic architecture of rice resistance to the blast fungus Magnaporthe oryzae
H. KANG (1), Y. Wang (2), S. Peng (2), Y. Zhang (3), Y. Xiao (2), D. Wang (2), S. Qu (4), Z. Li (1), S. Yan (5), Z. Wang (2), W. Liu (1), Y. Ning (1), P. Korniliev (6), H. Leung (7), J. Mezey (6), S. McCouch (6), G. Wang (8) (1) Institute of Plant Protection, Chinese Academy of Agricultural Sciences, China; (2) Hunan Agricultural University, China; (3) nstitute of Plant Protection, Chinese Academy of Agricultural Sciences, China; (4) Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, China; (5) Tianjin Crop Research Institute, Tianjin Academy of Agriculture Sciences, China; (6) Department of Plant Breeding & Genetics, Cornell University, U.S.A.; (7) International Rice Research Institute, China; (8) Department of Plant Pathology, Ohio State University, Columbus, U.S.A.

Resistance in rice cultivars to the rice blast fungus Magnaporthe oryzae is complex and is controlled by both major genes and quantitative trait loci (QTL). We undertook a genome-wide association study (GWAS) using the rice diversity panel 1 (RDP1) that was genotyped using a high-density (700,000 SNPs) array and inoculated with five diverse M. oryzae isolates. We identified 97 loci associated with blast resistance (LABRs). Among them, 82 were new regions and 15 co-localized with known blast resistance loci. The top 72 LABRs explained up to 98% of the phenotypic variation. The candidate genes in the LABRs encode NBS-LRR resistance proteins, receptor-like protein kinases, transcription factors, and defense-related proteins. Among them, LABR_64 was strongly associated with resistance to all five isolates. We analyzed the function of candidate genes underlying LABR_64 using RNAi technology and identified two new resistance alleles at the Pi5 locus. We demonstrate an efficient strategy for rapid allele discovery by leveraging the power of GWAS, coupled with RNAi technology for dissecting complex blast resistance in rice.

Abstract Number: P13-411
Session Type: Poster