Molecular mapping of the blast resistance gene Pi49 in the durably resistant rice cultivar Mowanggu Pingyong Sun • Jinling Liu • Yue Wang • Nan Jiang • Suhua Wang • Yangshuo Dai • Jia Gao • Zhiqiang Li • Sujun Pan • Dan Wang • Wei Li • Xionglun Liu • Yinghui Xiao • Erming Liu • Guo-Liang Wang • Liangying Dai Received: 20 June 2012 / Accepted: 1 November 2012 Ó Springer Science+Business Media Dordrecht 2012 Abstract Rice blast, caused by the fungus Magna- porthe oryzae, is the most devastating fungal disease of rice. Mowanggu, a local japonica cultivar in Yunnan Province, China, confers broad-spectrum resistance to this pathogen. To identify the resistance gene(s) in Mowanggu, we obtained an F 2 population and 280 F 8 recombinant inbred lines (RILs) from a cross between Mowanggu and CO39, a highly susceptible indica cultivar. A linkage map with 145 simple sequence repeat (SSR) and single feature polymorphism markers over 12 chromosomes was constructed using the 280 RILs. The resistance evaluation of the F 2 and F 8 populations in both the growth chamber and in a natural rice blast nursery showed that a single dominant gene controls blast resistance in Mowanggu. Moreover, nine quantitative trait loci, which were responsible for different partial resistance components, were mapped on chromosomes 2, 3, 6, 8, 9, and 12, making contributions to the phenotypic variation ranging from 3.03 to 6.18 %. The dominant resistance gene, desig- nated Pi49, was mapped on chromosome 11 with genetic distance of 1.01 and 1.89 cM from SSR markers K10 and K134, respectively. The physical distance between K10 and K134 is about 181 kb in the Nipponbare genome. The Pi49 gene accounted for the major phenotypic variation of disease severity in the growth chamber (where plants were inoculated with single blast isolates) and also accounted for most of the phenotypic variance of disease severity, lesion number, diseased leaf area, and lesion size in the blast nursery. Our study not only identified tightly linked markers for introgression of Pi49 into elite rice cultivars via marker-aided selection but also provides a starting point for map-based cloning of the new resistance gene. Keywords Oryza sativa Á Magnaporthe oryzae Á Resistance gene Á Quantitative trait locus (QTL) P. Sun Á J. Liu Á Y. Wang Á N. Jiang Á S. Wang Á Y. Dai Á J. Gao Á Z. Li Á S. Pan Á D. Wang Á W. Li Á X. Liu Á Y. Xiao Á E. Liu Á G.-L. Wang (&) Á L. Dai (&) Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha 410128, Hunan, China e-mail: wang.620@osu.edu L. Dai e-mail: liangying_99@yahoo.com P. Sun Á L. Dai Hunan Provincial Key Laboratory of Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Changsha 410128, Hunan, China P. Sun State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, Hunan, China G.-L. Wang Department of Plant Pathology, Ohio State University, Columbus, OH 43210, USA 123 Euphytica DOI 10.1007/s10681-012-0829-3