ARS | Publication request: Confirming QTLs and finding additional Loci responsible for resistance to Sheath Blight in Rice

Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 15, 2010
Publication Date: February 22, 2010
Citation: Lui, G., Jia, Y., Mcclung, A.M., Oard, Correll, J.C. 2010. Confirming QTLs and finding additional Loci responsible for resistance to Sheath Blight in Rice. In: Proceedings of the 33rd Rice Technical Working Group Meeting, Feb. 22-24, 2010, Biloxi, MS. CDROM

Technical Abstract: Rice sheath blight (ShB) caused by the soil borne pathogen Rhizoctonia solani, is one of the most destructive diseases of rice around the globe, causing severe losses in rice yield and quality annually. Major genes governing resistance to ShB have not been found in cultivated rice worldwide; however, quantitative trait loci (QTLs) for resistance have been identified using field evaluations and greenhouse assays. This study was conducted to verify previously identified ShB-QTLs under greenhouse conditions using microchamber and mist-chamber methods, and to determine additional loci conditioning ShB resistance. Field evaluations of recombinant inbred lines derived from Lemont/Jasmine 85 were conducted in replicated inoculated trials conducted in Arkansas, Texas and Louisiana during 2008-2009. The results from all locations verified the presence of the major QTL qShB9-2 on chromosome 9 with LOD value of 2.6-6.5. The results from Arkansas and Texas verified QTL regions on chromosomes 2 and 3 with the LOD value of 3.3-4.1 and 3.3-3.7, respectively. An additional locus responsible for ShB resistance on chromosome 7 (LOD = 4.0-6.0) was identified between markers RM125 and RM214. These confirmed ShB-QTLs will be useful in marker-assisted breeding programs to improve ShB resistance.