title: Mapping quantitative trait loci for sheath blight disease resistance in Yangdao 4 rice.
abstract: Rice sheath blight (ShB), which is caused by Rhizoctonia solani, has become the most serious rice disease in China. Yangdao 4, a cultivar with partial resistance to ShB, was crossed with Lemont, a susceptible cultivar, to develop mapping populations that were used to analyze quantitative trait loci (QTL) that confer resistance to ShB. QTL analysis were performed in 3 environments (E1-E3) using 2 F2 and 1 F2:3 populations, respectively. Three traits were recorded to evaluate ShB resistance, including disease rating (DR), lesion height (LH), and percentage of lesion height (PLH). Based on field evaluation of ShB resistance and the 2 genetic maps constructed, we identified a total of 8 QTLs for DR (4 in E1, 4 in E2, and 3 in E3), 6 QTLs for LH (1 in E1, 3 in E2, and 2 in E3), and 7 QTLs for PLH (1 in E1, 4 in E2, and 2 in E3). Sixteen of the ShB-QTLs co-localized as 6 clusters on chromosomes 3, 7, 11, and 12. Four of the 6 clusters contained ShB-QTLs that were detected in 2 environments, while the other 2 clusters with ShB-QTLs were detected in 1 environment. Three ShB-QTLs (qSBD-3-2, qSBL-3-1, and qSBPL-3-1) were delimited to a 581-kb region flanked by markers D333B and D334 on chromosome 3. The resistance alleles of Yangdao 4 at the qSBD-3-2 locus decreased DR by 0.68 and 0.79 in E2 and E3, respectively.
authors: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.
authors: Z H
authors: ZH
authors: Wen
authors: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.
authors: Y X
authors: YX
authors: Zeng
authors: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.
authors: Z J
authors: ZJ
authors: Ji
authors: State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China yangchangdeng@126.com.
authors: C D
authors: CD
authors: Yang
mesh_terms: D000483:Alleles; D002681:China; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D012275:Oryza / Q000235:genetics* / Q000382:microbiology; D010641:Phenotype; D058974:Phylogeography; D010935:Plant Diseases / Q000382:microbiology; D040641:Quantitative Trait Loci; D012232:Rhizoctonia / Q000302:isolation & purification
chemical_list: D005819:Genetic Markers