title: Mapping and validation of QTLs for rice sheath blight resistance.
abstract: Sheath blight, caused by Rhizoctonia solani, is one of the most serious diseases of rice. Among 33 rice accessions, mainly from National Institute of Agrobiological Sciences (NIAS) Core Collection, we found three landraces from the Himalayas-Jarjan, Nepal 555 and Nepal 8-with resistance to sheath blight in 3 years' field testing. Backcrossed inbred lines (BILs) derived from a cross between Jarjan and the leading Japanese cultivar Koshihikari were used in QTL analyses. Since later-heading lines show fewer lesions, we used only earlier-heading BILs to avoid association with heading date. We detected eight QTLs; the Jarjan allele of three of these increased resistance. Only one QTL, on chromosome 9 (between markers Nag08KK18184 and Nag08KK18871), was detected in all 3 years. Chromosome segment substitution lines (CSSLs) carrying it showed resistance in field tests. Thirty F2 lines derived from a cross between Koshihikari and one CSSL supported the QTL.
authors.affiliation: National Institute of Agrobiological Sciences , 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602 , Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Taguchi-Shiobara
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Ozaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sato
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Maeda
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Kojima
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ebitani
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yano
keywords: CSSL; Oryza sativa L.; QTL; Rhizoctonia solani; chromosomal segment substitution line; rice sheath blight resistance