title: Fine mapping ofRBG2, a quantitative trait locus for resistance toBurkholderia glumae, on rice chromosome 1.
abstract: Bacterial grain rot (BGR), caused by the bacterial pathogenBurkholderia glumae, is a destructive disease of rice. At anthesis, rice panicles are attacked by the pathogen, and the infection causes unfilled or aborted grains, reducing grain yield and quality. Thus, increasing the level of BGR resistance is an important objective for rice breeding. A quantitative trait locus (QTL) on rice chromosome 1 that controls BGR resistance was previously detected in backcross inbred lines (BILs) derived from a cross between Kele, a resistant traditional lowland cultivar (indica) that originated in India, and Hitomebore, a susceptible modern lowland cultivar (temperate japonica) from Japan. Further genetic analyses using a BC3F6population derived from a cross between a resistant BIL (BC2F5) and Hitomebore confirmed that a QTL for BGR resistance was located on the long arm of chromosome 1. To define more precisely the chromosomal region underlying this QTL, we identified nine BC2F6plants in which recombination occurred near the QTL. Substitution mapping using homozygous recombinant and nonrecombinant plants demonstrated that the QTL, here designated asResistance to Burkholderia glumae 2(RBG2), was located in a 502-kb interval defined by simple sequence repeat markers RM1216 and RM11727.
authors.affiliation: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602 Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Mizobuchi
authors.affiliation: National Agriculture and Food Research Organization, Kyushu Okinawa Agricultural Research Center (NARO/KARC), 496 Izumi, Chikugo, Fukuoka 833-0041 Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sato
authors.affiliation: National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602 Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Fukuoka
authors.affiliation: National Institute of Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604 Japan.
authors.forename: Seiya
authors.initials: S
authors.lastname: Tsushima
authors.affiliation: NARO Institute of Crop Science (NICS), 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yano
keywords: Bacterial grain rot; Disease resistance; Linkage analysis; Oryza sativa L.; Panicle blight; QTL