Abstract: Two residual heterozygous lines (RHLs),which contained a heterozygous region flanked by RM1-RM3746 and RM151-RM243 on the short arm of chromosome 1 were used to develop the F6 populations,respectively. By QTL analysis of two F6 populations and comparison of the common heterozygous segment presented in these RHLs,QTLs including qGL-1 and qGW-1 for grain length and grain width were identified in the same interval between RM3746 and RM243,respectively. Four RHLs carrying heterozygous segments in the intervals RM151-RM10404,RM10398-RM5359,RM10435-RM259 and RM10381-RM243 on the short arm of rice chromosome 1 were selected from one population by SSR marker survey,respectively. Ten maternal homozygotes and 10 paternal homozygotes were selected from each of the four F2 populations derived from the four RHLs. The four sets of near isogenic lines (NILs) were grown for phenotyping on grain length and grain width. With analysis on the phenotype differences among overlapping chromosome segment substitution lines,two QTLs of qGL-1 and qGW-1 for grain length and grain width were resolved,respectively. qGL-1 and qGW-1 were located in the intervals 437.5 kb and 392.9 kb flanked by RM10390-RM1344 and RM10376-RM10398,respectively. Alleles were all from maternal parent contributing to increase in grain length and grain width. The results clearly suggested that qGL-1 and qGW-1 were tightly linked. Genetic dissection of qGL-1 and qGW-1 has laid a foundation for cloning of the QTLs and molecular breeding of appearance quality in rice.

Key words: grain shape, residual heterozygous line, near isogenic line, quantitative trait locus, rice, fine mapping

摘要： 以第1染色体短臂RM1-RM3746和RM151-RM243区间内呈杂合、背景基本纯合的2个水稻剩余杂合体（RHL）衍生两个F6群体，将控制水稻粒长和粒宽的2个粒形QTL（qGL1和qGW1）定位于RM3746-RM243区间内。在此基础上，应用SSR标记检测，从其中1个群体中筛选到杂合区间分别为RM151-RM10404、RM10398-RM5359、RM10435-RM259和RM10381-RM243的4个单株，应用SSR标记进一步检测4套F2群体，从每套F2群体中分别筛选到母本珍汕97B和父本密阳46纯合型材料各10株，自交获得4套近等基因系材料并考查其粒长和粒宽。利用交迭重组染色体片段代换系分析法，将控制粒长和粒宽的QTL （qGL1和qGW1）界定于437.5 kb的RM10390-RM1344区间和392.9 kb的RM10376-RM10398区间，增效等位基因均来自母本珍汕97B，表明qGL1和qGW1是紧密连锁的不同座位。

关键词: 粒形, 剩余杂合体, 近等基因系, 数量性状座位, 水稻, 精细定位