水稻株高QTL Qph1的精细定位

利用珍汕97B与南阳占的重组自交系(recombinant inbred line,RILs)构建了以珍汕97B为背景的近等基因系(near isogenic line,NILs)BC3F2,通过对其320株随机分离小群体的研究,发现Qph1同时具有加性效应和显性效应,其可解释的遗传变异达71.28%,局部QTL连锁分析把该QTL定位于2.1cM、180.2kb的RM6333-RM11961区间内;进一步发展6 000株大群体,筛选出230株极端隐性重组单株,利用重叠作图法将Qph1进一步精细定位于距离约为90kb的SSR标记SHL4和InDel(Insertl Deletion)标记HL13间,通过与已克隆的sd1基因比较,发现二者并不在同一个区域,这为进一步克隆该QTL和分子标记辅助选择培育矮秆水稻新品种奠定了基础。

Fine mapping of a plant height QTL Qph1 in rice

Dwarfism is one of the most important agronomic traits of rice.Fine mapping and functional studies of the plant height gene reveal the mechanisms for high yielding rice.In early research of this study,a main QTL Qph1 for plant height was mapped between the interval RM472-RM104 on the long arm of chromosome 1 in recombinant inbred line(RILs) population of Zhenshan 97B/Nanyangzhan.Then this QTL was used as a target fragment to construct a near isogenic line(NILs) BC3F2 whose genetic background was Zhenshan 97B.Firstly we detected the effect of Qph1 in NILs by a random population contained 320 plants,and it can explain 71.28% of phenotypic variation.Then the Qph1 was located between the interval RM6333-RM11961 through local QTL linkage analysis.In order to further reduce the target region,we planted a large genetic population which segregate in regions covering Qph1 and screened about 230 extreme recessive recombinant plants.The Qph1 locus was delimited to a 90 kb region flanked by SSR marker SHL4 and InDel marker HL13 by overlapping mapping,and compared with the sd1 has been cloned and found that they were not in the same area.It is a good foundation for cloning of the QTL.