Fine mapping of QTL qPH6-1 for plant height on the short arm of rice chromosome 6.

Populations derived from residual heterozygous lines(RHLs) were used for the detection and fine mapping of quantitative trait loci(QTLs) for plant height in rice.An F2:3 population which segregates in a 7.3-Mb region on the short arm of rice chromosome 6 in an isogenic background were transplanted in two trial sites in Hainan and Zhejiang Provinces,respectively.Two QTLs for plant height were detected,of which qPH6-1 exhibited a consistent effect across the two sites.Three plants having smaller heterozygous segments which overlap the qPH6-1 region were selected.Using the three F2 populations produced,qPH6-1 was validated and delimitated to a 96.4-kb region flanked by SSR markers RM3414 and RM19417.Three more F2 populations which segregate in smaller regions covering qPH6-1 were developed.The qPH6-1 locus was delimited to a 51.7-kb region flanked by STS marker Si2925 and SSR marker RM19417.It was also shown that this gene is non-allelic to all the major genes for dwarfism mapped or cloned in rice.