QTL Detection and Epistasis Analysis for Heading Date Using Single Segment Substitution Lines in Rice （Oryza sativa L.）

摘要

cqvip:Heading date of rice is a key agronomic trait determining cultivated areas and seasons and affecting yield. In the present study, five primary single segment substitution lines with the same genetic background were used to detect quantitative trait loci(QTLs) for heading date in rice. Two QTLs, q HD3 and q HD6 on the short arm of chromosome 3 and the short arm of chromosome 6, respectively, were identified under natural long-day(NLD). Nineteen secondary single segment substitution lines(SSSLs) and seven double segments pyramiding lines were designed to map the two QTLs and to evaluate their epistatic interaction between them. By overlapping mapping, q HD3 was mapped in a 791-kb interval between SSR markers RM3894 and RM569 and q HD6 in a 1 125-kb interval between RM587 and RM225. Results revealed the existence of epistatic interaction between q HD3 and q HD6 under natural long-day(NLD). It was also found that q HD3 and q HD6 had significant effects on plant height and yield traits, indicating that both of the QTLs have pleiotropic effects.