用单片段代换系（SSSLs）研究水稻株高及其构成因素QTL加性及上位性效应

株高是典型的数量性状，易受遗传背景和环境等因素的影响。单片段代换系和双片段聚合系减少了个体间遗传背景的干扰，是鉴定QTL和研究QTL上位性的新型遗传材料。本研究采用随机区组试验设计方法以初级单片段代换系间杂交衍生的16个次级单片段代换系和15个双片段聚合系分析了株高及其构成因素QTL的加性效应及加性×加性上位性效应。共鉴定出11个QTL，其中3个株高QTL，1个倒1节间长QTL，2个倒2节间长QTL，2个倒3节间长QTL和3个倒4节间长QTL，分布于第4、6和10染色体上。鉴定出23对双基因互作，其中7对为没有显著效应的座位间互作，16对为有显著效应的QTL与没有显著效应的座位间互作。结果表明，QTL加性效应和QTL间的上位性效应都是株高及构成因素的重要遗传组成。通过单片段代换系杂交衍生的次级单片段代换系和双片段聚合系可提高QTL鉴定和上位性分析的灵敏度。

Additive Effects and Epistasis Effects of QTL for Plant Height and Its Components Using Single Segment Substitution Lines (SSSLs) in Rice

Plant height is a typical quantitative trait that is liable to be influenced by genetic backgrounds and environments. As a novel research material, single segment substitution lines and double segment pyramiding lines in rice will make QTL identification and epistasis analysis more accurate because of diminishing the interference of genetic backgrounds among plants. In this study, Detection of QTLs controlling plant height and its components and analysis of epistasis effects were done with 16 secondary single segment substitution lines and 15 double segment pyramiding lines derived from crossing of primary SSSLs by randomized blocks design. The main results showed that 11 QTLs were detected and distributed on chromosomes 4, 6, and 10, of which three QTLs controlling plant height, one QTL coffering length of the first inernode from the top, two QTLs harboring length of the second internode from the top, two QTLs for length of the third internode from the top and three QTL controlling length of the fourth internode from the top were included. Twenty-three digenic interactions were detected for plant height and its components, of which seven interactions occurred between two loci both not having main effects on the traits, and 16 interactions each involved one locus having a main effect at the single-locus level and another locus that did not show significant effect at the single-locus level. The results indicated that both additive effects of QTL and epistasis effects between QTLs were important genetic components. Efficiency of QTLs identification and epistasis effects analysis between QTLs could be improved using secondary single segment substitution lines and double segment pyramiding lines derived from crossing of primary single segment substitution lines.