水稻株高构成因素的QTL剖析

利用水稻籼粳杂交 (圭 6 30× 0 2 42 8) F1 的花药离体培养建立的一个含 81个 DH家系的作图群体 ,对水稻株高构成因素 (穗长、第 1节间长、……、第 5节间长 )进行基因定位。DH群体中株高构成因素均呈正态分布。相邻的构成因素间呈极显著的正相关 ,而相距较远的构成因素间的相关较弱或不显著。采用 QTL(Quantitative trait lo-cus)分析 ,定位了影响株高构成因素的 6个 QTL:qtl7同时影响穗长和第 1、2、3节间长 ,qtl1 和 qtl2 同时影响第 4和第 5节间长 ,qtl1 0 a和 qtl1 0 b仅影响第 1节间长 ,qtl3 仅影响第 3节间长。采用 QTL 互作分析 ,检测到 19对显著的互作 ,每个构成因素受 2个或 2个以上的 QTL 互作对的影响。并且还发现 ,同一个 QTL 互作对可能影响不同的性状 ,以及一个 QTL 可以分别与不同的 QTL 产生互作而影响同一个性状或影响不同的性状 ,但总的看来 ,加性效应是主要的。这些结果揭示了株高构成因素间相关的遗传基础 ,在水稻育种中运用这些 QTL 将有助于对株高 ,以及对穗长和上部节间长度进行精细的遗传调控。

QTL Dissection of Plant Height Components in Rice (Oryza sativa L.)

Main-effect and epistatic QTLs (Quantitative trait locus) for plant height components (lengths of panicle,first internode,second internode,and so on) in rice were investigated by using a doubled-haploid population derived from the F 1 hybrid of a cross between an indica cultivar and a japonica cultivar.All plant height components exhibited continuous variations and normal distributions.The correlation between adjacent plant height components was positively significant while the significance of the correlation between non-adjacent plant height components was less.QTL mapping detected 6 QTLs affecting plant height components.Of these,qtl 7 had effects simultaneously on lengths of panicle,and first,second and third internodes;qtl 1 and qtl 2 simultaneously on lengths of forth and fifth internodes.A total of 19 pairs of significant epistatic QTLs were detected.Among these,there were 2 or more pairs of epistatic QTLs for each plant height component,and it was found that one pair of epistatic QTLs simultaneously controlled several different traits and one QTL interacted with other different QTLs to affect diffe- rent traits.These results have revealed the genetic basis of plant height components in rice which correlated more or less with each other,and are of benefit to fine genetic manipulation of plant height in rice breeding.