利用籼粳交探讨水稻株高和抽穗期的遗传基础

广亲和基因的发现,克服了籼粳交杂种不育的矛盾,但杂种后代株高过高、抽穗期延迟等问题仍然限制着籼粳亚种间杂种优势的利用。本试验利用一个籼粳交(珍汕97/武育粳2号)双单倍体群体(doublehaploidpopulation,DH系)及其分别与两亲本回交构建的两个回交群体,考查了株高和抽穗期的遗传,将三个群体的表型值和两个回交群体的中亲优势值进行了数量性状位点(quantitativetraitlocus,QTL)检测及效应分析,并对结果进行了比较。2个性状在3个相关群体中一共检测到了21个主效QTL和10个上位性QTL,主效QTL的数目和贡献率都比上位性QTL大,而且,在10个上位性QTL中,发生在2个主效QTL间的互作有3个,主效QTL与背景位点间的互作有6个,2个互补位点间的互作仅有1个,进一步说明了主效QTL在株高和抽穗期遗传中的重要作用。比较加性和非加性QTL的作用,发现加性效应、显性效应和上位性效应是籼粳亚种间杂种株高和生育期变化的共同遗传基础。

The Genetic Bases Analysis of Plant Height and Heading Date in Indica/Japonica Hybrids

The discovery of wide-compatibility gene has partly resolved the problem of serious sterility in indica/japonica hybrids. However, the higher plant height and later heading date in hybrids still limited the application of indica/japonica hybridization in breeding program. In the present study, a double haploid (DH) population which was developed from an indica/japonica (Zhenshan 97/Wuyujing 2) crossing and two backcross populations were derived by backcrossing DHs with their parents were used to investigate the plant height and heading date, for each trait, the phenotypic means of the three populations and the midparental heterosis values of the two BCF1 populations were used to identify quantitative trait locus (QTL). 21main effect QTL (M-QTL) and 10 epistatic QTL (E-QTL) were detected in the three populations for three trait, the QTL number and contribution rate of M-QTL was larger than E-QTL's, in addition, of 3 the 10 E-QTL, occurred between alleles at two main effect QTL, 6 between alleles at a main effect QTL and a "background" locus, and 1 between alleles at two complementary loci, which further indicate the importance of the main effect QTL. By comparing the additive and non-additive gene effect, it was indicated that the additive, dominant and over-dominant effect togetherly explained the genetic basis of the plant height and heading date.