小麦株高及节间长度的杂种优势和遗传分析

Heterosis and genetic effect of plant height and internode length in wheat

为改良小麦株型提供依据,以7个株高有较大差异的冬小麦品种为亲本,按Griffing双列杂交法Ⅱ配制21个杂交组合,探讨株高及节间长度的杂种优势、配合力和遗传力。结果表明:小麦株高及各节间长度的杂种优势均存在较大变异,各节间平均优势强弱为倒1节长>倒2节长>倒3节长>倒4节长>倒5节长;倒5节间长的遗传主要受加性基因效应作用,株高、倒1、倒2、倒3和倒4节间长的遗传受加性基因和非加性基因效应共同作用,但主要以加性基因效应为主;7个亲本中,宁麦8号和扬麦9号的株高及各节间长度的一般配合力较好,均表现为较大的负向效应,能极显著降低杂种后代株高及各个节间长度,在小麦矮化育种中利用价值较高;宁麦9号×扬麦11和扬麦9号×扬麦11这两个杂交组合的特殊配合力效应值在株高及各节间长度上均表现为较大的负向效应,可作为半矮秆小麦育种的重点组合;株高及各节间长度的狭义遗传力高,其后代变异受环境影响小,早代选择有效。

To provide the basis for improvement of plant type in wheat breeding,heterosis,combining ability and heritability of plant height and internode length were studied by a 7×7 complete diallel crosses with seven wheat parents during 2009-2010 growing season.The results showed the heterosis of plant height and internode length had extensive variation.The order of the average heterosis for each internode length was first internodesecond internodethird internodefourth internodefifth internode.The inheritance of the fifth internode was mainly controlled by additive genes.The inheritance of plant height,and the first,second,third and fourth internode length was controlled by both additive and non-additive genetic effects,but the additive effect was much greater than the non-additive effect.Ningmai 8 and Yangmai 9 held the best general combining ability of plant height and each internode length,which could significantly reduce plant height and each internode length in their crossing progenies,and they might be used as the best parents in dwarf wheat breeding.The relative values of specific combining ability of plant height and each internode length in the two crosses involving Ningmai 9×Yangmai 11 and Yangmai 9×Yangmai 11 were all negative,and they could be considered as the key crosses in the semi-dwarf wheat breeding.The narrow sense heritability of plant height and internode length was much higher,which indicated that selection for these traits would be effective in the early generation.