小麦籽粒淀粉分支酶遗传多样性及对支链淀粉含量的影响

Genetic Polymorphism of Starch Branching Enzyme and Its Contribution to Amylopectin Content in Wheat Grain

采用非变性聚丙烯酰胺凝胶电泳,对90份小麦品种的淀粉分支酶同工酶(SBE)进行检测,以分析不同基因型对支链淀粉含量的遗传效应。结果表明:(1)SBEⅠ型显现出较为丰富的变异,具有A、B、Dⅰ和Dⅱ4个等位基因位点;SBEⅡ型仅具有SBEⅡa单一等位基因位点。根据SBEⅠ型4个基因位点在不同品种中的分布,可将90个品种分为7种基因型。不同基因型对支链淀粉含量的遗传效应分析表明,含有A位点的基因型(ADⅰDⅱ和ADⅰB)所对应的支链淀粉含量较高,且与由1个基因位点组成的基因型(Dⅰ)和2个基因位点组成的基因型(DⅰB和DⅰDⅱ)的支链淀粉含量差异显著。

The property of starch in wheat（Triticum aestivum L.） grain endosperm is a very important determinant for wheat quality,and it is essential to understand genetic effect of isoforms of starch branching enzyme（SBE） on starch biosynthesis for wheat quality improvement.The starch contents were assessed with 90 wheat cultivars,including 83 domestic hexaploid wheat from different province of China and 7 exotic ones.The genotypes of SBE were also investigated using native polyacrylamide gel electrophoresis（Native-PAGE）.The result indicated that there were two loci,SBEⅠ and SBEⅡ,of SBE.SBEⅠ menifested diverse polymorphism with the allele loci of A,B,Dⅰ and Dⅱ.SBEⅡ only exhibited one locus,ie,SBEⅡa.Among all 90 wheat cultivars,seven genotypes were observed based on four allele loci of SBEⅠ.In order to explore the relationship between the genotype and amylopectin content,genetic effects of different genotype on amylopectin content and multiple comparison analysis were conducted.It showed that the amylopectin content of genotypes containing A locus（A DⅰDⅱ and ADⅰB） were relatively higher,which there was significant differences at 0.05 level compared to that of DⅰB and DⅰDⅱ,especially to Dⅰ.It was concluded that there was different genetic effects for different genotype of SBE on amylopectin content.