通过ISSR标记分析,研究了异源多倍体基因组的进化现象.结果表明,基因组组成和普通小麦相同的人工合成异源六倍体小麦,在形成早期发生了迅速、广泛、以非随机性为主的基因组变化,包括遗传变异---主要表现为序列变异和表观遗传变异---主要表现为DNA甲基化变异.而且异源六倍体小麦中来自父本的基因组比来自母本的基因组发生了更多的遗传和表观遗传变异.说明异源多倍体中不同亲本基因组之间的相互作用可能导致了变异的发生.这些变异不但有助于生物体恢复到二倍体的协调状态,而且产生新的遗传类型和影响表达的类型,促成了异源多倍体物种形成和进化成功.
By using ISSR technology,it was found that rapid,extensive and mainly non-random genomic changes,including genetic and epigenetic changes,i.e.DNA methylation changes,occurred in the early generation of synthetic allohexaploid wheat whose genomic constitution is identical to that of natural common wheat.The paternally donated nuclear genome showed more changes than maternally donated one.Intergenomic interactions in allopolyploid probably lead to these genomic variations.The changes could not only lead to diploid-like harmonization,but also generate genetic and expression variability,thereby contributing to speciation and evolution of allopolyploid.