表观遗传变异在植物杂交与多倍化过程中的作用

The roles of epigenetic variation in plant hybridization and polyploidization

杂交(hybridization)与多倍化(polyploidization)普遍存在于现存植物类群中,并对物种形成(speciation)与多样化(diversification)起到了重要作用。在以往的研究中,已有众多的学者分别从生态学、生理学与遗传学等角度对植物杂交与多倍化进行了广泛的探讨。本综述侧重于从进化生物学的角度探讨表观遗传变异在植物杂交与多倍化过程中所起到的作用,并基于在拟南芥(Arabidopsis thaliana)、水稻(Oryza sativa)和芸薹属物种(Brassica spp.)中已有的实例探讨表观遗传变异与表型革新(phenotypic novelty)的相关性。通过对已有研究的总结与展望,我们建议将进化表观遗传学研究扩展到自然群体和多个近缘物种间比较的水平,并同时需要改进从全基因组水平鉴定关键表观遗传变异的检测方法。

Hybridization and polyploidization are common phenomena in plants and play important roles in speciation and diversification of extant species. Previous studies using ecological, physiological and molecu- lar investigations have provided a framework for understanding the underlying mechanisms of plant hybridi- zation and polyploidization. In this review, we examine the roles of epigenetic variation in species evolution from an evolutionary perspective. We summarize recent advances in Arabidopsis thaliana, Oryza sativa and species of Brassica to elucidate the correlations between phenotypic novelty and epigenetic variation. Based on currently available observations, we propose that future studies should emphasize the roles of epigenetic variation at both the natural population and species levels, and that statistical methods need to be improved to identify causative epigenetic variations at the genome-wide level.