中文摘要：

杂种优势作为自然界的普遍现象,其产生机理一直是人类研究的热点。在此基础上,关于杂种优势的原因产生了众多理论假说,诸如显性假说、上位效应、基因表达调控网络等。多年来,众多科研工作者试图从生理生化水平和分子水平求解杂种优势产生的机理,发现杂种优势植株光合能力强,组织相对发达,对外界环境变化的适应和缓冲能力较强;杂种优势在相对弱光、低温、低CO2浓度条件下往往表现得更为明显;此外,遗传距离、基因表达差异、DNA甲基化等都与杂种优势关系密切。文中对农业和林业上的研究成果进行了综述和思考,并对这一领域今后的研究方向进行了探讨。

英文摘要：

Heterosis is the universal phenomena in nature,and its formation mechanism has been the focus of research.On this basis,a number of theoretical hypotheses have been proposed for the reason of heterosis,such as the dominance hypothesis,epistatic effect,gene regulation networks,etc.For the past years,many researchers have attempted to elaborate the mechanism of heterosis at physiological biochemical level and molecular level.The results showed heterosis plants have a stronger photosynthetic capacity,relatively well-developed tissues and greater adaption and buffering ability to external environment.The heterosis is often more pronounced in relatively low light,low temperature and low CO2 concentration.In addition,genetic distance,differences in gene expression and DNA methylation are all closely related with heterosis.This study reviewed research results of forestry and agriculture,and discussed the future research direction of this field.