Research Progress of Mechanism of Heterosis in Plant

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.