生境片断化对植物种群遗传结构的影响及植物遗传多样性保护

Effects of habitat fragmentation on genetic structure of plant populations and implications for the biodiversity conservation

生境片断化是指大而连续的生境变成空间隔离的小种群的现象。生境片断化对植物种群遗传效应包括生境片断化过程中的取样效应及其后的小种群效应 (遗传漂变、近交等 )。理论研究表明 ,生境片断化后 ,植物种群的遗传变异程度将降低 ,而残留小种群间的遗传分化程度将升高。然而对一些植物的研究表明 ,生境片断化对植物种群的遗传效应要受其他一些因素的影响 ,如世代长度、片断化时间、片断种群的大小、基因流的改变等。最后 ,针对生境片断化的种群遗传后果 ,讨论了在植物种群遗传多样性保护中的应用。

Habitat fragmentation is the phenomenon that large,continuous habitat was destroyed into several spatially distant patchy habitats.Genetic effects of habitat fragmentation on plant populations include the sampling effect during habitat fragmentation and small population effect .Theoretical studies predict that genetic variation decreases and the genetic differentiation between remnant populations increases when habitats were fragmented.Empirical studies,however,are not always consistent with theoretical predictions.It suggests the role of many other factors,such as generation length,duration of fragmentation,size of fragmented population,change of gene flow,etc.We discussed the approaches of conserving genetic diversity of plant populations in fragmented habitats.