Effects of environmental stresses on genetic diversity in microalgae

种群的遗传多样性被认为是决定生物能否克服人为环境压力的因素之一，种群内遗传变异的维持受到变异来源和种群规模的影响。在这项研究中。我研究了从假定使用除草剂的稻田和其他浅水池(如池塘和低地湿地)分离的接合绿藻Closterium ehrenbergii的当地种群的遗传变异。从冲绳低地湿地分离的种群中观察到等位酶的变异。，而在假定使用除草剂的Yeyama lsls稻田分离的种群中没有观察到这种变异。这些结果表明，像除草剂这样的环境压力可以减少微藻种群的遗传变异。

Genetic diversity of a population is considered as one of the factors which determine whether or not organisms could conquer anthropogenic environmental stresses.Maintenance of genetic variations in populations is affected by the source of variation and population size. In this study. I examined genetic variation in local populations of the conjugating green alga Closterium ehrenbergii isolated from paddy fields, where herbicides were assumed to be applied, and from other shallow water pools like ponds and lowland wetlands, where herbicides were not assumed to be applied. Allozyme variation was observed in the populations isolated from lowLand wetlands in Okinawa lsl. , whereas the variation was not observed in the populations isolated from paddy fields in Yaeyama lsls, where herbicides were assumed to be applied. These results suggest that an environmental stress like a herbicide could reduce genetic variation in microalgal populations.