长江中下游地区湖泊大多属典型的亚热带浅水湖泊，水环境的季节变化明显，溞属Daphnia物种多样性较为丰富。本项目运用线粒体DNA（如12S rDNA、16S rDNA、COI）和核DNA（如ITS2）等分子标记技术，研究亚热带浅水湖泊沉积物中溞属枝角类休眠卵的遗传多样性，以及处于不同深度的沉积物中溞属休眠卵的遗传分化；研究栖息于不同湖泊中溞属种类的种群遗传结构差异、不同Daphnia基因型的克隆群的竞争潜力和个体适合度；研究Daphnia雄体、两性生殖雌体及休眠卵的遗传结构的变化。从而揭示浅水湖泊沉积物中Daphnia休眠卵的遗传分化规律及优势种种群适应水环境季节变化的分子机理，这对深入理解亚热带浅水湖泊中Daphnia种群的季节演替规律及历史演变都具有十分重要的科学价值。此外，Daphnia遗传多样性的检测可以弥补其在传统形态分类上的不足，有助于Daphnia种类的准确鉴定和分类。

Most of lakes are subtrapical and shallow in the middle and lower reaches of Yangtze River. They have obviously seasonal variations in water environments. The species diversity of Daphnia are abundant in these lakes. Using molecular markers of mitochondrial DNA（such as 12S rDNA、16S rDNA、COI）and nuclear DNA (such as ITS2), genetic diversity of Daphnia resting eggs in the sediments of these lakes were studied, including that genetic differences of Daphnia resting eggs located in different depths of the sediments. We studied the differences of genetic structure of Daphnia species in these selected lakes. Competitive potential and individual fitness of different genotypes in Daphnia were also researched. Moreover, the change of genetic structure in males, sexual females and resting eggs of Daphnia were studied. By these works, the differences of genetic structure of Daphnia resting eggs in the sediments and genetic mechanism of the adaptation of dominant Daphnia to seasonal variations of water environment could be elucidated in shallow lakes. It is very important to further understand seasonal and historical succession of Daphnia populations in subtropical and shallow lakes. In addition, the determination of genetic diversity of Daphnia may make up the deficiency in traditional morphology classify. It will make for exact identification and classify of Daphnia species.