|Other Abstract||As producer and primary consumer in the aquatic ecosystem, plankton plays an important role in the nutrient cycling and energy flow. Experts can obtain assistance from plankton data in aquatic resource usage，manual aquaculture and environment monitoring.
The Three-Gorges Reservoir has been playing an important role in aquatic resource utilizing and flood controlling, however, few studies were focused on the plankton by molecular biology methods.
Molecular biology methods are used to explore structure and function of biomacromolecule, and explain essence of vital phenomena ultimately. In this thesis, data of species composition and physico-chemical factors have been combined to analyse the plankton DNA polymorphism in the 7 sampling stations A, B, C, D, E, F and G of TGRR. The results showed the statistic results on DNA polymorphism of plankton community, species composition and physico-chemical factors is not accordant, the idiographic content are:
1) 41 species were found in all, clustering results based on species composition showed: the 7 station cluster as one group;
2) Clustring results based on RAPD showed: station A, C, D and E cluster as one group, station B and F cluster as another group, and station G is different from all of others;
3) Clustring results based on physico-chemical factors showed: station D and E cluster together at first, then A and C join in this group; B and F cluster as another group, and G is different from all the others.
The possible reasons are losing of some species information; effect of some natural and artificial factors, such as water flow, weather, man-made operations and so on. Accordingly, it’s better to identify the species of plankton community as soon after the samples has obtained, and apply cuter molecular biology methods to study quarterly and annually. In conclusion, a new approach has applied to research microbe in reservoir, which provides scientific evidence to estimate the health status of
reservoir in our country.|