Abstract: Rhizosphere and non-rhizosphere soil samples were collected from the vineyards having been planted for 3 and 30 years, and PCR-DGGE technique was adopted to study the effects of grape-replanting on the population structure and diversity of soil bacteria and fungi. The bacterial and fungal diversities were higher in 30-year-planted vineyard than in 3-year-planted vineyard, and higher in rhizosphere soil than in non-rhizosphere soil. After 30 years replanting, the population structure of bacteria and fungi approached the same in rhizosphere soil and non-rhizosphere soil but differed from that in fallow soil; while in the 3-year-planted vineyard, the population structure in rhizosphere soil was different from that in non-rhizosphere soil and fallow soil. Comparing with that in 3-year-planted vineyard, the rhizosphere soil microbial population in 30-year-planted vineyard had a greater change. In bacterial population, Flavobacterium sp.(DQ339585) and Bacillus sp.(AY039821) decreased while Pedobacter sp. (AJ871084) increased; in fungal population, Omphalina farinolens (EF413029) appeared, Pestalotiopsis sp.(DQ657877, DQ657875, DQ657871), Phacidium lacerum (DQ470976), and Lecythophora decumbens (AF353597) decreased, while Pilidium acerinum voucher (AY48709) increased. acillus sp., Flavobacterium sp., and Pestalotiopsis sp. had antagonism to pathogen, and their decrease reduced the resistance of grape against pathogen. The increase of Pilidium acerinum voucher might relate to the severe disease after grape- replanting.

Key words: grape, replanting, bacteria, fungi, population, PCR-DGGE, Acacia auriculiformis, Azadirachta indica, nutrient cycling, dry-hot valley.