Abstract: By using epifluorescence microscopy with SYBR Green I, the vertical distribution patterns of bacterial and viral abundance in Aha Lake and Baihua Lake in Guizhou Province of China were studied, with the effects of water temperature, pH, DO, conductivity, and DOC concentration analyzed. In the two lakes, the DOC concentration ranged from 1.48 to 2.96 mg·L^-1, bacterial abundance was 3.32×10⁶-16.6×10⁶ cells·ml^-1, and viral abundance was 1.87×10⁷-12.5×10⁷ cells·ml^-1. The virus/bacteria ratio (VBR) varied from 4.09 to 12.77, with the mean value in the sequence of Baihua Lake > Aha Lake entrance > central Aha Lake. The bacterial and viral abundance decreased from surface water to bottom water. In the two lakes, bacterial abundance was significantly positively correlated with water temperature, pH, DO, and viral abundance, and negatively correlated with water conductivity. There was a significant positive relationship between bacterial abundance and DOC in Aha Lake, and between viral abundance and DOC in central Aha Lake, but no significant relationships were observed between viral abundance and DOC in Aha Lake entrance, and between bacterial and viral abundance and DOC in Baihua Lake.

Key words: Paddy rice, Biochemical qualities, Climate conditions, Anning River Valley