Ammonia Oxidizing Bacteria Community Structure in Napahai Farmland Soil
In order to explore the variation characteristics of ammonia oxidizing bacteria community structure in Napahai farmland soil in different season,soil samples were collected by plum point method in upper(0~20 cm) and lower(20~40 cm) soil layers in representative farmlands in dry and wet seasons,and the effects on ammonia oxidizing bacteria community structure were explored combined with soil environmental factors.High-throughput sequencing technique and redundancy analysis method were used to analyze the relationship among environmental factors and these ammonia oxidizing bacterial community structure based-on amoA gene from soil total DNA,and to determine the main environmental factors.Results:Contents of organic matter,total nitrogen,hydrolysable nitrogen,rapidly available phosphorus,rapidly available K,and nitrate nitrogen are the highest in upper soil in wet season,respectively 70.79 g/kg,2.90 g/kg,389.04 mg/kg,78.84 mg/kg,768.92 mg/kg,49.04 mg/kg.In dry season,the upper farmland soil has the highest content of total phosphorus and total K,respectively 1.33 g/kg and 15.13 g/ kg.By high throughput sequencing,Nitrosospira-sp.-Nsp2 and uncultured-Nitrosospira-sp.are mainly the dominant ammonia oxidation bacteria,belongs to the Nitrosospira at genus level.The diversity of ammonia oxidation bacteria shows that the upper soil in dry season> the upper soil in wet season> the lower soil in wet season> the lower soil in dry season.Known from the analysis of redundancy,the mainly environmental factors affect the upper farmland soil ammonia oxidizing bacteria in dry season shows the rule of rapidly available phosphorus> total nitrogen> nitrite nitrogen,for the lower soil in dry season is ammonium nitrogen > nitrite nitrogen> total K> nitrate nitrogen> total phosphorus.The soil ammonia oxidizing bacteria community structure in wet season is obviously affected by multiple environmental factors.