连续水旱轮作对水稻冷浸田土壤细菌群落结构的影响

利用高通量测序技术,采用单季稻-冬闲(CK)、油菜-水稻(R-R)、春玉米-水稻(C-R)、紫云英-水稻(M-R)和蚕豆-水稻(B-R)五个处理探究水旱轮作模式对水稻冷浸田土壤细菌群落结构的影响,同时分析了土壤理化因子与细菌群落结构的关系。结果表明:水旱轮作能够显著增加水稻产量18%~44%。与CK相比,绝大多数水旱轮作降低了土壤细菌的丰富度,而细菌多样性与CK处理无显著差异。变形菌门和酸杆菌门为土壤中的优势细菌类群,其中变形菌门的丰度最高。与CK相比,轮作后酸杆菌、放线菌、硝化螺旋菌、慢生根瘤菌和亚硝化螺菌等参与碳氮循环的菌群丰度明显增加。聚类分析表明CK和M-R轮作土壤细菌群落单独聚为一类,而B-R、C-R和R-R轮作土壤聚为另一类。冗余分析表明土壤全磷、有效磷和p H是影响水旱轮作土壤细菌群落结构的主要因子。

Effect of Continuous Paddy-upland Crop Rotation on Bacterial Community Structure in Cold Waterlogged Paddy Soil

A paddy-upland crop rotation field experiment, consisting of 5 treatments, i.e. fallow-rice (CK), rape-rice (R-R), corn-rice (C-R), milk vetch-rice (M-R) and bean-rice (B-R), was conducted to investigate effects of the rotation modes on bacterial community structure in cold waterlogged paddy soil, using the high-throughput sequencing technique, and relationship between soil physicochemical properties and bacterial community structure as well. Results show that compared with CK, paddy-upland rotation significantly increased rice yield by 18%~44%, but decreased richness of the soil bacterial community in most cases. However, the rotation did not affect much bacterial diversity. Proteobacteria and Acidobacteira were dominant bacterial groups in all the soil samples, and Proteobacteria was the highest in relative abundance. Compared with CK, rotation significantly increased relative abundances of Acidobacteria, Actinobacteria, Nitrospirae, Bradyrhizobium and Nitrosospira and various bacterial groups involved in carbon and nitrogen recycling. Cluster analysis shows that CK and M-R belonged to a group, B-R, C-R and R-R to the other group in terms of soil bacterial community. Redundancy analysis demonstrates that soil total phosphorous, available phosphorous and pH were the main factors affecting soil bacterial community structure.