四川凉山会东县不同海拔农田土壤phoD基因群落组成及多样性特征

Composition and diversity of phoD gene communities in farmland soils at different altitudes in Huidong County,Liangshan Mountain,Sichuan Province,China

通过分析四川省凉山会东县农田土壤phoD基因群落组成及多样性对不同海拔高度的响应,以期深入认识凉山高原地区不同海拔农田土壤磷素及涉磷微生物群落的分布特点,为建立合理的施肥制度提供科学依据。以凉山州会东县不同海拔高度(1700 m、1900 m、2100 m)土壤为研究对象,通过化学分析和高通量测序技术对土壤理化性质、有机磷组分和含量以及phoD基因群落进行分析。结果表明,pH与海拔高度呈正相关。海拔2100 m的土壤全磷和有效磷含量最高,1900 m的有机磷(OP)、活性有机磷(LOP)、中等活性有机磷(MLOP)和中稳性有机磷(MROP)含量最高,而1700 m海拔的无机磷含量最高。对于不同海拔下的phoD基因群落变化,Shannon指数在高海拔地区最高。同时,3个海拔高度下phoD群落结构差异明显,变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和酸杆菌门(Acidobacteria)是3个海拔高度的主要门类,而慢生根瘤菌(Bradyrhizobium)是低海拔1700 m的主要优势属。土壤pH和总磷(TP)是驱动不同海拔土壤phoD基因群落组成的关键因子。综上,凉山会东高原地区不同海拔高度农田土壤中的phoD基因群落变异明显(P<0.05),且受到土壤pH和总磷的显著影响(P<0.05)。农业生产上应采取因地制宜的施肥措施。

By analyzing the response of phoD gene community composition and diversity of farmland soils to different altitudes in Huidong County,Liangshan Mountain,Sichuan Province,we aim to gain an in-depth understanding of the distribution characteristics of phosphorus and the microbial communities involved in phosphorus cycling in farmland soils at different altitudes in the Liangshan Mountain Plateau region.This knowledge will provide a scientific basis for establishing a rational fertilizer application system.Soils at different altitudes(1700 m,1900 m,and 2100 m)in Huidong County,Liangshan Mountain,were analyzed for their physicochemical properties,organic phosphorus fractions and contents,and phoD gene communities by chemical analysis and high-throughput sequencing technology.The results showed that pH was positively correlated with altitude.Soil total and effective phosphorus contents were the highest at 2100 m altitude,organic phosphorus(OP),reactive organic phosphorus(LOP),moderately reactive organic phosphorus(MLOP),and moderately stabilized organic phosphorus(MROP)at 1900 m,and inorganic phosphorus content was the highest at 1700 m altitude.For variation of the phoD gene community at different altitudes,Shannon index was the highest at high altitude.Meanwhile,the structure of phoD communities at the three altitudes differed significantly,with Proteobacteria,Actinobacteria and Acidobacteria being the dominant phyla at the three altitudes,while Bradyrhizobium was the main dominant genus at the low altitude 1700 m.Soil pH and total phosphorus(TP)were the key factors driving the composition of soil phoD gene communities at different altitudes.In conclusion,the phoD gene community in farmland soils at different altitudes in the Huidong Plateau region of Liangshan Mountain varied significantly(P<0.05)and was significantly affected by soil pH and total phosphorus(P<0.05).Fertilization measures should be adopted in agricultural production according to local conditions.