研究农田生态系统的多样性对保护农田生态系统的生物多样性具有重要意义,结构,功能,农田土壤微生物的生物地理分布及其影响因素。利用高通量测序技术分析土壤细菌多样性分布特征,群落结构,宁夏黄土丘陵区农田沿海拔的代谢功能及其对土壤理化性质的响应.结果表明:①土壤细菌的Alpha多样性指数与海拔呈极显著负相关(P<0.05),沿海拔呈先降低后略有升高的趋势。②七门,包括变形杆菌,放线菌,和酸细菌,是占主导地位的群体,其中5个海拔高度差异极显著(P<0.01)。③在二级分类级别,细菌有36种代谢功能,包括膜运输,碳水化合物代谢,和氨基酸代谢,其中22个表现出显著差异,12个在不同海拔高度之间表现出极其显著的差异。④Pearson相关分析表明,土壤含水量,堆积密度,pH值,和碳氮比对细菌α多样性的影响最显著,而土壤养分如总有机碳,总氮,总磷对细菌β多样性有显著影响。⑤Mantel试验分析表明,土壤含水量,总有机碳,和碳氮比在门水平上影响细菌群落结构,土壤pH值,总有机碳,总氮,总磷,碳氮比与细菌代谢功能显著相关。方差划分分析表明,土壤水分对土壤细菌群落结构的解释力最高,而土壤pH对代谢功能的解释最高。总之,土壤含水量和pH是影响土壤多样性的主要因素,社区组成,宁夏黄土丘陵区农田土壤细菌代谢功能研究.
It is of great significance for the conservation of biodiversity in farmland ecosystems to study the diversity, structure, functions, and biogeographical distribution of soil microbes in farmland and their influencing factors. High-throughput sequencing technology was used to analyze the distribution characteristics of soil bacterial diversity, community structure, and metabolic function along elevation and their responses to soil physicochemical properties in farmland in the loess hilly areas of Ningxia. The results showed that:① The Alpha diversity index of soil bacterial was significantly negatively correlated with elevation (P < 0.05) and showed a trend of decreasing and then slightly increasing along the elevation. ② Seven phyla, including Proteobacteria, Actinobacteria, and Acidobacteria, were the dominant groups, and five of them showed highly significant differences between altitudes (P < 0.01). ③ At the secondary classification level, there were 36 metabolic functions of bacteria, including membrane transport, carbohydrate metabolism, and amino acid metabolism, of which 22 showed significant differences, and 12 showed extremely significant differences among different altitudes. ④ Pearson correlation analysis showed that soil water content, bulk density, pH, and carbon-nitrogen ratio had the most significant effects on bacterial Alpha diversity, whereas soil nutrients such as total organic carbon, total nitrogen, and total phosphorus had significant effects on bacterial Beta diversity. ⑤ Mantel test analysis showed that the soil water content, total organic carbon, and carbon-nitrogen ratio affected bacterial community structure at the phylum level, and soil pH, total organic carbon, total nitrogen, total phosphorus, and carbon-nitrogen ratio were significantly correlated with bacterial metabolic function. Variance partitioning analysis showed that soil water content had the highest explanation for the community structure of soil bacteria, whereas soil pH had the highest explanation for metabolic function. In conclusion, soil water content and pH were the main factors affecting the diversity, community composition, and metabolic function of soil bacteria in farmland in the loess hilly region of Ningxia.