温度水分对秸秆降解微生物群落功能多样性影响

秸秆腐解微生物群落结构受环境因子(温度和水分)影响显著。本试验利用BIOLOG技术,以秸秆腐解微生物碳源利用的平均颜色变化率(averagewell colordevelopment,AWCD)为指标,研究了不同温度(15℃,25℃和35℃和水分(40%,70%和90%田间持水量)条件下小麦和玉米秸秆腐解过程中微生物碳源代谢多样性的差异试验结果表明不同处理的AWCD随培育温度升高而降低,即15℃25℃35℃。随着培育时间的增加,其降低的趋势更加明显。同样地,小麦玉米秸秆腐解微生物的物种丰富度指数Shannon-Wiener(H)和优势度指数Simpson(D)也呈现出随温度升高而降低的趋势。微生物主要利用糖类和脂类物质。主成分分析结果表明在不同腐解时间,腐解微生物代谢多样性在不同温度下差异显著,而在不同水分下差异不显著。

Effects of Temperature and Moisture on Microbial Community Function Responsible for Straw Decomposition

Environment factors, especially temperature and moisture, have significant effects on microbial community associated with straw decomposition. The present study investigated the differences of metabolic diversity of microbes during decomposition of straws under different temperatures(15°C, 25°C and 35°C) and moisture contents (40%, 70% and 90% water holding content) by BIOLOG analysis. Litterbag method was used to distinguish the straw-decomposing microbial community and soil microbial community. The results showed that the average well color development (AWCD) of microbial community responsible for straw decomposition declined with increasing incubation temperatures, as 15°C >25°C >35°C. The decrease of AWCD was more significant with increasing incubation time. Besides, the richness index and dominance index decreased with the increasing temperature. The sugar and lipid were the most important sources used by microbes during the incubation. Principal component analysis showed that temperature strongly affected the metabolic diversity of microbes during the decomposition period, not moisture contents.