干旱沙漠区2种深根植物根际微生物数量分布及根际效应研究

Quantity Distribution and Rhizosphere Effect of Rhizosphere Microorganisms of Two Deep-root Plants in Arid Desert Area

本研究以古尔班通古特沙漠东南缘2种深根植物疏叶骆驼刺、多枝柽柳不同土层深度根际土壤、根外土壤为研究对象,运用平板划线法研究根际土壤、跟外土壤微生物数量,并对其根际效应进行探讨。研究结果显示,细菌占根际可培养微生物数量中的绝大多数。每种植物根际细菌数量、微生物总数在不同土层有相同的波动变化规律。根际真菌、放线菌在不同植物不同土层也呈现差异性分布。根际细菌数量、微生物总数排序为疏叶骆驼刺>多枝柽柳。根际真菌、放线菌数量排序为疏叶骆驼刺>多枝柽柳。除多枝柽柳根际细菌、放线菌、微生物总数在0～50 cm和200～250 cm土层呈现负效应,其余样本根际效应均为正效应。

This study was conducted in the southeastern margin of the Gurbantungut Desert,and two deep-root plants(Alhagi sparsifolia Shap.and Tamarix ramosissima Ledeb.)were selected.The number of rhizosphere and extrarhizosphere microorganisms in different depths was counted,and the rhizosphere effect was also discussed.The results showed that bacteria accounted for most of the number of culturable microorganisms in the rhizosphere.The number of bacteria and the total number of microorganisms in the rhizosphere of different plants had the same fluctuation in different soil layers.Rhizosphere fungi and actinomycetes showed different distribution in different soil layers of different plants.The number of rhizosphere bacteria,microbial total order was A.sparsifolia>T.ramosissima.Rhizosphere fungi and actinomycetes were as follows:A.sparsifolia>T.ramosissima.In addition,the total number of rhizosphere bacteria,actinomycetes and microorganisms in T.ramosissima were negative in 0-50 cm and 200-250 cm soil layers,and the rhizosphere effect was positive in other samples.