返青前后草地早熟禾草坪根际微生物区系动态

根际是土壤-植物生态系统物质及能量交换的活跃界面,根际微生物不仅直接影响植物对水分、养分的吸收,而且也同时影响植物对不良环境的抵抗能力。利用选择性培养基对草地早熟禾(PoapratensisL.)返青前后根际与非根际的细菌、真菌以及放线菌类群进行分离测数,拟从根际及非根际土壤微生物区系动态变化方面来阐述草地早熟禾返青前后其根际微生态的变化规律。结果表明:(1)草地早熟禾草坪的返青后,根际及非根际细菌、真菌数量明显增加,但放线菌数量呈减少趋势;(2)无论返青前后或者根际以及非根际,细菌的数量都占整个土壤微生物量的绝大部分,细菌数量的变化代表了整个微生物类群数量的变化趋势,使得草地早熟禾返青后根际土壤由"真菌型"向"细菌型"转化;(3)返青前后,各微生物类群都表现出明显的根际效应。

Rhizosphere microflora dynamics of Kentucky bluegrass before and after turning green

The rhizosphere is an active interface of material and the energy exchanges within the soil-plant ecosystem. Plants are influenced by rhizosphere microorganism in uptaking moisture and nutrients, and resisting against unhealthy environment. In this study, the selective culture medium is adopted to investigate the dynamic changes of both rhizospheral and non-rhizospheral bacteria, actinomycetes and fungi of Kentucky bluegrass. It aims to finding out the microflora dynamics regular response of this grass in be- fore and after it turns green; The main results indicated that, 1) Both bacterium and fungi, rhizospheral or non-rhizospheral, have a remarkable increase after the grass turns green, while actinomycetes witness a declining tendency. 2) Both rhizospheral and non-rhizospheral bacteria account for the majority of the whole microbial before and after it turns green. Since the quantitative change of bacteria well accounts for the tendency of the whole microorganism groups, it is concluded that the rhizospheral soil of Kentucky bluegrass is to transfer from the "fungi type" to the "bacterium type". 3) The rhizospheral effect is noticeable in various bacterial groups of Kentucky bluegrass before and after the grass turns green.