Soil fungi: diversity and detection
Soil fungi: diversity and detection
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DOI：
10.1023/a:1010346305799
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发表时间：
2001-01-01
期刊：
影响因子：
4.9
通讯作者：
Spooner, B
中科院分区：
文献类型：
--
作者：
Bridge, P;Spooner, B
到目前为止命名和描述的8万多种真菌中，绝大多数可能在其生活史的某个阶段出现在土壤环境中。因此，真菌在土壤中有许多不同的功能，其中既包括积极的作用，如降解枯死的植物材料，也包括不活跃的作用，即在土壤中以休眠状态存在繁殖体。目前关于土壤真菌多样性的知识主要是基于对环境中存在的子实体的观察，或从土壤隔离实践中获得的培养物。这两种方法在检测任何选择的环境中的真正多样性方面都有严重的局限性。如果不形成子实体，只以菌丝形式存在于土壤中的有机体不太可能从直接观察中被识别出来。因此，通过直接显微镜的经典观察将大大减少对环境中真实多样性的测量。从土壤分离中培养真菌只会检测到那些能够在所用的分离介质上生长和产生孢子的繁殖体。这将再次导致多样性的措施大大减少，因为目前只有大约17%的已知真菌物种可以在培养中成功生长。从土壤中恢复培养物也不能区分真菌是原始生态系统中活跃的部分还是处于不活跃的休眠状态。分子技术的发展提供了一系列新的工具，可以清楚地洞察土壤环境中的特定相互作用和活动。将广谱聚合酶链式反应(PCR)检测与单链构象多态(SSCP)或变性梯度凝胶电泳(DGGE)相结合，可以更准确地回答生态系统多样性的基本问题。然而，这项技术不区分活动阶段和休息阶段，为了准确地解释结果，需要对生物体的生态和功能有一些先验知识。
The great majority of the 80 000+ fungal species so far named and described are likely to occur in the soil environment at some stage in their life-cycle. Fungi therefore have many different functions in soils, which include both active roles, such as the degradation of dead plant material, or inactive roles where propagules are present in the soil as resting states. Current knowledge of fungal diversity in soil is based largely on observations of fruiting bodies present in an environment, or from cultures obtained from soil isolation exercises. Both of these approaches have serious limitations for the detection of the true diversity in any chosen environment. An organism that exists only in a mycelial form in the soil is unlikely to be identified from direct observation if a fruiting body is not formed. Therefore, classical observation through direct microscopy will give a greatly reduced measure of the true diversity in the environment. Culturing fungi from soil isolations will only result in the detection of those propagules that are able to grow and sporulate on the isolation medium used. This again will lead to a greatly reduced measure of diversity, as at the present time only about 17% of the known fungal species can be successfully grown in culture. The recovery of a culture from soil also does not distinguish whether the fungus was an active part of the original ecosystem or present in an inactive resting state. The development of molecular techniques has provided a new range of tools that can provide clear insights into specific interactions and activities in soil environments. The combination of broad spectrum polymerase chain reaction (PCR) detection, coupled with single strand conformation polymorphisms (SSCP) or denaturing gradient gel electrophoresis (DGGE), can give more accurate answers to fundamental questions on ecosystem diversity. This technique does not however distinguish between active and resting stages, and in order to interpret results accurately, some a priori knowledge of the ecology and function of the organisms is required.