SGER: Assessing Nematode Biodiversity

由于人类的干预，自然栖息地的生物种类和数量正在迅速减少。通过目测以外的手段监测生境破坏已变得至关重要。早期发现生态系统退化的一种可能是监测线虫种群多样性的变化。线虫在所有生态系统中无处不在，是陆地和水生栖息地食物网的主要组成部分。对全球生态系统中线虫群落结构和功能的研究表明，它们在土壤系统中具有重要的生态意义。土壤线虫一般分为五类：植食性、细菌食性、真菌食性、杂食性和捕食性。最近，细菌喂食者被认为是水生和陆地系统污染的指标。对不同生境中以细菌为食的线虫种类的数量估计很少。由于土壤中以细菌为食的线虫的重要性，在检查生态系统功能的稳定性/变化时，物种确定变得至关重要，针对这一群体的分类学研究有限。物种鉴定的困难之一是，大多数线虫是透明的、微观的，需要特殊的处理技术来辨别细微的分类特征，这是一个极其费力的过程。提出了一种不同的探索性方法来检查细菌摄食线虫的物种多样性。将使用两种方法：1)传统的形态学分析和2)最近发展的分子生物学技术。预计这些技术将允许快速确定线虫种群内的生物多样性以及确定物种分离。这些技术最终将使物种计数和确定濒危生境中线虫种群多样性的丧失成为可能。

The loss of variety as well as the numbers of organisms in natural habitats is occurring at a rapid pace due to human intervention. It has become crucial to monitor habitat destruction by more than visual observation. One possibility for early detection of ecosystem degradation is to monitor changes in diversity of nematode populations. Nematodes are ubiquitous in all ecosystems and are a major component of the food web in both terrestrial and aquatic habitats. Previous research on the structure and function of nematode communities in global ecosystems has shown that they are of ecological significance in soil systems. Soil nematodes are generally classified into five feeding groups: plant feeders, bacterivores, fungivores, omnivores and predators. More recently, the bacterial feeders have been considered as indicators of pollution in both aquatic and terrestrial systems. There are very few estimates of the numbers of species of bacterial feeding nematodes in various habitats. Species determinations become crucial as ecosystems are examined for stability/change in functioning due to the importance of bacterial feeding nematodes in soil, there has been limited taxonomic research directed at this group. One of the difficulties in species determinations is that most nematodes are transparent, microscopic, and require special techniques in handling in order to discern minute taxonomic characters, a process that is extremely laborious. A different, exploratory approach is proposed for examining the species diversity of bacterial feeding nematodes. Two methods will be used: 1) traditional morphological analyses, and 2) recently developed molecular biological techniques. It is anticipated that these techniques will allow for the rapid determination of biodiversity within a nematode population as well as delimitation of species isolates. These techniques should eventually allow the enumeration of species and determination of the loss of diversity within nematode populations from endangered habitats.