Functional structure and diversity of soil free-living nematodes in a desert environment depend on plant gender and sampling site. The objective of this study was to compare the composition, abundance and tropic group of soil free-living nematodes in the upper 0–10 cm soil layer under the male and female Acanthosicyos horridus Welw. ex Hook. f. plants and in the inter-shrub open areas (control) in the Namib Desert, Namibia in April 2015. Soil moisture, organic matter (OM) and pH was also analyzed. Free-living nematodes were extracted from 100 g soil using the Baermann funnel procedure, and total number of nematodes was counted under a microscope. Community composition and diversity of soil free-living nematodes were analyzed using 18S rDNA sequences. Results indicated that a total of 67 groups, including 64 species, 2 genera and 1 family were identified. Feeding behavior of 58 species were identified as follows: 15 bacteria-feeding species, 12 fungi-feeding species, 10 plant-parasite species, 5 omnivorous-predator species, 8 animal-parasite species, 5 invertebrate-parasite species and 3 non-free-living nematodes, known as marine species. Moreover, soil free-living nematodes were found to be affected by sampling locations and plant gender, and community composition and density of these nematodes were strongly influenced by soil OM content. Result confirmed that spatial location and plant cover were main factors influencing the diversity of soil free-living nematodes. Moreover, molecular tools were found to be very useful in defining the richness of soil non-free-living nematodes. In conclusion, the results elucidated the importance of biotic variables in determining the composition and abundance of soil free-living nematodes in the Namib Desert, Namibia.

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分析纳米比亚纳米布沙漠中土壤自由生活的线虫

沙漠环境中土壤自由生活线虫的功能结构和多样性取决于植物性别和采样地点。本研究的目的是比较雄性和雌性 Acanthosicyos horridus Welw 下上部 0-10 cm 土层中土壤自由生活线虫的组成、丰度和热带群。前钩。F。2015 年 4 月，纳米比亚纳米布沙漠的植物和灌木间开放区域（对照）。还分析了土壤水分、有机质 (OM) 和 pH 值。使用贝尔曼漏斗法从 100 g 土壤中提取游离线虫，并在显微镜下计算线虫总数。使用 18S rDNA 序列分析了土壤自由生活线虫的群落组成和多样性。结果表明，共有67组，包括64种，鉴定出2属1科。58种取食行为鉴定如下：15种食菌种、12种食菌种、10种植物寄生虫、5种杂食性捕食者、8种动物寄生虫、5种无脊椎动物寄生虫和3种非自由- 活线虫，被称为海洋物种。此外，发现土壤自由生活线虫受到采样地点和植物性别的影响，这些线虫的群落组成和密度受土壤有机质含量的强烈影响。结果证实空间位置和植物覆盖是影响土壤自由生活线虫多样性的主要因素。此外，发现分子工具在定义土壤非自由生活线虫的丰富度方面非常有用。综上所述，