Abstract:

In order to explore the relationship between cucumber root-knot nematode disease and rhizosphere soil microbial community， the microbial community structures between healthy and diseased cucumber root topsoil and rhizosphere soil were analyzed by high-throughput sequencing. The results showed that there was no significant difference in microbial Alpha diversity among 4 soil samples （healthy cucumber root topsoil， healthy cucumber rhizosphere soil， diseased cucumber root topsoil， diseased cucumber rhizosphere soil）， while Beta diversity existed significantly differences among the 4 groups. At the phylum level， the compositions of bacterial and fungal communities were similar among the 4 groups. The relative abundances of Bacteroidetes and Basidiomycota were significantly different among groups， with the highest relative abundance of Bacteroidetes （13.58%） in diseased cucumber root topsoil and Basidiomycota （6.69%） in healthy cucumber root topsoil. At the genus level， the compositions of bacteria and fungi were similar among the groups. The relative abundances of Flavobacterium， Pseudomonas， Streptomyces， Rhizobium， Devosia， Novosphingobium， Ensifer， Cellvibrio and Chitinophaga were significantly different among the groups， which abundances were highest in the diseased cucumber root topsoil with 3.62%， 2.58%， 1.93%， 2.34%， 1.14%， 1.60%， 1.30%， 1.13% and 1.59%， respectively. The relative abundance of Steroidobacter was the highest in healthy cucumber root topsoil with 1.50%. The relative abundance of Pseudallescheria and Chaetomium were the highest in the healthy cucumber rhizosphere soil with 13.73% and 11.00%. Myrothecium had the highest relative abundance in healthy cucumber root topsoil with 7.51%. The relative abundance of Metarhizium was highest in the diseased cucumber rhizosphere soil with 3.99%. The relative abundance of Corynespora was highest in the diseased cucumber root topsoil with 2.64%. Above results should provide some theoretical basis for controlling root-knot nematodes by regulating microbial community structure in plant rhizosphere soil.

Key words: root-knot nematode disease, rhizosphere soil, microorganism diversity, cucumber

摘要：

为探明黄瓜根结线虫病与根际土壤微生物群落的关系，通过高通量测序分析对比了受根结线虫危害和健康黄瓜根系的根表土和根围土中微生物群落结构组成及丰富度的差异。结果表明，健康黄瓜根表土、健康黄瓜根围土、病害黄瓜根表土和病害黄瓜根围土4组土壤样品之间微生物Alpha多样性无显著差异，但Beta多样性在各组间差异显著。在门水平上，各组间细菌和真菌群落组成相似，但拟杆菌门（Bacteroidetes）和担子菌门（Basidiomycota）在各组的相对丰度存在显著差异，其中拟杆菌门在病害黄瓜根表土（13.58%）、担子菌门在健康黄瓜根表土（6.69%）中的相对丰度较高。在属水平上，各组间细菌和真菌的组成也基本一致，细菌中黄杆菌属（Flavobacterium）、假单胞菌属（Pseudomonas）、链霉菌属（Streptomyces）、根瘤菌属（Rhizobium）、德沃斯氏菌属（Devosia）、鞘氨醇杆菌属（Novosphingobium）、剑菌属（Ensifer）、纤维弧菌属（Cellvibrio）和噬几丁质菌属（Chitinophaga）在不同组中的相对丰度存在显著差异，且均在病害黄瓜根表土中的相对丰度最高，分别为3.62%、2.58%、1.93%、2.34%、1.14%、1.60%、1.30%、1.13%和1.59%；而黄色类固醇杆菌属（Steroidobacter）在健康黄瓜根表土中的相对丰度最高，为1.50%；真菌中假埃希氏菌属（Pseudallescheria）、毛壳菌属（Chaetomium）在健康黄瓜根围土中的相对丰度最高，分别为13.73%、11.00%；漆斑菌属（Myrothecium）在健康黄瓜根表土中的相对丰度最高，为7.51%；绿僵菌属（Metarhizium）在病害黄瓜根围土中的相对丰度较高，为3.99%；棒孢菌属（Corynespora）在病害黄瓜根表土中的相对丰度较高，为2.64%。研究结果为通过调控植物根际土壤微生物群落结构防治根结线虫提供了理论依据。

关键词: 根结线虫病, 根际土, 微生物多样性, 黄瓜