三七连作根际微生物多样性研究

The Study on Microbial Diversity of Rhizosphere in Continuous Cropping System of Panax notoginseng

【目的】针对三七土传病害根腐病日益突出的问题,探讨三七根际土壤和根内生微生物多样性、生物群落组成及代谢活性与根腐病发生的相关性。【方法】对连作3年三七和连作4年三七的健康植株和感病植株根际土壤进行Biolog ECO代谢功能多样性分析,对三七根际土和根组织采用多种培养基进行微生物的分离培养,根据细菌16S r DNA序列和真菌ITS区序列的通用引物进行PCR扩增、Blast同源比对及其系统进化树分析。【结果】健康植株组与感病植株组根际土壤微生物群落的丰富度和均匀度存在显著差异(P<0.05),健康植株组土壤微生物群落的生理活性高于感病植株组;从根际土壤中培养出172株菌株,其中,健康植株组土壤以芽孢杆菌(Bacillus)、假单胞菌(Pseudomonas)、节杆菌(Arthrobacter)等为优势菌群;感病植株组土壤以黄杆菌(Flavobacterium)、毛霉菌(Mucor)和镰刀菌(Fusarium)等为优势菌群;从根组织中分离出121株菌株,其中,健康植株根部以芽孢杆菌(Bacillus)、假单胞菌(Pseudomonas)为优势菌群,感病植株根部以镰刀菌(Fusarium)、拉恩氏菌(Rahnella)、欧文氏菌(Erwinia)等为优势菌群。【结论】三七土传病害根腐病的发生与植株根际微生物群落结构组成及代谢功能多样性密切相关,为从微生态角度改善三七土壤健康状况及控制三七根腐病的发生提供科学理论依据。

[Purposes]This research aimed at the problem of soil-borne root rot in Panax notoginseng replant failure protrude increasingly, to explore correlation among microbial diversity, community composition and metabolic activity with root rot.[Methods]The metabolic functional diversity analysis was used to study the rhizosphere soils that originated from continuous cropping for 3 years and 4 years healthy plants and root rot plants. Microorganisms in soils and roots were isolated and cultured by various medium, PCR based on the consensus primers of 16 S r DNA sequences and ITS regions, Blast homology comparison and phylogenetic tree analysis.[Results]The Shannon and Mc Intcosh of microbial community had a significant difference between healthy plant group and root rot group（P〈0.05）, and the physiological activity of soil microbial communities of healthy plants were higher than that of rot plants. There were 172 strains isolated in the rhizosphere soil, Bacillus,Pseudomonas, Arthrobacter as the dominant microflora in healthy plants soils, and Flavobacterium,Mucor and Fusarium as the dominant microflora in rot plant soils. There were 121 strains isolated in roots, Bacillus and Pseudomonas as the dominant microflora in healthy roots, and Fusarium, Rahnella and Erwinia as the dominant microflora in rot root.[Conclusions]Soil-borne disease in P. notoginseng replant failure is closely related to the community structure and metabolic functional diversity.From the perspective of micro ecology, this study provides a scientific theoretical basis for improving the soil health status and controling P. notoginseng root rot.