连作花生田根际土壤优势微生物的分离和鉴定

Isolation and identification of dominant microorganisms in rhizosphere of continuous cropping with peanut

【目的】从不同连作年限的花生田根际土壤中分离优势微生物并进行鉴定,为研究花生连作后优势微生物的变化奠定基础。【方法】采用土壤稀释分离法从不同连作年限花生根际土壤中分离优势细菌、真菌和放线菌,结合菌株形态特征、培养性状、生理生化特征及16S rDNA序列分析对细菌、放线菌进行鉴定,通过形态特征、培养特征和分子鉴定方法对优势真菌进行鉴定。【结果】从连作花生田根际土壤中分离鉴定出7种优势细菌、7种优势真菌和7种优势放线菌。7种优势细菌分别为Leifsonia xyli、氯酚节杆菌(Arthrobacterchlorophenolicus)、黄色微杆菌(Microbacterium flavescens)、鞘氨醇单胞菌属(Sphingomonas sp.)、巴斯德菌属(Pasteurella sp.)、简单芽孢杆菌(Bacillus simplex)和巨大芽孢杆菌(Bacillus megaterium)。7种优势真菌分别为枝状枝孢菌(Cladosporium cladosporioides)、产紫青霉(Penicillium purpurogenum)、哈茨木霉有性型(Hypocrea lixii)、Exophiala pisciphila、微紫青霉(Penicillium janthinellum)、曲霉(Aspergillus sp.)和大丽轮枝菌(Verticillium dahliae)。7种优势放线菌分别为紫红链霉菌(Streptomyces violaceoruber)、华丽黄链霉菌(Streptomyces flaveus)、Streptomyces panaciterrae、不产色链霉菌(Streptomyces achromogenes)、假浅灰链霉菌(Streptomyces pseudogriseolus)、纤维素链霉菌(Streptomyces cellulosae)和金色链霉菌(Streptomyces aureus)。【结论】本研究是第一次系统的从连作花生根际土中分离鉴定优势微生物,种植花生后根际土壤中优势微生物的种类发生了明显变化,但变化没有规律。

[Objective] We isolated and identified dominant microorganisms from the rhizosphere of continuous cropping with peanut,to study the relationship between dominant microorganisms and peanut continuous cropping.[Methods] By using dilution-plate method we isolated dominant bacteria,dominant fungi and actinomycetes from the rhizosphere of continuous cropping with peanut.Morphological specificity,culture shape,physiological-biochemical characteristic and partial 16S rDNA sequences were used to identify bacteria and actinomycetes.Morpholog,growth on various media,and Internal Transcribed Spacer（ITS） rDNA sequences homology analysis were performed to identify dominant fungi.[Results] We isolated seven dominant bacteria strains,seven dominant fungi and seven dominant actinomycetes.Dominant bacteria were identified as Leifsonia xyli,Arthrobacter chlorophenolicus,Microbacterium flavescens,Sphingomonas sp.,Pasteurella sp.,Bacillus simplex and Bacillus megaterium.Dominant fungi were identified as Cladosporium cladosporioides,Penicillium purpurogenum,Hypocrea lixii,Exophiala pisciphila,Penicillium janthinellum,Aspergillus sp.and Verticillium dahliae.Dominant actinomycetes were identified as Streptomyces violaceoruber,Streptomyces flaveus,Streptomyces panaciterrae,Streptomyces achromogenes,Streptomyces pseudogriseolus,Streptomyces cellulosae and Streptomyces aureus.[Conclusion] This study was the first time to isolate and identify dominant microorganisms from the rhizosphere of continuous cropping with peanut.The type of dominant microorganisms changed obviously after planting peanut,although the change was without regularity.