[目的]分离、筛选樱桃园土壤优势放线菌菌株,研究其在生物防治与植物促长中的应用潜力.[方法]采用皿内拮抗与发酵液促生试验分析优势放线菌菌株抗生与促进生长功能.对具有良好抑菌与促进生长作用的菌株F4-5,通过16S rDNA序列分析研究其分类地位.[结果]从樱桃[(Cerasus avium Moench (L.)/C.sachalinensis (L.) Kom.)园土壤中共分离获得32株优势放线菌菌株.与5月和11月相比,8月土壤中放线菌数量最多.各时期分离优势放线菌的抑菌作用与促进生长能力随生育期而各异,总体上,2010年8月分离菌株抑菌与促进生长效果较为明显.放线菌菌株F4-5对金黄色葡萄球菌(Staphylococcus aureus)、大肠杆菌(Escherichia coli)、枯草芽孢杆菌(Bacillus subtilis)和蜡质芽孢杆菌(Bacillus cereus) 4株供试细菌,以及木霉(Trichoderma viride)、根霉(Rhizopus stolonifer)和黑曲霉(Aspergillus niger) 3株供试真菌均表现出明显抑制效果,具有广谱抗生性.同时,菌株F4-5亦可显著促进山荆子(Malus baccata (L.) Brokh.)种子萌发与胚根生长,较对照分别提高了201.1％和43.5％,表现出抗生与促进生长双重效应.根据形态、培养特征及16S rDNA序列分析,初步鉴定菌株F4-5为灰黄链霉菌(Streptomyces flavogriseus).[结论]不同时期樱桃园土壤放线菌数量、分布、抗生及促进种子萌发特性变化较大,灰黄链霉菌F4-5菌株具有良好的广谱抗生性与促进种子萌发、胚根生长的作用.%[Objective] The dominant actinomycetes in cherry orchard soil were isolated and collected at different growth phases to study their application potential in biocontrol and plant growth promotion.[Method] All isolates were assayed for antagonistic activity,fermentation activity in vitro experiments to analyze their antagonistic and growth promoting function.Strain F4-5 with good microorganism inhibiting effect and plant growth promoting functions was explored through 16S rDNA sequence analysis to ascertain its taxonomic status.[Result] There were 32 dominant actinomycetes were isolated from Cerasus avium (L.)Moench / C.sachalinensis (L.) Kom.Rhizosphere soil at different growth stages.The number of soil actinomycetes in August was the highest compared with that in May and November.The isolates from different growth stages also varied in their microorganism inhibiting and plant growth promoting capabilities.In general,isolates from August 2010 expressed obvious effect on antagonistic pathogen and plant growth promotion.Among all the 32 isolates,strain F4-5 showed a significant inhibitive effect on 4 tested bacteria including Staphylococcus aureus,Escherichia coli,Bacillus subtilis and B.cereus,as well as 3 tested fungi including Trichoderma viride,Rhizopus stolo and Aspergillus niger,exhibiting a broad-spectrum antibiosis.In the experiment of seeding growth of Malus baccata (L.) Brokh.,strain F4-5 also displayed a positive effect on seed germination and root growth,increased by 201.1％ and 43.5％,respectively,compared with the control,indicating both antibiosis and plant promoting effects.In addition,strain F4-5 was identified as Streptomyces flavogriseum,according to the morphological characteristics,cultural characteristics and 16S rDNA sequence analysis.[Conclusion] The actinomycete number,distribution,antibiotic and seed germination promotion in Cerasus avium (L.) Moench / C sachalinensis (L.) Kom.Rhizosphere soil varied greatly at different stages.The proper strain F4-5 (S.flavogriseum) screened from 32 actinomycete strains showed a good probiotic role and seed germination promotion.
展开▼
