云南元江蔗田土壤放线菌多样性及对几种植物病原菌的抑菌活性

利用高氏I号培养基分离培养及菌株形态、生理生化鉴定和16S rDNA序列分析法研究了云南元江县甘蔗田土壤放线菌，并采用对峙生长法测定了各放线菌对小麦全蚀病病原菌（Gaeumannomyces graminisr）、小麦根腐病病原菌（Cochliobolus sativus）、烟草赤星病病原菌（Alternar iaalternata）和水稻稻瘟病病原菌（Magnaporthe oryzae）的抑菌活性。结果表明：元江甘蔗田土壤中共发现典型土壤放线菌29株，其中28株为链霉菌属（Streptomyces），1株为纤维单胞菌属（Cellulomonas）。菌株G27对小麦根腐病病菌的抑制活性最高，抑菌率达到82.66%；对烟草赤星病菌和稻瘟病菌亦有较强的抑制作用，抑菌率分别为67.85%和65.88%。由此表明，云南元江蔗区甘蔗田土壤放线菌群落结构较单一，链霉菌为优势种群。G27菌株具有作物真菌病害生物防治资源菌开发的潜在价值。

Diversity and Antagonistic Activity of Actinomycetes from Sugarcane Soil in Yunnan against Plant Pathogenic Fungi

Actinomycetes were isolated from the sugarcane soils by improved Gao's No.1 synthetic medium. Physiological and biochemical characteristics, molecular identification and phylogenetic analysis were carried out on 29 isolates selected by morphology. Antimicrobial activity of the soil actinomycetes to plant pathogenic fungi was studied using the Dual-culture method. The results of identification showed that only one strain was identified as Cellulomonas and the other twenty-eight strain were identified as Streptomyces. The strain G27 was active against Cochliobolus sativu, Alternar iaalternata and Magnaporthe oryzae. It's inhibition rates of mycelium growth were 82.66%, 67.85%, 65.88%, respectively. Sugarcane community structure of soil actinomycetes is single, and Streptomyces advantage for sugarcane populations. G27 showed a development potential for the biological control of crop disease.