番茄早疫病菌拮抗放线菌10-4的鉴定

为明确放线菌10-4菌株在植物病害生物防治中的应用潜力,采用琼脂块法、菌丝生长速率法和温室盆栽试验测定其抑菌作用,并通过多相分类法研究其分类地位。结果表明:菌株10-4对20种植物病原真菌均有抑制作用,其中对小麦根腐病菌、稻瘟病菌、番茄早疫病菌、立枯丝核病菌、小麦全蚀病菌、苹果炭疽病菌和玉米大斑病菌的抑制作用较强,生长抑制率均达到90%以上;菌株10-4的代谢产物对植物病原真菌菌丝有致畸作用;其发酵原液和5倍稀释液在活体植株上对番茄早疫病具有良好的生防作用,防治效果分别为77.2%和70.9%。根据形态特征、培养性状、生理生化特性、细胞壁化学组分及16SrDNA序列分析结果,将菌株10-4初步鉴定为腐生链霉菌Strepto-myces saprophyticus。

Identification of the antagonistic actinomycetes strain 10-4 against tomato early blight

In order to define the potential application of strain 10-4 to plant diseases in biological control, using agar block method, inhibition rate of mycelium growth and bonsai experiment in greenhouse to determine the bactriostasis, the classification status of 10-4 was confirmed by multiphase taxonomy. The results showed that strain 10-4 had strong inhibiting activity to all 20 plant pathogenic fungi, especially to Bipolaris sorokiniana, Magnaporthe grisea, Alternaria solani, Rhizoctonia solani, Geaumannomyces graminis, Colletotrichum gloeosporioides and Exserohilum turcicum,the inhibition rate of mycelium growth were exceed 90%. The metabolite of strain 10-4 showed teratogenic effects on mycelia of plant pathogenic fungi. The original fermentation and its five times dilution of strain 10-4 showed strong biocontrol effects on tomato early blight with 77.2% and 70.9% respectively.According to the morphology,cultural, physiological and biochemical characteristics, chemical components of cell wall and 16S rDNA sequence, the strain 10-4 was identified as Streptomyces saprophyticus.