6株生防放线菌对辣椒疫霉的皿内拮抗研究

采用琼脂块法研究了6株生防放线菌在不同培养基、培养时间及紫外线处理等多种条件下对2株辣椒疫霉的皿内拮抗作用。结果表明,6株放线菌(10号除外)在供试培养基上的拮抗性表现为PDA>黄豆粉>腐殖酸,PDA琼脂培养基可作为辣椒疫霉生防放线菌的筛选培养基;6株放线菌不同培养时间对辣椒疫霉的抗菌活性表现为13d>20d>7d,以培养13d时的拮抗效果较好;6株拮抗放线菌对陕西岐山辣椒疫霉P4的拮抗效果均优于青海辣椒疫霉P3菌株;用紫外线直接照射拮抗性放线菌琼脂块,不能准确地指示放线菌分泌的抗生素化学结构是否稳定,还需提取发酵产物进行紫外线照射处理加以判断。

Study on the antagonistic activity of 6 strains of actinomycetes against Phytophthora capsici in plate

The paper studied the antagonism of 6 strains of actinomycetes against two kinds of Phytophthora capsici in different cultural media,cultural times and ultraviolet radiation treatments by agar lump method.The results showed that:The antagonism of 6 strains of actinomycetes had close relationship with their cultural media.Antagonistic activity was best in the PDA cultural medium,which can be used for the selecting of the actinomycetes against Phytophthora capsici.The antagonism of 6 strains of actinomycetes had close relationship to their cultural time.Using the agar lump method for the selecting of the antagonistic actinomycetes against Phytophthora capsici,the actinomycetes should be cultivated for 13 days.The 6 strains of actinomycetes had stronger antagonistic activity against Phytophthora capsici isolated from Qishan than that from Qinghai.The method of ultraviolet radiation irradiating the agar lump didn't reflect the structure of antibiotics secreted by strains whether it is stable or not.The product extracted from the fermentation liquids of the strains can reflect the structure of antibiotics whether it is stable or not.