烟草赤星病菌拮抗放线菌的筛选与鉴定

采用稀释平板分离法从张家界金鞭溪采集的土样中分离到20株放线菌。以烟草赤星病菌为靶标菌进行筛选,通过平皿对峙培养的方法,筛选出S-1,S-6,S-16,S-20等4株抑菌效果明显的菌株(抑菌率≥50%),抑菌率分别为51.7%,53.4%,51.9%,71.4%。进一步应用管碟法对菌株发酵液的代谢产物进行测定,结果表明,菌株S-20的抑菌圈直径为26.3 mm,抑菌带最宽,对烟草赤星病菌的抑制作用最显著。为了加深对该菌株的了解,本研究还对其形态特征、培养特征以及生理生化特性作了测定,初步鉴定菌株S-20为链霉菌属(Streptomycesspp.)的球孢类群(Globis-porus)。最后,抑菌谱试验表明,菌株S-20不仅对烟草赤星病菌作用明显,对其他病原真菌同样有抑制作用,抑菌谱广。

Screening and Identification of the Antagonistic Actinomyces Against Alterna ria Alternata

Twenty Actinomyces were isolated from soil with dilution isolation,which collected from Jin bian brook,Zhang Jiajie.Antagonistic strains were screened for the bioactivity targeted against Alternaria alternata.Pair-culture showed S-1,S-6,S-16 and S-20 were screened which had higher inhibition rate(inhibition rate>50%).The inhibition rate were 51.7%,53.4%,51.9%,71.4%,and then the fermentation liquid of strains was determined,The results showed S-20 had the best anti-bacteria effect.The inhibition zones was 26.3 mm,In order to recognize this strain,based on its cultural,physiological and biochemical characteristics,S-20 was designated as the series globisporus of stretomyce The inhibition range showed that S-20 not only effect on Altermaria altermata but also on the other pathogens.The inhibition range widely.