产几丁质酶菌的分离、筛选及其对烟草病原真菌的抑制作用

从福建、河南、安徽、云南、湖北采集了烟草根际土样100份,用几丁质选择培养基法共分离出产几丁质酶菌株62株,其中真菌32株、细菌22株、放线菌8株。通过透明圈法和还原糖法对分离的菌株进行了筛选,结果表明链霉菌属(Streplomycessp)产几丁质酶活性最高。并测定了几丁质酶活性较高的菌株对烟草赤星病菌和黑胫病菌的抑制效果,其中菌株9-1-1、9-2-1和19-2-1对黑胫病菌均有不同程度的抑制作用,以菌株9-1-1的抑菌效果最好,而这3种菌株对赤星病菌的抑制效果不明显。因此,菌株9-1-1有开发成为生防制剂用于防治烟草黑胫病的潜力。

Isolation and Screening of Chitinase Producing Strains and Inhibition Action to Pathogenic Fungi of the same

100 samples of tobacco rhizosphere soil were collected from Fujian, Henan, Anhui, Yunnan and Hubei, 62 chitinase producing strains, including 32 fungi, 22 bacteria and 8 actinomyces, were isolated by chitin selective medium. The strains were screened with transparent zone and reducing sugar methods. The results showed that the chitinases produced by Streplomyces sp had the highest activity. The inhibition actions of the strains, which produced chitinases with high activity, to Alternaria alternata (Freis) Keissler and Phytophthora parasitica Dast var. nicotianae were determined. The strains, 9-1-1, 9-2-1, and 19-2-1, showed inhibition action to Phytophthora parasitica Dast var. nicotianae at different degress, headed by strain 9-1-1; however, they had no inhibition action to Alternaria alternata (Freis) Keissler. Strain 9-1-1 had the potential of becoming a biofungicide against Phytophthora parasitica Dast var. nicotianae.