Abstract:

The identification, biological characteristics and antagonistic spectrum of Panama disease bio-control Bacillus strain R31 were studied in this paper. R31 strain was identified as Bacillus subtilis based on the API identification system. The biological characteristics researches showed that R31 grew well at weak acid condition or weak alkalinity condition, the optimum pH in these two different condition were 5.13 or 8.99, respectively. Sucrose was its optimum carbon source while yeast extract was its optimum nitrogen source, it got the stationary growth phase by cultured in NA medium in 24 hours. This strain although had a broad antagonistic spectrum on fungi, lots of Fusarium pathogens included different F. oxysporum f. sp. cubense strains were inhibited obviously by R31 strain in petri dish culture, the hypha of fungi became malformation and broken finally with the protoplasm outflow.