马铃薯早疫病菌拮抗微生物的初步研究

Study on Screening of Antagonistic Strains to Alternaria solani and Their Inhibition Action

[目的]筛选马铃薯早疫病菌拮抗微生物,并研究其抑菌效果,为利用微生物资源更加有效地控制马铃薯早疫病提供依据。[方法]以对峙培养和滤纸片法筛选具有显著抑菌作用的微生物菌株及其胞内物质或发酵产物,用饱和硫酸铵沉淀法分离抑菌物质。[结果]供试真菌和细菌的12个菌株中,11个菌株均有显著的抑菌作用,但大多数菌株的直接抑菌作用强度与其胞内物质或发酵产物之间无明显相关性。枯草芽孢杆菌B309的直接抑菌率和发酵产物的抑菌率均为最高,分别为79.32%和75.22%;B401次之,其直接抑菌率和发酵产物的抑菌率分别为74.85%和72.03%。B309和B401的发酵产物硫酸铵饱和度分别在45%-55%和55%-65%时,获得的蛋白类物质的抑菌率最高,分别为69.34%和63.52%;蛋白类物质的含量也在上述硫酸铵饱和度时最高,B309为28.251μg/ml,B401为23.673μg/ml,非蛋白类物质无抑菌作用。[结论]枯草芽孢杆菌在防治马铃薯早疫病中有很大的应用潜力。

[Objective] The research aimed to screen antagonistic strains to Alternaria solani, and study their inhibition action, providing some knowledge for contrel potato early blight by microorganisms or their metabulites. [ Method] Antagonistic strains and their substance against A. solani were screened with dual-culture and filter disc method, and antibiotic substance were investigated with ammonium sulfate saturation. [ Result] Eleven of tested 12 straim had evident inhibition to A. solani, but there was no relation between direct inhibition of strains and indirect inhibitory activity of their metabolites. Bacillus subtilis B309 and B401 displayed the strongest inhibition to fungus. The rates of direct inhibition and fermentation for B309 were 79.32% and 75.22% respectively, and those for B401 were 79.32% and 75.22% respectively. Antifungal substances obtained by precipitating fermentations of B309in55%-65% and B401 in 45% - 55% ammonium sulfate saturation respectively, had the highest inhibition rates （69.34% for B309 and 63.52% for B401）. The highest contents of crude proteins were also acquired in ammonium sulfate grade 55% -65% for B309 （28.251μg/ml） and 45% - 55% for 13401 （23.673 μg/ml） respectively. The non-proteins had no inhibition. [ Conclusion] The isolates of B.subtilis possess a great potential in controlling potato early blight.