荷花腐败病生防菌的筛选及鉴定

【目的】筛选对荷花腐败病菌有较强拮抗作用的生防菌,为荷花的健康生产及荷花腐败病的有效控制提供参考。【方法】采用抑菌圈法和对峙培养法从106株供试拮抗细菌中筛选对荷花腐败病菌有较强拮抗作用的生防菌,经形态学、生理生化和分子鉴定确定生防菌分类地位,通过与其他6种作物病原真菌的对峙培养了解生防菌的抑菌谱,并通过田间小区试验明确生防菌的田间防治效果。【结果】从供试的106株测试菌株中筛选获得4株对荷花腐败病菌具有拮抗效果的生防菌,其中以DR1菌株的拮抗效果最佳,抑菌带宽为9.8 mm。DR1菌株的拮抗谱较宽,对供试6种植物病原真菌均具有良好的抑制活性。田间防效试验结果表明,DR1菌株对荷花腐败病的平均防效为41.83%。根据16S r DNA和gyr B基因序列分析结果并其结合生理生化特征,将DR1菌株鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。【结论】解淀粉芽孢杆菌的拮抗活性、耐热性和抗逆性强,且有较宽的抗菌谱,在荷花病害防治中具有较好的开发应用前景。

Screening and identification of biocontrol bacterium against lotus rhizome rot disease

Objective]The present study screened and identified the biocontrol bacteria against Fusarium commune,in order to provide reference for healthy planting of lotus and effective control of lotus rhizome rot disease.Method] Inhibition zone method and confrontation culture were employed to screen the biocontrol bacteria which had strong antagonism against F.commune out of 106 tested antagonistic bacteria.The biocontrol bacteria were identified according to morphology,physiology,biochemistry and molecular identification.Through confrontation culture with six phytopathogenic fungi,antimicrobial spectrum of the biocontrol bacteria was studied.Field control effects of biocontrol bacterium were explored through field experiment.Result]Four biocontrol bacteria with antagonism against lotus rhizome rot disease were selected out of 106 tested strains.Antagonist effects of strain DR1 was the best.Its bacteriostasis band width was 9.8 mm.Strain DR1 enjoyed wide antimicrobial spectrum,and showed inhibitory effects towards six tested phytopathogenic fungi.The field experiment results showed that average control effect of strain DR 1 was 41.83％.Strain DR1 was identified as Bacillus amyloliquefaciens for its biochemical characteristics based on 16S rDNA and gyrB gene sequence analysis.Conclusion]B.amyloliquefaciens has strong antagonism effect,heat resistance,strong stress resistance,and broad antimicrobial spectrum.Therefore,it possesses promising developing and applying prospect in lotus disease control.