细菌HT-6的鉴定及其对马铃薯致病疫霉抑制稳定性的研究

Identification of Bacterium HT-6 and Its Antagonistic Stability against Phytophthora infestans

为明确马铃薯致病疫霉拮抗菌HT-6的生物学特性及抑菌潜力,通过对其在不同培养基上的菌落特征观察、生理生化特性检测及16S rDNA序列分析,确定该菌株的分类地位,并测试了不同温度、pH、紫外线以及传代对该菌株菌液抑制致病疫霉菌丝生长的影响。综合菌落特征、生理生化特性及16S rDNA序列比对结果,确定细菌HT-6为枯草芽孢杆菌(Bacillus subtilis);该菌株菌液中抑制致病疫霉菌丝生长的物质经100℃处理60min、pH值6~8处理24h、30W紫外线照射8h、连续传代10次,抑菌率仍保持在80%以上。这些结果表明,枯草芽孢杆菌HT-6及其产生的抑菌物质除不耐酸碱外,耐热、抗紫外线且适于长期保存,将其开发成预防马铃薯晚疫病的生防制剂具有巨大潜力。

In order to clarify the biological characteristics and antagonistic stability of bacterium HT-6 strain on Phytophthora infestans,this experiment was conducted to observe its colony features on different media,detect physiological and biochemical characteristics and analyze 16S rDNA sequence,to determine its classification status.The effects of different temperature,pH,ultraviolet light,and continuous passage on the mycelial growth of Phytophthora infestans were tested.The HT-6 strain was identified as Bacillus subtilis based on results of its colony properties,physiological and biochemical characteristics and 16S rDNA sequence.The inhibition rates of HT-6 strain and its metabolites on P.infestans could keep more than 80%after treatment with 100℃ for 60min,pH 6-8 for 24h,30W ultraviolet irradiation for 8h,and continuous 10 passages.These results showed that HT-6 strain and its metabolites had thermostability,ultraviolet resistance,and could store for a long time,except toleration acid and alkali.It has great potential value to develop it into a biological control agent for the prevention of potato late blight.