杀虫芽孢杆菌HZ179的鉴定及其相关生物学功能研究

Study on biological functions and identification of Bacillus sp.insecticidal strain HZ179

为明确杀虫芽孢杆菌HZ179菌株的分类地位及相关生物学功能,用形态学、生理生化特性及16S rDNA和gyrB序列分析对HZ179进行种属鉴定,通过盆栽试验,测定HZ179对辣椒幼苗生长指数、防御酶活性及单宁含量的影响;通过诊断PCR方法测定HZ179对瓜蚜共生菌的影响。结果表明,HZ179为贝莱斯芽孢杆菌(Bacillus velezensis)。HZ179能显著促进辣椒幼苗生长,其中100倍稀释液处理的幼苗株高、茎粗、植株干重、根冠比、壮苗指数与对照相比分别提高44.19%、15.70%、22.47%、16.18%和16.71%。HZ179灌根能显著提高辣椒叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)等酶的活性及单宁含量,并在14 d内保持较高水平。HZ179处理组瓜蚜共生菌的感染种类和感染率均低于对照。贝莱斯芽孢杆菌HZ179具有促进辣椒幼苗生长、诱导产生系统抗性和抑制瓜蚜共生菌等功能。

To clarify the taxonomic category and related biological functions of Bacillus sp.strain HZ179,morphological,physiological and biochemical characteristics,as well as 16S rDNA and gyrB sequence analysis were conducted.Effects of strain HZ179 on the growth index,defense enzyme activity,and tannin content of pepper seedlings were determined through pot experiments;and the antibacterial activity on symbiont of Aphis gossypii was evaluated by diagnostic PCR method.The results indicated that strain HZ179 belonged to Bacillus velezensis.The plant height,stem diameter,dry weight,root to shoot ratio,and seedling strength index of seedlings irrigated with 100 times diluted HZ179 powder increased by 44.19%,15.70%,22.47%,16.18%,and 16.71%respectively,compared with the control.And the activities of enzymes such as superoxide dismutase(SOD),peroxidase(POD),polyphenol oxidase(PPO),phenylalanine ammonia lyase(PAL),and the content of tannin in leaves were significantly enhanced and maintained at a high level for 14 days.The infection species and infection rates of symbiont in Aphis gossypii in the HZ179 treatment group were lower than those in the control group.B.velezensis strain HZ179 could promote the growth of pepper seedlings,induce systemic resistance,and inhibite symbiont of Aphis gossypii.