烟草黑胫病拮抗菌XF10的筛选与鉴定

摘要

In order to quickly and effectively screen out antibacterial strains that have obvious antagonism against tobacco black shank, 300 soil samples were collected from the healthy plants'rhizosphere in serious tobacco black shank incidence areas. A strain, XF10, was obtained by rapid initial screening of pathogenic bacteria and confrontation culture. The appearance of XF10 colony was round with a smooth surface and neat edges. XF10 could produce orange pigment and was identified by morphological characteristics, biological phenotype identification, BIOLOG automatic microbiological identification system and 16S rDNA sequence analysis. The results showed that the homology of sequence between XF10 and several Pseudomonas chlororaphis strains in Pseudomonas reached 99%, therefore XF10 was identified as Pseudomonas chlororaphis. Both bacterial fluid and extracellular metabolite crude extract of XF10 possessed more than 80% inhibitory rate on Phytophthora parasitica var. nicotianae (Breda de Haan) Tucker. Moreover, the volatile metabolites of XF10 could inhibit the growth of pathogenic hyphae with an inhibition rate of 86%.%为丰富烟草黑胫病拮抗细菌菌株资源,有效利用生物防治方法控制烟草黑胫病,在烟草黑胫病发病严重地块的健株根际周围选取土壤样品300份,通过喷施病原指示菌快速初筛、平板对峙培养复筛等方法获得了对烟草黑胫病菌有明显拮抗作用的生防菌株XF10.该菌株菌落为圆形,表面光滑凸起,边缘整齐,可产生橙色色素.经形态特征观察、生理生化特性观察、BIOLOG自动微生物鉴定系统鉴定和16S rDNA序列分析,结果显示:该菌株与假单孢菌属的多个绿针假单胞菌序列的同源性达到99%,为假单孢菌属绿针假单胞菌(Pseudomonas chlororaphis).XF10菌株的菌液以及胞外代谢产物粗提液对烟草黑胫病菌的抑制率均达80%以上,且该菌株的挥发性代谢产物能有效抑制烟草黑胫病菌菌丝生长,抑制率为86%.