牛蒡根结线虫生防菌筛选、鉴定及杀线虫条件优化

Screening and Identification of Biocontrol Bacteria against Burdock Root-knot Nematode and Optimization of Nematicidal Conditions

[目的]分离、筛选杀根结线虫生防菌并进行杀线虫条件优化。[方法]通过抑制根结线虫卵孵化试验、毒杀根结线虫2龄幼虫试验、根结线虫趋避试验、盆栽试验和田间试验筛选出杀线能力最强的菌株Ba-2。[结果]初步鉴定菌株Ba-2为坚强芽孢杆菌(Bacillus firmus),最优杀线虫条件为初始pH值7.06、发酵温度29.83℃、盐质量浓度11.24 g/L。[结论]从药用植物牛蒡根际土壤中筛选出杀牛蒡根结线虫能力较强的生防菌,旨在为下一步研制牛蒡专用生物有机肥提供生防菌菌剂。

[Aims] This study aims to isolate and screen out biocontrol bacteria against root-knot nematodes from the rhizosphere soil of Arctium lappa L.[Methods] The strain Ba-2 with the strongest nematicidal ability was screened out by inhibiting the hatching of root-knot nematode eggs,poisoning the second-instar larvae of root-knot nematode,avoiding the root-knot nematode,pot experiment and field experiment.The colony characteristics,physiological and biochemical characteristics and 16 S rDNA of the strains were observed and identified.[Results] The strain Ba-2 was identified as Bacillus firmus,and the optimal nematicidal conditions were as follows:Initial pH value 7.06,fermentation temperature 29.83℃,salt concentration 11.24 g/L.[Conclusions] The biocontrol bacteria with strong ability to kill Burdock root-knot nematode were isolated from the rhizosphere soil of the medicinal plant A.lappa L.to provide biocontrol bacteria for further study.