亚低温条件下防控番茄南方根结线虫生防菌株的筛选与鉴定

【目的】筛选亚低温条件下抗线虫和促进植物生长发育的菌株。【方法】采用线虫击倒率测定、室内耐低温测定、拮抗测试和盆栽生物测定相结合的方法进行功能菌株的筛选;采用表型特征、生理生化特征、16S r RNA基因序列测定相结合的多相分类技术对筛选的菌株进行鉴定。【结果】从根结线虫多发的设施黄瓜和番茄病土中分离出细菌和放线菌297株;经对根结线虫击倒率的初步筛选,得到校正击倒率大于70%的活性菌株9株;通过复筛获得1株在亚低温条件下同时具有防线虫、防土传病原菌病、促生特性的生防菌株S205;菌株S205被鉴定为抗生素链霉菌(Streptomyces antibioticus)。【结论】获得一株在亚低温条件下同时具有抗线虫活性和促进植物生长发育的生防菌株S205,该研究对解决亚低温条件下根结线虫的防治具有重要意义。

Screening and identification of biocontrol strains on controling tomato Meloidogyne incognita under sub-low temperature

[Objective] Isolated bacterial strains which can resistance to root-knot nematodes and promote the growth of plant under the sub-low temperature condition. [Methods] Joint method was used to screen the bacterial strain, the joint method include nematodes resistance test, indoor low temperature resistance test, antagonism test and pot experiment. Phenotypic characteristic, physiological and biochemical characteristics and 16S rRNA gene sequencing method were used to identify the strains which passed screening method. [Results] 297 different bacteria and actinomyces strains were isolated from the soil of tomato and cucumber rhizosphere which are often seriously in root-knot nematode disease; After analysis the nematodes resistance rate, 9 strains which have more than 70% corrected death rate to the nematodes were isolated; A strain called S205 was isolated, it have excellent function in prevention and cure of root-knot nematode, soil-borne pathogens and promoting plant growth under sub-low temperature; Strain S205 was classified as Streptomyces antibioticus. [Conclusion] This research had isolated a biocontrol strain S205 which have the property of resistance root-knot nematode and promoting plant growth under sub-low temperature. The research is significant in prevention of root-knot nematode disease under sub-low temperature.