自烟草中分离获得对南方根结线虫Meloidogyneincognita具有较高杀线活性的拮抗细菌菌株YC-10。研究发现该菌株有伴胞晶体产生，菌体、芽胞形态及生理生化特性与苏云金芽胞杆菌库斯塔克亚种B．thuringiensissubsp．kurstaki相似，16srDNA序列分析表明其与苏云金芽胞杆菌相似性最高，初步确定该菌株为苏云金芽胞杆菌。菌株发酵液及伴胞晶体蛋白对南方根结线虫J2有很强的杀线活性，发酵液处理南方根结线虫，24h线虫死亡率为100％；伴胞晶体蛋白处理南方根结线虫，24h的LC50为5．86μg．mL^-1。研究结果显示该菌株在线虫生物防治上有较大的应用潜力。%The bacterium strain YC-10 isolated from a tobacco sample demonstrated high toxicity against Meloidogyne incognita. The strain could produce protein crystals. The morphology of the strain and spores and physiological-biochemical features were similar to those of B. thuringiensis subsp, kurstaki. In combination with 16S rDNA analysis, the strain was identified as B. thuringiensis. Bioassay results showed that the culture filtrate and the parasporal crystal proteins of the strain were highly toxic to M. javanica J2. The mortality of M. incognita J2 treated with the culture filtrate was 100% and the LCs0 value of parasporal crystal protein to M. incognita J2 was 5.86 gg.mL i in 24 h. The results indicated that the strain YC-10 has potential in nematode biocontrol.
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