摘要
分离戈壁土壤样品 ,获得 1株芽孢杆菌菌株B2 4 14 ,经 16SrDNA序列分析鉴定为苏云金杆菌 (Bacillusthuringiensis)。用乙醇分级沉淀和紫外扫描方法 ,提取B2 4 14菌株的 β 外毒素。用细胞培养板法检测其对松材线虫 (Bursaphelenchusxylophilus)的毒杀效果 ,结果表明 :在 4mg·mL-1质量浓度下处理 8h ,线虫的杀死率可以达到93 75 % ,致死中质量浓度为 5 74 μg·mL-1;随处理时间延长和外毒素质量浓度的提高 ,毒杀效果也明显增强 ;6种质量浓度的 β 外毒素处理线虫 ,其死亡率与毒素质量浓度的自然对数呈正相关 ,相关系数为 0 981。温室防病试验表明 ,B2 4 14菌株的液体菌剂可以有效地防治根结线虫 (Meloidogynespp .) ,处理 2 1d黄瓜苗根结减退率达到71 6 %～ 84 6 % ,经多次试验其防治效果均与对照呈显著差异。
Bacilli isolate B24-14 was isolated from Gobi soil in Gansu province.This bacterium was identified as Bacillus thuringiensis based on the analysis of 16?S rDNA and Bergey's Manual system. β-exotoxin produced by B24-14 was distilled by the technique of alcohol graded deposition. Nematodecide effectiveness of the β-exotoxin on Bursaphelenchus xylophilus was examined with the plate method. Responding to 8 hour treatment of β-exotoxin(4?mg/mL) on the nematode, motility of nematode reached to 93.75% and LC 50 was 574?μg/mL. Along with increasing concentration of β-exotoxin and lasting the time of treatment, the nematocide effectiveness of β-exotoxin raised obviously. Motility of B. xylophilus treated by 6 different concentrations of the β-exotoxin was examined. The correlation(r=0.981) between nematode survival and the natural logarithm of exotoxin concentration was positive. Experiments on control of root knot disease caused by Myloidogyne spp. were conducted in greenhouse. Reducing rate of root-knot with B-24-14 treatment compared with non-treated control reached to 71.6%-84.6% in 5 experiments. Statistic analysis showed that the difference was significant.
出处
《中国农业大学学报》
CAS
CSCD
北大核心
2004年第6期34-37,共4页
Journal of China Agricultural University
基金
北京市高廷根生物技术有限公司资助项目
