Bioassay of 51 strains of Bacillus thuringiensis to Bursaphelenchus xylophilus had been studied in laboratory. Two of them had higher toxicity to B. xylophilus. Extraction of endotoxin and exotoxin of the two isolates...Bioassay of 51 strains of Bacillus thuringiensis to Bursaphelenchus xylophilus had been studied in laboratory. Two of them had higher toxicity to B. xylophilus. Extraction of endotoxin and exotoxin of the two isolates to B. xylophilus showed the action of exotoxin higher than that of endotoxin.展开更多
文摘Bioassay of 51 strains of Bacillus thuringiensis to Bursaphelenchus xylophilus had been studied in laboratory. Two of them had higher toxicity to B. xylophilus. Extraction of endotoxin and exotoxin of the two isolates to B. xylophilus showed the action of exotoxin higher than that of endotoxin.
文摘从我国不同地区采集118份土样,利用温度筛选法分离获得一株苏云金芽胞杆菌(Bacillus thuringiensis,简称Bt)6618,镜检观察发现该菌株能产生典型的菱形晶体,PCR分析表明其含有cry1类杀虫基因。采用SDS-PAGE和质谱分析发现该菌株主要产生130 k D原毒素,其组分由Cry1Ae和Cry1Ac原毒素组成。基因序列分析表明该菌株的cry1Ac基因为已知的cry1Ac1,而cry1Ae为新型杀虫基因。毒力生测表明该菌株对棉铃虫(Helicoverpa armigera)幼虫具有显著的杀虫效果。筛选获得的高毒力Bt菌株6618为丰富我国苏云金芽胞杆菌储备和研发新型高效生物杀虫剂提供了菌株资源。