从韩国不同地区采集的 6 2 0个土壤样品中分离出 6 7株苏云金芽孢杆菌 ,分属于 1 0种不同的血清型 .毒力测定结果表明 ,在 6 7株分离株中 ,35 .82 %的菌株对鳞翅目昆虫具有生物活性 ,2 2 .39%的菌株对双翅目昆虫有毒 ,32 .84%的菌株对鳞翅目和双翅目昆虫都具有杀虫活性 ,8.95 %的菌株为没有杀虫活性的无毒菌株 .其中对鳞翅目昆虫有毒的菌株产生典型的双金字塔形伴孢晶体 ,对双翅目昆虫有毒的菌株和无毒菌株都产生球形伴孢晶体 ,而对鳞翅目和双翅目都有毒的菌株产生双金字塔形或球形伴孢晶体 .用对 cry ,cry ,cry ,cry 和 cry 基因特异性引物作 PCR分析的结果表明 ,cry C基因占优势 ,其次为 cry A (b)和 cry A基因 ,但无 cry G,cry ,cry C和cry 基因 Sixty-seven strains of B. thuringiensis were isolated from 620 soil samples collected from different regions of South Korea, belonging to 10 different serotypes. The virulence assay showed that of the 67 isolates, 35.82% Of the strains were bioactive to Lepidoptera, 22.39% were toxic to Diptera, 32.84% were insecticidal to Lepidoptera and Diptera, and 8.95% Is non-toxic non-toxic strains of insects which Lepidoptera insects toxic strains produce typical double pyramidal spore crystals, dipteran insects toxic strains and non-toxic strains have spherical spore crystals, and Lepidoptera and Diptera, both of which produced double-pyramidal or spherical parasporal crystals.The results of PCR analysis using cry-, cry-, cry-, cry-, and cry-specific primers indicated that cry C gene predominates, followed by Cry A (b) and cry A genes, but no cry G, cry, cry C and cry genes