N^+离子注入球孢白僵菌诱变育种的初步研究

Mutation breeding by N^+ ion implantation in Beauveria bassiana

不同剂量的N+注入球孢白僵菌后,存活率呈典型的“马鞍型”剂量—效应曲线,选择该曲线峰值区域所对应的注入剂量即(80×1.3×1014)ion/cm2作为诱变育种的最佳注入剂量。比较离子注入前与注入后不同菌株的产酶曲线的结果是:不同菌株之间的Pr1蛋白酶酶活存在着差异,但是其酶活曲线变化规律一致,说明离子注入没有改变白僵菌Pr1蛋白酶的产酶过程。选择诱导24 h作为最佳诱导时间。通过测定菌株产孢量与菌株Pr1蛋白酶酶活双重指标对菌株进行筛选,结果表明,Bb202IP50菌株在两个指标上表现均较好,产孢量达到(7.065±1.105 9)×108个孢子/cm2,A405达到了0.269 8±0.035 8,故将其确定为最佳突变菌株。

By implanting different doses of N^＋ ion, the curve of survival rate of Beauveria bassiana took a typical ＂saddle shape＂. The optimal dose of the mutagenic breeding was the value of the peak area of the curve,which was （80 × 1.3 × 10^14）ions/cm^2. The comparision of the Prl enzyme activity curve of the different strains before and after the implantation showed that there was difference among different strains,but the regularity of the variation was similar. The variety of the Prl enzyme activity curve of the strains before and after the implantation was similar too, which showed that ion implantation did not influence the process of producing enzyme. The optimal time of induction was 24 hours The strains＇ spore output and Prl enzyme activity was selected as the indices for screening, the result showed that Bb202IP50 was excellent on the two indexes, its spore output was up to （7.065 ± 1. 105 9） × 10^8 spores/cm^2, and A405 was up to 0.269 8 ± 0.035 8. So Bb202IP50 was chosen as the optimal mutational strain.