重离子束辐照诱变选育北冬虫夏草高产菌株

利用~(12)C~(6+)重离子束对北冬虫夏草出发菌株的菌悬液进行辐照诱变处理,采用平板分离法初筛变异菌株,通过培养子实体复筛高产菌株,并测定子实体的产量、多糖和虫草素含量。结果表明,在吸收剂量为150Gy时,出发菌株的致死率达到最高为82%;经过初筛和复筛,最终选育出3株高产子实体突变菌株G2、G5、G12,并经连续传代10次,测定子实体产量稳定在8.02~8.21 g/瓶,与出发菌株的子实体产量相比提高了52.47%~56.08%,且稳定性保持良好。研究表明,利用重离子束辐照诱变选育北冬虫夏草,可以获得高产子实体菌株。

Screening and mutation breeding of high-yieldCordyceps militaris via heavy ion irradiation

Strains ofCordyceps militaris grown in suspension culture were irradiated by12C6+ ion beam, screened using the plate separation method, and re-screened by culturing fruiting bodies to determine the fruiting-body yield, polysaccharide and cordycepin content. The strains displayed the highest lethality,i.e., 82%, at the optimal absorbed dose of 150 Gy. Three mutants (G2, G5, G12) were obtained, which could produce a greater number of fruiting bodies. Meanwhile, the ten times pass-generation test indicated that the fruiting bodies stabilized at 8.02 to 8.21 g/bottle in these three mutants, which were 52.47% to 56.08% higher than the original strain, and the hereditary characters of these mutants were stable. The present findings show that a high-yield fruiting body of C. militaris can be obtained by mutation breeding using a heavy ion beam irradiation.