Abstract:

The protoplasts of Volvariella volvacea V23 and V3552 were prepared by enzymatic method, and then were taken mutagenesis by UV and chemical 2 methods. A fusant displaying higher antifreeze capacity, as compared to that of its parents, was obtained by PEGinduced fusion between UVinactivated protoplasts of V3552 EMS and heatinactivated protoplasts of V23 UV through low temperature (0℃) selection. The best fusion condition is gained at 400g/LPEG6000, pH 8.0, for 30min fusion time, at 32℃ fusion temperature. The fusion rate could be as high as 0517%. And 200 fusants were obtained. Through screening with 0℃ low temperature, 15 Volvariella volvacea cold tolerant bacterial strains were obtained. The cold tolerant ability of hypha at 0℃ was improved by 4.5 times. The results proved that the fruit displayed higher antifreeze capacity, as compared with bacterial strains; and the liquefaction phenomenon was obviously postponed. This indicated that strains screened by this method were of further development value.

Key words: Volvariella volvacea, protoplast, ultraviolet mutagenesis, chemical mutagenesis, inactivation, PEG fusion

摘要：

为了选育耐低温草菇菌株，以草菇V23、V3552为亲本，采用酶解法制备原生质体，用紫外诱变、化学诱变两种方法对草菇菌株进行诱变，筛选到耐低温的突变株；然后利用紫外灭活（20 W，30 cm，110 s）和热灭活（50℃ 3 min）的双亲灭活标记法对突变株进行化学融合，结果表明在400 g/L的PEG6000、pH 8.0、融合时间30 min和融合温度32℃的条件下融合率最高，达到0.517%， 共获得200个融合子。经过0℃低温筛选，最终获得15株草菇耐低温菌株，菌丝在0℃的耐冻能力提高了4.5倍。经出菇实验证明其子实体与出发菌株相比具有明显的耐低温性，液化现象明显推迟，说明该方法筛选出的菌株具有进一步应用开发的价值。

关键词: 草菇；原生质体；紫外诱变；化学诱变；双亲灭活；PEG融合