双亲灭活原生质体融合技术在草菇耐低温菌株选育上的应用

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。

Application of Inactivated Parental Strain Protoplasts Fusion Technology in Selection of Volvariella volvacea with Higher Antifreeze Capacity

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.