^(60)Co γ辐照对食用菌菌丝的影响及ISSR分析

BIOLOGICAL EFFECTS AND ISSR ANALYSIS OF ^(60)Co γ-IRRADIATION ON EDIBLE MUSHROOM MYCELIA

以双环蘑菇(Agaricus bitorquis)、金针菇(Flammulina velutipes)和杏鲍菇(Pleurotus eryngii)3种食用菌菌丝为材料,用60Coγ射线200、500和800Gy3个不同剂量进行辐照处理,并开展了菌丝生长试验、电导率测定和ISSR分析。结果表明:随着辐照剂量的增加,食用菌菌丝生长受抑制增强;其中以双环蘑菇菌丝对辐照最为敏感,当剂量增强到800Gy时,其菌丝失去活力;经非致死剂量辐照的3种食用菌菌丝均随着继代培养次数的增加,萌发和生长速度加快,生长势增强,活力逐渐恢复。3种食用菌菌落浸出液的电导率均随着剂量的加大而增加,500Gy下的金针菇和杏鲍菇菌落及200Gy以上的双环蘑菇的电导率显著高于对照。经ISSR分析显示,3种食用菌菌丝的各辐照处理均与对照存在不同程度的多态性差异,经辐照处理后多态性条带数量发生变化,出现了特异性条带,既有新增的条带,又有缺失的条带。双环蘑菇变异最大,200和500Gy辐照引起的ISSR变异率分别为33.3%和50.5%;金针菇变异最小,200、500和800Gy下的ISSR变异率分别为2.3%、2.3%和3.1%,杏鲍菇菌丝的变异率分别为8.6%、13.4%和20.0%。本试验表明,200Gy和500Gy辐射双环蘑菇菌丝,以及800Gy辐射杏鲍菇菌丝引起较高的ISSR变异率,可以产生较高的突变率,因此,以此诱变选育新品种是可能的。

Mycelia of Agaricus bitorquis, Flammulina velutipes and Pleurotus eryngii were irradiated by 60^Co γ-rays at the dose of 0, 200, 500 and 800Gy. The results showed that irradiation inhibited their mycelia growth positively. Of the three edible mushroom, Agaricus bitorquis was the most sensitive one to irradiation, its mycelia died at the dose of 800Gy. Germination rate, growth rate and vigor of all mycelia irradiated with un-lethal doses increased along with the times of transfer of culture. Electrical conductivity（EC） analysis showed that irradiation increased EC of leaching solution of mycelia positively. The EC of leaching solution of mycelia of Flammulina velutipes and Pleurotus eryngii irradiated with 500Gy, Agaricus bitorquis irradiated with 200Gy, were significantly higher than CK. ISSR analysis revealed that 60^Co γ irradiation effect on DNA variation of Agaricus bitorquis, Flammulina velutipes and Pleurotus eryngii mycelia in varying degrees. Number of polymorphic bands changed after irradiation. Flawing bands and increasing bands were observed in amplified bands of 14 selected ISSR primers. The ISSR variation rates of Agaricus bitorquis for 200Gy and 500Gy treatments were 33.3 % and 50.5 % ; the ISSR variation rates of Flammulina velutipes for 200Gy, 500Gy and 800Gy treatments were 2.3 %, 2.3 % and 3.1%, that of Pleurotus eryngii were 8.6%, 13.4% and 20.0%. It is possible to use 60^Co γ irradiation as a mutagen to screen new mushroom varieties.