甜叶菊增殖培养及^(60)Co-γ诱变生物效应

Proliferation culture and ^(60)Co-γrays mutagenic biological effect of Stevia rebaudiana Bertoni

为获得甜叶菊的最佳增殖培养基以及60 Co-γ辐射诱变育种的剂量,以无菌甜叶菊茎段为外植体,采用正交实验对其增殖培养基的激素种类和浓度进行优化;在此基础上,分别采用5、15、30、60、90、120和150Gy剂量的60Co-γ射线对甜叶菊茎段进行辐照诱变,每隔15d记录其生长情况,统计死亡率;并测定≤30Gy剂量处理的叶片中可溶性多糖和可溶性蛋白质的含量。结果表明,甜叶菊茎段增殖的最佳培养基为MS+NAA 0.5mg·L-1+TDZ0.1mg·L-1+6-BA 1.0mg·L-1。60 Co-γ射线诱变的半致死剂量(LD50)为24Gy,处理后的甜叶菊外观呈现显著差异,随着辐射剂量的增强,30d后甜叶菊死亡率分别为1.7%,2.4%,20.5%,92.7%,98.9%,99.4%,100%,辐射剂量是5、15、30Gy时,可溶性多糖含量较对照组分别增加76.77%,26.73%,15.29%,表明辐照诱变导致甜叶菊试管苗短期的应激效应。研究结果为甜叶菊的辐照诱变育种提供了理论参考。

In order to obtain the optimized proliferation medium and the dose of 60Co-γradiation mutation breeding of Stevia rebaudiana Bertoni in vitro,with S.rebaudianastem as the explant,proliferation medium was optimized by L9(34)orthogonal experiment.Then,the S.rebaudianastems were irradiated under the 5,15,30,60,90,120and 150Gy doses of 60Co-γrays respectively.The growth state,including numbers of leaves,height of plantlet and the mortality were recorded.The soluble sugar and soluble protein were also detected in the groups which the dose≤30Gy.The results showed that the best proliferation medium was MS+NAA 0.5mg·L-1+TDZ 0.1mg·L-1+6-BA 1.0mg·L-1.The LD50of S.rebaudianaseedlings exposure to 60Co-γrays was 24Gy,and the irradiated samples were significant different in appearance in the different dos,with the enhancement of the radiation dose,the death rate of S.rebaudiana was 1.7%,2.4%,20.5%,92.7%,98.9%,99.4%,100%respectively in 30days.When the radiation dose was 5,15,30Gy,compared to the control group,the soluble sugar was increased by 76.77%、26.73%、15.29%respectively,which implied that irradiation made S.rebaudiana plantlets a short-term stress effect.The research results provide a theoretical reference for the irradiation induced breeding of S.rebaudiana.