60Co-γ辐射对切花菊试管苗的诱变效应

以‘神马’和‘长紫’两个切花菊品种的生根试管苗为试材，用60Co-γ射线进行辐射，设0（对照）、10、15和20 Gy等4个剂量处理，处理后以茎段和叶片为外植体进行离体培养，分析辐射对腋芽发生率、愈伤组织诱导率和分化率的影响，统计M1代田间主要性状及变异情况。结果表明：γ射线对试管苗茎段和叶片的愈伤组织诱导及分化有明显抑制作用，随着辐射剂量的增加抑制作用加强。不同品种、不同外植体对辐射的敏感程度都存在差异。茎段较叶片更适合做辐射后组培的外植体。‘长紫’M1代株高降低，花径减小；而‘神马’在株高和花径出现略微增加的趋势。茎段和叶片的再生植株田间主要性状的变异程度大于腋芽的再生植株。‘长紫’在花色和瓣形上的变异率高于‘神马’。

Effects of 60Co-gamma Rays Irradiation on in Vitro Cultured Cut Chrysanthemum and Variations of Main Morphological Characters in the M1 Generation

In vitro plantlets of two cut chrysanthemum cultivars were irradiated with 0，10，15 and 20 Gy of 60Co-gamma rays，respectively. The stems and leaves from irradiated plantlets were used as explants for further in vitro culture. The effects of radiation on the rate of produced axillary buds，induced callus and differentiated adventitious buds were analysed. Variations of the main morphological characters in M1 plants were documented. The results showed that 60Co-gamma rays dramatically inhibited the callus induction and differentiation from either leaves or stems explants，the inhibition effect increased with the increase in the dose of irradiation. The sensitivity to irradiation was upon to different cultivars and different types of explants. The irradiated stem was more suitable to be used as explants than the irradiated leaves. The plant height and flower diameter decreased in the M1 of‘Changzi’while increased slightly in M1 of‘Jinba’. The variation rate of morphological characters in plants regenerated from stems and leaves was higher than that regenerated from axillary buds. Rates of variation of flower color and petal type in ‘Changzi’were higher than that in‘Jinba’.