切花菊‘长紫’辐照后代减数分裂行为及ISSR遗传变异分析

MEIOSIS AND ISSR ANALYSIS ON GENETIC VARIATION OF ^(60)Co γ-RAYS IRRADIATED VARIANTS OF CUT CHRYSANTHEMUM

通过细胞学和分子标记技术对切花菊‘长紫’辐照后代进行分析,探讨辐射诱变机理,为菊花辐射育种提供理论依据。结果发现,辐照后代在减数分裂后期Ⅰ和后期Ⅱ出现落后染色体和染色体桥的异常率明显高于对照,且随着剂量升高异常率增加,两种异常现象发生的最高比率在后期Ⅰ分别为9.0%和11.3%,后期Ⅱ为15.5%和8.6%。用21个ISSR引物扩增得到多态性条带112条,多态性比率为71.3%,表明DNA在不同程度上发生了变异。通过UPGMA法将它们分为5类,聚类结果基本上与花型和花色的变异类型相关。

Cytology and ISSR technology were used to analyze genetic variations of ^60Co γ-rays induced variants of cut chrysanthemum Changzi ,for further exploring the mechanism of irradiation and providing theoretical basis for breeding of chrysanthemum.The results showed that,meiotic abnormality ratio of lagging chromosome and chromosome bridge in variants were significantly higher than those in the control at anaphaseⅠand Ⅱ.The abnormality ratio was also raised with irradiation doses increasing. The highest ratio of two abnormal phenomena at anaphase Ⅰ was 9.0 %, 11.3 %, and at anaphase Ⅱ 15.5%, 8.6%, respectively. Polymorphic bands of 112 were amplified by 21 ISSR primers and the polymorphism rate was 71.3 %, which proved that DNA changed in different degrees. These variants were divided into 5 groups by UPGMA based on Jaccard coefficient. It was observed that the clustering result related to their characters of flower shape and color variations.