大叶铁线莲四倍体的诱导及初步鉴定

以毛茛科铁线莲属植物大叶铁线莲为试验材料,采用初生分生组织处理法用0.2%秋水仙碱溶胶诱导大叶铁线莲顶芽以期获得多倍体。本研究探讨了秋水仙碱诱导大叶铁线莲的最佳处理时间,并对所得的诱变株进行形态学和细胞遗传学鉴定。结果表明:0.2%秋水仙碱诱导多倍体最佳时间为48h,诱导率可高达80%。形态学方面,所得变异株与对照株叶片相比,叶片加长、加宽、增厚,叶形指数变小。变异株的叶片下表皮气孔明显大于对照,而气孔密度明显小于对照;保卫细胞中的叶绿体数目明显高于其二倍体对照;SPAD值表明叶绿素含量也有明显增加。根尖有丝分裂细胞学鉴定结果表明:对照株的染色体数目均为16(2n=2x),而变异株的染色体数为32(2n=4x),由此表明本研究通过秋水仙碱诱导大叶铁线莲成功获得四倍体。

TETRAPLOID INDUCTION AND CYTOLOGY IDENTIFICATION OF Clematis heracleifolia

Clematis heracleifolia is an important medicinal plant in China.By apical meristem method,0.2% colchicine semi-solgel was used to induce tetraploid of Clematis heracleifolia.In this study we set up 24h,48h and 72h to select the best treatment time,and morphological and cytological identifications were conducted.The results showed that 48h of the treatment period gave the highest variation rate up to 80%.Leaf of variations was longer,wider,thicker,and showed smaller leaf index than that of the control.The differences of stomata size and stomata density in the abaxial epidermis of leaf between variations and the control were significant.Chloroplast number in guard cells and chlorophyll content of variations were all increased significantly as compared with the control by microscope observation of abaxial epidermis of leaf and SPAD value.Chromosome number of most variations was 32(2n=4x),while that of the control was 16(2n=2x) by the cytological observation of root tip cells.As a result,tetraploid of Clematis heracleifolia was successfully obtained.