秋水仙素诱导党参四倍体

TETRAPLOIDY INDUCEMENT OF Codonopsis pilosula (Franch.) Nannf. BY COLCHICINE

以党参(Codonopsis pilosula(Franch.)Nannf.)为诱变材料,用改良秋水仙素涂抹法进行多倍体诱变,以获取四倍体,研究了秋水仙素对党参的诱导效果以及变异株的形态学与细胞学变化。本试验利用0.2%秋水仙素琼脂凝胶处理党参幼苗获得了四倍体材料,结果表明党参经秋水仙素诱导后,以处理24h加倍率最高,为34.14%。四倍体植株形态学变异表现为苗期生长受阻,叶片变大变厚,叶形指数变小;花器变大,茎杆加粗,茎节变短;结实率下降而千粒重增加等。党参四倍体植株的细胞学表现为叶下表皮气孔器变大,气孔密度下降,保卫细胞内叶绿体的含量增加;花粉粒变大而花粉育性降低;根尖细胞有丝分裂染色体数目为2n=4x=32,其对照为2n=2x=16。四倍体党参减数分裂染色体行为复杂,同源染色体出现了多种联会方式。

In order to obtain the tetraploid,Codonopsis pilosula（Franch.） Nannf.was induced by 0.2% colchicine solution with 24,48 and 72h.Results showed that 24h was the most effective treating time for obtain tetraploid plants,and the efficiency was up to 34.14%.The morphology and cytology of mutation plants were surveyed.In comparison with normal plants,mutation plants expressed the following features：the seedling growth retarded, the leaves became bigger and thicker than that of diploid, the leaf shape index became smaller; the flowers became larger, the diameter of stem became widening, the internode of the main stem became shorter; seed setting rate was decreased and the 1000-grain weight of mutants was higher than that of the control. The cytology variation of the tetraploid plants expressed the following features ： the stomatal cell was larger and stomatal frequency was reduced, the number of chloroplast in stomata was increased ; the diameter of pollen became larger and the pollen viability was increased ; microscopic examination of root tips showed that the chromosome number of tetraploid was 2n = 4x = 32, while that of diploid was 2n = 2x = 16. We noticed many forms of homologous chromosomes synapsis in meiosis of tetraploid plants.