秋水仙素诱导美洲商陆四倍体的研究

利用改良L.D.Cua法对美洲商陆进行多倍体诱变，在秋水仙碱浓度为0.2%条件下，设置24h、48h和72h三个诱变时间，并对所得到的变异株和对照株进行形态学、细胞学等方面的比较研究，结果表明：诱变48h效果最好；与对照相比，变异株的叶片厚度增加43.75%；叶形指数减少37.95%；气孔纵横径分别增加52.94%和73.01%；保卫细胞内叶绿体数目增加20.91%；花直径增加22.96%；花粉粒直径增加22.47%；果实直径增加23.66%。对变异株进行花粉母细胞减数分裂染色体鉴定，小孢子细胞的染色体数为n=2x=36，而对照小孢子细胞的染色体数为n=x=18，证明变异株为四倍体。

Studies on the induction of autotetraploid pokeweed

The diploid pokeweed（Phytolancca American L.）was induced by 0.2% colchicine solution. Three treatments（24h、48h and 72h） were done and morphologic and cytologic comparison between obtained variant plant and CK were studied. The results showed that the treatment of 48h was the best. Comparing with CK, leaf thickness was increased by 43.75%, length and width of stomata by 52.94% and 73.01% respectively, number of chloroplasts by 20.91%, diameter of flower by 22.96%, diameter of pollen by 22.47%, diameter of fruit by 23.66%. Leaf index was declined by 37.95%. By chromosome observation of pollen mother cells, it showed that the chromosome number of microspore in the variant plants is n=2x=36, but the chromosome number of microspore in CK is n=x=18, so it was tested that the variant plants were autotetraploid.