阳桃四倍体植株诱导试验

利用秋水仙素对阳桃茎尖进行四倍体植株诱导．结果表明，浸泡法处理的效果最好，诱导频率最高可达29．6％，而混培法和点滴法较差．浸泡法以质量分数为0．002的秋水仙素处理25h为最适宜，混培法以质量分数为0．002的秋水仙素处理20d效果最好．秋水仙素诱导产生的变异植株经染色体倍性鉴定，其染色体数目为2n=44，属四倍体植株类型．同时，对阳桃二倍体和四倍体植株进行形态观察发现，四倍体植株叶色浓绿，叶面积增大，但叶长与叶宽的比值却减小，保卫细胞的长度、宽度．以及叶绿体含量也增大，气孔密度变小．

Inducing Tetraploid Plantlet of Averrhoa carambola

To induce tetraploid plantlet of Averrhoa carambola by applying colchicine,the apical meristem of its cultivar 'B_(10)' were treated with colchicine solution in different concentrations and in different ways of treatments.The optimal effect can be obtained either by immersing it in 0.2% colchicine solution for 25 hrs or by culturing it in the medium supplemenled with 0.2% colchichine for 20 days.Its mutant plantlet engendered by colchicine induction contains chromosome in a number of 44(2n=44) and belongs to the type of tetraploid plantlet.Differing from diploid plantlet in morphology,this tetraploid plantlet is characterized by the deep green leaves with larger leaf area and smaller ratio of leaf length to leaf width and also by the increase in length and width of stomatal guard cells and the increase in the quantity of chloroplasts but the decrease in the density of stomas.