番木瓜四倍体的诱导及形态学分析

在离体培养条件下,将二倍体穗中红番木瓜无菌试管苗茎尖浸入0.05%、0.1%、0.2%、0.4%秋水仙素水溶液中处理1、2、3、4、5d,诱导多倍体,对照用无菌水处理2d。结果表明0.2%的秋水仙素溶液浸泡处理3d效果最好,诱导率为36.7%。通过体细胞染色体数目检测,变异芽为四倍体或嵌合体,四倍体染色体数目为36(2n=4x=36)。对获得的四倍体和二倍体进行了形态及气孔特征的比较,结果表明四倍体与二倍体植株在叶长、叶宽、叶厚、气孔大小、气孔密度、气孔保卫细胞大小及叶绿体数目等方面存在明显的差异,其中叶片厚度、气孔密度和保卫细胞内叶绿体数目可作为鉴别四倍体与二倍体的重要性状。

Polyploid induced from Carica papaya and morphological characteristics compared between tetraploids and diploids

Under the condition of tissue culture, the induced polyploids of the Meizhonghong papaya cultivar were carried out by colchicines. The plantlets were obtained by immersing buds in various solutions of colchicines for various days such as 1, 2, 3, 4, 5 d. For control the buds were immersed by sterilized water for 2 days. The results indicated: the polyploids could be most effectively induced by immersing buds in 0.2% colchicines solution for 3 days, the inductive frequency was 36.7%. The number of chromosomes of mutated plantlets was observed. Some belonged to tetraploid plants. Others were different chimeras needed to be separated. The number of chromosomes of tetraploids was 36(2n=4x=36). Comparing the characteristics of leaves and stomata of tetraploids and diploids, the results showed that these characteristics including length, width and thickness of leaf, stoma and guard cell, density of stoma and the number of chloroplast of tetraploid were distinctly different from diploid. And the width of leaf, density of stoma and the number of chloroplast could be used to distinguish diploids and tetraploids.