航天诱导的凤仙花突变株性状及减数分裂过程的研究

TRAITS AND MEIOSIS IN MUTANT OF Impations balsamina INDUCED BY SPACE TREATMENT

本文报道了种子经神舟 4号飞船搭载的凤仙花突变植株的性状及减数分裂过程的变化。该突变株在花色及花型等宏观性状上有很大变异。观察减数分裂过程 ,发现其小孢子母细胞减数第 1次分裂前期基本正常 ,但到后期Ⅰ出现染色体分配的严重不均 ,并出现落后染色体、分散染色体等。减数第 2次分裂完成时 ,多数形成 4分孢子 ,但同时也出现各种形式的多分孢子。小孢子中染色体数目从 1～ 2 1条不等 ,甚至多达 30多条。小孢子的形状和大小变异明显 ,且小孢子的大小与所含染色体的数目呈正相关。碘液染色检查发现绝大多数花粉不育 ,并与该突变株的低结实率一致。分析认为花粉的大小差异和花粉的育性与减数分裂异常有关 。

A mutant of Impations balsamina was obtained after space induction, and its traits and meiosis were investigated. Characters such as color and form of the mutant expressed great variation. Observation of meiosis showed that most of pollen mother cells were normal in meiosis phase I, except the disproportion of chromosomal segregation, lagging chromosome and dispersal chromosome in anaphase I. Most pollen mother cells developed into microspores tetrad after meiosis, but paraspores also appeared. The number of chromosome in microspore varied from 1 to 21, even more than 30. The shape and size of the microspores fluctuated apparently, and the size of the microspores was in positive correlation to chromosome number. When staining with iodic solution, most of the pollens showed sterility, which was in consistence with the low setting percentage of the mutant plant. It was thought that space induction caused the variation of size, fertility and the abnormal meiosis.