人参细胞培养过程中染色体变异的研究

本文对继代培养了1～8年的人参愈伤组织和细胞株系进行了染色体变异和形态特征的显微观察。研究认为,人参细胞在长期培养过程中逐步向脱分化、薄壁化、球形和液泡化方向变化,同时,细胞分裂生长的速度加快,遗传变异不断增加。对细胞株SI796—1的观察,发现了具双核、四核和八个核的细胞变异类型以及细胞染色体倍数性变异和非整倍性变异;在细胞分裂后期相中,有较多的染色体桥和无着丝点染色体落后以至散失在细胞质中的现象。分析了长期培养细胞形态特征变异和遗传变异的原因以及选育高产细胞株的问题。

CHROMOSOME VARIATIONS IN THE CELL CULTURE OF PANAX GINSENG

Some cell lines of Panax ginseng subcultured for 1-8 years were studied with a view to determining genetic variations and morphological changes in the process of culture. Main resutls obtained are as follows: Some cell lines subcultured for two, five and eight years were studied in morphological characters and genetic variations, comparing with the callus induced in 1987. The characteristics of cultured cell change gradually in the long-term culture toward dedifferentiation, thin wall, ball and vacuolization. In the meantime, the rate of cell division, growth and genetic variation were increasing. After a detailed study on a high-producing cell line SI 796-1 subcultured for eight years, binucleated, tetranucleated and octonucleated cells were found, a lot of genetic variations including polyploid(triploid tetraploid, hexaploid and octoploid) and aneuploid took place in the cell line. In the anaphase of mitosis, many chromosome bridges were observed, some acentric fragments of chromosme lagged behind and were left in cytoplasm. Discussion also are the reasons of morphological changes and genetic variations in longterm cultured cell and the problems in developing high-yield cell line to produce secondary metabolites used for pharmaceutical purpose through selection and breeding in plant cell culture.