香蕉苗试管繁殖染色体数量畸变的研究

对在常规培养以及高６－ＢＡ、高腺嘌呤、高继代数、长继代时间等培养条件下，分化芽的染色体数目变化的规律以及一些苗期变异性状与染色体数量变异的关系进行了研究。主要结果有：（１）以上因素均能不同程度地促使染色体数量畸变率增高。其中，高腺嘌呤和高继代数加长继代时间２种处理效果最明显；（２）细胞畸变以非整倍体为主，可以在培养中逐代积累、增加。植株畸变以混倍体为主，非整倍体次之。植株畸变率明显低于细胞畸变率；（３）观察到一些苗的畸变的类型以及其对应的细胞学变化。结果显示，高继代代数的苗畸变率显著增高；在继代培养中，采取用核酸盐或高激动素以及片面地选用分化率高的芽丛作进一步扩大培养，以提高分化率的做法是危险的；根据苗期的形态特征，可将部分变异苗清除

Chromosome Aberration in Banana micropropagation

In this paper, we investigated the regularity of chromosome number variation in the micropropagated buds under different cultural conditions: High concentration of 6-BA and adenine; long duration of culture, and the relation between the chromosome number aberrations and the morphological variant characters in plantlets. The results are as follows: 1. All the treatment could make the rate of the chromosome Aberdeen increasing in different degrees. Among them the treatments of high concentration of adenine and more times of subculture plus long duration of culture were more effective. 2. Aneuploid was the major type in the aberration of cells, which could be accumulated during the cultural period. But for the whole plant, the major aberration was mixoploid, while aneuploid was secondary. The proportion of aberration observed in cells was obviously higher than that expressed on whole plants. 3. Some abnormal piantlets and the related cytogenedcal changes were described Conclusions were made from our results as follows Long time culture in vitro can increase the rate of aberration; It is dangerous to use nucleate, high concentration of kinetir in the subculture and only choose the rapidly propagated buds as explants for increasing the multiplication rate; some piantlets with chromosome aberration can be eliminated in nursery according to their morphological characters