莎草科两个物种全着丝粒染色体形态鉴定

CHARACTERIZATION OF THE HOLOCENTROMERE IN TWO SPECIES OF CYPERACEAE

本实验检测了莎草科的两个种:普通莎草和旋鳞莎草。普通莎草的染色体数目变动很大;旋鳞莎草的染色体数目可初步确定为44。在分裂前期和分裂中期均未看到有初级缢痕,亦末观察到有V,J型染色体,中期染色体高度浓缩,与已报道的确属全着丝型染色体的小伞莎草极为相似。早后期姐妹染色体相向排列,无X形态出现。在所观察的大量分裂相中不存在通常情况下某些种属会偶而形成的落后染色体,基本上合乎全着丝粒型染色体的特征类型。两个莎草种根尖细胞混倍性普遍分布这一共性反映出有全着丝粒型染色体断片存在的可能性。

Cyotological observations strongly suggest that the chromosomes of both Cyperus rotundus and Cyperus michelianus are holokinetic and fall into the category of holocentric chromosomes. The behavior and appearance of these chromosomes are in agreement with some of the known characteristic features of holocentric chromosomes, namely, absence of a morphologically visible chromosomal constriction at metaphase and prophase, separation of sister chromatids in parallel during mitotic anaphase, and absence of lagging chromosomal fragments.