大葱、洋葱的小孢子和根尖细胞的核型比较

Karyotype Comparison between Microspores and Root Tip Cells of Allium Fistulosum and A.Cepa

本实验以大葱和洋葱为材料,对其小孢子和根尖细胞的核型进行了分析与比较.实验结果发现,小孢子的核型不仅与根尖细胞的核型相同,而且还有下列优点;1)染色体自然收缩适中、着丝点清楚、分散良好;2)细胞分裂的同步性较高,可获得较多的中期分裂相;3)由于染色体数目减半,自然分散良好,省略了染色体制备及核型分析的许多步骤.因此,以小孢子分裂中期染色体进行大葱和洋葱的核型分析可能是一条比较理想的途径.

The kaiyotypes between the microspores and root tip cells were compared in Allium fistulosum and A.cepa re pectively.It was foundthat the karyotypes of microspores were the same as those of fhe root tipcells and they had the following advantages:First,the chromosomalcondensation is more moderate and their kinetochores are clearer inmicrospores without any pretreating than in root tip cells with pretreating;second,the development of microspores is somewhat synchronous,so thatmore metaphase cells can be obtained;and third,the chromosomes ofmicrospores are one half less than Those of root tip cells,so theirchromsomoes are easier to be dispersed and many steps used in kayotypeanalysis of root tip cells can be omitted.This study suggests that microspores are an ideal material forkaryotypic analysis of A.fistulosum and A.cepa.