黄瓜花粉母细胞减数分裂过程中微核仁现象的研究

Observation on Micronucleolus during Meiosis of Pollen Mother Cell in Cucumber

在黄瓜(CucumissativusL.)高代自交系花粉母细胞减数分裂过程中,首次观察到了微核仁现象。在被观察的430个花粉母细胞(PMCs)中,有279个含有微核仁,占64.9%。微核仁在PMCs中数目变化范围在1～7之间。从细线期到四分孢子期都可观察到微核仁,其数量和大小在分裂的不同时期有所差异,但在第一次和第二次减数分裂时期内的变化趋势相似。在微核仁的周期性变化过程中,染色体的行为正常,并没有发现染色体畸变或染色体桥等现象。将此高代自交材料与3个商品种对照,分别在不同的季节种植在不同的地点,证明微核仁仅在此高代自交系上发生,且不受栽培季节和环境的影响。

Micronucleolus was firstly observed during meiosis of pollen mother cells (PMCs) in a high-generation inbred line of cucumber (Cucumis sativus L.).Among the 430 PMCs observed,279 PMCs contained micronucleoli,and the percentage was 64.9%.The number of micronucleoli varied from 1 to 7 in the PMCs containing micronucleolus.Micronucleoli can be seen from leptotene through tetrad.Although the number and size varied at stages,no significant differences were observed between the meiosis Ⅰand Ⅱ.The chromosomes behavior normally and no chromosome aberrances or chromosome bridge was observed during meiosis.Three commercial varieties used to compare with the high-generation inbred line as they were planted in different seasons at different fields.The results indicated that micronucleolus only occurred in the high-gene-(ration) inbred line,and the occurrence of micronucleoli was not affected by the seasonal and environmental factors.