Studies on Meiotic Behaviors of Pollen Mother Cells in Cucumbers (Cucumis sativus L.)

Meiotic behaviors of pollen mother cells (PMCs) in North,South and Southwest Chinese cucumbers (Cucumis sativus L.) were characterized herein.All cucumbers observed have a simultaneous cytokinesis and a relative high synchronization in nuclear division.Nucleolus disappeared gradually from prophase I to metaphase I,reappeared at prophase Ⅱ and then disappeared.With condensation of chromatins,chromosome became more and more identifiable from prophase I to metaphase I,and illegible at telophase I with de-helixation.Chromosomes were prominent again at both poles in PMC at prophase Ⅱ.At diakinesis,most chromosome configurations were ring bivalents for all cucumbers.In C.sativus var.xishuangbannesis,nucleolus number was different from the other two ecotype cucumbers both at prophase I and Ⅱ,and a case of chromosome bridge occurred at anaphase I,which both demonstrating the speciality of C.sativus var.xishuangbannesis.Under cold weather,high frequent polyads were observed in all ecotype cucumbers,which was likely related to the cold weather adversity.