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    杜仲大小孢子母细胞减数分裂进程对应关系的研究

    Corresponding relation between MMC and PMC meiosis of Eucommia ulmoides

    • 摘要: 以杜仲雌雄花芽为材料,通过对杜仲大、小孢子母细胞减数分裂时期的观察对比发现:①杜仲小孢子母细胞减数分裂一般在3月下旬到4月上旬之间进行,花药从团聚开始向四周伸展时,小孢子母细胞开始进入减数分裂,前期持续时间较长,中期Ⅰ到末期Ⅱ分裂进行较快.杜仲花粉为2-细胞型,发育过程经历小孢子单核期(早期、中期、晚期)、二核期(前期-后期)、成熟花粉期,自减数分裂结束后至散粉历时15d左右.②杜仲大、小孢子母细胞减数分裂时间相差很长,大孢子母细胞减数分裂开始的时间相对较晚、延续的时间较长.大约在小孢子母细胞减数分裂结束后10d左右,大孢子母细胞才刚刚开始进入减数分裂,此时花粉发育至二核期;恰好当花粉成熟散粉时,大孢子母细胞发育到减数分裂的细线末期到粗线期.根据雌雄配子发生、发育的时序性对应关系,通过相同培养条件下小孢子发育进程的观察,可以对杜仲大孢子母细胞减数分裂进程进行即时判别.

       

      Abstract: The meiosis stages of megaspores and microspores of Eucommia ulmoides and their relations were studied. It indicates that 1) Pollen mother cell (PMC) meiosis of E. ulmoides is processing between the last ten days of March and the first ten days of April. When the anther begins outspreading, PMC comes into meiosis. The time of prophase is long, yet meiosis processes quickly since metaphase I. Pollen of E. ulmoides has two nucleoli. Pollen development goes through uninucleate stage, including prophase, metaphase and anaphase, binucleate stage, including prophase and anaphase, and pollen mature stage. It is about 15 days from finishing meiosis to mature pollen. 2) The macrospore mother cell (MMC) meiosis begins later and persists for longer time compared with PMC. When pollen becomes two nucleoli and it is about 10 days after PMC meiosis, MMC meiosis just begins. And when pollen is mature, MMC develops into bouquet stage or pochytene of meiosis. According to the corresponding relation of male and female gamete development of E. ulmoides, the period of MMC meiosis could be distinguished through the observation of PMC development in the same conditions.

       

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