| 摘要: |
| 【目的】对毛白杨大、小孢子母细胞减数分裂进程的相关性进行研究，为毛白杨多倍体诱导提供细胞学理论基础与技术支持。【方法】2014-01采集毛白杨雌、雄花枝于温室水培，自水培46 h开始每隔2～3 h取雌、雄花芽样品，采用石蜡切片和醋酸洋红压片技术对毛白杨大、小孢子母细胞减数分裂进程及其对应关系进行观察研究。【结果】毛白杨小孢子母细胞在水培52 h开始减数分裂，发育到双核花粉粒共历时约10 d；大孢子母细胞在水培118 h开始减数分裂，发育至二核胚囊期共历时约13 d。毛白杨大、小孢子母细胞减数分裂的进程以及与雌、雄花芽外部形态的变化之间均存在一定的相关性，在水培118 h毛白杨大孢子母细胞开始减数分裂进入细线期时，其小孢子母细胞减数分裂至四分体时期，此时雌花序微微露出芽鳞，雄花序1/4以上伸出芽鳞，花药呈块状微红色；在水培144 h大孢子母细胞减数分裂发育到粗线期时，其小孢子母细胞大多已发育至单核期，此时雌花序1/5伸出芽鳞，雄花序1/3以上伸出芽鳞，花药呈块状浅红色；在水培237 h大孢子母细胞减数分裂发育到中期Ⅰ时，其小孢子母细胞已发育至双核期，此时雌花序1/3伸出芽鳞，雄花序1/2以上伸出芽鳞，花药呈块状红色。【结论】根据大、小孢子母细胞减数分裂进程的时序相关性，通过观察相同培养条件下小孢子母细胞减数分裂的时期，可即时判别大孢子母细胞的减数分裂进程；还可从花芽长度、花药颜色等来估计大、小孢子母细胞减数分裂所处的时期。 |
| 关键词: 毛白杨 大孢子 小孢子 减数分裂 |
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| 基金项目:河北省自然科学基金资助项目(C2013104053)；国家自然科学基金资助项目（31300562）；保定学院科研基金资助项目（2010Z02）；保定学院科研团队项目（KYTD2013001） |
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| Correlations between megasporocytes and microsporocytes meiosis stages of Populus tomentosa Carr. |
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ZHANG Yan,CUI Bin-bin,WEI Jun-jie,et al
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| Abstract: |
| 【Objective】This study investigated the correlations in meiotic process of Populus tomentosa Carr.megasporocytes and microsporocytes to provide cytological basis and technical support for polyploid hybrid breeding.【Method】Flowering branches of P.tomentosa Carr.planted in water in greenhouse were collected and flower buds were picked every two to three hours after being cultured in water for 46 hours.The mother cell meiosis stages and their corresponding relations between megasporocytes and microsporocytes of P.tomentosa Carr.were studied using paraffin section method and acetic carmine squash technique.【Result】After being cultured in water for 52 hours,microspore mother cells of P.tomentosa Carr.started meiosis and it took 10 days for them to develop into binucleate pollen grains.Megaspore mother cells began meiosis after 118 hours and binucleate embryo sacs formed after 13 days.The meiosis stages and flower bud morphologies of megaspores and microspores closely related.After 118 hours in water,the meiosis of megaspore mother cells entered leptotene,while that of microspore mother cells developed into tetrads.Little female catkin and more than 1/4 of male catkin appeared and anthers appeared patches of slight redness.The meiosis of most megaspore mother cells developed into pachytene after 144 hours,and microspores developed into mononuclear.At the same time,1/5 of female catkin and more than 1/3 of male catkin extended and patches of pale redness appeared on anthers.When the meiosis of megasporocytes entered metaphase Ⅰ after 237 hours in water,the microsporocytes developed into binucleate.Meantime,1/3 of female catkin and more than 1/2 of male catkin extended and anthers had red patches.【Conclusion】According to the relationship of female and male gametes,the meiosis stages of megasporocytes could be discriminated timely through observing the meiosis of microsporocytes under the same culture circumstances.In addition,the meiosis stages of P.tomentosa Carr.megasporocytes and microsporocytes could be estimated based on flower bud morphology such as the length of the flower buds and the color of anther. |
| Key words: Populus tomentosa Carr. megasporocyte microsporocyte meiosis |
