西瓜小孢子发育过程中几种细胞器的变化  

ORGANELLAR CHANGES IN MICROSPORES OF CITRULLUS VULGARIS SCHRAD

作　　者：刘林[1] 许秋生[1] 张再君[1] 张恒悦[2] 叶秀麟[1] 梁承邺[1] 

机构地区：[1]中国科学院华南植物研究所,广州510650 [2]山东农业大学,泰安271018

出　　处：《武汉植物学研究》2000年第4期266-270,T002,T004,共7页Journal of Wuhan Botanical Research

摘　　要：用透射电子显微镜观察了西瓜 ( Citrullus vulgaris Schrad.)小孢子发育过程中核糖体、线粒体、质体、内质网、高尔基体等细胞器的变化。核糖体和线粒体变化都有明显的规律性 :核糖体密度在四分体时期高 ,液泡化时期降低 ,液泡化结束后再回升 ;线粒体经历一个脱分化与再分化周期 ,液泡化时期该细胞器数量及其内嵴数目减少而脱分化 ,液泡化结束后形状多样化、内嵴重新增多而再分化 ;质体结构不变 ,但体积变化明显 ,大多数在液泡化时期缩小数倍 ,液泡化结束后又扩大数倍 ;内质网在液泡化前后属于不同类型 ,之前为光滑型 ,之后为粗面型 ;高尔基体在早期小孢子中数量多 ,但液泡化结束后大大减少。显然 ,小孢子细胞质发生了深刻改造 ;细胞质改造可能是小孢子的固有特征 ,为各种活动所必须 。Some organelles of watermelon microspores were observed by using transmission electron microscope.Ribosome density was high in tetrad microspores, very low in vacuoli zing ones,and high again after vacuolization came to an end.Mitochondria showed a cycle of dedifferentiation and redifferentiation.Disappearance of mitochondrial cristae and decrease of such organelle number during vacuolization stage were implications of the dedifferentiation,and reappearance of cristae and a variety of variations in shape after vacuolization indicated the redifferentiation.Plastids showed no structural modifications,but underwent evident changes in size.Most individuals reduced by several times when microspores were in va cuolization process,and then enlarged several times again after the process.Endoplasmic reticula changed from smooth type in tetrad microspores to rough type in vacuolized ones.Dictyosomes were copious before vacuolization,sparse after vacuolization stopped.It is evident that cytoplasm of watermelon microspores was reorganized.Cytoplasmic reorganization might be an inherent characteristic,for it conformed to spore development and was necessary for further development into 2 celled pollens.

关 键 词：西瓜 小孢子 细胞器 超微结构 发育过程 

分 类 号：S651.01[农业科学—果树学]