灵武长枣正常果及裂果中Ca^(2+)的细胞化学定位研究

Ultracytochemical Localization of Ca^(2+) in the Normal Fruits and Cracking Ones of Lingwu Long-jujube

采用焦锑酸钾沉淀法,对灵武长枣正常果发育过程中的Ca2+及不同开裂度果实中的Ca2+进行细胞化学定位,在透射电镜下观察并比较Ca2+的分布特征和积累规律.结果表明:(1)正常长枣青果期的外果皮细胞及胞间隙中检测到大量的钙沉淀颗粒,而果肉细胞以及叶绿体中很少有钙沉淀颗粒.红果期很多外果皮细胞中钙沉淀颗粒特异性地沿细胞壁呈一圈分布,且越靠近内方的细胞中钙沉淀颗粒越少、越小.果肉细胞中仍无钙沉淀颗粒分布.(2)具轻微开裂的长枣很多外果皮细胞中无钙沉淀颗粒,只有少数细胞中有且集中分布于大液泡中;细胞质沿细胞壁分布,也无钙沉淀颗粒;在果肉细胞中几乎看不到钙沉淀颗粒分布.(3)完全开裂的长枣中钙沉淀颗粒只分布在少数体积较小的外果皮细胞中,而果肉细胞的细胞壁边缘或细胞壁以及胞间隙中分布有大量的钙沉淀颗粒.

In this study,potassium antimonite was used to deposit Ca^2＋ in the normal fruits and various degree of cracking fruits of Lingwu Long-jujube.We observed the distribution and accumulation of Ca^2＋ by the transmission electron microscope.The results showed that：（1）Great amounts of Ca^2＋ precipitate grains were detected in the exocarp cells and intercellular spaces of the normal green Long-jujube（Ziziphus jujuba Mill.） fruits.In the intercellular spaces of the mesocarp cells great amounts of Ca^2＋ precipitate grains were also detected,while there were a little Ca^2＋ precipitate grains in the mesocarp cells including the chloroplasts.In the red normal fruits,many Ca^2＋ precipitate grains specifically distributed along the cell wall in many exocarp cells.In addition,more closely the exocarp cells the Ca^2＋ precipitate grains were more numerous and bigger.But there were no Ca^2＋ precipitates in mesocarp cells.（2）In the Long-jujube with slight cracking,only a few exocarp cells had Ca^2＋ precipitate grains which concentrated in the large vacuole.Cytoplasm distributed along the cell wall without Ca^2＋ precipitate grains.There were hardly Ca^2＋ precipitate grains in mesocarp cells.（3） In the Long-jujube cracking completely,Ca^2＋ precipitate grains distributed in a little of exocarp cells which had smaller volume.While in the mesocarp a great number of Ca^2＋ precipitate grains were detected in cell walls,the edge of the cell wall and the intercellular space.