猕猴桃花粉原位生长过程中Ca^2＋的超微细胞化学定位

Ultracytochemical Localization of Calcium of Kiwifruit Pollen Growth in Situ

应用扫描电镜和荧光显微镜对软枣猕猴桃同种花粉在柱头上原位萌发及花粉管生长情况进行了观察,并用焦锑酸盐沉淀法对其授粉前后柱头及花柱中Ca2+进行超微细胞化学定位。结果显示:(1)猕猴桃柱头属于干性柱头,具有一道裂沟,乳突呈长圆柱形,授粉前后形态差异不明显。(2)授粉后3 h,花粉管生长穿过柱头表面,授粉后7 h,花粉管生长到达花柱底部;(3)授粉前后,柱头接受面靠近柱头外围细胞的角质层一侧细胞器内含有丰富的钙,而柱头非接受表面钙颗粒分布很少;(4)授粉前和授粉后3 h,花柱顶端钙颗粒较少,基部钙颗粒较多;授粉后7h,花柱顶端和基部钙分布密度无明显差别;(5)授粉前后花柱顶端钙主要均匀分布在细胞质膜位置;在花柱基部授粉前钙主要分布在引导组织胞间隙中,授粉后3 h主要分布在细胞质内,授粉后7 h主要存在于细胞质、内质网上。研究表明,猕猴桃授粉前后,柱头和花柱组织中均含有钙,授粉前和授粉后3 h花柱中的钙呈现出梯度分布,授粉后7 h钙的梯度分布现象减弱甚至消失。

Fluorescence microscope and scanning electron microscopy were used to observe pollen germination and pollen tube growth,potassiam antimonate was used to localize calcium in stigma and style tissue of Actinidia arguta before and after pollination.（1）Stigma of A.arguta was dry,it was long cylindrical shape and had a crack ditch,the form difference was not obvious before and after pollination.（2）After pollination 3 h,pollen tube grew through stigma surface,and got to basal style after pollination 7 h.（3）Receptive surface of stigma,cuticle organelles were rich in calcium granules before and after pollination,but no-receptive surface of stigma,organelles had little calcium granules.（4）Top style had little calcium,but basal style had more calcium before pollination and after pollination 3 h.The calcium contents were briefly identical in top and basal style after pollination 7 h.（5）The calcium distributed in plasma membrane of top style before and after pollination,in intercellular gap of basal style before pollination,in plasma membrane of basal style after pollination 3 h,and in plasma membrane and endoplasmic reticulum of basal style after pollination 7 h.Stigma and style tissue of A.arguta were rich in calcium before and after pollination.Calcium of style showed the gradient distribution before pollination and after pollination 3 h,it weakened or disappeared after pollination 7 h.