Abstract The stigma (tip of the pistil) of medlar is wet and covered with stigmatic exudate at anthesis. The exudate contains many vesicles with abundant calcium precipitates. After deposition on the stigma, the pollen grain undergoes hydration, displaying signs of calcium ion (Ca2+) transfer from the exudate vesicles into the pollen grains. Calcium precipitates in the pollen cytoplasm are concentrated into small vacuoles that fuse to form large vacuoles, which provide turgor pressure to push the cytoplasm to the apical region of the growing pollen tube. Many calcium precipitates are present in the stylar transmitting tract, which displays a calcium gradient: fewer precipitates are localised in the distal (upper) transmitting tissue below the stigma, and more precipitates are present in the transmitting tract at the style base. The emporal and spatial distribution of calcium in the stigma and style of medlar suggests that it satisfies the demand for calcium in vivo and played some functional significance.

中文翻译：

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在花粉萌发和花粉管生长期间，枸杞 (Lycium barbarum L.) 柱头和花柱中的钙快照表明存在活跃的钙振荡

摘要 枸杞的柱头（雌蕊尖）湿润，开花时被柱头渗出液覆盖。渗出液含有许多囊泡，含有丰富的钙沉淀。在柱头上沉积后，花粉粒经历水合作用，显示出钙离子 (Ca2+) 从渗出液囊泡转移到花粉粒中的迹象。花粉细胞质中的钙沉淀浓缩成小液泡，这些液泡融合形成大液泡，提供膨胀压力将细胞质推向生长的花粉管的顶端区域。许多钙沉淀存在于花柱传导束中，呈现出钙梯度：较少的沉淀位于柱头下方的远端（上部）传导组织中，而更多的沉淀存在于花柱基部的传导束中。