Abstract:Calcium distribution during the anther development of Jatropha curcas L. was observed under transmission electron microscopy by ultra-thin sectioning. At the sporogenous cell stage, very few calcium precipitates are found in the anther, but they are accumulated in the parenchymatous cells outside the vascular bundles. At the microspore mother cell stage, there are still few calcium precipitates in cytoplasm, but abundant calcium precipitates accumulate in the tapetal cell walls. After the tetrads form, abundant calcium precipitates appear in the cytoplasm of the microspores and tapetal cells. At the early microspore stage, numerous calcium precipitates accumulate in the microspore intine and abundant precipitates are found in the tapetal cells. At the late microspore stage, calcium precipitates accumulate on the vacuole membrane, but decrease in the tapetal cells. As starch grains accumulate in the mature pollen, very little calcium is found. At the same time, some calcium precipitates accumulate in the parenchymatous cells outside the vascular bundles. The character of calcium distribution during anther development of Jatropha curcas means that calcium plays some roles in biological significance during microspore development. Calcium precipitates are transported from the connective parenchyma cells into the tapetal cells, and they are transported into the pollen wall and cytoplasm. Quantity of calcium in the anthers during its whole developmental progress showed a changing tendency of few — increase — decrease.
