Ultrastructural Studies of Microsporogenesis in Phaseolus vulgaris L.

Microsporogenesis in dwarf Phaseolus vulgaris was studied under the electron microscope. Before meiosis the microspore mother cell had a lot of organelles especially plastids and ER in its cytoplasm. There were many osmiophilic granules adhering to the membranes of the plastids and vesicular ER until meiosis began. Some cytoplasmic channels were present between adjacent microsporocytes from pachytene to telophase Ⅱ. The organelles were at early stage in the early rnlcrospore, the plastids and mitochondria of which showed regional distribution. Original vacou[es were produced by smooth ER. The organelles in the tapetum cells were mainly mitochondria, plastids and ER. The ER was concentric circles in shape in transverse section.