Microsporogenesis and development of the male gametophyte in Allium senescens L. (Liliaceae) in China

Microsporogenesis and development of the male gametophyte of Allium senescens L. were studied by use of paraffin sections. The anther was found to be four-sporangia. Its wall includes four layers: epidermis, endothecium, middle layer, and secretory tapetum. Cytokinesis during meiosis of microspore mother cells (MMCs) is successive. Most mature pollen grains are two-celled, a few are three-celled. In addition, anomalies were observed during meiosis of MMC and in uninucleate microspores, including laggard chromosomes, lagging chromosomes, anaphase bridges, and micronucleus. These anomalies are possible reasons for abortive pollen.