Anther wall and pollen development in Ophrys mammosa L. (Orchidaceae)

The objective of this study was to investigate anther wall and pollen development in Ophrys mammosa. Primary sporogen tissue resembles longitudinal cells with divided archeosporal cells. Thereafter these primary sporogen tissue cells re-divide anticlinally and periclinally forming secondary sporogen tissue. Microsporogenesis was successive type. Microgametogenesis occurred at the distal poles of the microspores. In addition, dense starch accumulation was detected in the pollen. Pollinia and massulae are separated from each other by dead cells filled with callose, according to histochemical preparations. The anther wall was a four-layered “monocotyledon” type. There was ring-like wall thickening in the endothecium. The tapetum is of the glandular type. When these two developmental processes are compared, it is seen that the anther wall has become mature by the sporogen tissue phase and is composed of only epidermis and endothecium at the beginning of microgametogenesis.