A STUDY OF THE KINETICS OF MICROSPOROGENESIS IN CAMPELIA ZANONIA (L.) H.B.K.

During maturation, microspores pass through a series of morphologically distinguishable stages or compartments. A study has been made of the systematic fluctuations in the frequency of microspores in these compartments, when plants are grown under rigidly controlled conditions. A new approach to the construction of cumulative flux rate curves is described; these give the number of cells passing the compartment boundaries per unit time. The curves obtained indicate that simple models, which assume constant flux rates and compartment transit times, will not explain the observations. It is evident that not only do microspores mature at different rates, but that the maturation rate of individual microspores varies during the developmental sequence. The overall process may be controlled by the intimate relationship which exists between the microspores and the tapetal periplasmodium in the Tradescantiae.