Male phenology and pollen production of Cupressus sempervirens in Tetouan (Morocco)

Abstract

Male phenology, processes of microsporogenesis and pollen differentiation were studied for Cupressus sempervirens from the city of Tetouan (Morocco). Five phenological phases are described based on morphological and structural characters. Pollen mother cells stage, meiosis, microspore maturation and pollen development occurred in winter from December to February. Meiotic development shows typical coniferous pattern. Anthesis takes place two months after bud burst. The flowering phenophase takes place over one month and is associated with the main pollen emission period which started in the last week of February 2007. The pollen production of individual trees in C. sempervirens is also estimated. Tree size, cone density and number of pollen grains per cone are investigated. The results indicate that the number of pollen grains per cone and the total pollen production per tree were in the production range to those obtained in anemophilous trees. This study provides the first data on the onset of the pollen season and on the pollen production in C. sempervirens in Morocco and the contribution of this species to the total amount of airborne pollen content in Tetouan city.