Pollen production and release in Mesua ferrea Linn. (Guttiferae): a spatio-temporal pattern

Abstract

Based on a five-year study of pollen production and release in two different natural populations of Mesua ferrea from Indo-Burma region of Northeast India, we determined that pollen output follows a spatio-temporal pattern. Pollen productivity determinations considered various sources of variability, including the number of flowers per branch, flowers per tree, anthers per tree and pollen grains per tree. Each of these parameters revealed significant year-to-year and population effects. Anthesis follows a forenoon pattern, whereas anther dehiscence pursues the diurnal pattern. The former was significantly correlated with the timing of floral visitation and pollen deposition on stigmas. The latter, however, had significant relationship with the deposition of pollen grains on microscopic slides. The Apis and Xylocopa bees are the efficient pollinators to achieve the reproductive success in M. ferrea. Annual production of pollen per tree varied from averages of 1.07 ± 0.10 × 1010 and 3.24 ± 0.16 × 1010 in years of low production, with alternate high years, producing 3.85 ± 0.34 × 1010 and 8.22 ± 0.76 × 1010 pollen grains per tree.