Fenología floral, viabilidad de polen y receptividad del estigma en Magnolia hernandezii (Molinillo)

Abstract

The floral phenology of Magnolia hernandezii was studied to understand the behavior, flowering times, fruiting, and adaptation of the species. In addition, the receptivity of their stigmas and pollen viability were evaluated in order to provide knowledge to recover their population. The objective was to identify the floral phenology in individuals of Magnolia Hernandezii located in the José Celestino Mutis Botanical Garden of Bogotá for the construction of a phenological baseline. The work was carried out from March 2023 to March 2024, in the Andean Forest with an emphasis on Magnolias, five adult individuals were marked and observed every fifteen days. Foliage fall and foliar shoot appearance were continuous during the research, while flowering occurred at various periods during the year and decreased in the months of less rainfall, fruiting did not occur during the study. In terms of viability, three flowers per individual and three anthers per flower were taken and the viability of pollen was evaluated by the direct method of exclusion with trypan blue, when counting the viable pollen grains, a percentage of 82% viability was reached, this result is not conclusive at the time of fertilization. Finally, the receptivity of stigma was examined during a period between 6:00 p.m. and 11:00 p.m. with the Osborn method.