First report on generalized pollination systems in Melastomataceae for the Andean páramos

Abstract

AbstractMelastomataceae is a megadiverse family with records of transitions from specialized to generalized pollination systems for several species. These transitions are associated with the colonization of new, unpredictable and/or impoverished pollinator habitats or habitats where specialized pollinators are scarce (e.g., in highland environments). The bee species diversity is low in highlands. Therefore, autonomous breeding systems such as apomixis and self‐pollination emerge in these environments. In this paper, we studied the floral traits associated with the generalization of pollination systems and registered the floral visitors of two species in the Colombian Andes: Miconia cataractae and M. elaeoides. We investigated the breeding system of M. elaeoides. Both species presented small flowers, short anthers of medium pore size, and nectar‐producing stomata on the base of the anthers. Miconia cataractae produced an average of 1.62 μl nectar/flower, a sugar concentration of 6.78%, whereas M. elaeoides produced 0.09 μl nectar/flower, a sugar concentration of 6.13%. We recorded a wide diversity of pollinators for both species, mainly insects from the orders Hymenoptera and Diptera. Miconia elaeoides presented a mixed breeding system and was also capable of setting fruits by apomixis. We conclude that flower and anther morphology, combined with nectar production, thus represent convergent traits resulting in a generalist pollination system shared by M. cataractae and M. elaeoides. Here, we presented the first generalist pollination system recorded for Miconia (and the Melastomataceae) in the Andes, the first report for a species from the small‐pored section Amblyarrhena, and the first report for a species from the large‐pored section Cremanium in Colombia.