Aspectos reprodutivos de Miconia chamissois Naudin (Miconieae, Melastomataceae) em um habitat de Vereda do Cerrado

Abstract

Melastomataceae is among the most representative in terms of apomictic species, with a highlight on the tribe Miconieae. These species have broader distributions compared to sexual and self-incompatible species of the same tribe, with some considered potentially invasive. Moreover, some species exhibit reproductive flexibility, with the coexistence of apomictic and sexual systems. Similarly, Miconia chamissois Naudin occupies Cerrado environments such as Veredas in a broad and growing manner. Such a fact, combined with the high fruit production, led us to consider the possibility of reproduction by apomixis, given that these attributes are common to apomictic plants of the same tribe and family. Considering this, the reproductive biology of M. chamissois was investigated based on the mating system, pollen quality, natural pollination success, and female reproductive success. The controlled pollination experiments indicated that the studied population of this species was mainly xenogamous. There was a higher proportion of fruits formed under open and cross-pollination conditions. This finding was further supported by the high pollen viability and the greater number of seeds formed in these treatments. Only a few fruits were produced by self-pollination, which contrasted with the initial observation of self-pollen deposition. No evidence of autonomous apomixis was found. Our results suggest that the establishment of new individuals in the population is directly related to the success of pollination and pollen dispersal performed by biotic vectors. While autogamy may also play a role, its contribution to the reproductive success of the species population is limited.