Aspectos reprodutivos e conservacionistas de Quesnelia Gaudich (Bromelioideae: Bromeliaceae)

Abstract

The genus Quesnelia Gaudich. (Bromeliaceae), endemic to the Atlantic Forest, comprises species with remarkable morphological and ecological diversity, many of them microendemic, In this context, understanding species distribution, conservation status, and reproductive biology is essential to support management and conservation strategies within the genus. The present work integrates different approaches to increase the knowledge regarding Quesnelia, and is structured in two chapters. Chapter 1 “From field data to political actions: accessing the distribution and conservation of Quesnelia (Bromelioideae: Bromeliaceae), an endemic genus of the Atlantic Forest” aimed to map the geographic distribution and assess the conservation status of the 24 recognized species. Herbarium records, databases, and results from field expeditions were analyzed, totaling over one thousand validated records. Results indicated that 46% of the species are under some level of threat, including “Critically Endangered” and “Endangered” categories, with the highest concentration of occurrences in Southeastern Brazil. The main threats identified were deforestation, urbanization, silviculture, and illegal collection for the ornamental plant trade. Chapter 2 “Morphology, pollen viability, and stigma receptivity of different species of Quesnelia Gaudich. (Bromelioideae: Bromeliaceae)” focused on the reproductive biology of 22 species, includes pollen and stigma morphology, pollen viability, and stigma receptivity. Analyses revealed a predominance of biporate pollen grains, but also rare occurrences of triporate and pantoporate types, reflecting distinct adaptive trajectories among species. Pollen viability was generally highest at anthesis, exceeding 99% in species such as Q. quesneliana and Q. humilis, whereas Q. violacea showed markedly reduced viability values. All stigmas were of the conduplicate-spiral type, with variations in papilla size suggesting different strategies for pollen capture. Taken together, the results of this thesis provide unprecedented contributions to the systematics of the genus, by clarifying morphological and reproductive variation patterns, and to biodiversity conservation, by identifying priority areas, critical species, and complementary strategies for in situ and ex situ conservation. Therefore, this work strengthens knowledge of some reproductive biology aspects and offers applicable bases for the protection of threatened species of the Atlantic Forest.