Enantiostilia e relações reprodutivas em espécies da subtribo Cassiinae (Fabaceae-Caesalpinioideae)

Abstract

Enantiostyly is a kind of reciprocal herkogamy known for over a century, however few studies investigated its functionality. It is well represented within the Cassiinae subtribe The aim of this study was to evaluate the reproductive biology of Cassiinae subtribe species, focusing on the functionality of enantiostyly and its reproductive relations. In Chapter 1, the flowering dynamics was noticed in eight species, four Chamaecrista and four Senna. Isoplethy was found in all studied species, beyond different strategies in flowering dynamics that generate functionally dimorphic individuals, increasing cross pollination rates. Chapter 2 brings results about patterns of pollen deposition and capture, floral visitors’ behavior and breeding system of seven species, four Chamaecrista and three Senna. Most species presented a pattern of pollen deposition and capture recorded in other enantiostylous species. In Chapter 3 it was suggested seven enantiostylous types based on heteranthery type of 62 Cassiinae. The Chapter 4 brings the report of a possible new enantiostyly reproductive strategy in two species of Senna genus. The species presented two gynoecium, an unusual feature in Fabaceae species. This floral variation seems to be related to an increase in the reproductive fitness. These results, in general, show the reproductive diversity in species of Cassiinae subtribe, with adoption of different reproductive strategies leading to floral morphology changes and subsequent differentiation in the flowers and visitors relations. This study brings relevant and unpublished informations for reproductive knowledge of Cassiinae species.