Características vegetativas e reprodutivas das plantas e fatores abióticos do meio e suas relações com a alocação de biomassa floral e a seleção sexual em angiospermas / Vegetative and reproductive characteristics of plants and abiotic factors of the environment and their relations with floral biomass allocation and sexual selection in angiosperms

Carina Lima da Silveira

Plants are sessile organisms exposed to the effects of environmental stress. The flowers are fundamental structures in the evolution of angiosperms, because through them is sexual reproduction. For this, the flowers exhibit strategies that help the plant to achieve better reproductive success. Animals visit flowers in search of resources, however, to carry pollen between individuals of the same plant species, act as mediators in the process of sexual selection, major force in floral evolution. Ecological factors affecting the relationship between plants atid pollinators may influence the evolution of reproductive strategies of species. Abiotic factors, spatial distribution, population size and life history of plants can modify the abundance and distribution of resources for pollinators by changing patterns of pollen transfer, gene flow and selective pressures responsible for floral evolution. This work seeks to understand the diversity of reproductive strategies in different tropical vegetation types, the modulated vegetative and reproductive features of plants and the abiotic environment in resource allocation as well, check for consistency biogeographical of allometric patterns in reproductive strategies in relation to plants. The study was conducted in areas of tropical vegetation, with an area of Atlantic Rain Forest, an area of Savannah, both in the state of Sao Paulo and an area of Campo Rupestre, in the state of Minas Gerais, allowing the comparison of variation among floral biomass the three vegetation types and between tropical angiosperm morphological peculiarities related to the areas of collection and bibliographic data of extra-tropical species. The richness of plant forms and environments in tropical acts in modulating the interaction between plants and pollinators, influencing the variation of biomass in the floral and vegetative and reproductive characteristics of species. The positive allometry and isometry floras found in tropical and extra-tropical growth over the floral biomass indicate the presence and development of secondary sexual characteristics as important tools in the permanence and success of cross-breeding. Vegetative and reproductive characteristics influence the interspecific variation of floral biomass and that the function of male flowers have a strong impact on the evolution of floral traits, regardless of the phylogenetic connection between the angiosperms, highlighting the need for theories that allow a synthesis of these relationships.

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