Biologia reprodutiva de Melastomataceae do Parque Nacionalda Serra da Canastra, Minas Gerais Reprocuctive biology of Melastomataceae from ParqueNacional da Serra da Canastra, Minas Gerais

by Milla dos, Ana Paula

Abstract (Summary)
Most Melastomataceae species have hermaphrodite flowers with spacial separation of stigmaand poricidal anthers, which favours the predominance of xenogamy in this family. Manypapers have described the occurrence of self-compatible and apomitic Melastomataceae, butin general, there are few studies yet on the reproductive biology of species with restricteddistribution, as common on the campos rupestres. This work verified the reproductive biologyof six species of Melastomataceae with distribution restricted to the campos rupestres andrelated their geographic distribution patterns with the reproductive systems. The reproductivesystems was studied by controlled hand pollinations, pollen tube growth analysis, pollenviability, seed germination and initial seedling growth. The relationships between thereproductive systems and geographic distribution of the Melastomataceae was analyzed usingthe results of this work plus the available data in literature. The controlled hand pollinationexperiments and pollen tube growth analysis suggest that the species studied, Cambessedesiaregnelliana, Miconia angelana, Microlicia inquinans, Svitramia hatschbachii, S. minor andSvitramia sp. were self-compatible, producing viable seeds from self-pollination and withoutindication of self-incompatibility reactions of pollen tubes along the pistils. The spontaneousself-pollination and production of nectar was observed only in Miconia angelana. The othersspecies, although self-compatible, are dependent on buzz pollination by bees. All the studiedspecies had above 90% pollen viability (estimated by stainability) and were apparently apt tosexual reproduction. The germinability and initial growth of the seeds formed after crosspollination was larger than others treatments, probably due to the greater genetic variability.The exception was M. angelana, in which the germinability and initial growth of seedlingsformed by spontaeous self-pollination were significantly larger. The results had confirmed thehypothesis that species with restricted distribution, studied so far, are sexual, mainly selfcompatible(70%). The majority of the studied apomitic species and the self-incompatibleones possesss wide geographic distribution and belongs mainly to the Miconieae tribe.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Paulo Eugenio Alves Macedo de Oliveira; Renato Goldenberg; Rosana Romero

School:Universidade Federal de Uberlândia

School Location:Brazil

Source Type:Master's Thesis

Keywords:melastomatacea reprodução plantas ecologia


Date of Publication:02/22/2008

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