Efeito da distância da fonte de pólen no sucesso reprodutivo de Esterhazya splendidaMikan (Orobanchaceae)

• Ano de defesa: 2012
• Autor(a) principal: Gomes, Carolina Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; BR; Programa de Pós-graduação em Biologia Vegetal; Ciências Biológicas; UFU
• Palavras-chave em Português: Ornitofilia; Depressão endogâmica; Autocompatível; Cerrado; Germinação; Esterhazya splendida; Ornithophily; Inbreeding depression; Autocompatible; Germination; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/12432; https://doi.org/10.14393/ufu.di.2012.37

The seed set of an angiosperm depends on the quality and quantity of pollen that reach its stigma. This is influenced by a number of factors, including behavior of the floral visitors, availability of pollen on the donor plant, the structure of the habitat between individuals, and the distance separating them. The distance can be associated to genetic differences between individuals, being closer individuals more related genetically. Butmuch of the work that evaluated how distance affects the reproductive successuntil today has been done in temperate zones or in tropical forests. Although Savannas are an important ecosystem in the tropics and subtropics,we know little about how distance influence plant reproduction success in these systems. The aim of this study was to determine if the crossing distance affects the reproductive success components of Esterhazya splendidaMikan. The study was carried out at the Cerrado sensustrictu area of the Caça e PescaItororó Club, Uberlândia, MG. Esterhazya splendida (Orobanchaceae) is an autocompatible species, pollinated mainly by hummingbirds. We characterized its floral biology, individuals density, fenology and energy reward. We made pollination treatments with fonts of pollen ranging from 0m (self-pollination) to 2000m, and then we did a germination experiment. The species presented a random distribution (c 2=101,26; p>0,05; GL=99) and a density of 124 individuals per hectare. The nectar offer in the area was quantified in 22.19kcal/ha. The fruit set was not affected by the distance from the pollen donor. The fruits from self-pollination were smaller, presented lower weight and less seeds andthe seeds presented lower germination rate, but there was no difference in the seedlings length between treatments. Eupetomena macrouraand Amazilia sp.effectively pollinated the flowers, and E. macroura presented a territorial behavior. The results indicate that E. splendida presents inbreeding depression but no outbreeding depression. The presence of inbreeding depression and absence of outbreeding depression implies in populations with high genetic heterogeneity.It would be interesting to apply this kind of study to endemic species or rare species given that they are more susceptible to extinction, because they occur generally in small populations, which increase the expression and fixation of deleterious alleles.