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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Reproductive barriers and genetic differentiation between continental and island populations of Epidendrum fulgens (Orchidaceae)

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Autor(es):
Pinheiro, Fabio [1] ; Veiga, Giovanna Seleghin [1] ; Chaves, Cleber Juliano Neves [1] ; da Costa Cacossi, Tami [1] ; da Silva, Clarisse Palma [1]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] Univ Estadual Campinas, Dept Biol Vegetal, Inst Biol, Campinas, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: PLANT SYSTEMATICS AND EVOLUTION; v. 307, n. 3 JUN 2021.
Citações Web of Science: 0
Resumo

Studies on insular organisms provide an important framework for investigating patterns of genetic differentiation and reproductive isolation. By focusing on populations of the same species, we have the opportunity to study the mechanisms operating during the earliest stages of speciation, as reproductive barriers can be examined among divergent lineages in a geographic context. We investigated the genetic differentiation and the evolution of early stages of intrinsic postmating reproductive isolation between continental and insular populations of Epidendrum fulgens, a neotropical orchid distributed in southeastern Brazil. Genetic diversity and structure were estimated for both nuclear and plastid markers by using genetic differentiation measures and model-based assignment test. Furthermore, two components of reproductive isolation were examined by analyzing fruit set and seed viability in interpopulation crosses. Strong plastid genetic structure (F-ST = 0.679) was found between insular and remaining populations, indicating that E. fulgens reduced gene flow via seed dispersal, although significant nuclear genetic structure was lower (D-ST = 0.179), likely due to the smaller effective population size of the plastid genome. Significant differences in seed viability between self- and cross-pollinated plants were found, indicating the occurrence of inbreeding depression in all populations. Seed viability was significantly lower in crosses between insular and remaining populations, suggesting a late postzygotic reproductive barrier due to low migration associated with genetic drift (i.e., bottleneck) and its consequences. Our results confirm the importance of islands as drivers for populational differentiation and suggest a central role for outbreeding depression during the early stages of lineage diversification. (AU)

Processo FAPESP: 20/02150-3 - Sobrevivência no limite: como gradientes ambientais podem limitar a distribuição geográfica de uma espécie de orquídea distribuída ao longo do litoral?
Beneficiário:Fábio Pinheiro
Modalidade de apoio: Auxílio à Pesquisa - Regular
Processo FAPESP: 09/15052-0 - Filogeografia das espécies de Epidendrum (Orchidaceae) integrantes do clado Atlântico (subgênero Amphiglottium)
Beneficiário:Fábio Pinheiro
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado