Delimitação de espécies do complexo Aspidosperma pyrifolium Mart. & Zucc. (Apocynaceae)
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Data
2019-03-01
Autores
Messias, Patrícia
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Universidade Estadual Paulista (Unesp)
Resumo
Aspidosperma pyrifolium Mart. & Zucc. é uma espécie com distribuição ampla e disjunta, variação morfológica e taxonomia complexa. Neste estudo é tratada como um complexo de espécies, e utilizada como modelo para delimitação de espécies através de múltiplos critérios operacionais (genéticos, morfológicos e ecológicos). Consideramos que espécies são segmentos de linhagens de uma metapopulação evoluindo separadamente, pois este é um conceito universal que diminuiu as visões conflitantes do que é considerado espécie. Realizamos análises filogenéticas com dados concatenados (ITS e rpl32-trnL) e de coalescência para testar o monofiletismo do complexo e seus grupos. Desenvolvemos marcadores microssatélites polimórficos para A. pyrifolium usados na avaliação da diversidade genética e estruturação de cinco populações naturais. Analisamos a morfologia através de morfometria, incluindo características quantitativas, tanto vegetativas quanto reprodutivas. As análises ecológicas, incluíram modelagem e testes de similaridade de nicho ecológico. Nossos resultados recuperaram o complexo A. pyrifolium como monofilético, com 3 subclados relacionados a regiões geográficas e vegetações específicas, resultados também corroborados na árvore de espécies. O clado 1 ocorre na Caatinga no Nordeste do Brasil, o clado 2 nas manchas de Floresta Estacional na região Centro-Oeste no Brasil e clado 3 na vegetação chaqueana no Mato grosso do Sul, Paraguai e Bolívia. Todas as análises de estrutura populacional sugeriram a formação de dois grupos genéticos, um com as populações do Mato Grosso do Sul (clado 3) e o outro com as populações do Nordeste (clado 1), concordando com os resultados da filogenia e coalescência. Entretanto, ressaltamos que o clado 2 não pode ser testado nas análises populacionais pois essas mesmas não puderam ser coletadas. Esses clados não foram recuperados nas análises morfométricas (PCAs), devido a grande sobreposição dos caracteres morfológicos. Os modelos de nicho ecológico e o teste de similaridade indicaram baixa sobreposição do nicho entre os clados. Assim, com base nos resultados obtidos, propormos uma nova circunscrição de Aspidosperma pyrifolium, com segregação dos clados 2 (A. martii) e 3 (A. guaraniticum), que são diferenciados pela genética, nicho ecológico e áreas de distribuição geográfica. Essa nova circunscrição foi apresentada em uma monografia que inclui descrições, chave de identificação, pranchas, informações sobre distribuição, habitat preferencial, fenologia e status de conservação.
Aspidosperma pyrifolium Mart. & Zucc. is a species with wide distribution and disjunct, morphological variation and complex taxonomy. In this study, we treated it as a species complex, and used as a model for species delimitation using multiple operational criteria (genetic, morphological and ecological). We consider species as segments of separately evolving metapopulation lineages, since this is a universal concept that diminished the conflicting visions of what is considered species. For this, we performed phylogenetic with concatenated data (ITS and rpl32-trnL) and coalescence analyzes to test the monophyly of the complex and its groups. We developed polymorphic microsatellites for complex A. pyrifolium for evaluated the genetic diversity and structure of five natural population. We analyzed morphology through morphometry, including quantitative characteristics, both vegetative and reproductive. The ecological analyzes included modeling and testing of ecological niche similarity. Our results recovered Aspidosperma pyrifolium complex as monophyletic, with 3 subclades related to geographic regions and specific vegetation, results also corroborated in the species tree. Clade 1 occurs in the Caatinga in Northeast Brazil, clade 2 in the Seasonal Forest patches in the Center-West region of Brazil and clade 3 in the Chaqueana vegetation in Mato Grosso do Sul, Paraguay and Bolivia. All analyzes of population structure suggested the formation of two genetic groups, one with the populations of Mato Grosso do Sul (clado 3) and the other with the populations of the Northeast (clado 1), agreeing with the results of phylogenetic and coalescence analyzes. However, we emphasize that clade 2 can not be tested in the population analyzes because they could not be collected. These clades were not recovered in the morphometric analyzes (PCAs), due to the great overlapping of the morphological characters. The ecological niche models and the similarity test indicated that there little niche overlap among the clades. Thus, based on the results obtained, we propose a new circumscription of Aspidosperma pyrifolium, with the segregation of clades 2 (A. martii) and 3 (A. guaraniticum), which are distinguished mainly by the ecological niche and geographic distribution areas. This new circumscription was presented in a monograph that includes descriptions, identification keys, plates, information about distribution, preferential habitat, phenology and conservation status.
Aspidosperma pyrifolium Mart. & Zucc. is a species with wide distribution and disjunct, morphological variation and complex taxonomy. In this study, we treated it as a species complex, and used as a model for species delimitation using multiple operational criteria (genetic, morphological and ecological). We consider species as segments of separately evolving metapopulation lineages, since this is a universal concept that diminished the conflicting visions of what is considered species. For this, we performed phylogenetic with concatenated data (ITS and rpl32-trnL) and coalescence analyzes to test the monophyly of the complex and its groups. We developed polymorphic microsatellites for complex A. pyrifolium for evaluated the genetic diversity and structure of five natural population. We analyzed morphology through morphometry, including quantitative characteristics, both vegetative and reproductive. The ecological analyzes included modeling and testing of ecological niche similarity. Our results recovered Aspidosperma pyrifolium complex as monophyletic, with 3 subclades related to geographic regions and specific vegetation, results also corroborated in the species tree. Clade 1 occurs in the Caatinga in Northeast Brazil, clade 2 in the Seasonal Forest patches in the Center-West region of Brazil and clade 3 in the Chaqueana vegetation in Mato Grosso do Sul, Paraguay and Bolivia. All analyzes of population structure suggested the formation of two genetic groups, one with the populations of Mato Grosso do Sul (clado 3) and the other with the populations of the Northeast (clado 1), agreeing with the results of phylogenetic and coalescence analyzes. However, we emphasize that clade 2 can not be tested in the population analyzes because they could not be collected. These clades were not recovered in the morphometric analyzes (PCAs), due to the great overlapping of the morphological characters. The ecological niche models and the similarity test indicated that there little niche overlap among the clades. Thus, based on the results obtained, we propose a new circumscription of Aspidosperma pyrifolium, with the segregation of clades 2 (A. martii) and 3 (A. guaraniticum), which are distinguished mainly by the ecological niche and geographic distribution areas. This new circumscription was presented in a monograph that includes descriptions, identification keys, plates, information about distribution, preferential habitat, phenology and conservation status.
Descrição
Palavras-chave
Filogenia, Coalescência, Análise morfométrica, Modelagem de nicho ecológico, Similaridade de nicho, Phylogeny, Coalescence, Morphometric analysis, Ecological niche modeling, Niche similarity