Filogenia molecular de Utricularia sect. Utricularia (Lentibulariaceae) baseada em dois loci nucleares e um espaçador cloroplastidial
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Data
2016-07-29
Autores
Seber, Guilherme Camara [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Utricularia sect. Utricularia é uma das mais ricas do gênero Utricularia, com 35 espécies. A seção Utricularia possui distribuição cosmopolita, ocorrendo desde os trópicos até altas latitudes. Tratam-se de macrófitas aquáticas de padrão vegetativo muito semelhante. U. sect. Utricularia é um dos grupos mais derivados dentro do gênero Utricularia, o maior de Lentibulariaceae. A família comporta três gêneros de plantas carnívoras, com Pinguicula compondo um grupo irmão a Genlisea e Utricularia. As armadilhas de Pinguicula são as próprias folhas, que possuem uma mucilagem adesiva que captura principalmente insetos. As armadilhas de Genlisea e Utricularia são modificações foliares que possuem mecanismos bastante complexos para a captura de presas, destacando-se os utrículos, que possuem um mecanismo ativo de sucção de pequenos organismos e dão o nome ao gênero Utricularia. O presente estudo empregou dados moleculares para a reconstrução filogenética de 21 espécies de U. sect. Utricularia, utilizando-se como grupo externo outras onze espécies do mesmo gênero e três de Genlisea. Foram construídas matrizes a partir do alinhamento de sequências homólogas de dois genes nucleares, RBP2 e LEAFY, bem como de um espaçador do DNA plastidial, rpl20-rps12. Os resultados convergem quanto à parafilia de U. sect. Utricularia, com U. olivacea alocando-se como grupo irmão de Utricularia sect. Vesiculina, evidenciando a necessidade de modificações taxonômicas e criação de uma nova seção. Os dados sugerem também a ocorrência de sucessivos eventos de hibridação entre alguns táxons da seção Utricularia. Determinados caracteres morfológicos suportam grupos de espécies, como as características florais, o padrão de deiscência das cápsulas, a estrutura morfológica das sementes, a ocorrência de dimorfismo acentuado nos ramos e a presença de flutuadores na base da inflorescência, e convergem com os resultados do presente estudo, que se basearam no DNA.
Utricularia sect. Utricularia is one of the richest in the genus Utricularia, with 35 species. The section Utricularia has worldwide distribution, occurring from the tropics to high latitudes. It is a group of aquatic plants with very similar vegetative patterns. U. sect. Utricularia is one of the most derivative group of the genus Utricularia, the biggest of Lentibulariaceae. The family comprises three genera of carnivorous plants, with Pinguicula as a sister group to Genlisea and Utricularia clade. The traps of Pinguicula are mucilaginous leaves, adapted to capture mainly insects. The traps of Genlisea and Utricularia are leaf modifications that have very complex mechanisms to capture prey, standing out the utricles, that have an active mechanism to suction small organisms and gave the origin of the name of genus Utricularia.This study used molecular data for phylogenetic reconstruction of 21 species of U. sect. Utricularia, using eleven other species of the same genus and three of Genlisea as outgroup. We constructed matrices from the alignment of homologous sequences of two nuclear genes, RBP2 and LEAFY, and a spacer of cpDNA, rpl20-rps12. The results converge as the paraphyly of U. sect. Utricularia, with U. olivacea allocating up as a sister group of Utricularia sect. Vesiculina, highlighting the need for taxonomic modifications and the creation of a new section. The data also suggests the occurrence of successives hybridization events between some species of the section Utricularia. Some groups are also supported by the morphological pattern, with the same floral characteristics, the same pattern of dehiscence of the capsules, the same morphological structure of seeds, the occurrence of dimorphism pronounced in branches and the presence of floats at the base of inflorescences, and it converges with the results of this study, based on DNA.
Utricularia sect. Utricularia is one of the richest in the genus Utricularia, with 35 species. The section Utricularia has worldwide distribution, occurring from the tropics to high latitudes. It is a group of aquatic plants with very similar vegetative patterns. U. sect. Utricularia is one of the most derivative group of the genus Utricularia, the biggest of Lentibulariaceae. The family comprises three genera of carnivorous plants, with Pinguicula as a sister group to Genlisea and Utricularia clade. The traps of Pinguicula are mucilaginous leaves, adapted to capture mainly insects. The traps of Genlisea and Utricularia are leaf modifications that have very complex mechanisms to capture prey, standing out the utricles, that have an active mechanism to suction small organisms and gave the origin of the name of genus Utricularia.This study used molecular data for phylogenetic reconstruction of 21 species of U. sect. Utricularia, using eleven other species of the same genus and three of Genlisea as outgroup. We constructed matrices from the alignment of homologous sequences of two nuclear genes, RBP2 and LEAFY, and a spacer of cpDNA, rpl20-rps12. The results converge as the paraphyly of U. sect. Utricularia, with U. olivacea allocating up as a sister group of Utricularia sect. Vesiculina, highlighting the need for taxonomic modifications and the creation of a new section. The data also suggests the occurrence of successives hybridization events between some species of the section Utricularia. Some groups are also supported by the morphological pattern, with the same floral characteristics, the same pattern of dehiscence of the capsules, the same morphological structure of seeds, the occurrence of dimorphism pronounced in branches and the presence of floats at the base of inflorescences, and it converges with the results of this study, based on DNA.
Descrição
Palavras-chave
Utricularia sect. Utricularia, Lentibulariaceae, Plantas carnívoras, Hibridação, Filogenia, Carnivorous plants, Hybridization, Phylogeny