Estudos taxonômicos e biossistemáticos do gênero Dryadella Luer (Orchidaceae: Pleurothallidinae)
Data
2022-04-04
Autores
Imig, Daniela Cristina
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Dryadella é um gênero pertencente à subtribo Pleurothallidinae que contém 61 espécies. As espécies de Dryadella são epífitas ou raramente rupícolas, cespitosas, raramente reptantes ou pendentes. As inflorescências podem apresentar de 1 a 4 flores sucessivas dispostas em um racemo congesto. Nas flores, as sépalas laterais apresentam um calo espesso próximo à base, pétalas multiangulares e o labelo longo unguiculado com lâmina provida de dois lobos basais, geralmente retrorsos. A distribuição desse gênero é neotropical e disjunta, desde a América Central através das florestas úmidas dos Andes, até o norte da Argentina e do sul ao nordeste do Brasil na Floresta Atlântica. As relações filogenéticas de Dryadella foram investigadas usando o espaçados nuclear ITS e a região plastidial matK, analisadas por máxima verossimilhança e máxima parcimônia para inferir as relações evolutivas entre as espécies. Datações moleculares e análises biogeográficas também foram realizadas. Os resultados obtidos indicam que Dryadella é monofilético, com alto suporte, inserido na Afinidade Specklinia, com provável origem no noroeste da América do Sul, no final do Mioceno (~7 Ma). A primeira diversificação de Dryadella ocorreu no início do Plioceno (~5Ma), envolvendo um evento de dispersão e três clados foram identificados. O clado 1 tem origem no noroeste da América do Sul e em seguida dispersão para o Sul da Amazônia e para a Floresta Atlântica. O clado 2 tem origem no noroeste da América do Sul com dispersão para América Central e em seguida dispersão para o sul dos Andes. O clado 3 tem origem no noroeste da América do Sul com dispersão para o Cerrado e para a Mata Atlântica, diversificado em torno de 3 Ma. A elaboração da monografia das espécies brasileiras de Dryadella resultou em uma nova espécie, novos sinônimos e novas ocorrências, resultando em 14 espécies reconhecidas para o país. O tratamento taxonômico é apresentado para as espécies brasileiras, incluindo descrições morfológicas, ilustrações, fotografias, chave de identificação e distribuição geográfica. Devido a dificuldade taxonômica encontrada em D. zebrina, D. edwallii e D. wuerstlei durante a revisão taxonômica, dedicamos nossos esforços para explorar morfometricamente populações destes táxons, levantamos as variáveis minuciosamente e tratamos a partir de análises multivariadas a fim de clarear a taxonomia e apresentar uma nova circunscrição para estes táxons. Investigações da micromorfologia dos órgãos vegetativos a partir da anatomia da raiz, rizoma, ramicaule e folha de representantes de Dryadella foram descritas com achados inéditos, como ráfides de cristal de oxalato, ausência de tricomas ou cicatrizes destes na superfície foliar e superfície cuticular verrucosa em algumas espécies.
Dryadella is a genus belonging to the subtribe Pleurothallidinae, comprising 61 species. They are epiphytic or rarely rupicolous, cespitose, rarely repent or pending; inflorescence always a single or 2-4 successive flowers in a congested raceme; lateral sepals with thick callus near the base, multi-angular petals and long unguiculated lip with two basal lobes. Exclusively neotropical with disjunct distribution, from Central America through the humid forests of the Andes, to northern Argentina and southern Brazil in the Atlantic Rainforest. Dryadella phylogenetic relationships were investigated using nrITS and the matK plastid region, analysed for Maximum likelihood and Maximum parsimony to infer evolutionary relationships. Molecular dating and biogeographic analyses were also performed. The results obtained provide high support for Dryadella monophyly, inserted in the Specklinia Affinity. with probable origin in northwestern South America, at the end of the Miocene (~7Ma). The first diversification of Dryadella occurred in the early Pliocene (~5Ma), involving a dispersion event and three clades clades were identified. Clade 1 originated in northwestern South America and later dispersal to southern Amazonia and a posterior dispersion event for the Atlantic Rainforest. Clade 2 originates from northwest South America with a dispersion event to Central America and subsequent dispersion to the south of the Andes. Clade 3 originates from northwest South America to the Cerrado and the Atlantic Forest, diversified around 3 My. The elaboration of the monograph of the Brazilian species of Dryadella resulted in a new species, in addition to new synonyms and new occurrences, a taxonomic treatment is presented for the Brazilian species, including morphological descriptions, illustrations, photographs, identification key and geographic distribution. Due to the taxonomic difficulty found in D. zebrina, D. edwallii and D. wuerstlei found during the taxonomic review, we dedicated our efforts to morphometrically explore populations of these taxa, survey the variables in detail and treat from multivariate analyzes in order to clarify the taxonomy and present a new circumscription for these taxa. Investigations of the micro morphology of vegetative organs from the anatomy of the root, rhizome, ramicaule and leaf of representatives of Dryadella were described with unpublished findings.
Dryadella is a genus belonging to the subtribe Pleurothallidinae, comprising 61 species. They are epiphytic or rarely rupicolous, cespitose, rarely repent or pending; inflorescence always a single or 2-4 successive flowers in a congested raceme; lateral sepals with thick callus near the base, multi-angular petals and long unguiculated lip with two basal lobes. Exclusively neotropical with disjunct distribution, from Central America through the humid forests of the Andes, to northern Argentina and southern Brazil in the Atlantic Rainforest. Dryadella phylogenetic relationships were investigated using nrITS and the matK plastid region, analysed for Maximum likelihood and Maximum parsimony to infer evolutionary relationships. Molecular dating and biogeographic analyses were also performed. The results obtained provide high support for Dryadella monophyly, inserted in the Specklinia Affinity. with probable origin in northwestern South America, at the end of the Miocene (~7Ma). The first diversification of Dryadella occurred in the early Pliocene (~5Ma), involving a dispersion event and three clades clades were identified. Clade 1 originated in northwestern South America and later dispersal to southern Amazonia and a posterior dispersion event for the Atlantic Rainforest. Clade 2 originates from northwest South America with a dispersion event to Central America and subsequent dispersion to the south of the Andes. Clade 3 originates from northwest South America to the Cerrado and the Atlantic Forest, diversified around 3 My. The elaboration of the monograph of the Brazilian species of Dryadella resulted in a new species, in addition to new synonyms and new occurrences, a taxonomic treatment is presented for the Brazilian species, including morphological descriptions, illustrations, photographs, identification key and geographic distribution. Due to the taxonomic difficulty found in D. zebrina, D. edwallii and D. wuerstlei found during the taxonomic review, we dedicated our efforts to morphometrically explore populations of these taxa, survey the variables in detail and treat from multivariate analyzes in order to clarify the taxonomy and present a new circumscription for these taxa. Investigations of the micro morphology of vegetative organs from the anatomy of the root, rhizome, ramicaule and leaf of representatives of Dryadella were described with unpublished findings.
Descrição
Palavras-chave
Análise filogenética, Anatomia vegetativa, Taxonomia, Monocotiledônea, Nomenclatura, Morfometria, Phylogenetic analysis, Vegetative anatomy, Taxonomy, Monocots, Nomenclature, Morphometry