Implicações taxonômicas das variações anatômicas em Hypotrachyna s.l. (Parmeliaceae, Ascomycota liquenizados).
Carregando...
Data
2018-03-01
Autores
Zanetti, Camila Aparecida [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Hypotrachyna (Parmeliaceae) foi proposto por Hale em 1974 baseado em Parmelia subgênero Parmelia seção Hypotrachyna. Sua circunscrição incluía espécies com ramos sublineares, as vezes alongados e apicalmente subtruncados, apotécios imperfurados e adnatos, raramente subestipitados, rizinas dicotomicamente ramificadas, uniformemente distribuídas na superfície inferior negra. Segundo ele, o córtex superior seria plectenquimático paliçádico com epicórtex porado. Foi apenas cerca de 30 anos depois que Divakar et al. mostraram que Hypotrachyna, como então circunscrito, é polifilético e sugeriram uma detalhada revisão morfológica e anatômica para a reestruturação do gênero. Em 2013 Parmelinopsis, Cetrariastrum e Everniastrum foram reduzidos a subgêneros de Hypotrachyna, mas Parmelinopsis e Hypotrachyna continuaram sendo polifiléticos. Estudos morfológicos recentes têm levantado a possibilidade de que algumas características anatômicas ainda não estudadas, aliadas a uma abordagem minuciosa de outras já consideradas, muito provavelmente forneceriam importante subsídio a um rearranjo na classificação de gêneros e definição de espécies em Parmeliaceae, especialmente Hypotrachyna. Tendo isso em vista foram aqui anatomicamente estudadas 23 espécies de Hypotrachyna s.l., que foram processadas de acordo com o protocolo de Barbosa et al. e adaptado por Zanetti et al., desenvolvidos na UNESP/Botucatu. O córtex superior continua sendo um caráter útil na separação de espécies, apresentando características próprias dentro de um mesmo grupo. A medula e a camada de algas, no entanto, apresentam variações específicas, não sendo bons caracteres para a separação de gêneros. O córtex inferior, por não apresentar grande variação dentro de Parmeliaceae, não é um bom caráter para separar grupos. Foi possível sugerir que a atual delimitação de Hypotrachyna não é monofilética e que da forma como se encontra organizado apresenta grupos de espécies que podem ser separadas em diferentes gêneros, o que pode ser visto aqui baseado principalmente nas características do córtex superior. Em Hypotrachynella, Lyngenella e Vainia (gêneros ainda não publicados), foi possível concluir que as características anatômicas do córtex superior são constantes para cada gênero estudado corroborando com a recente segregação de Hypotrachyna, embora esta característica não tenha sido eficiente para separar sozinha Lyngenella de Vainia, que apresentam características muito parecidas entre si. Para Parmelinopsis, as características anatômicas encontradas são diferentes daquelas vistas em Hypotrachyna s.s. e desta forma, os estudos anatômicos não corroboram com a sua sinonimização em Hypotrachyna.
Hypotrachyna (Parmeliaceae) was proposed by Hale in 1974 based on Parmelia subgenus Parmelia section Hypotrachyna. Its circumscription included species with sublinear branches, sometimes elongated and apically subtruncate, imperforate apothecia and adnate, rarely subestipitate, and dichotomically branched rhizines, uniformly distributed in the lower black surface. According to him, the upper cortex would be palisade plectenchymatous with porate epicortex. It was only about 30 years later that Divakar et al. showed that Hypotrachyna, as then circumscribed, is polyphyletic and suggested a detailed morphological and anatomical revision for the restructuring of the genus. In 2013 Parmelinopsis, Cetrariastrum and Everniastrum were reduced to Hypotrachyna subgenera, but Parmelinopsis and Hypotrachyna remained polyphyletic. Recent morphological studies have raised the possibility that some anatomical features not yet studied, coupled with a thorough approach to others already considered, would probably provide important support for a rearrangement of genus classification and species definition in Parmeliaceae, especially in Hypotrachyna. Twenty-three species of Hypotrachyna s.l. were anatomically studied and processed according the protocol of Barbosa et al. adapted by Zanetti et al., both developed in studies developed at UNESP / Botucatu. The upper cortex continues to be a useful character in the separation of species, that present its own characteristics within a same group. The medulla and algal layer, however, present specific variations, not being good characters for the separation of genera. The lower cortex does not show significative variation within Parmeliaceae and is not a good character to separate groups. It was possible to suggest that the current delimitation of Hypotrachyna is not monophyletic and the manner how it is organized nowadays this name encloses several groups of species, some of them here represented mainly by the variation of the upper cortex structure. In Hypotrachynella, Lyngenella and Vainia (unpublished genera), it was possible to conclude that the anatomical characteristics of the upper cortex are constant for each genus studied, corroborating the recent segregation of Hypotrachyna, although this characteristic was not efficient alone to separate Lyngenella from Vainia, which are very similar in anatomy. For Parmelinopsis, the anatomical features found are quite 9 different from those seen in Hypotrachyna s.s. and thus the anatomical studies do not corroborate with its synonymizing under Hypotrachyna
Hypotrachyna (Parmeliaceae) was proposed by Hale in 1974 based on Parmelia subgenus Parmelia section Hypotrachyna. Its circumscription included species with sublinear branches, sometimes elongated and apically subtruncate, imperforate apothecia and adnate, rarely subestipitate, and dichotomically branched rhizines, uniformly distributed in the lower black surface. According to him, the upper cortex would be palisade plectenchymatous with porate epicortex. It was only about 30 years later that Divakar et al. showed that Hypotrachyna, as then circumscribed, is polyphyletic and suggested a detailed morphological and anatomical revision for the restructuring of the genus. In 2013 Parmelinopsis, Cetrariastrum and Everniastrum were reduced to Hypotrachyna subgenera, but Parmelinopsis and Hypotrachyna remained polyphyletic. Recent morphological studies have raised the possibility that some anatomical features not yet studied, coupled with a thorough approach to others already considered, would probably provide important support for a rearrangement of genus classification and species definition in Parmeliaceae, especially in Hypotrachyna. Twenty-three species of Hypotrachyna s.l. were anatomically studied and processed according the protocol of Barbosa et al. adapted by Zanetti et al., both developed in studies developed at UNESP / Botucatu. The upper cortex continues to be a useful character in the separation of species, that present its own characteristics within a same group. The medulla and algal layer, however, present specific variations, not being good characters for the separation of genera. The lower cortex does not show significative variation within Parmeliaceae and is not a good character to separate groups. It was possible to suggest that the current delimitation of Hypotrachyna is not monophyletic and the manner how it is organized nowadays this name encloses several groups of species, some of them here represented mainly by the variation of the upper cortex structure. In Hypotrachynella, Lyngenella and Vainia (unpublished genera), it was possible to conclude that the anatomical characteristics of the upper cortex are constant for each genus studied, corroborating the recent segregation of Hypotrachyna, although this characteristic was not efficient alone to separate Lyngenella from Vainia, which are very similar in anatomy. For Parmelinopsis, the anatomical features found are quite 9 different from those seen in Hypotrachyna s.s. and thus the anatomical studies do not corroborate with its synonymizing under Hypotrachyna
Descrição
Palavras-chave
Anatomia comparada, córtex superior, Liquens, Parmelinopsis, Compared anatomy, upper cortex, Lichens