Publication: Especie, filogeografía y producción de extrolitos en Bryoria y Pseudephebe (Parmeliaceae)
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2018-01-10
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Universidad Complutense de Madrid
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Abstract
Bryoria y Pseudephebe son dos géneros de hongos liquenizados que se incluyen dentro del Clado Alectorioide de la familia Parmeliaceae (Divakar et al. 2015). Aunque su distribución es cosmopolita, siempre crecen ligados a áreas frescas y húmedas, con frecuencia ambientes similares a los boreo-alpinos. Pseudephebe es el género con menos especies del clado, con tan solo dos, en principio, morfológicamente diferenciadas, aunque con frecuencia se encuentran ejemplares con características intermedias que imposibilitan una identificación fiable. Por otra parte, el género Bryoria, es con diferencia el más numeroso de entre todos los alectorioides (c. 80 especies; Myllys et al. 2011a). Su aspecto, bastante homogéneo, con lacinias cilíndricas de apariencia capilar, la relativa simplicidad de sus estructuras vegetativas y, salvo excepciones, la ausencia de caracteres sexuales desarrollados, propicia que las especies de este género sean de difícil identificación (Brodo & Hawksworth 1977). La poca variabilidad morfológica, favoreció que en el pasado la taxonomía basada en la composición de las sustancias que se acumulan formando cristales extracelulares (extrolitos) en sus talos cobrara mucha importancia. Tal es así, que incluso algunas especies se describieron simplemente porque poseían extrolitos distintos a otras. Los análisis moleculares realizados por Myllys et al. (2011b) condujeron a la descripción de cinco secciones infragenéricas, de las cuales, Bryoria sect. Implexae resulto ser la más necesitada de una revisión taxonómica basada en caracteres moleculares. Velmala et al. (2014) se centraron en resolver el concepto de especie en esta sección, utilizando para ello tres marcadores moleculares estándar. El resultado reveló la presencia de cuatro linajes, dos de ellos formados por varias especies filogenéticamente entremezcladas...
Bryoria and Pseudephebe are two lichen-forming fungal genera included in the Alectorioid Clade of the family Parmeliaceae (Divakar et al. 2015). Despite its cosmopolitan distribution, its occurrence is mainly linked to clean and humid environments, usually in boreoalpine habitats. Pseudephebe is the smallest genera of the clade, with only two morphologically delimited species. However, specimens with intermediate characteristics are common, impeding a reliable identification. Contrarily, the genus Bryoria is the most numerous among the alectorioids, with c. 80 species (Myllys et al. 2011a). Its appearance is quite homogeneous, with cylindrical capillarylike lacinae, relatively simple vegetative structures, and, with some exceptions, without sexual reproductive features; making this genus taxonomically complicated (Brodo & Hawksworth 1977). The scarce distinctive features to identify the samples across the genus favoured, in the past, a taxonomy based on the composition of the chemical substances accumulated forming extracellular crystals (extrolites). In fact, some species were described solely based on its extrolite composition. Molecular analyses performed by Myllys et al. (2011b) conducted to the description of five infrageneric sections, of these Bryoria sect. Implexae resulted unresolved and needed a revision. Velmala et al. (2014) performed a study focusing on this section and using a higher number of specimens and three standard DNA markers. Results revealed the presence of four lineages; two of them including different species phylogenetically intermixed. However, traditional species showed a consistently observed close agreement between chemical constituents, thallus morphology, and, in some cases, ecological preferences. Moreover, different species can be found growing in the same habitat, discarding environmental adaptations. For this, authors decided to do not synonyms them without more exhaustive molecular analyses...
Bryoria and Pseudephebe are two lichen-forming fungal genera included in the Alectorioid Clade of the family Parmeliaceae (Divakar et al. 2015). Despite its cosmopolitan distribution, its occurrence is mainly linked to clean and humid environments, usually in boreoalpine habitats. Pseudephebe is the smallest genera of the clade, with only two morphologically delimited species. However, specimens with intermediate characteristics are common, impeding a reliable identification. Contrarily, the genus Bryoria is the most numerous among the alectorioids, with c. 80 species (Myllys et al. 2011a). Its appearance is quite homogeneous, with cylindrical capillarylike lacinae, relatively simple vegetative structures, and, with some exceptions, without sexual reproductive features; making this genus taxonomically complicated (Brodo & Hawksworth 1977). The scarce distinctive features to identify the samples across the genus favoured, in the past, a taxonomy based on the composition of the chemical substances accumulated forming extracellular crystals (extrolites). In fact, some species were described solely based on its extrolite composition. Molecular analyses performed by Myllys et al. (2011b) conducted to the description of five infrageneric sections, of these Bryoria sect. Implexae resulted unresolved and needed a revision. Velmala et al. (2014) performed a study focusing on this section and using a higher number of specimens and three standard DNA markers. Results revealed the presence of four lineages; two of them including different species phylogenetically intermixed. However, traditional species showed a consistently observed close agreement between chemical constituents, thallus morphology, and, in some cases, ecological preferences. Moreover, different species can be found growing in the same habitat, discarding environmental adaptations. For this, authors decided to do not synonyms them without more exhaustive molecular analyses...
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Tesis inédita de la Universidad Complutense de Madrid, Facultad de Farmacia, Departamento de Biología Vegetal II, leída el 06/07/2017