Comparative thallus anatomy of two Parmotrema (Parmeliaceae, lichenized Ascomycetes) with reticulate maculae

Abstract

RESUMO -(Anatomia comparada do talo de duas espécies de Parmotrema (Parmeliaceae, Ascomycota liquenizados) com máculas reticulares). Através de técnicas convencionais para estudos histológicos em microscopia de luz com auxílio de luz polarizada e microscopia eletrônica de varredura, é descrita e comparada a anatomia do talo de duas espécies de Parmotrema com máculas reticulares, antigamente gênero Rimelia: Parmotrema cetratum (Ach.) Hale e P. clavuliferum (Räsänen) Streimann. Os dados obtidos neste estudo mostram que as espécies são anatomicamente semelhantes, incluindo-se a presença de epicórtex, a anatomia do córtex superior e as características das rizinas e dos cílios. Na medula das duas espécies é possível observar a ocorrência de aglomerados de hifas em forma estrelada associados à presença de ácido salazínico medular. Este estudo indica que as características anatômicas são constantes para o grupo estudado de Parmotrema com máculas reticulares. Palavras-chave: anatomia, máculas reticulares, Parmotrema, Rimelia ABSTRACT -(Comparative thallus anatomy of two Parmotrema (Parmeliaceae, lichenized Ascomycota) with reticulate maculae). Using conventional techniques for structural studies under conventional microscopy, polarizing light microscopy and scanning electron microscopy this work describes and compares the thallus anatomy of two Parmotrema species with reticulate maculae, previously included in the genus Rimelia: Parmotrema cetratum (Ach.) Hale and P. clavuliferum (Räsänen) Streimann. The data showed that the species are anatomically similar, including the presence of epicortex, the upper cortex anatomy and the characteristics of rhizines and ciliae. In the medulla of the two species there are star-shaped clusters of hyphae associated with the presence of salazinic acid. This study showed that the anatomical characteristics are constant for the Parmotrema group studied.

Comparative anatomy ofCanoparmeliaandCrespoaspecies (Parmeliaceae, lichenized fungi)

“…crozalsiana was it possible to distinguish some piled up cells that could be considered a not obvious palisade-like arrangement. The upper cortex in Crespoa is similar to that described for Parmotrema (Barbosa et al 2009a,b;Barbosa & Marcelli 2010a), corroborating the molecular results obtained by Crespo et al (2010) and discussed by Hawksworth (2011), who considered this group of species more closely related to Parmotrema than to Canoparmelia.…”

“…This light microscopy protocol made it possible to visualize the epicortex, lichen acid crystals and their relationships with the medullary hyphae, the ontogeny of some structures of great taxonomic importance (Barbosa et al 2009b), and several other important aspects, such as details of rhizines, isidia, soredia, medulla and cortical structure (Barbosa & Marcelli 2010a;Barbosa et al 2009aBarbosa et al ,b, 2010.…”

“…Anatomical studies of some genera of Parmeliaceae (Barbosa & Marcelli 2009, 2010a demonstrated the taxonomic potential of tissue characters in this family and pointed out differences in cortical structure and in hyphal organization in the internal medullary layers, as well as the distribution of the lichen acid crystals of the thallus in different species.…”

“…This species has a lacunar cortex, with large amount of intercellular spaces (lacunae). Barbosa & Marcelli (2010a) studied two species with reticulate maculae, Parmotrema cetratum (Ach.) Hale and Parmotrema clavuliferum (Räs.)…”

Effect of UV‐B radiation on the content of UV‐B absorbing compounds and photosynthetic parameters in Parmotrema austrosinense from two contrasting habitats

“…The results on thallus anatomy are comparable with data reported by Bissacot Barbosa & Marcelli (2010). The algal layer thickness in P. austrosinense was similar to values found for P. perlatum (22 lm; Carniel et al 2015).…”