14 research outputs found
Isoetes dubsii and Isoetes santacruzensis, two new species from lowland areas in South America
Isoetes dubsii sp. nov. and I. santacruzensis sp. nov., two new species from lowland areas in South America, are described, illustrated and compared to similar species. Isoetes dubsii can be distinguished from other species of the Brazilian Pantanal wetlands by a set of characters including leaves that are long, flexuous and trigonal in transverse section, tri-lobate stems, rudimentary velum, pustulate megaspores of 310‒390 µm diameter and laesurae of the megaspore at least four times wider than high. Isoetes santacruzensis has flexuous, filiform leaves, 0.4–0.8 mm wide at mid length and reaching up to 15 cm long, black or reddish-black sporangia, sclerified phyllopodia and sparsely verrucate megaspores of 320‒390 µm in diameter. We also include a key for species from the Brazilian Pantanal wetlands and Bolivia and spore images for all species that are discussed. Isoetes dubsii and I. santacruzensis are only known from their type localities and they may deserve special attention concerning their conservation status. However, based on our current knowledge on these species and according to IUCN Red List criteria, they are assessed here as data deficient (DD)
A new species of Mollinedia (Monimiaceae, Laurales) from the Quadrilátero Ferrífero, Brazil
Monimiaceae comprises approximately 26 genera and 250 species, with a pantropical distribution, predominantly occurring in humid forests. In Brazil, it is represented by five genera and 47 species, most of which are found in the Atlantic Forest, particularly in dense ombrophilous forest. Nevertheless, studies on this family in other biomes and vegetation types in Brazil are still scarce. The Quadrilátero Ferrífero (QF), a region located in the state of Minas Gerais, exhibits high plant species richness and endemism. During collections and analysis of herbarium materials from this region, some specimens of Mollinedia caught our attention due to a combination of characteristics that do not match those of any described species within the genus. For this reason, we describe this new taxon and assess its risk of extinction. Additionally, we review the occurrences of Monimiaceae in the QF and provide maps of its geographical distribution. With the description of this new species, the region now hosts eight species of Monimiaceae, two from the genus Macropeplus and six from Mollinedia. The new species is the first endemic species of the Monimiaceae family to be described in the QF. Concerning the extinction risk assessment, the new species was assessed as critically endangered
Edaphic Endemism in the Amazon: Vascular Plants of the canga of Carajás, Brazil.
Amazonia is one of the most diverse biomes worldwide, and, as well as luxuriant forest, it includes mountain areas which, despite their small surface area, display fascinating endemism. In these regions, the specificity of edaphic factors is mirrored by a highly specialised, isolated flora adapted to survive adverse conditions. The Serra dos Carajás in the Brazilian state of Pará is one of world’s largest iron ore reserves. Known locally as , this ironstone formation occupies an area of 115.9 km , and supports of vegetation on outcrops that are mostly in the Floresta Nacional de Carajás (FLONA of Carajás) and Parque Nacional dos Campos Ferruginosos (PNCF). The recent publication of the Flora of the s of Carajás lists 856 species of seed plants and 186 species of ferns and lycophytes. This project assessed the endemic species growing in the region, and further expeditions guided by SDM were carried out in order to ascertain their distribution outisde the area. Departing from an initial list of 58 putative endemics, the final list comprises 38 species of vascular plants (c. 4% of the local flora). These are distributed in 31 genera and 22 families, including three monotypic genera: (Rubiaceae), and (Asteraceae). From these, 24 are classified as Rare Species for Brazil and seven as Highly Restricted Endemic (EEO
A Amazôna é um dos mais diversos biomas do mundo e inclui, bem como florestas luxuriantes, regiões montanhosas que, apesar de ocuparem uma área superficial relativamente pequena, apresentam endemismo fascinante. Ali, a especificidade de fatores edáficos é espelhada por uma flora isolada e altamente especializada para sobreviver em condições adversas. A Serra dos Carajás, no estado do Pará, é uma das maiores reservas de minério de ferro do mundo. Conhecidas localmente como cangas, as áreas de minério exposto ocupam uma área de 115,9 km , sobre as quais a vegetação de campo rupestre ocorre. A maioria destes afloramentos está incluída na Floresta Nacional de Carajás (FLONA of Carajás) e no Parque Nacional dos Campos Ferruginosos (PNCF). A publicação recente da Flora das cangas de Carajás listou 856 espécies de fanerógamas e 186 de samambaias e licófitas. Este projeto categorizou as espécies endêmicas da canga na região e valeu-se de expedições a áreas circunvizinhas delineadas por SDM, buscando estabelecer o endemismo dessas espécies fora da área contemplada na Flora. Partindo de uma lista inicial com 58 possíveis endêmicas, a lista final inclui 38 espécies de plantas vasculares (c. 4% da flora local). Estas são distribuídas em 31 gêneros e 22 famílias, incluindo três gêneros monotípicos: (Rubiaceae), e (Asteraceae). Destas, 24 foram classificadas como plantas de distribuição restritas no Brasil e sete como endêmicas altamente restritas (EE
Unraveling the plant diversity of the Amazonian canga through DNA barcoding.
Abstract The canga of the Serra dos Carajás, in Eastern Amazon, is home to a unique open plant community, harboring several endemic and rare species. Although a complete flora survey has been recently published, scarce to no genetic information is available for most plant species of the ironstone outcrops of the Serra dos Carajás. In this scenario, DNA barcoding appears as a fast and effective approach to assess the genetic diversity of the Serra dos Carajás flora, considering the growing need for robust biodiversity conservation planning in such an area with industrial mining activities. Thus, after testing eight different DNA barcode markers (matK, rbcL, rpoB, rpoC1, atpF‐atpH, psbK‐psbI, trnH‐psbA, and ITS2), we chose rbcL and ITS2 as the most suitable markers for a broad application in the regional flora. Here we describe DNA barcodes for 1,130 specimens of 538 species, 323 genera, and 115 families of vascular plants from a highly diverse flora in the Amazon basin, with a total of 344 species being barcoded for the first time. In addition, we assessed the potential of using DNA metabarcoding of bulk samples for surveying plant diversity in the canga. Upon achieving the first comprehensive DNA barcoding effort directed to a complete flora in the Brazilian Amazon, we discuss the relevance of our results to guide future conservation measures in the Serra dos Carajás
Free radicals and antioxidants at a glance using EPR spectroscopy
The delicate balance between the advantageous and detrimental effects of free radicals is one of the important aspects of human (patho)physiology. The controlled production of reactive oxygen and nitrogen species has an essential role in the regulation of various signaling switches. On the other hand, imbalanced generation of radicals is highly correlated with the pathogenesis of many diseases which require the application of selected antioxidants to regain the homeostasis. In the era of growing interest for redox processes, electron paramagnetic resonance (EPR) spectroscopy is arguably the best-suited technique for such research due to its ability to provide a unique insight into the world of free radicals and antioxidants. Herein, I present the principles of EPR spectroscopy and the applications of this method in assessing: (i) the oxidative status of biological systems, using endogenous long-lived free radicals (ascorbyl radical (Asc(center dot)), tocopheroxyl radical (TO center dot), melanin) as markers; (ii) the production of short-lived radicals (hydroxyl radical (OH center dot), superoxide radical anion (O-2(-)), sulfur-and carbon-centered radicals), which are implicated in both, oxidative stress and redox signaling; (iii) the metabolism of nitric oxide (NO center dot); (iv) the antioxidative properties of various drugs, compounds, and natural products; (v) other redox-relevant parameter. Besides giving a comprehensive survey of up-to-date literature, I also provide illustrative examples in sufficient detail to provide a means to exploit the potential of EPR in biochemical/physiological/medical research. The emphasis is on the features and characteristics (both positive and negative) relevant for EPR application in clinical sciences. My aim is to encourage fellow colleagues interested in free radicals and antioxidants to expand their base knowledge or methods used in their laboratories with data acquired by EPR or some of the EPR techniques outlined in this review, in order to boost up the exciting area of redox science