Usnea dasaea, a further new addition to the Lichen Flora of Tamil Nadu State, India

The present study addresses the addition of one new fruticose lichen species for the first time to the state of Tamil Nadu in Western Ghats, India. Usnea dasaea Stirt. is a new occurrence in Tamil Nadu. Descriptions of identification keys and distributions of such new species in south India provide useful information for identification. The new species addition of such lichen was identified and deposited at lichen herbaria, National Botanical Research Institute, Lucknow, Uttar Pradesh, India and Bharathiar University, Coimbatore, Tamil Nadu, India for further studies.

Characterization of Sunflower Oil Extracts from the Lichen Usnea barbata

The increasing global emergence of multidrug resistant (MDR) pathogens is categorized as one of the most important health problems. Therefore, the discovery of novel antimicrobials is of the utmost importance. Lichens provide a rich source of natural products including unique polyketides and polyphenols. Many of them display pharmaceutical benefits. The aim of this study was directed towards the characterization of sunflower oil extracts from the fruticose lichen, Usnea barbata. The concentration of the major polyketide, usnic acid, was 1.6 mg/mL extract as determined by NMR analysis of the crude mixture corresponding to 80 mg per g of the dried lichen. The total phenolics and flavonoids were determined by photometric assays as 4.4 mg/mL (gallic acid equivalent) and 0.27 mg/mL (rutin equivalent) corresponding to 220 mg/g and 13.7 mg/g lichen, respectively. Gram-positive (e.g., Enterococcus faecalis) and Gram-negative bacteria, as well as clinical isolates of infected chickens were sensitive against these extracts as determined by agar diffusion tests. Most of these activities increased in the presence of zinc salts. The data suggest the potential usage of U. barbata extracts as natural additives and mild antibiotics in animal husbandry, especially against enterococcosis in poultry.

Study of Ecophysiological Responses of the Antarctic Fruticose Lichen Cladonia borealis Using the PAM Fluorescence System under Natural and Laboratory Conditions

Antarctic lichens have been used as indicators of climate change for decades, but only a few species have been studied. We assessed the photosynthetic performance of the fruticose lichen Cladonia borealis under natural and laboratory conditions using the PAM fluorescence system. Compared to that of sun-adapted Usnea sp., the photosynthetic performance of C. borealis exhibits shade-adapted lichen features, and its chlorophyll fluorescence does not occur during dry days without rain. To understand its desiccation-rehydration responses, we measured changes in the PSII photochemistry in C. borealis under the average light intensity of dawn light and daylight and the desiccating conditions of its natural microclimate. Interestingly, samples under daylight and rapid-desiccation conditions showed a delayed reduction in Fv’/Fm’ and rETRmax, and an increase in Y(II) and Y(NPQ) levels. These results suggest that the photoprotective mechanism of C. borealis depends on sunlight and becomes more efficient with improved desiccation tolerance. Amplicon sequencing revealed that the major photobiont of C. borealis was Asterochloris irregularis, which has not been reported in Antarctica before. Collectively, these results from both field and laboratory could provide a better understanding of specific ecophysiological responses of shade-adapted lichens in the Antarctic region.

STUDIES ON THE CYTOTOXIC POTENTIAL OF THE EXTRACT OF USNEA BARBATA (L.) F.H.WIGG

Usnea barbata (L.) F.H.Wigg. is a fruticose lichen widespread in coniferous forests in the temperate zone of Europe and North America. The special dual structure of lichens, the result of the symbiosis between a fungus and an alga / cyanobacteria and the specific conditions in which they live, determine the synthesis of many special organic compounds - secondary metabolites - which ensure optimal protection against disturbing physical and biological factors. The present study aims to evaluate the cytotoxic activity of the extract of Usnea barbata (L.) F H Wigg. The cytotoxic activity was evaluated on the swimming larvae of Artemia salina L. The results was appreciated by the larvae mortality in contact with solutions of different concentrations of extract in dimethyl sulfoxide, comprised in the range 30 - 266 μg/mL; the highest mortality rate was obtained at 266 μg/mL. In conclusion, the present study shows that the extract of Usnea barbata (L.) F.H.Wigg. has cytotoxic properties; the cytotoxicity is directly proportional to the concentration of the applied extract solution.

Gowardia zebrina sp. nov., a new species in a little-known genus of arctic-alpine lichens (Parmeliaceae)

The fruticose lichen genus Gowardia (Parmeliaceae) was recently segregated from Alectoria based on phylogeny, morphology, secondary chemistry, ecology and distribution. As currently circumscribed, Gowardia comprises two wide-ranging species of arctic-alpine regions. Here we describe a third species, G. zebrina sp. nov., apparently endemic to subalpine regions in mountainous northwestern North America. Gowardia zebrina differs from other species in the genus by its combined subpendent habit, uniformly capillary branches, predominantly isotomic branching, pale-and-dark banding of the terminal branches, and epiphytic ecology. Morphological examination of North American herbarium specimens filed under A. nigricans suggests the existence of several additional undescribed species of Gowardia. A brief overview of morphological diversity in these species is given, shedding new light on the question of whether Gowardia should be subsumed under Alectoria, as some have suggested, or is more appropriately recognized as a distinct genus.

Draft genome sequences of five Calonectria species from Eucalyptus plantations in China, Celoporthe dispersa, Sporothrix phasma and Alectoria sarmentosa

Draft genome sequences of five Calonectria species [including Calonectria aciculata, C. crousiana, C. fujianensis, C. honghensis and C. pseudoturangicola], Celoporthe dispersa, Sporothrix phasma and Alectoria sarmentosa are presented. Species of Calonectria are the causal agents of Eucalyptus leaf blight disease, threatening the growth and sustainability of Eucalyptus plantations in China. Celoporthe dispersa is the causal agent of stem canker in native Syzygium cordatum and exotic Tibouchina granulosa in South Africa. Sporothrix phasma was first discovered in the infructescences of Protea laurifolia and Protea neriifolia in South Africa. Alectoria sarmentosa is fruticose lichen belongs to the alectorioid clade of the family Parmeliaceae. The availability of these genome sequences will facilitate future studies on the systematics, population genetics, and genomics of these fungi.

Epiphyte type and sampling height impact mesofauna communities in Douglas-fir trees

Branches and boles of trees in wet forests are often carpeted with lichens and bryophytes capable of providing periodically saturated habitat suitable for microfauna, animals that include tardigrades, rotifers, nematodes, mites, and springtails. Although resident microfauna likely exhibit habitat preferences structured by fine-scale environmental factors, previous studies rarely report associations between microfaunal communities and habitat type (e.g., communities that develop in lichens vs. bryophytes). Microfaunal communities were examined across three types of epiphyte and three sampling heights to capture gradients of microenvironment. Tardigrades, rotifers, and nematodes were significantly more abundant in bryophytes than fruticose lichen or foliose lichen. Eight tardigrade species and four tardigrade taxa were found, representing two classes, three orders, six families, and eight genera. Tardigrade community composition was significantly different between bryophytes, foliose lichen, fruticose lichen, and sampling heights. We show that microenvironmental factors including epiphyte type and sampling height shape microfaunal communities and may mirror the environmental preferences of their epiphyte hosts.

Phytochemical screening of macrolichens Acroscyphus sphaerophoroides andDirinaria consimilis from North East India for antioxidant and antibacterial activities

This report deals with studies related to phytochemical screening, antioxidant potential and antibacterial activity of two macrolichens Acroscyphus sphaerophoroides Lev., a fruticose lichen and Dirinaria consimilis (Stirton) D.D. Awasthi, a foliose lichen. Qualitative phytochemical analysis showed the presence of alkaloids, terpenoids, saponins, glycosides, tannins and phenols. Acroscyphus sphaerophoroides and Dirinaria consimilis showed relatively antioxidant activity as revealed by DPPH study. A moderate iron chelation has been noted. Both the species showed antibacterial activity against gram-positive bacterial strain Staphylococcus aureus.