Latest Research on Alternaria: Jan – 2020

Alternaria Redefined

Alternaria may be a ubiquitous fungal genus that has saprobic, endophytic and pathogenic species related to a good sort of substrates. In recent years, DNA-based studies revealed multiple non-monophyletic genera within the Alternaria complex, and Alternaria species clades that don’t always correlate to species-groups supported morphological characteristics. The Alternaria complex currently comprises nine genera and eight Alternaria sections. The aim of this study was to delineate phylogenetic lineages within Alternaria and allied genera supported nucleotide sequence data of parts of the 18S nrDNA, 28S nrDNA, ITS, GAPDH, RPB2 and TEF1-alpha gene regions. Our data reveal a Pleospora/Stemphylium clade sister to Embellisia annulata, and a well-supported Alternaria clade. The Alternaria clade contains 24 internal clades and 6 monotypic lineages, the assemblage of which we recognise as Alternaria. [1]

The genus Alternaria: biology, epidemiology, and pathogenicity.

This book deals with the biology, pathogenicity and epidemiology of plant pathogenic Alternaria spp. The 14 chapters are: introduction; species, formae speciales, and strains; predisposing and age-conditioned influences on susceptibility; sporulation; infection; the biotic and physiological components of pathogenesis; survival and overseasoning; dispersal; the effect of weather on epidemics; forecasters, simulators and control; crop and yield losses; resistance and breeding; comparison of the knowledge of various Alternaria pathogens and diseases; and, the hypothesis of ecological and physiological affinity among pathogenic Alternaria. an in depth bibliography and a topic index are provided. [2]

Clinical Importance of Alternaria Exposure in Children

The fungus Alternaria is understood to be allergenic and is one among the foremost common fungi worldwide. We investigated the extent to which exposure to Alternaria increases the severity of asthma. We undertook a prospective cohort study in Australia of 399 school children who had positive skin tests to at least one or more aeroallergens. Airway responsiveness to histamine, wheeze, and bronchodilator use in 1 mo was measured five times between 1997 and 1999. Airway hyperresponsiveness was defined as PD20FEV1 = 3.9 μ mol histamine. Airborne concentrations of Alternaria spores were measured throughout the study, and mean daily concentrations over 1 mo ranged from 2.2 to 307.7 spores/m3 of ambient air. [3]

Isolation, characterization and toxicological potential of Alternaria-mycotoxins (TeA, AOH and AME) in different Alternaria species from various regions of India

Alternaria species produce various kinds of toxic metabolites during their active growth and causes severe diseases in many plants by limiting their productivity. These toxic metabolites incorporate various mycotoxins comprising of dibenzo-α-pyrone and a few tetramic acid derivatives. during this study, we’ve screened out total 48 isolates of Alternaria from different plants belonging to different locations in India, on the idea of their pathogenic nature. Pathogenicity testing of those 48 strains on susceptible tomato variety (CO-3) showed 27.08% of the strains were highly pathogenic, 35.41% moderately pathogenic and 37.5% were less pathogenic. Phylogenetic analysis showed the presence of a minimum of eight evolutionary cluster of the pathogen. [4]

In vitro Effect of Essential Oil of Peppermint (Mentha x piperita L.) on the Mycelial Growth of Alternaria alternata

Aims: The research aimed to guage the in vitro antifungal effect of the volatile oil of peppermint (Mentha x piperita L.) within the control of Alternaria alternata.

Study Design: The experiment was conducted during a completely randomised experimental design with five treatments in four replicates each.

Place and Duration: The work was conducted at the middle of Science and Technology Agri-food of the Federal University of Campina Grande, Pombal-PB, Brazil, between February and March of 2018.

Methodology: The volatile oil was added to the PDA medium (Potato-Dextrose-Agar) autoclaved and subsequently poured into Petri plates. The treatments comprised five concentrations of the oil (0.0, 0.4, 0.6, 0.8, and 1.0%). After the inoculation with fungi, the plates were incubated for 14 days during a B.O.D incubator at 27±2°C. With the info of mycelial diameters, the share of mycelial growth inhibition (PGI) and index of mycelial growth speed (IMGS) were calculated. [5]

Reference

[1] Woudenberg, J.H.C., Groenewald, J.Z., Binder, M. and Crous, P.W., 2013. Alternaria redefined. Studies in mycology, 75, (Web Link)

[2] Rotem, J., 1994. The genus Alternaria: biology, epidemiology, and pathogenicity. American Phytopathological Society. (Web Link)

[3] Downs, S.H., Mitakakis, T.Z., Marks, G.B., Car, N.G., Belousova, E.G., Leuppi, J.D., Xuan, W.E.I., Downie, S.R., Tobias, A. and Peat, J.K., 2001. Clinical importance of Alternaria exposure in children. American Journal of Respiratory and Critical Care Medicine, 164(3), (Web Link)

[4] Isolation, characterization and toxicological potential of Alternaria-mycotoxins (TeA, AOH and AME) in different Alternaria species from various regions of India
Mukesh Meena, Prashant Swapnil & R. S. Upadhyay
Scientific Reports volume 7, (Web Link)

[5] França, K. R. S., Silva, T. L., Cardoso, T. A. L., Ugulino, A. L. N., Rodrigues, A. P. M. and Júnior, A. F. de M. (2018) “In vitro Effect of Essential Oil of Peppermint (Mentha x piperita L.) on the Mycelial Growth of Alternaria alternata”, Journal of Experimental Agriculture International, 26(5), (Web Link)

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