Showing papers by "Hiran A. Ariyawansa published in 2020"

Unambiguous identification of fungi: where do we stand and how accurate and precise is fungal DNA barcoding?

Abstract: True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses.

Refined families of dothideomycetes: Dothideomycetidae and pleosporomycetidae

Abstract: The class Dothideomycetes is the largest and most ecologically diverse class of fungi, comprising endophytes, epiphytes, saprobes, human and plant pathogens, lichens, and lichenicolous, nematode trapping and rock-inhabiting taxa. Members of this class are mainly characterized by bitunicate asci with fissitunicate dehiscence, and occur on broad range of hosts in aquatic and terrestrial habitats. Since the last monograph of families of Dothideomycetes in 2013, numerous novel species, genera, families and orders have been discovered. This has expanded information which has led to the modern classification in Dothideomycetes. In this paper, we provide a refined updated document on families of Dothideomycetes with emphasis on Dothideomycetidae and Pleosporomycetidae. We accept three orders with 25 families and four orders with 94 families in Dothideomycetidae and Pleosporomycetidae, respectively. The new family Paralophiostomataceae is introduced in Pleosporales. Each family is provided with an updated description, notes, including figures to represent the morphology, list of accepted genera, and economic and ecological significances. We also provide an overall phylogenetic tree of families in Dothideomycetes based on combined analysis of LSU, SSU, rpb-2 and tef1 sequence data, and phylogenetic trees for each order in Dothideomycetidae and Pleosporomycetidae. Familylevel trees are provided for the families which include several genera such as Mycosphaerellaceae and Teratosphaeriaceae. Two new genera (Ligninsphaeriopsis and Paralophiostoma) are introduced. Five new species (Biatrisopora borsei, Comoclathris galatellae, Ligninsphaeriopsis thailandica, Paralophiostoma hysterioides and Torula thailandica) are introduced based on morphology and phylogeny, together with nine new reports and seven new collections from

Refined families of Dothideomycetes: orders and families incertae sedis in Dothideomycetes

Abstract: Numerous new taxa and classifications of Dothideomycetes have been published following the last monograph of families of Dothideomycetes in 2013. A recent publication by Honsanan et al. in 2020 expanded information of families in Dothideomycetidae and Pleosporomycetidae with modern classifications. In this paper, we provide a refined updated document on orders and families incertae sedis of Dothideomycetes. Each family is provided with an updated description, notes, including figures to represent the morphology, a list of accepted genera, and economic and ecological significances. We also provide phylogenetic trees for each order. In this study, 31 orders which consist 50 families are assigned as orders incertae sedis in Dothideomycetes, and 41 families are treated as families incertae sedis due to lack of molecular or morphological evidence. The new order, Catinellales, and four new families, Catinellaceae, Morenoinaceae Neobuelliellaceae and Thyrinulaceae are introduced. Seven genera (Neobuelliella, Pseudomicrothyrium, Flagellostrigula, Swinscowia, Macroconstrictolumina, Pseudobogoriella, and Schummia) are introduced. Seven new species (Acrospermum urticae, Bogoriella complexoluminata, Dothiorella ostryae, Dyfrolomyces distoseptatus, Macroconstrictolumina megalateralis, Patellaria microspora, and Pseudomicrothyrium thailandicum) are introduced base on morphology and phylogeny, together with two new records/reports and five new collections from different families. Ninety new combinations are also provided in this paper.

Diversity and pathogenicity of Colletotrichum species causing strawberry anthracnose in Taiwan and description of a new species, Colletotrichum miaoliense sp. nov.

Abstract: Strawberry is a small fruit crop with high economic value. Anthracnose caused by Colletotrichum spp. poses a serious threat to strawberry production, particularly in warm and humid climates, but knowledge of pathogen populations in tropical and subtropical regions is limited. To investigate the diversity of infectious agents causing strawberry anthracnose in Taiwan, a disease survey was conducted from 2010 to 2018, and Colletotrichum spp. were identified through morphological characterization and multilocus phylogenetic analysis with internal transcribed spacer, glyceraldehyde 3-phosphate dehydrogenase, chitin synthase, actin, beta-tubulin, calmodulin, and the intergenic region between Apn2 and MAT1-2-1 (ApMAT). Among 52 isolates collected from 24 farms/nurseries in Taiwan, a new species, Colletotrichum miaoliense sp. nov. (6% of all isolates), a species not previously known to be associated with strawberry, Colletotrichum karstii (6%), and three known species, Colletotrichum siamense (75%), Colletotrichum fructicola (11%), and Colletotrichum boninense (2%), were identified. The predominant species C. siamense and C. fructicola exhibited higher mycelial growth rates on potato dextrose agar and caused larger lesions on wounded and non-wounded detached strawberry leaves. Colletotrichum boninense, C. karstii, and C. miaoliense only caused lesions on wounded leaves. Understanding the composition and biology of the pathogen population will help in disease management and resistance breeding.

Species diversity of Pleosporalean taxa associated with Camellia sinensis (L.) Kuntze in Taiwan.

Abstract: Pleosporales species are important plant pathogens, saprobes, and endophytes on a wide range of economically important plant hosts. The classification of Pleosporales has undergone various modifications in recent years due to the addition of many families described from multiple habitats with a high level of morphological deviation. Numerous asexual genera have been described in Pleosporales that can be either hyphomyceteous or coelomycetous. Phoma- or coniothyrium-like species are common and have been revealed as polyphyletic in the order Pleosporales and linked with several sexual genera. A total of 31 pleosporalean strains were isolated in different regions of Taiwan between 2017 and 2018 from the leaves of Camellia sinensis plants with symptoms of leaf spot disease. These strains were evaluated morphologically and genotypically using multi-locus sequence analyses of the ITS, LSU, SSU, rpb2, tef1 and tub2 genes. The results demonstrated the affiliation of these strains with the various families in Pleosporales and revealed the presence of one new genus (Neoshiraia) and eight new species (Alloconiothyrium camelliae, Amorocoelophoma camelliae, Leucaenicola camelliae, L. taiwanensis, Neoshiraia camelliae, N. taiwanensis, Paraconiothyrium camelliae and Paraphaeosphaeria camelliae). Furthermore, to the best of our understanding, Didymella segeticola, Ectophoma pomi and Roussoella mexican were reported for the first time from C. sinensis in Taiwan.

In vitro inferred interactions of selected entomopathogenic fungi from Taiwan and eggs of Meloidogyne graminicola

Abstract: Nematophagous fungi, mostly belonging to the phylum Ascomycota, have raised great attention because of their potential use against plant-pathogenic nematodes. In this investigation, entomopathogenic fungi were collected in Taiwan and isolated and identified based on molecular phylogenetic analyses of six nuclear loci including LSU, ITS, TEF1, RPB1, RPB2, and TUB2 combined with morphological data. Two novel fungal taxa are described in the present study, namely, Paraboeremia taiwanensis (Pleosporales) and Polycephalomyces elaphomyceticola (Hypocreales), respectively. Both species showed the ability to parasitize eggs of the rice root-knot nematode, Meloidogyne graminicola, in in vitro assays. Size ranges of conidiomata and conidia distinguish Paraboeremia taiwanensis from other currently known Paraboeremia species. Polycephalomyces elaphomyceticola differs from other Polycephalomyces species by producing single stromata, smaller perithecia, awl-shaped phialides, and monomorphic conidia. It was encountered as a parasite on Elaphomyces muricatus. Both examined strains grew and sporulated well on artificial media. Pathogenicity testing showed that they were capable of parasitizing eggs of Meloidogyne graminicola. In addition, our study elucidated the teleomorph of Polycephalomyces agaricus for the first time.

Special issue: The contributions of Erio Camporesi

Abstract: We are proud to publish a special issue of Fungal Diversity in honour of the contributions made by Erio Camporesi, who has promoted mycological research as a prodigious amateur mycologist and collector of fungi. The special issue includes Fungal Diversity notes 11, with many taxa named in Erio’s honour and a monograph of hyaline-spored Coelomycetes, both incorporating many of Erio’s collections. Erio obtained a certificate of accountancy in 1982 and worked as an accountant at the express courier company, TNT Global Express SPA. He was always interested in collecting microfungi, mushrooms and toadstools and in doing so this passion has occupied much of his spare time. His first collection in 1984 was of a mushroom, Suillellus luridus (: Boletus luridus). Erio was particularly interested in microfungi associated with plants. He started to collaborate with Kevin D. Hyde through the AscoFrance website (http://www.ascofrance.com). The first fungal specimen to be loaned to Kevin D. Hyde was Dothidella ulmi. Since then, Erio has sent thousands of herbarium specimens for study. Erio’s mother, Maria Ghetti, who accompanied Erio on many forays (Fig. 1), died on 21 April 2012 leaving Erio to care for his aging father, Nello Camporesi, who also accompanied Erio on forays and died on 24 February 2019 (Fig. 1). Erio retired from his permanent accounting job in 2013 and, thereafter, his interest in mycology became a top priority. He also had a talent for painting and many of his paintings incorporated fungi in imaginative ways (Fig. 2). Italian mycology has an exceptional history with the early contributions by Giuseppe De Notaris (1805–1877), Vincenzo de Cesati (1806–1883) and Pier Andrea Saccardo (1845–1920) who greatly contributed to the fungal

The Evaluation of Egg-Parasitic Fungi Paraboeremia taiwanensis and Samsoniella sp. for the Biological Control of Meloidogyne enterolobii on Chinese Cabbage

Abstract: Meloidogyne enterolobii, an aggressive plant-parasitic nematode, has been causing great yield loss worldwide in recent years. With no resistant Chinese cabbage cultivar available currently, a biological control strategy is needed to offer an eco-friendly option for sustainable farming. In this study, the nematode suppression efficacy of two newly isolated fungi, Paraboeremia taiwanensis and Samsoniella sp., were evaluated against M. enterolobii and compared to the known biological control agents Hyalorbilia oviparasitica strain DoUCR50 and Purpureocillium lilacinum strain 251 (PL251). Both P. taiwanensis and Samsoniella sp. reduced 29%-63% disease severity as effectively as the commercial product PL251 on Chinese cabbage in greenhouse trails. The in vitro egg infection rate was 47.83% by P. taiwanensis and 47.50% for Samsoniella sp., respectively. A special protocol for scanning electron microscope observation of the fungi-infected nematodes was established in this study, and the egg parasitism of the four fungi against M. enterolobii was further confirmed. For all fungi examined in this study, fungal hyphae were seen apparently penetrating into M. enterolobii eggs without destructive damage of the overall outer eggshell and the hyphae continued to grow within eggs after 6 days of infection. The results of this study imply a similar egg-parasitism mechanism for P. taiwanensis, Samsoniella sp., H. oviparasitica DoUCR50, and P. lilacinum PL251. It further enlightens the application potential of nematophagous fungi as biocontrol agents against plant-parasitic nematodes in vegetable crop management.

Leucaenicola osmanthi sp . nov . (Bambusicolaceae, Pleosporales), causing leaf spot of Osmanthus fragrans in Taiwan

Abstract: Osmanthus fragrans naturally occurs in Taiwan, and is now widely cultivated as an ornamental plant. Signs of leaf spots caused by unknown species has been detected on O. fragrans saplings in Nangang District, Taipei City, Taiwan. This investigation aimed to illustrate the fungal species by engaging morphological features, pathogenicity tests, and DNA sequence comparisons for the ITS, LSU, SSU, rpb2 and tef1 gene sequences. A new species is proposed and identified here as Leucaenicola osmanthi. Leucaenicola osmanthi can be differentiated from the phylogenetically close taxa, L. aseptata and L. phraeana, by much larger conidiomata, conidiogenous cells and conidia. Moreover, this is the first report of a species belonging to Leucaenicola on Osmanthus fragrans in Taiwan.

Diaporthe taiwanensis : A new taxon causing leaf spots and necrosis on Ixora chinensis in Taiwan

Abstract: Diaporthe taiwanensis sp. nov. (Diaporthales, Sordariomycetes, Ascomycota) isolated on living leaves of Ixora chinensis from Taiwan, is characterized using both phenotypic and genetic characters. Phylogenetic reconstructions based on concatenated DNA sequence data of four nuclear genetic markers (ITS, tef1-α, β-tubulin and cal) show that the new taxon is separated from other representative species of Diaporthe with high statistical support. The new taxon differs from its phylogenetically related congeners mainly by having larger alpha conidia and producing beta conidia in culture and further by host and geographical distribution. Artificial inoculation on leaves confirmed the pathogenicity of the novel fungus to Ixora. The present study is the first report of Diaporthe species causing leaf spots and necrosis on Ixora chinensis in Taiwan.