ITSxpress: Software to rapidly trim internally transcribed spacer sequences with quality scores for marker gene analysis

The internally transcribed spacer (ITS) region between the small subunit ribosomal RNA gene and large subunit ribosomal RNA gene is a widely used phylogenetic marker for fungi and other taxa. The eukaryotic ITS contains the conserved 5.8S rRNA and is divided into the ITS1 and ITS2 hypervariable regions. These regions are variable in length and are amplified using primers complementary to the conserved regions of their flanking genes. Previous work has shown that removing the conserved regions results in more accurate taxonomic classification. An existing software program, ITSx, is capable of trimming FASTA sequences by matching hidden Markov model profiles to the ends of the conserved genes using the software suite HMMER. ITSxpress was developed to extend this technique from marker gene studies using Operational Taxonomic Units (OTU’s) to studies using exact sequence variants; a method used by the software packages Dada2, Deblur, QIIME 2, and Unoise. The sequence variant approach uses the quality scores of each read to identify sequences that are statistically likely to represent real sequences. ITSxpress enables this by processing FASTQ rather than FASTA files. The software also speeds up the trimming of reads by a factor of 14-23 times on a 4-core computer by temporarily clustering highly similar sequences that are common in amplicon data and utilizing optimized parameters for Hmmsearch. ITSxpress is available as a QIIME 2 plugin and a stand-alone application installable from the Python package index, Bioconda, and Github.

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New observations on Miculenchus Andrássy, 1959 (Nematoda: Tylenchidae) with descriptions of two new and one known species from Iran

Nematology ◽

10.1163/15685411-00003267 ◽

2019 ◽

Vol 21 (9) ◽

pp. 937-956 ◽

Cited By ~ 1

Author(s):

Yousef Panahandeh ◽

Ebrahim Pourjam ◽

Sergio Álvarez-Ortega ◽

Farahnaz Jahanshahi Afshar ◽

Majid Pedram

Keyword(s):

New Species ◽

Ribosomal Rna ◽

Large Subunit ◽

Small Subunit ◽

Lsu Rdna ◽

Natural Forests ◽

Electron Microscopic ◽

Pharyngeal Bulb ◽

Ribosomal Rna Gene ◽

Molecular Approaches

Summary During nematological surveys in grasslands and natural forests of north and north-western Iran, three species of Miculenchus, including two new and one known species, were recovered and characterised based upon morphological and molecular approaches. Miculenchus brevisalvus n. sp., the first new species, is mainly characterised by its short females 334-388 μm long and with a short 6.0-7.5 μm long stylet, pyriform to pyriform-elongate pharyngeal bulb, 4-8 μm long post-uterine sac (PUS), offset rounded spermatheca filled with small spheroid sperm, elongate conoid tail 62-83 μm long with a sharp tip, and males with simple cloacal lips. Miculenchus muscus n. sp., the second new species, is characterised by a combination of the following features: body 401-467 μm long, well-developed protuberant labial plate at the anterior end under light microscopy, stylet 7-9 μm long, pyriform pharyngeal bulb, PUS 4-9 μm long, gradually narrowing conical tail 62-74 μm long with a finely pointed or sharp end and bearing several fine bristles at tip, and a male with projecting cloacal lips. Both newly described species were morphologically compared with four currently known species of the genus, viz., M. elegans, M. salmae, M. salvus, and M. tesselatus. Miculenchus salmae was also recovered and reported from Iran for the first time. It is mainly characterised by lacking a PUS and the characteristic vagina shape. Miculenchus muscus n. sp. and M. salmae were both characterised using scanning electron microscopic images, yielding new morphological observations for the genus. All three species are studied for their molecular phylogenetic characters using sequences of near-full length fragments of the small subunit ribosomal RNA gene (SSU rDNA) and the D2-D3 expansion segments of the large subunit ribosomal RNA gene (LSU rDNA D2-D3). In both SSU and LSU phylogenies, all currently sequenced species of Miculenchus formed a monophyletic group with maximal clade support in both Bayesian inference and maximum likelihood analysis.

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Five Fungal Pathogens Are Responsible for Bayberry Twig Blight and Fungicides Were Screened for Disease Control

Microorganisms ◽

10.3390/microorganisms8050689 ◽

2020 ◽

Vol 8 (5) ◽

pp. 689 ◽

Cited By ~ 3

Author(s):

Wenjun Li ◽

Ming Hu ◽

Yang Xue ◽

Zhijun Li ◽

Yanfei Zhang ◽

...

Keyword(s):

Ribosomal Rna ◽

Fungal Pathogens ◽

Large Subunit ◽

Elongation Factor ◽

Morphological Characteristics ◽

Its Region ◽

Small Subunit ◽

Field Application ◽

Financial Loss ◽

Twig Blight

Bayberry (Myrica rubra) is a commercial fruit in China. For the past seven years, twig blight disease has been attacking bayberry plantations in Shantou City, Guangdong Province, China, leading to destructive damage and financial loss. In this study, five fungal species associated with twig dieback and stem blight were identified based on morphological characteristics combined with multilocus sequence analysis (MLSA) on the internal transcribed spacer (ITS) region, partial sequences of β-tubulin (tub2), translation elongation factor 1-α (tef1-α), large subunit ribosomal RNA (LSU) and small subunit ribosomal RNA (SSU) genes, which are Epicoccum sorghinum, Neofusicoccum parvum, Lasiodiplodia theobromae, Nigrospora oryzae and a Pestalotiopsis new species P. myricae. P. myricae is the chief pathogen in fields, based on its high isolation rate and fast disease progression after inoculation. To our knowledge, this is the first study reporting the above five fungi as the pathogens responsible for bayberry twig blight. Indoor screening of fungicides indicates that Prochloraz (copper salt) is the most promising fungicide for field application, followed by Pyraclostrobin, 15% Difenoconazole + 15% Propiconazole, Difenoconazole and Myclobutanil. Additionally, Bacillus velezensis strain 3–10 and zeamines from Dickeya zeae strain EC1 could be used as potential ecofriendly alternatives to control the disease.

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Multi-Gene Phylogeny and Taxonomy of Hydnellum (Bankeraceae, Basidiomycota) from China

Journal of Fungi ◽

10.3390/jof7100818 ◽

2021 ◽

Vol 7 (10) ◽

pp. 818

Author(s):

Yan-Hong Mu ◽

Jia-Rui Yu ◽

Ting Cao ◽

Xiang-Hua Wang ◽

Hai-Sheng Yuan

Keyword(s):

New Species ◽

Rna Polymerase Ii ◽

Ribosomal Rna ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Morphological Characteristics ◽

Small Subunit ◽

Phylogenetic Position ◽

Ribosomal Rna Gene ◽

Morphological Studies

The genus Hydnellum is an important group of stipitate hydnaceous fungi which can form ectomycorrhiza with many species of woody plants. In recent decades, the frequency and number of basidiocarps observed in China have been declining significantly. So far, however, we know little about the species diversity of Hydnellum in China. In this study, we conducted molecular phylogenetic analyses based on sections of multiple loci, including the large subunit of nuclear ribosomal RNA gene (nLSU), the internal transcribed spacer regions (ITS), the small subunit of nuclear ribosomal RNA gene (SSU) and the second-largest subunit of RNA polymerase II gene (RPB2), as well as morphological studies, of collected samples of Hydnellum from China. We also inferred Maximum Likelihood and Bayesian phylogenies for the order Thelephorales from the dataset of the combined nLSU and ITS. This study has revealed the phylogenetic position of Hydnellum in the order Thelephorales, and phylogenetically confirmed ten major clades in Thelephorales; Twenty-nine taxa are proposed, described or reported, including 10 new subgenera (Hydnellum subgenus Hydnellum, subg. Caesispinosum, subg. Croceum, subg. Inflatum, subg. Rhizomorphum, subg. Scabrosum, subg. Spongiosum, subg. Subindufibulatum, subg. Violaceum and subg. Zonatum), 11 new species (Hydnellum atrorubrum, H. atrospinosum, H. bomiense, H. brunneorubrum, H. fibulatum, H. granulosum, H. inflatum, H. rubidofuscum, H. squamulosum, H. sulcatum and H. yunnanense), 3 newly recorded species (H. caeruleum, H. peckii and H. spongiosipes) and 5 notable specimens (Hydnellum sp 1, H. sp 2, H. sp 3, H. sp 4 and H. sp 5). A classification system based on the morphological characteristics (especially the hyphal structure types) and molecular analyses is proposed to accommodate most species in Hydnellum. The distinguishing characters of the subgenera and the new species with their closely related taxa are discussed. A key to the species of Hydnellum from China is provided.

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Description of Ektaphelenchus berbericus n. sp. (Rhabditida: Ektaphelenchinae) from eastern Iran

Nematology ◽

10.1163/15685411-00003015 ◽

2016 ◽

Vol 18 (9) ◽

pp. 1063-1077 ◽

Cited By ~ 9

Author(s):

Somaye Alvani ◽

Esmat Mahdikhani-Moghadam ◽

Robin M. Giblin-Davis ◽

Majid Pedram

Keyword(s):

New Species ◽

Ribosomal Rna ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Small Subunit ◽

Slight Variation ◽

Internal Transcribed Spacer Region ◽

Lateral Field ◽

Ribosomal Rna Gene ◽

Eastern Iran

Ektaphelenchus berbericus n. sp. was recovered from soil samples collected in eastern Iran and is described and illustrated based on morphological, morphometric and molecular data. The new species is characterised by having female body 512-691 μm long, lip region separated from rest of body by a shallow depression, lips separated and equally sized, 19-22 μm long stylet with wide lumen and lacking knobs or swellings at its base, cuticle with fine, but distinct transverse annuli and three lines in lateral field, excretory pore located at base of metacorpus (with slight variation in position), reproductive system monodelphic-prodelphic with spheroid and fine sperm cells inside spermatheca in some individuals and short post-vulval uterine sac (PUS), rectum and anus vestigial (invisible in few individuals), conical posterior body end (tail), narrowing at mid-point between anus and rounded tail tip, and males lacking. The new species is typologically similar to species belonging to four genera: Devibursaphelenchus, Ektaphelenchoides, Ektaphelenchus and Seinura, by a combination of morphological characters, e.g., gross morphology of stylet (lacking knobs or swellings at base), morphology of posterior body end (having short conical tail), PUS length, and having a vestigial anus and rectum in most individuals. In molecular phylogenetic analyses using sequences of the partial small subunit of the ribosomal RNA gene (SSU) and the D2-D3 expansion segments of the large subunit (LSU) ribosomal RNA gene, the new species is close to the Ektaphelenchoides/Cryptaphelenchus clade in an inferred SSU tree, and formed a clade with Ektaphelenchoides and Devibursaphelenchus spp. in a D2-D3 LSU tree. Further phylogenetic analyses using full length sequences of the internal transcribed spacer region (ITS) (= ITS1 + 5.8S + ITS2) corroborated results from the SSU and D2-D3 LSU trees, and the multilocus analyses using the combined SSU and LSU data placed the new species in a robustly supported clade with Ektaphelenchoides poinari and Devibursaphelenchus lini.

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Taxonomy and Phylogeny of the Favolaschia calocera Complex (Mycenaceae) with Descriptions of Four New Species

Forests ◽

10.3390/f12101397 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1397

Author(s):

Qiu-Yue Zhang ◽

Yu-Cheng Dai

Keyword(s):

New Species ◽

Ribosomal Rna ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Elongation Factor ◽

Small Subunit ◽

Rrna Gene ◽

Ribosomal Rna Gene ◽

Worldwide Distribution ◽

Three New Species

Favolaschia calocera was originally described from Madagascar, and reported to have a worldwide distribution. In the current study, samples of the Favolaschia calocera from Central America, Australia, China, Kenya, Italy, New Zealand, and Thailand were analyzed by using both morphological and molecular methods. Phylogenetic analyses were based on the internal transcribed spacer (ITS) dataset, and the combined five-locus dataset of ITS, large subunit nuclear ribosomal RNA gene (nLSU), the small subunit mitochondrial rRNA gene (mt-SSU), the small subunit of nuclear ribosomal RNA gene (nu-SSU), and the translation elongation factor 1α (TEF1). Our study proves that Favolaschia calocera is a species complex, and six species are recognized in the complex including four new species. Three new species F. brevibasidiata, F. brevistipitata, and F. longistipitata from China; and one new species F. minutissima from Asia. In addition, Favolaschia claudopus (Singer) Q.Y. Zhang & C. Dai, earlier treated as a variety of Favolaschia calocera R. Heim, were raised to species rank. Illustrated descriptions of these five new taxa are given. An identification key and a comparison of the characteristics of species in the Favolaschia calocera complex are provided.

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Species Diversity and Molecular Phylogeny of Cyanosporus (Polyporales, Basidiomycota)

Frontiers in Microbiology ◽

10.3389/fmicb.2021.631166 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shun Liu ◽

Lu-Lu Shen ◽

Yan Wang ◽

Tai-Min Xu ◽

Genevieve Gates ◽

...

Keyword(s):

New Species ◽

Rna Polymerase ◽

Rna Polymerase Ii ◽

Ribosomal Rna ◽

Phylogenetic Analyses ◽

Large Subunit ◽

Brown Rot ◽

Small Subunit ◽

Rrna Gene ◽

Ribosomal Rna Gene

Cyanosporus is a cosmopolitan brown-rot fungal genus, recognizable by blue-tinted basidiocarps. Species in this genus were usually treated as belonging to the Postia caesia complex, however, recent phylogenetic analyses showed that this complex represents an independent genus. During further studies on Cyanosporus, five new species were discovered based on morphological features and molecular data. Phylogenetic analyses of Cyanosporus were conducted using the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the small subunit of nuclear ribosomal RNA gene (nSSU), the small subunit of mitochondrial rRNA gene (mtSSU), the largest subunit of RNA polymerase II (RPB1), the second largest subunit of RNA polymerase II (RPB2), and the translation elongation factor 1-α gene (TEF); illustrated descriptions of the new species are provided. In addition, fifteen species previously belonging to the Postia caesia complex are transferred to Cyanosporus and proposed as new combinations.

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