Phylogenetic Analyses of Septoria Species Based on the ITS and LSU-D2 Regions of Nuclear Ribosomal DNA

Mycologia ◽  
2004 ◽  
Vol 96 (3) ◽  
pp. 558 ◽  
Author(s):  
Gerard J. M. Verkley ◽  
Mieke Starink-Willemse ◽  
Arien van Iperen ◽  
Edwin C. A. Abeln
Phytotaxa ◽  
2019 ◽  
Vol 427 (3) ◽  
pp. 186-199
Author(s):  
ARCHANA SINGH ◽  
NIKHIL KUMAR SINGH ◽  
PARAS NATH SINGH ◽  
RAGHVENDRA SINGH ◽  
NAWAL KISHORE DUBEY

Ochroconis helicteris, a novel species of the oligotrophic genus Ochroconis (Sympoventuriaceae, Venturiales), has been described and illustrated. Morphologically, this species has characters similar to allied species in the genus Ochroconis, but differs in conidial dimensions and shape. Phylogenetic analyses using nuclear ribosomal DNA gene ITS and protein coding gene BT2 revealed it clustering as monophyletic clade which was separated from known Ochroconis species. New species was isolated from leaf surface of medicinal plant Helicteris isora L.


2007 ◽  
Vol 85 (8) ◽  
pp. 762-773 ◽  
Author(s):  
Alexandra T.E. Koziak ◽  
Kei Chin Cheng ◽  
R. Greg Thorn

Hohenbuehelia (Agaricales, Pleurotaceae) and Nematoctonus (Hyphomycetes) are the names for the sexual and asexual stages of a genus of nematode-destroying fungi (Basidiomycota). We obtained partial sequences of nuclear ribosomal DNA, including the internal transcribed spacer region and the 5′ end of the large subunit, of 37 isolates of Hohenbuehelia and Nematoctonus representing 13 of the 16 described species in Nematoctonus. Phylogenetic analyses support Hohenbuehelia–Nematoctonus as a monophyletic clade of the Pleurotaceae, within which the species were placed in five main subclades. Exclusively predatory species ( Nematoctonus brevisporus Thorn & G.L. Barron, Nematoctonus campylosporus Drechsler, Nematoctonus robustus F.R. Jones, and Nematoctonus sp. UAMH 5317) appear to be basal. In these species, adhesive knobs to capture prey are produced on their hyphae but not on their conidia. A single mycelial individual may feed on many nematodes. From these have arisen both exclusively parasitoid species ( Nematoctonus cylindrosporus Thorn & G.L. Barron, Nematoctonus leiosporus Drechsler, Nematoctonus leptosporus Drechsler, Nematoctonus pachysporus Drechsler, Nematoctonus tylosporus Drechsler), and species that we call intermediate predators ( Nematoctonus angustatus Thorn & G.L. Barron, Nematoctonus concurrens Drechsler, Nematoctonus geogenius Thorn & GL. Barron, Nematoctonus hamatus Thorn & G.L. Barron, and Nematoctonus subreniformis Thorn & G.L. Barron). Exclusively parasitoid species have conidia that germinate to form sticky knobs that attach to passing nematodes but lack adhesive knobs on the hyphae. Each mycelial individual feeds on only one nematode. Intermediate predators have adhesive knobs both on hyphae and on germinated conidia and can act in both predatory and parasitoid modes. Most morphospecies are resolved as monophyletic, but sequences of additional gene regions are required to clarify species limits within the N. angustatus – N. geogenius group.


Phytotaxa ◽  
2018 ◽  
Vol 358 (1) ◽  
pp. 83 ◽  
Author(s):  
SOUMITRA PALOI ◽  
KANAD DAS ◽  
KRISHNENDU ACHARYA

Russula darjeelingensis is characterized by its small sized white pileus with a tall and narrow stipe, white spore print, basidiospores with amyloid suprahilar spot and a pileipellis containing encrusted pileocystidia and absence of primordial hyphae. The combination of all these characters and molecular phylogenetic analyses of internal transcribed spacer sequences of nuclear ribosomal DNA confirmed it as a new species in genus Russula Pers., subg. Russula Romagn. emend. sect. Polychromae (Maire) Sarnari subsect. Paraintegrinae Sarnari. A comprehensive morphological description, illustrations, and comparisons with morphologically similar and phylogenetically related species are provided in the present study.


Mycotaxon ◽  
2020 ◽  
Vol 135 (1) ◽  
pp. 143-150
Author(s):  
Xin Zhang ◽  
Kun-Ying Wang ◽  
Peng-Peng Ren ◽  
Yu-Lan Jiang

A new species, Ochroconis terricola, was isolated from soil in Guizhou Province, China. Morphology and phylogenetic analyses of the combined sequence data of nuclear ribosomal DNA genes (ITS, LSU, SSU) revealed the strain as different from other Ochroconis species.


PhytoKeys ◽  
2020 ◽  
Vol 140 ◽  
pp. 11-22
Author(s):  
Izai A. B. Sabino Kikuchi ◽  
Paul J. A. Keβler ◽  
André Schuiteman ◽  
Jin Murata ◽  
Tetsuo Ohi-Toma ◽  
...  

The orchid tribe Tropidieae comprises three genera, Tropidia, Corymborkis and Kalimantanorchis. There are three fully mycoheterotrophic species within Tropidieae: Tropidia saprophytica, T. connata and Kalimantanorchis nagamasui. A previous phylogenetic study of K. nagamasui, based only on plastid matK data, placed K. nagamasui outside the clade of Tropidia and Corymborkis without support. In this study, we performed phylogenetic analyses using a nuclear ribosomal DNA spacer (ITS1-5.8S-ITS2), a low-copy nuclear coding gene (Xdh) and a mitochondrial intron (nad1b-c intron) to study the phylogenetic relationships within Tropidieae. We included six photosynthetic and all three fully mycoheterotrophic Tropidieae species. The resulting phylogenetic trees placed these fully mycoheterotrophic species inside the Tropidia clade with high support. In our trees, these three species do not form a monophyletic group together, because the photosynthetic T. graminea is nested amongst them. Our results also suggest that the loss of photosynthetic ability occurred at least twice in Tropidia.


2021 ◽  
Author(s):  
Bin-Bin Liu ◽  
Zhi-Yao Ma ◽  
Chen Ren ◽  
Richard G.J. Hodel ◽  
Miao Sun ◽  
...  

With the decreasing cost and availability of many newly developed bioinformatics pipelines, next-generation sequencing (NGS) has revolutionized plant systematics in recent years. Genome skimming has been widely used to obtain high-copy fractions of the genomes, including plastomes, mitochondrial DNA (mtDNA), and nuclear ribosomal DNA (nrDNA). In this study, through simulations, we evaluated optimal (minimum) sequencing depth and performance for recovering single-copy nuclear genes (SCNs) from genome skimming data, by subsampling genome resequencing data and generating 10 datasets with different sequencing coverage in silico. We tested the performance of the four datasets (plastome, nrDNA, mtDNA, and SCNs) obtained from genome skimming based on phylogenetic analyses of the Vitis clade at the genus-level and Vitaceae at the family-level, respectively. Our results showed that optimal minimum sequencing depth for high-quality SCNs assembly via genome skimming was about 10x coverage. Without the steps of synthesizing baits and enrichment experiments, we showcase that deep genome skimming (DGS) is effective for capturing large datasets of SCNs, in addition to plastomes, mtDNA, and entire nrDNA repeats, and may serve as an economical alternative to the widely used target enrichment Hyb-Seq approach.


1998 ◽  
Vol 76 (5) ◽  
pp. 791-803 ◽  
Author(s):  
Stephen R Downie ◽  
Deborah S Katz-Downie ◽  
Erica J Rogers ◽  
Heidi L Zujewski ◽  
Ernest Small

A previous polymerase chain reaction based survey for the occurrence of the intron in chloroplast gene rpoC1 revealed its absence in one of the eight species of Medicago (Fabaceae; Trifolieae) examined. We extend the survey of Medicago to include 65 of the 86 species, representing all 12 sections and seven of the eight subsections recognized in the most recent comprehensive treatment of the genus. Our results indicate that 17 species from five sections lack the intron and that three of these sections are heterogeneous with regard to intron content. DNA sequencing across the rpoC1 intron-exon boundary in three of these species reveals the precise excision of the intron from the gene. Phylogenies derived from nuclear ribosomal DNA internal transcribed spacer sequences, estimated using maximum parsimony and maximum likelihood methods, suggest that most of the previously recognized sections in Medicago are not monophyletic as currently circumscribed. Furthermore, these results suggest that the rpoC1 intron has been lost independently a minimum of three times during the evolution of the group. The occurrence of multiple independent intron losses severely reduces the utility of this character as a phylogenetic marker in Medicago.Key words: Medicago, Fabaceae, chloroplast DNA, rpoC1 intron, nuclear ribosomal DNA internal transcribed spacer (ITS) sequences.


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