Phylogenetic analysis based on full-length large subunit ribosomal RNA gene sequence comparison reveals that Neospora caninum is more closely related to Hammondia heydorni than to Toxoplasma gondii1Note: Nucleotide sequence data reported in this paper are available in the EMBL, GenBank™ and DDJB databases under the accession numbers AF159240 (Hammondia heydorni), AF101077 (Hammondia hammondi), AF076899 (Sarcocystis tenella) and AF076901 (Toxoplasma gondii ME49 strain).1

Greening disease of citrus in South Africa is associated with ‘Candidatus Liberibacter africanus’ (Laf), a phloem-limited bacterium vectored by the sap-sucking insect Trioza erytreae (Triozidae). Despite the implementation of control strategies, this disease remains problematic, suggesting the existence of reservoir hosts to Laf. The current study aimed to identify such hosts. Samples from 234 trees of Clausena anisata, 289 trees of Vepris lanceolata and 231 trees of Zanthoxylum capense were collected throughout the natural distribution of these trees in South Africa. Total DNA was extracted from samples and tested for the presence of liberibacters by a generic Liberibacter TaqMan real-time PCR assay. Liberibacters present in positive samples were characterized by amplifying and sequencing rplJ, omp and 16S rRNA gene regions. The identity of tree host species from which liberibacter sequences were obtained was verified by sequencing host rbcL genes. Of the trees tested, 33 specimens of Clausena, 17 specimens of Vepris and 10 specimens of Zanthoxylum tested positive for liberibacter. None of the samples contained typical citrus-infecting Laf sequences. Phylogenetic analysis of 16S rRNA gene sequences indicated that the liberibacters obtained from Vepris and Clausena had 16S rRNA gene sequences identical to that of ‘Candidatus Liberibacter africanus subsp. capensis’ (LafC), whereas those from Zanthoxylum species grouped separately. Phylogenetic analysis of the rplJ and omp gene regions revealed unique clusters for liberibacters associated with each tree species. We propose the following names for these novel liberibacters: ‘Candidatus Liberibacter africanus subsp. clausenae’ (LafCl), ‘Candidatus Liberibacter africanus subsp. vepridis’ (LafV) and ‘Candidatus Liberibacter africanus subsp. zanthoxyli’ (LafZ). This study did not find any natural hosts of Laf associated with greening of citrus. While native citrus relatives were shown to be infected with Laf-related liberibacters, nucleotide sequence data suggest that these are not alternative sources of Laf to citrus orchards, per se.

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Amanita mansehraensis, a new species in section Vaginatae from Pakistan

Phytotaxa ◽

10.11646/phytotaxa.409.4.1 ◽

2019 ◽

Vol 409 (4) ◽

pp. 189-201 ◽

Cited By ~ 1

Author(s):

MALKA SABA ◽

DANNY HAELEWATERS ◽

MUHAMMAD FIAZ ◽

ABDUL NASIR KHALID ◽

DONALD H. PFISTER

Keyword(s):

New Species ◽

Ribosomal Rna ◽

Internal Transcribed Spacer ◽

Sequence Data ◽

Large Subunit ◽

Pine Forests ◽

Evolutionary Relationships ◽

Internal Transcribed Spacer Region ◽

Bayesian Inferences ◽

A New Species

A new species of Amanita subgenus Amanita sect. Vaginatae is described and illustrated based on material collected in pine forests in district Mansehra, Khyber Pakhtoonkhaw, Pakistan. Amanita mansehraensis is recognized by the presence of a light brown or light greyish olive pileus with strong brown or deep brown pileus center; non-appendiculate, rimose, sulcate or plicate striate pileus margin; subglobose to ellipsoid basidiospores; and a saccate volva. The internal transcribed spacer region (ITS) and large subunit of the nuclear ribosomal RNA gene (nrLSU) were used for the delimitation of this species based on sequence data. The evolutionary relationships of A. mansehraensis with other species of Amanita were inferred by means of Maximum Likelihood and Bayesian inferences of the nrLSU dataset and concatenated ITS+nrLSU dataset. Amanita mansehraensis is most closely related to A. brunneofuliginea, A. pseudovaginata, and the recently described A. glarea.

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Ceriporia albomellea (Phanerochaetaceae, Basidiomycota), a new species from tropical China based on morphological and molecular evidences

Phytotaxa ◽

10.11646/phytotaxa.298.1.2 ◽

2017 ◽

Vol 298 (1) ◽

pp. 20 ◽

Cited By ~ 2

Author(s):

YUAN YUAN ◽

XIAO-HONG JI ◽

FANG WU ◽

JIA-JIA CHEN

Keyword(s):

Phylogenetic Analysis ◽

New Species ◽

Ribosomal Rna ◽

Internal Transcribed Spacer ◽

Large Subunit ◽

Morphological Characteristics ◽

Molecular Evidence ◽

Its Regions ◽

Tropical China ◽

A New Species

A new polypore, Ceriporia albomellea, collected from tropical China, is described and illustrated based on morphological characteristics and molecular evidence. It is characterized by thin, resupinate basidiome with a white subiculum, cottony margin, white to cinnamon-buff pores, clavate cystidia and oblong-ellipsoid basidiospores measured as 3.1–3.8 × 1.7–2 µm. Phylogenetic analysis based on the internal transcribed spacer (ITS) regions and nuclear large subunit (nLSU) ribosomal RNA gene regions supported C. albomellea as a distinctive species belonging to Ceriporia.

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Molecular phylogeny of the heterocystous cyanobacteria (subsections IV and V) based on nifD

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijs.0.02821-0 ◽

2004 ◽

Vol 54 (2) ◽

pp. 493-497 ◽

Cited By ~ 60

Author(s):

Brian J. Henson ◽

Sharon M. Hesselbrock ◽

Linda E. Watson ◽

Susan R. Barnum

Keyword(s):

Phylogenetic Analysis ◽

Gene Sequence ◽

Sequence Data ◽

Rrna Gene ◽

Rrna Gene Sequence ◽

Cellular Division ◽

Heterocystous Cyanobacteria ◽

Nitrogen Fixation Gene ◽

True Branching ◽

Gene Sequence Data

The heterocystous cyanobacteria are currently placed in subsections IV and V, which are distinguished by cellular division in one plane (false branching) and in more than one plane (true branching), respectively. Published phylogenies of 16S rRNA gene sequence data support the monophyly of the heterocystous cyanobacteria, with members of subsection V embedded within subsection IV. It has been postulated that members of subsection V arose from within subsection IV. Therefore, phylogenetic analysis of nucleotide sequences of the nitrogen-fixation gene nifD from representatives of subsections IV and V was performed by using maximum-likelihood criteria. The heterocystous cyanobacteria are supported as being monophyletic, with the non-heterocystous cyanobacteria as their closest relative. However, neither subsection IV nor subsection V is monophyletic, with representatives of both subsections intermixed in two sister clades. Analysis of nifD does not support recognition of two distinct subsections.

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