scholarly journals Global distribution and richness of Armillaria species inferred from public databases and amplicon sequencing datasets

2021 ◽  
Author(s):  
Rachel A Koch ◽  
Joshua R Herr
Keyword(s):  
Species Richness ◽  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Amplicon Sequencing ◽  
Biogeographic Region ◽  
Ribosomal Operon ◽  
Biogeographic Regions ◽  
Using Data ◽  
Globally Distributed ◽  
Armillaria Species

Armillaria is a globally distributed fungal genus most notably recognized as economically important plant pathogens that are found predominantly in forest and agronomic systems. Armillaria has more recently received attention for ecologically diverse roles as woody plant decomposers and as mycorrhizal symbionts with specific plants. Previous phylogenetic analyses suggest that around 50 species are recognized globally. Despite this previous work, no studies have analyzed the global species richness and distribution of the genus using data derived from fungal community sequencing datasets. In order to assess the global diversity and species richness of Armillaria, we mined publicly available sequencing datasets derived from numerous primer pairs for the ribosomal operon. Our estimates reveal that species richness ranges from 50 to 60 species, depending on which marker is used. Eastern Asia represents the biogeographic region with the highest species richness. We also assess the overlap of species across geographic regions and propose some hypotheses regarding the drivers of variability in species diversity and richness between different biogeographic regions.

The global biogeography of avian haemosporidian parasites is characterized by local diversification and intercontinental dispersal

Parasitology ◽  
2018 ◽  
Vol 146 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Vincenzo A. Ellis ◽  
Eloisa H. R. Sari ◽  
Dustin R. Rubenstein ◽  
Rebecca C. Dickerson ◽  
Staffan Bensch ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Emerging Infectious Diseases ◽  
Free Living ◽  
Molecular Barcoding ◽  
Haemosporidian Parasites ◽  
Single Region ◽  
Biogeographic Region ◽  
Living Species ◽  
Biogeographic Regions ◽  
Globally Distributed

AbstractThe biogeographic histories of parasites and pathogens are infrequently compared with those of free-living species, including their hosts. Documenting the frequency with which parasites and pathogens disperse across geographic regions contributes to understanding not only their evolution, but also the likelihood that they may become emerging infectious diseases. Haemosporidian parasites of birds (parasite genera Plasmodium, Haemoproteus and Leucocytozoon) are globally distributed, dipteran-vectored parasites. To date, over 2000 avian haemosporidian lineages have been designated by molecular barcoding methods. To achieve their current distributions, some lineages must have dispersed long distances, often over water. Here we quantify such events using the global avian haemosporidian database MalAvi and additional records primarily from the Americas. We scored lineages as belonging to one or more global biogeographic regions based on infection records. Most lineages were restricted to a single region but some were globally distributed. We also used part of the cytochrome b gene to create genus-level parasite phylogenies and scored well-supported nodes as having descendant lineages in regional sympatry or allopatry. Descendant sister lineages of Plasmodium, Haemoproteus and Leucocytozoon were distributed in allopatry in 11, 16 and 15% of investigated nodes, respectively. Although a small but significant fraction of the molecular variance in cytochrome b of all three genera could be explained by biogeographic region, global parasite dispersal likely contributed to the majority of the unexplained variance. Our results suggest that avian haemosporidian parasites have faced few geographic barriers to dispersal over their evolutionary history.

scholarly journals Mealybug Transmission of Grapevine Leafroll Viruses: An Analysis of Virus–Vector Specificity

2010 ◽  
Vol 100 (8) ◽  
pp. 830-834 ◽  
Author(s):  
Chi-Wei Tsai ◽  
Adib Rowhani ◽  
Deborah A. Golino ◽  
Kent M. Daane ◽  
Rodrigo P. P. Almeida
Keyword(s):  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Virus Vector ◽  
Disease Spread ◽  
Virus Species ◽  
Vector Species ◽  
Vector Transmission ◽  
Planococcus Ficus ◽  
Grapevine Leafroll Disease ◽  
Leafroll Disease

To understand ecological factors mediating the spread of insect-borne plant pathogens, vector species for these pathogens need to be identified. Grapevine leafroll disease is caused by a complex of phylogenetically related closteroviruses, some of which are transmitted by insect vectors; however, the specificities of these complex virus–vector interactions are poorly understood thus far. Through biological assays and phylogenetic analyses, we studied the role of vector-pathogen specificity in the transmission of several grapevine leafroll-associated viruses (GLRaVs) by their mealybug vectors. Using plants with multiple virus infections, several virus species were screened for vector transmission by the mealybug species Planococcus ficus and Pseudococcus longispinus. We report that two GLRaVs (-4 and -9), for which no vector transmission evidence was available, are mealybug-borne. The analyses performed indicated no evidence of mealybug–GLRaV specificity; for example, different vector species transmitted GLRaV-3 and one vector species, Planococcus ficus, transmitted five GLRaVs. Based on available data, there is no compelling evidence of vector–virus specificity in the mealybug transmission of GLRaVs. However, more studies aimed at increasing the number of mealybug species tested as vectors of different GLRaVs are necessary. This is especially important given the increasing importance of grapevine leafroll disease spread by mealybugs in vineyards worldwide.

The Phylogenetic Position of Crenea in the Lythraceae Based on Molecular Evidence, and the Transfer of Its Two Species to Ammannia

2021 ◽  
Vol 106 ◽  
pp. 325-339
Author(s):  
Shirley A. Graham ◽  
Peter W. Inglis ◽  
Taciana B. Cavalcanti
Keyword(s):  
Morphological Character ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Phylogenetic Position ◽  
Molecular Evidence ◽  
Monophyletic Lineage ◽  
The Family ◽  
Mangrove Vegetation ◽  
Molecular Phylogenetic ◽  
Globally Distributed

Crenea Aubl. (Lythraceae) is a ditypic genus of subshrubs occurring in mangrove vegetation on the coasts of northern South America. Phylogenetic analyses based on morphology have offered unresolved and conflicting phylogenetic positions for the genus in the family. This study presents the first molecular sequences for Crenea, from nrITS, rbcL, trnL, trnL-F, and matK regions. Molecular phylogenetic analyses find full support for Crenea within Ammannia L., a relationship not previously recognized. Ammannia is a globally distributed genus of terrestrial to amphibious herbs mostly occurring in freshwater marshes and wetlands. It was recently reconfigured based on phylogenetic evidence to include the genera Nesaea Comm. ex Kunth and Hionanthera A. Fern. & Diniz. The transfer of Crenea to Ammannia further extends the morphological, ecological, and biogeographical diversity of Ammannia and provides the final evidence defining Ammannia as a monophyletic lineage of the Lythraceae. A revised circumscription of Ammannia s.l. adds several new morphological character states and the first species in the genus restricted to mangrove vegetation. Two changes in taxonomic status are made: Ammannia maritima (Aubl.) S. A. Graham, P. W. Inglis, & T. B. Cavalc., comb. nov., and Ammannia patentinervius (Koehne) S. A. Graham, P. W. Inglis, & T. B. Cavalc., comb. nov. The new combinations are described, a list of exsiccatae examined is provided, and the effects of the reconfiguration to the morphology and biogeography of the genus are detailed.

scholarly journals Comparative Genomics and Phylogenetic Analyses Suggest Several Novel Species within the Genus Clavibacter, Including Nonpathogenic Tomato-Associated Strains

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Ebrahim Osdaghi ◽  
Touraj Rahimi ◽  
S. Mohsen Taghavi ◽  
Maryam Ansari ◽  
Sadegh Zarei ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Comparative Genomics ◽  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Sensu Stricto ◽  
Bacterial Canker ◽  
Agricultural Crops ◽  
Content Type ◽  
Canker Disease

ABSTRACT Members of the genus Clavibacter are economically important bacterial plant pathogens infecting a set of diverse agricultural crops (e.g., alfalfa, corn, potato, tomato, and wheat). Tomato-associated Clavibacter sp. strains account for a great portion of the genetic diversity of the genus, and C. michiganensis sensu stricto (formerly C. michiganensis subsp. michiganensis), causing bacterial canker disease, is considered one of the most destructive seed-borne agents for the crop worldwide. However, current taxonomic descriptions of the genus do not reflect the existing diversity of the strains, resulting in unsatisfactory results in quarantine surveys for the pathogens. In this study, we used all the available genome sequences of Clavibacter sp. strains, including the type strains of newly described subspecies, to provide precise insight into the diversity of tomato-associated members of the genus and further clarify the taxonomic status of the strains using genotypic and phenotypic features. The results of phylogenetic analyses revealed the existence of nine hypothetical new species among the investigated strains. None of the three new subspecies (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) is included within the tomato-pathogenic C. michiganensis sensu stricto lineage. Although comparative genomics revealed the lack of chp and tomA pathogenicity determinant gene clusters in the nonpathogenic strains, a number of pathogenicity-related genes were noted to be present in all the strains regardless of their pathogenicity characteristics. Altogether, our results indicate a need for a formal taxonomic reconsideration of tomato-associated Clavibacter sp. strains to facilitate differentiation of the lineages in quarantine inspections. IMPORTANCE Clavibacter spp. are economically important bacterial plant pathogens infecting a set of diverse agricultural crops, such as alfalfa, corn, pepper, potato, tomato, and wheat. A number of plant-pathogenic members of the genus (e.g., C. michiganensis sensu stricto and C. sepedonicus, infecting tomato and potato plants, respectively) are included in the A2 (high-risk) list of quarantine pathogens by the European and Mediterranean Plant Protection Organization (EPPO). Although tomato-associated members of Clavibacter spp. account for a significant portion of the genetic diversity in the genus, only the strains belonging to C. michiganensis sensu stricto (formerly C. michiganensis subsp. michiganensis) cause bacterial canker disease of tomato and are subjected to the quarantine inspections. Hence, discrimination between the pathogenic and nonpathogenic Clavibacter sp. strains associated with tomato seeds and transplants plays a pivotal role in the accurate detection and cost-efficient management of the disease. On the other hand, detailed information on the genetic contents of different lineages of the genus would lead to the development of genome-informed specific detection techniques. In this study, we have provided an overview of the phylogenetic and genomic differences between the pathogenic and nonpathogenic tomato-associated Clavibacter sp. strains. We also noted that the taxonomic status of newly introduced subspecies of C. michiganensis (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) should be reconsidered.

Across Lydekker's Line - first report of mite harvestmen (Opiliones : Cyphophthalmi : Stylocellidae) from New Guinea

2007 ◽  
Vol 21 (3) ◽  
pp. 207 ◽  
Author(s):  
Ronald M. Clouse ◽  
Gonzalo Giribet
Keyword(s):  
Sequence Data ◽  
Phylogenetic Analyses ◽  
New Guinea ◽  
Single Male ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
The Family ◽  
Biogeographic Region ◽  
Molecular Phylogenetic ◽  
History Of

Opiliones (harvestmen) in the suborder Cyphophthalmi are not known to disperse across oceans and each family in the suborder is restricted to a clear biogeographic region. While undertaking a revisionary study of the South-east Asian family Stylocellidae, two collections of stylocellids from New Guinea were noted. This was a surprising find, since the island appears never to have had a land connection with Eurasia, where the rest of the family members are found. Here, 21 New Guinean specimens collected from the westernmost end of the island (Manokwari Province, Indonesia) are described and their relationships to other cyphophthalmids are analysed using molecular sequence data. The specimens represent three species, Stylocellus lydekkeri, sp. nov., S. novaguinea, sp. nov. and undescribed females of a probable third species, which are described and illustrated using scanning electron microscope and stereomicroscope photographs. Stylocellus novaguinea, sp. nov. is described from a single male and it was collected with a juvenile and the three females of the apparent third species. Molecular phylogenetic analyses indicate that the new species are indeed in the family Stylocellidae and they therefore reached western New Guinea by dispersing through Lydekker’s line – the easternmost limit of poor dispersers from Eurasia. The New Guinean species may indicate at least two episodes of oceanic dispersal by Cyphophthalmi, a phenomenon here described for the first time. Alternatively, the presence in New Guinea of poor dispersers from Eurasia may suggest novel hypotheses about the history of the island.

scholarly journals Colletotrichum species associated with anthracnose of Pyrus spp. in China

2019 ◽  
Vol 42 (1) ◽  
pp. 1-35 ◽  
Author(s):  
M. Fu ◽  
P.W. Crous ◽  
Q. Bai ◽  
P.F. Zhang ◽  
J. Xiang ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Novel Species ◽  
Phylogenetic Analyses ◽  
Koch’S Postulates ◽  
Colletotrichum Species ◽  
Organ Specific ◽  
Pathogenicity Tests ◽  
Koch's Postulates

Colletotrichum species are plant pathogens, saprobes, and endophytes on a range of economically important hosts. However, the species occurring on pear remain largely unresolved. To determine the morphology, phylogeny and biology of Colletotrichum species associated with Pyrus plants, a total of 295 samples were collected from cultivated pear species (including P. pyrifolia, P. bretschneideri, and P. communis) from seven major pear-cultivation provinces in China. The pear leaves and fruits affected by anthracnose were sampled and subjected to fungus isolation, resulting in a total of 488 Colletotrichum isolates. Phylogenetic analyses based on six loci (ACT, TUB2, CAL, CHS-1, GAPDH, and ITS) coupled with morphology of 90 representative isolates revealed that they belong to 10 known Colletotrichum species, including C. aenigma, C. citricola, C. conoides, C. fioriniae, C. fructicola, C. gloeosporioides, C. karstii, C. plurivorum, C. siamense, C. wuxiense, and two novel species, described here as C. jinshuiense and C. pyrifoliae. Of these, C. fructicola was the most dominant, occurring on P. pyrifolia and P. bretschneideri in all surveyed provinces except in Shandong, where C. siamense was dominant. In contrast, only C. siamense and C. fioriniae were isolated from P. communis, with the former being dominant. In order to prove Koch's postulates, pathogenicity tests on pear leaves and fruits revealed a broad diversity in pathogenicity and aggressiveness among the species and isolates, of which C. citricola, C. jinshuiense, C. pyrifoliae, and C. conoides appeared to be organ-specific on either leaves or fruits. This study also represents the first reports of C. citricola, C. conoides, C. karstii, C. plurivorum, C. siamense, and C. wuxiense causing anthracnose on pear.

scholarly journals Carving up Australia's arid zone: a review of the bioregionalisation of the Eremaean and Eyrean biogeographic regions

2020 ◽  
Vol 68 (3) ◽  
pp. 229 ◽  
Author(s):  
M. C. Ebach ◽  
D. J. Murphy
Keyword(s):  
Arid Zone ◽  
Temporal Patterns ◽  
Biogeographic Region ◽  
Distributional Patterns ◽  
The Future ◽  
Biogeographic Regions ◽  
Sister Relationships ◽  
Australian Flora ◽  
Made In

The Eremaean region, Australia’s arid biome and biogeographic region, has been discussed by botanists (and as the Eyrean, its counterpart for zoogeographers) for over 150 years, yet little progress was made in defining it as an area of endemism until the 2000s. As Australia’s largest biome and biogeographic region, the Eremaean has been defined in a climate sense, but is a historically composite biogeographic area. Taxa that inhabit the Eremaean (Eyrean) tend to display sister relationships to those outside the biome in temperate and monsoonal biome areas, indicating that two or more temporally discordant distributional patterns exist in the Australian flora and fauna. The future of Eremean and Eyrean bioregionalisation will need to incorporate these temporal patterns when constructing new bioregionalisations and historical and climate-based biogeographic models.

Diaporthe sinensis, a new fungus from Amaranthus sp. in China 

Phytotaxa ◽  
2019 ◽  
Vol 425 (5) ◽  
pp. 259-268
Author(s):  
XIAO-XIAO FENG ◽  
JIA-JIE CHEN ◽  
GUO-RONG WANG ◽  
TING-TING CAO ◽  
YONG-LI ZHENG ◽  
...  
Keyword(s):  
Internal Transcribed Spacer ◽  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Elongation Factor ◽  
Fungal Species ◽  
Translation Elongation Factor ◽  
Translation Elongation ◽  
Stems And Leaves ◽  
Elongation Factor 1 ◽  
Β Tubulin

During an exploration of plant pathogens in vegetables occuring in Zhejiang province, China, a novel fungal species, was found. Three strains ZJUP0033-4, ZJUP0038-3 and ZJUP0132 were isolated from black round lesions in the stems and leaves of Amaranthus sp. Phylogenetic analyses based on sequences from four genes including rDNA internal transcribed spacer (ITS), translation elongation factor 1-α (EF1-α), histone (HIS) and β-tubulin (TUB) indicated that D. sinensis clustered in a distinct clade closely related to D. neoarctii, D. angelicae, D. subordinaria, D. arctii, D. cuppatea, D. lusitanicae, D. novem, D. infecunda, D. ganjae and D. manihotia. Morphologically, D. sinensis is distinguished by brown, scattered, globose pycnidia and ellipsoid alpha conidia with bi- to multiguttulate.

scholarly journals Inferring global species richness from megatransect data and undetected species estimates

2019 ◽  
Vol 88 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Bernhard A. Huber ◽  
Anne Chao
Keyword(s):  
Species Richness ◽  
New Species ◽  
Confidence Interval ◽  
Incidence Data ◽  
Total Species Richness ◽  
Species Incidence ◽  
Biogeographic Regions ◽  
Global Patterns ◽  
The Impact ◽  
Total Species

Ratio-like approaches for estimating global species richness have been criticised for their unjustified extrapolation from regional to global patterns. Here we explore the use of cumulative percentages of ‘new’ (i.e., not formally described) species over large geographic areas (‘megatransects’) as a means to overcome this problem. In addition, we take into account undetected species and illustrate these combined methods by applying them to a family of spiders (Pholcidae) that currently contains some 1,700 described species. The raw global cumulative percentage of new species (‘new’ as of the end of 2008, when 1,001 species were formally described) is 75.1%, and is relatively constant across large biogeographic regions. Undetected species are estimated using the Chao2 estimator based on species incidence data (date by species and locality by species matrices). The estimated percentage of new species based on the date by species matrices is 76.0% with an estimated standard error (s.e.) of 2.6%. This leads to an estimated global species richness of about 4,200 with a 95% confidence interval of (3,300, 5,000). The corresponding values based on locality by species matrices are 84.2% (s.e. 3.0%) and 6,300 with a 95% confidence interval of (4,000, 8,600). Our results suggest that the currently known 1,700 species of Pholcidae may represent no more than about 25–40% of the total species richness. The impact of further biasing factors like geography, species size and distribution, cryptic species, and model assumptions needs to be explored.

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