Nuclear ribosomal internal transcribed spacer phylogeny and host diversity in the coelomycete Phomopsis

1994 ◽  
Vol 72 (11) ◽  
pp. 1666-1674 ◽  
Author(s):  
Stephen A. Rehner ◽  
Francis A. Uecker

Species concepts in Phomopsis are based primarily on host association because morphological and cultural characters are generally insufficient for species diagnosis. Increasingly, there are reports that some species of Phomopsis are not host restricted but are capable of infecting several or more taxonomically unrelated host genera. Phylogenetic analysis of nuclear ribosomal DNA internal transcribed spacer sequences (ITS1 and ITS2) for 43 North American and Caribbean strains of Phomopsis isolated from diverse plant hosts and geographic origins resolved three clades, provisionally termed groups A, B, and C. Group A consists of isolates from shrubs and trees originating primarily from eastern North America. Group B includes isolates from woody and herbaceous plants that originate from tropical to subtropical regions and produce paraphyses among their conidiogenous cells. Group C occurs primarily on herbaceous plant hosts, including agricultural field crops, and is widely distributed throughout temperate to subtropical North America. Isolates from Europe and Asia may be significantly different in ITS sequences compared with North American isolates. The diversity of host taxa associated with terminal clades in the ITS phylogeny suggests that either Phomopsis species infect more than one host or host switching occurs frequently during speciation. Key words: Ascomycotina, coelomycetes, Diaporthe, ITS, molecular phylogeny, Phomopsis.

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 737-743 ◽  
Author(s):  
I. Ben Salem ◽  
K. C. Correia ◽  
N. Boughalleb ◽  
S. J. Michereff ◽  
M. León ◽  
...  

Three Monosporascus eutypoides–like isolates recovered from cucurbit plants with symptoms of Monosporascus root rot and vine decline in Tunisia were compared to 28 isolates of M. cannonballus from 12 countries for phenotypic, genomic, and pathogenicity characteristics. Morphologically, M. cannonballus and M. eutypoides–like cultures were similar, each producing fertile perithecia in culture containing globose, smooth, dark brown to black ascospores. Nevertheless, all M. cannonballus isolates had one ascospore per ascus, while M. eutypoides–like isolates had mainly two to three ascospores per ascus (rarely one). The employment of the internal transcribed spacer (ITS) of nuclear ribosomal DNA, the elongation factor 1-α (EF-1α), and the β-tubulin (β-tub) gene sequence diversity analyses and the resulting phylogenies identified a level of polymorphism that enabled separation of M. cannonballus and M. eutypoides–like isolates. All isolates of M. cannonballus had identical EF-1α and β-tub sequences irrespective of very diverse geographic origins, which were different from the EF-1α and β-tub sequences of the M. eutypoides–like isolates (96 and 97% similarity, respectively). Similar results were obtained for the ITS region of rDNA. In addition, of three M. eutypoides–like isolates tested for pathogenicity, all three were pathogenic on watermelon, two were pathogenic on muskmelon, but only one was pathogenic on cucumber. The results demonstrate that the M. eutypoides–like isolates belong to the species M. eutypoides, and that M. cannonballus and M. eutypoides are distinct species.


2001 ◽  
Vol 79 (10) ◽  
pp. 1195-1201 ◽  
Author(s):  
J L Golden ◽  
Y D Kim ◽  
J F Bain

The recent transfer of the Queen Charlotte island endemic, Senecio newcombei Greene (Senecioneae: Asteraceae), to the Asiatic genus Sinosenecio extends the biogeographic range of Sinosenecio to North America and introduces a large amphi-Beringian gap in the distribution of the genus. However, the closely related genus Tephroseris includes a number of North American species with distributions in the vicinity of S. newcombei. We provide molecular sequence data from the ITS region of nuclear ribosomal DNA and micromorphological data from anther endothecial cells that indicate S. newcombei is closely related to North American Tephroseris species. However, the overall relationship between Sinosenecio and Tephroseris remains unresolved, so that transfer of S. newcombei to Tephroseris is not proposed.Key words: Tephroseris, Sinosenecio, phylogeny, ITS, anther endothecial cells.


Botany ◽  
2012 ◽  
Vol 90 (4) ◽  
pp. 327-335 ◽  
Author(s):  
Joseph F. Ammirati ◽  
Tess E. Barlow ◽  
Michelle T. Seidl ◽  
Oldriska Ceska ◽  
Mary Berbee ◽  
...  

Cortinarius parkeri , a new vernal species in subgenus Cortinarius , section Veneti , is described from the Pacific Northwest of North America. Within its subgenus, C. parkeri is unique in that its membranous universal veil is attached to the pileus edge of young mushrooms and extends as a covering over the pileus surface. At maturity, the universal veil forms a sheathing membranous volva-like structure that flares out above the stipe base. Sequences of the nuclear ribosomal DNA internal transcribed spacer region (ITS1-5.8s-ITS2) determined for 13 collections of C. parkeri were all identical, except for a polymorphic two base pair indel. In a phylogeny including other related species from North America and Europe, C. parkeri is monophyletic. In contrast to intraspecific distances, the interspecific genetic distance between C. parkeri and other Veneti species sequences was large. Being dikaryotic, mushrooms of C. parkeri contain genomes from two parents. As expected in a dikaryon in an interbreeding population, the polymorphic indel was homozygous in some collections but heterozygous in three collections, with conflicting sequences resulting from mixed parental types. Taken together, morphological and molecular results strongly support C. parkeri as a new and distinctive species.


1938 ◽  
Vol 16c (9) ◽  
pp. 354-376 ◽  
Author(s):  
Irene Mounce ◽  
Ruth Macrae

Studies of sexuality in Fomes pinicola (Sw.) Cooke based on material from 43 new sources, combined with results already published (1929) have led to the following conclusions: (i) Collections from North America may be divided into two groups, a large Group A, and a small Group B. Monosporous mycelia of any culture in Group A are compatible (mutually fertile) with those of every other member of the group; similarly monosporous mycelia of any member of Group B are compatible with other monosporous mycelia of Group B; but monosporous mycelia of Group A are almost completely incompatible (sterile) when paired with those of Group B. (ii) Collections of European and Japanese origin form a third Group C. These are almost completely compatible with Group A and only partially incompatible with Group B. (iii) In Group B are several isolates of the so-called Populus or hardwood form of F. pinicola which has been designated at times as a separate species F. marginatus. The remainder are, however, the typical coniferous or "red-belt" form.


2017 ◽  
Vol 26 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Chun-Chieh Yeh ◽  
Ling-Jia Wang ◽  
James J. Mcgarrigle ◽  
Yong Wang ◽  
Chien-Chang Liao ◽  
...  

This study investigates manufacturing procedures that affect islet isolation outcomes from donor pancreata standardized by the North American Islet Donor Score (NAIDS). Islet isolations performed at the University of Illinois, Chicago, from pancreata with NAIDS ≥65 were investigated. The research cohort was categorized into two groups based on a postpurification yield either greater than (group A) or less than (group B) 400,000 IEQ. Associations between manufacturing procedures and islet isolation outcomes were analyzed using multivariate logistic or linear regressions. A total of 119 cases were retrieved from 630 islet isolations performed since 2003. Group A is composed of 40 cases with an average postpurified yield of 570,098 IEQ, whereas group B comprised 79 cases with an average yield of 235,987 IEQ. One third of 119 cases were considered successful islet isolations that yielded >400,000 IEQ. The prepurified and postpurified islet product outcome parameters were detailed for future reference. The NAIDS (>80 vs. 65–80) [odds ratio (OR): 2.91, 95% confidence interval (CI): 1.27–6.70], cold ischemic time (≤10 vs. >10 h) (OR: 3.68, 95% CI: 1.61–8.39), and enzyme perfusion method (mechanical vs. manual) (OR: 2.38, 95% CI: 1.01–5.56) were independent determinants for postpurified islet yield ≥400,000 IEQ. The NAIDS (>80, p < 0.001), cold ischemic time (≤10 h, p < 0.05), increased unit of collagenase ( p < 0.01), and pancreatic duct cannulation time (<30 min, p < 0.01) all independently correlated with better islet quantity parameters. Furthermore, cold ischemic time (≤10 h, p < 0.05), liberase MTF ( p < 0.001), increased unit of collagenase ( p < 0.05), duct cannulation time (<30 min, p < 0.05), and mechanical enzyme perfusion ( p < 0.05) were independently associated with better islet morphology score. Analysis of islet manufacturing procedures from the pancreata with standardized quality is essential in identifying technical issues within islet isolation. Adequate processing duration in each step of islet isolation, using liberase MTF, and mechanical enzyme perfusion all affect isolation outcomes.


1997 ◽  
Vol 75 (9) ◽  
pp. 1540-1545 ◽  
Author(s):  
E. A. Remigio ◽  
D. Blair

The taxonomic relationships among four stagnicoline snail species from North America were reassessed by analysing nucleotide sequences from their nuclear ribosomal internal transcribed spacer (ITS) region. Three of the species (Stagnicola catascopium, Stagnicola emarginata, and Stagnicola elodes) are representatives of the subgenus Stagnicola s.str. from the northern U.S.A. and the fourth is a closely related Canadian species (Stagnicola caperata) belonging to the subgenus Hinkleyia. Members of the two subgenera differed considerably in their ITS sequences, demonstrating the usefulness of these sequences for distinguishing species from closely related lymnaeid subgenera. In contrast, ITS sequences for the three members of the subgenus Stagnicola s.str. were very similar, which supports an earlier view that they may not be separate species.


Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.


VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).


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