Determination of the origin of the cold-adapted populations of barnyard grass (Echinochloa crus-galli) in eastern North America: a total-evidence approach using RAPD DNA and DNA sequences

2000 ◽  
Vol 78 (12) ◽  
pp. 1505-1513 ◽  
Author(s):  
Sophie Roy ◽  
Jean-Pierre Simon ◽  
François-Joseph Lapointe

This survey attempts to establish the origin of cold-adapted populations of barnyard grass (Echinochloa crus-galli (L.) Beauv.) in North America using molecular techniques, including random amplified polymorphic DNA (RAPD) and two types of sequences: chloroplast intron (trnL (UAA)) and rDNA nuclear spacer (ITS 1). There exists many possible scenarios to explain the origin of E. crus-galli in eastern Canada (Quebec), but we dwelled on two particular hypotheses, which are not mutually exclusive. The first hypothesis stipulates that the populations originated only from Europe, whereas the second implies that native subtropical and warm-temperate populations migrated from the south towards northern regions. To assess the likelihood of these hypotheses, the genetic distance matrices obtained from RAPD markers, nuclear, and chloroplastic sequences were combined and tested against the competing models. A principal coordinate analysis was used to discriminate among populations sampled from three different regions (i.e., Quebec, American east coast, and western Europe) and an analysis of molecular variance (AMOVA) detected a significant genetic structure among these populations (FST = 0.110, p < 0.05). Pairwise comparisons further indicated that European populations were significantly different from all other populations, whereas North American populations were not different from one another. The combined sequences revealed eight different haplotypes. Six populations were characterized by unique haplotypes, while one haplotype was shared by 3 of the 12 North American populations. The last and most common haplotype was observed in 9 of the 18 populations from all three regions. The tests computed thus supported the second hypothesis suggesting that the cold-adapted populations of eastern Canada are probably derived from other North American populations rather than European populations.Key words: AMOVA, RAPD, rDNA, cpDNA, genetic variation, population structure.

2002 ◽  
Vol 80 (11) ◽  
pp. 1151-1159 ◽  
Author(s):  
M Dusabenyagasani ◽  
G Laflamme ◽  
R C Hamelin

We detected nucleotide polymorphisms within the genus Gremmeniella in DNA sequences of β-tubulin, glyceraldehyde phosphate dehydrogenase, and mitochondrial small subunit rRNA (mtSSU rRNA) genes. A group-I intron was present in strains originating from fir (Abies spp.) in the mtSSU rRNA locus. This intron in the mtSSU rRNA locus of strains isolated from Abies sachalinensis (Fridr. Schmidt) M.T. Mast in Asia was also found in strains isolated from Abies balsamea (L.) Mill. in North America. Phylogenetic analyses yielded trees that grouped strains by host of origin with strong branch support. Asian strains of Gremmeniella abietina (Lagerberg) Morelet var. abietina isolated from fir (A. sachalinensis) were more closely related to G. abietina var. balsamea from North America, which is found on spruce (Picea spp.) and balsam fir, and European and North American races of G. abietina var. abietina from pines (Pinus spp.) were distantly related. Likewise, North American isolates of Gremmeniella laricina (Ettinger) O. Petrini, L.E. Petrini, G. Laflamme, & G.B. Ouellette, a pathogen of larch, was more closely related to G. laricina from Europe than to G. abietina var. abietina from North America. These data suggest that host specialization might have been the leading evolutionary force shaping Gremmeniella spp., with geographic separation acting as a secondary factor.Key words: Gremmeniella, geographic separation, host specialization, mitochondrial rRNA, nuclear genes.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 751
Author(s):  
Francesco Dovana ◽  
Paolo Gonthier ◽  
Matteo Garbelotto

Phlebiopsis gigantea (Fr.) Jülich is a well-known generalist conifer wood saprobe and a biocontrol fungus used in several world countries to prevent stump infection by tree pathogenic Heterobasidion fungal species. Previous studies have reported the presence of regional and continental genetic differentiation in host-specific fungi, but the presence of such differentiation for generalist wood saprobes such as P. gigantea has not been often studied or demonstrated. Additionally, little information exists on the distribution of this fungus in western North America. The main purposes of this study were: (I) to assess the presence of P. gigantea in California, (II) to explore the genetic variability of P. gigantea at the intra and inter-continental levels and (III) to analyze the phylogeographic relationships between American and European populations. Seven loci (nrITS, ML5–ML6, ATP6, RPB1, RPB2, GPD and TEF1-α) from 26 isolates of P. gigantea from coniferous forests in diverse geographic distribution and from different hosts were analyzed in this study together with 45 GenBank sequences. One hundred seventy-four new sequences were generated using either universal or specific primers designed in this study. The mitochondrial ML5–ML6 DNA and ATP6 regions were highly conserved and did not show differences between any of the isolates. Conversely, DNA sequences from the ITS, RPB1, RPB2, GPD and TEF1-α loci were variable among samples. Maximum likelihood analysis of GPD and TEF1-α strongly supported the presences of two different subgroups within the species but without congruence or geographic partition, suggesting the presence of retained ancestral polymorphisms. RPB1 and RPB2 sequences separated European isolates from American ones, while the GPD locus separated western North American samples from eastern North American ones. This study reports the presence of P. gigantea in California for the first time using DNA-based confirmation and identifies two older genetically distinct subspecific groups, as well as three genetically differentiated lineages within the species: one from Europe, one from eastern North America and one from California, with the latter presumably including individuals from the rest of western North America. The genetic differentiation identified here among P. gigantea individuals from coniferous forests from different world regions indicates that European isolates of this fungus should not be used in North America (or vice versa), and, likewise, commercially available eastern North American P. gigantea isolates should not be used in western North America forests. The reported lack of host specificity of P. gigantea was documented by the field survey and further reinforces the need to only use local isolates of this biocontrol fungus, given that genetically distinct exotic genotypes of a broad generalist microbe may easily spread and permanently alter the microbial biodiversity of native forest ecosystems.


2003 ◽  
Vol 66 (10) ◽  
pp. 1932-1934 ◽  
Author(s):  
PETER VADAS ◽  
BORIS PERELMAN

Peanut allergens are both stable and potent and are capable of inducing anaphylactic reactions at low concentrations. Consequently, the consumption of peanuts remains the most common cause of food-induced anaphylactic death. Since accidental exposure to peanuts is a common cause of potentially fatal anaphylaxis in peanut-allergic individuals, we tested for the presence of peanut protein in chocolate bars produced in Europe and North America that did not list peanuts as an ingredient. Ninety-two chocolate bars, of which 32 were manufactured in North America and 60 were imported from Europe, were tested by the Veratox assay. None of the 32 North American chocolate products, including 19 with precautionary labeling, contained detectable peanut protein. In contrast, 30.8% of products from western Europe without precautionary labeling contained detectable levels of peanut protein. Sixty-two percent of products from eastern Europe without precautionary labeling contained detectable peanut protein at levels of up to 245 ppm. The absence of precautionary labeling and the absence of the declaration of “peanut” as an ingredient in chocolate bars made in eastern and central Europe were not found to guarantee that these products were actually free of contaminating peanut protein. In contrast, North American manufacturers have attained a consistent level of safety and reliability for peanut-allergic consumers.


2000 ◽  
Vol 74 (3) ◽  
pp. 444-463 ◽  
Author(s):  
Xueping Ma ◽  
Jed Day

The cyrtospiriferid brachiopod genus Tenticospirifer Tien, 1938, is revised based on restudy of the type species from the Frasnian (Late Devonian) of the Russian Platform. As revised the genus includes cyrtospiriferid species with pyramidal ventral valves, catacline ventral interareas, a narrow delthyrium, few sinal plications, and lack a median dorsal septum and pseudodeltidium. All species retained in the genus are of Givetian and Frasnian age. All Famennian age species described from South China and North America are rejected from the genus. It appears that Tenticospirifer evolved during the early Givetian in western Europe and remained endemic to that region during the remainder of the Givetian. Successive migrations of Tenticospirifer from eastern Laurussia to North America, then to South China and possibly Australia, coincided with middle and late Frasnian eustatic sea level rises, respectively. The North American species Spirifera cyrtinaformis Hall and Whitfield, 1872, and related species identified as Tenticospirifer by North American workers, are reassigned to Conispirifer Lyashenko, 1985. Its immigration to and widespread dispersal in carbonate platforms of western Laurussia, northern Gondwana and tropical island arcs (?) coincided with a major late Frasnian eustatic sea level rise. The new family Conispiriferidae is proposed with Conispirifer Lyashenko, 1985, selected as the type genus. The new family also includes the new genus Pyramidaspirifer with Platyrachella alta Fenton and Fenton, 1924, proposed as the type species. The affinity of the new family remains uncertain pending restudy of key genera currently included in the Superfamily Cyrtospiriferoidea. Available data from the Devonian brachiopod literature indicate that species of Pyramidaspirifer are restricted to late Frasnian deposits of central and western North America.


2021 ◽  
Author(s):  
Christian Schmidt ◽  
Alexandre Anctil

The geometrid moth Hemithea aestivaria (Hübner, 1789) was introduced from Europe to North America, first detected in British Columbia in 1973. Until 2019, its North American range was limited to a restricted area of the Pacific Northwest. Here, we report on the first records of H. aestivaria for eastern North America from three widely separated urban centers in eastern Canada during 2019-2020.


Author(s):  
Douglas J. Futuyma

Anyone who is even slightly acquainted with plants or animals knows that different species inhabit different parts of the world, live in different habitats, and, in the case of animals, eat some imaginable kinds of food and not others. As with many other familiar facts, it may not occur to us to ask why the geographic and ecological ranges of species are limited, until we realize that species vary drastically in their geographic, ecological, and physiological amplitudes. The bracken fern (Pteridium aquilinum) is broadly distributed in temperate climates of every continent (except Antarctica), whereas the curly-grass fern (Schizaea pusilla) is limited to parts of eastern Canada and central New Jersey in the United States. The black-billed magpie (Pica pica) is a familiar bird from western Europe through eastern Asia and from Alaska to the Great Plains of North America, but the very similar yellow-billed magpie (Pica nuttalli) is restricted to central California. What accounts for the much narrower distribution of one than the other species? Related species often differ in the variety of habitats they occupy. The thistle Cirsium canescens is restricted to well-drained sandhills in the American prairie, whereas Cirsium arvense is a European species that has become a rampant weed in North America, growing in many types of soil. The endangered Kirtland's warbler (Dendroica kirtlandii) nests only in stands of jack pine of a certain age, while its relatives, such as the yellow warbler (Dendroica aestiva), nest in many types of vegetation and have far broader geographic ranges as well. (Species with narrow and broad habitat associations are referred to as stenotopic and eurytopic, respectively.) Stenotopic species or populations frequently have a narrower tolerance of certain physical variables than do others. Most plants and animals from warm tropical environments cannot survive freezing temperatures, and Antarctic notothenioid fishes cannot tolerate temperatures above 6°C. In contrast, species that inhabit environments where the temperature varies widely often have broad temperature tolerance. In many such species, individuals are capable of biochemical and physiological alterations that acclimate them to pronounced changes in temperature.


2002 ◽  
Vol 34 (2) ◽  
pp. 101-111 ◽  
Author(s):  
C. Printzen ◽  
S. Ekman

AbstractThe fruticose lichen Cavernularia hultenii exhibits a strongly disjunct distribution between north-western North America, Newfoundland and north-western Europe. An investigation of its population structure, based on nuclear ITS and IGS DNA sequences, shows that western North America has a higher number of haplotypes than the two other areas. Most of the haplotypes confined to this region are rare and occur outside the area that was affected by Pleistocene glaciations. Three haplotypes are common in all three areas. The high number of haplotypes in western North America might be due to a combination of events during the Pleistocene and Holocene epochs, viz. increased lineage survival by repeated fragmentation of populations and reduced lineage extinction through rapid postglacial expansion and population growth.


1967 ◽  
Vol 99 (1) ◽  
pp. 85-93 ◽  
Author(s):  
W. J. Brown

AbstractThe Atlantic Provinces received many coleopterous immigrants from Europe during colonial times. These immigrants live in man-made habitats, and they show unnaturally restricted distributional patterns. Many were introduced independently to regions about Puget Sound, and there were multiple introductions in the East. Parthenogenesis is a factor in the establishment of imported otiorhynchine weevils. Imported species not previously reported from North America are Abax parallelopipedus (Pill. & Mitt.), Eusphalerum torquatum (Marsh.), Meligethes viridescens (Fab.), and Longitarsus luridus (Scop.). Aphodius tenellus Say is strictly North American and has been confused with the Eurasian species that should be known as uliginosus Hardy. American records of Sitona tibialis (Hbst.) and probably those of S. discoideus Gyll. are based on S. scissifrons Say, which is native to North America. The Alaskan Philostratus ptinoides (Germ.) occurs, evidently as an import, in eastern Canada. New synonymy is proposed: Thes bergrothi (Reitter, 1880) = Enicmus tricarinatus Brown, 1934; Aphodius borealis Gyllenhal, 1827 = A. errans Brown, 1930. Notes are given on the distribution, characters, or nomenclature of other species.


2021 ◽  
Vol 9 ◽  
Author(s):  
Christian Schmidt ◽  
Alexandre Anctil

The geometrid moth Hemithea aestivaria (Hübner, 1789) was introduced from Europe to North America, first being detected in British Columbia in 1973. Until 2019, its North American range was limited to a restricted area of the Pacific Northwest. Here, we report on the first records of H. aestivaria for eastern North America from three widely separated urban centres in eastern Canada during 2019-2020.


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