RAPD analysis of the relationship of North and South American subspecies of Fragaria chiloensis

1998 ◽  
Vol 76 (10) ◽  
pp. 1812-1817 ◽  
Author(s):  
Sue Porebski ◽  
Paul M Catling
Keyword(s):  
North American ◽  
Random Amplified Polymorphic Dna ◽  
Molecular Evidence ◽  
South American ◽  
Cophenetic Correlation ◽  
The North ◽  
Fragaria Chiloensis ◽  
Protection And Utilization ◽  
Relationship Of ◽  
North And South

To improve the intraspecific classification of Fragaria chiloensis (L.) Duchesne, 35 plants including 5 North American ssp. lucida, 15 North American ssp. pacifica, and 15 South American ssp. chiloensis were analysed using random amplified polymorphic DNA (RAPDs). From 100 primers screened, 12 were selected providing 62 scorable polymorphic bands. The phenogram (cophenetic correlation, r = 0.99) based on UPGMA clustering of Jaccard's coefficients revealed a clear division between North American and South American plants, but only partial separation was shown between the two North American subspecies. This is the first comprehensive molecular evidence for major genetic divergence between the North American and South American subspecies of F. chiloensis and suggests greater genetic variation within the Canadian material of the North American ssp. pacifica than within the South American ssp.chiloensis. These findings strongly support protection and utilization of wild Canadian Fragaria germplasm for crop improvement.Key words: strawberry, Fragaria chiloensis, ssp. chiloensis, ssp. pacifica, ssp. lucida, RAPD, variation, germplasm, Canada, United States, Chile.

scholarly journals Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America

2016 ◽  
Vol 12 (4) ◽  
pp. 20160062 ◽  
Author(s):  
Kieren J. Mitchell ◽  
Sarah C. Bray ◽  
Pere Bover ◽  
Leopoldo Soibelzon ◽  
Blaine W. Schubert ◽  
...  
Keyword(s):  
South America ◽  
North American ◽  
Convergent Evolution ◽  
Phylogenetic Analyses ◽  
Early Pleistocene ◽  
South American ◽  
The North ◽  
Molecular Phylogenetic ◽  
North And South America ◽  
North And South

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear ( Tremarctos ornatus ), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears ( Tremarctos ), South American short-faced bears ( Arctotherium ) and North American short-faced bears ( Arctodus ) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears ( Arctodus and Arctotherium ), potentially as an adaptation to dominate competition for megafaunal carcasses.

Differences in bleaching responses from fungal- versus bacterial-derived enzymes

TAPPI Journal ◽  
2012 ◽  
Vol 11 (3) ◽  
pp. 21-27 ◽  
Author(s):  
PETER W. HART
Keyword(s):  
North American ◽  
Cost Savings ◽  
Operating Conditions ◽  
South American ◽  
Oxygen Delignification ◽  
The North ◽  
Eucalyptus Pulp ◽  
The One ◽  
Enzyme Bleaching ◽  
North And South

Several mills in North America have been successful in using xylanase enzymes expressed from Trichoderma reesei (a fungus) as part of their bleaching sequence for many years. These mills process hardwood and softwood species, with and without oxygen delignification. These mills also use three-, four-, and five-stage bleaching sequences. North American mills tend to report increased pulp brightness ceilings and decreased bleaching costs as benefits associated with the application of enzymes in the bleaching process. Laboratory testing suggests that eucalyptus pulp is highly susceptible to fungal- and bacterial-derived enzyme bleaching and should result in significant cost savings in South American mills. At least four different mills in South America have attempted to perform enzyme bleaching trials using bacterial-derived enzymes. Each of these mill trials resulted in significantly increased operating costs and/or unsustainable operating conditions. More recently, one of these South American mills performed a short trial using a commercially available, fungal-derived enzyme. This trial was technically successful. This report attempts to determine why the South American mill experiences with bacterial-derived enzymes have been poor, while North American mills and the one South American mill trial have had good results with fungal-derived enzymes. Operating conditions and trial goals for the North and South American mills also were examined.

CYTOTAXONOMIC STUDIES ON NEW WORLD SPECIES OF ANEMONE (SECTION ERIOCEPHALUS) WITH TUBEROUS ROOTSTOCKS

1966 ◽  
Vol 44 (7) ◽  
pp. 899-928 ◽  
Author(s):  
Cecily Joseph ◽  
Margaret Heimburger
Keyword(s):  
North American ◽  
New World ◽  
Diploid Species ◽  
Pollen Grain ◽  
South American ◽  
New Taxon ◽  
South American Species ◽  
The North ◽  
Additional Support ◽  
North And South

The American species of Anemone L. (section Eriocephalus Hook. f. & Thoms.) with tuberous rootstocks were studied by biosystematic methods. Anemone caroliniana Walt., A. heterophylla Nutt. ex Torr. & Gray, A. tuberosa Rydb., and A. edwardsiana Tharp (tentatively) are recognized from North America and A. decapetala Ard., A. triternata Vahl, and A. cicutifolia Johnst. from South America. Karyotypes of the diploid species (2n = 16), A. heterophylla, A. tuberosa, A. decapetala, and A. triternata are described. They resemble the karyotype of A. caroliniana published earlier. Anemone edwardsiana and A. cicutifolia are also presumed diploid from stomatal and pollen grain studies. A new taxon (2n = 32), of undecided status, was obtained from Chile. North American plants included by authors in A. decapetala are here referred to A. heterophylla. The North and South American species appear to form two separate groups, the species of each continent being more closely related among themselves than to those of the other continent. Fewer stomata, larger chromosome size, and higher DNA content are characteristic of the North American species. Additional support for the separation of the two groups derives from limited meiotic studies which indicate a larger number of inversion differences in inter- than in intra-continental hybrids.

Relationships among subspecies of New World octoploid strawberry species, Fragaria virginiana and Fragaria chiloensis, based on simple sequence repeat marker analysis

2006 ◽  
Vol 84 (12) ◽  
pp. 1829-1841 ◽  
Author(s):  
K.E. Hokanson ◽  
M.J. Smith ◽  
A.M. Connor ◽  
J.J. Luby ◽  
James F. Hancock
Keyword(s):  
North American ◽  
Simple Sequence Repeat ◽  
Distinct Species ◽  
South American ◽  
Sequence Repeat ◽  
Similarity Coefficients ◽  
The North ◽  
Fragaria Chiloensis ◽  
Fragaria Virginiana ◽  
Simple Sequence

Simple sequence repeat (SSR) markers, developed from Fragaria  ×ananassa Duchesne ex Rozier ‘Earliglow’, were used to assess diversity among all of the proposed taxa of Fragaria virginiana Mill. and Fragaria chiloensis (L.) Mill. to facilitate strawberry germplasm utilization and conservation and to help resolve taxonomic relationships. DNA was obtained from 111 individuals representing F. chiloensis subsp. pacifica Staudt, F. chiloensis subsp. lucida (E. Vilm. ex Gray) Staudt, F. virginiana subsp. virginiana Mill., F. virginiana subsp. glauca (S. Watson) Staudt, F. virginiana subsp. grayana (Vilm. ex J. Gay) Staudt, and F. virginiana subsp. platypetala (Rydb.) Staudt from North America, F. chiloensis subsp. chiloensis f. chiloensis and F. chiloensis subsp. chiloensis f. patagonica from South America, F. chiloensis subsp. s andwicensis (Decne.) Staudt from Hawaii, as well as F. ×ananassa subsp. cuneifolia (Nutt ex Howell), and F. ×ananassa subsp. ananassa . A total of 108 bands were scored among all accessions using the five SSR primer pairs, for a mean of 21.6 bands per primer pair with 3–8 bands in individual accessions. Cluster analysis and principal coordinate analysis using Jaccard similarity coefficients based on presence or absence of bands supported the separation of F. virginiana and F. chiloensis as distinct species. The various F. virginiana subspecies were not distinguishable. The two South American forms of F. chiloensis subsp. chiloensis are very similar to each other and distinct from the North American subspecies. The F. chiloensis subsp. sandwicensis accessions were distinct from other taxonomic classes. The F. ×ananassa cultivars clustered most closely with the South American F. chiloensis supporting the origin of F. ×ananassa primarily from South American rather than North American F. chiloensis. While the North and South American F. chiloensis subspecies should remain separated based on their molecular distinction, consideration should be given to classifying F. chiloensis subsp. pacifica and subsp. lucida as different forma of a single North American F. chiloensis subspecies, rather than as separate subspecies. This is similar to the current classification of the two South American forma of F. chiloensis subsp. chiloensis (L.) Mill. Similarly, the F. virginiana subspecies should be reclassified as forms of a single subspecies, F. virginiana subsp. virginiana, rather than separate subspecies.

Systematics and paleobiogeography of Late TriassicGryphaea(Bivalvia) from the North American Cordillera

1992 ◽  
Vol 66 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Christopher A. Mcroberts
Keyword(s):  
North American ◽  
Late Triassic ◽  
South American ◽  
Long Distance ◽  
Low Latitude ◽  
North American Cordillera ◽  
The North ◽  
North American Craton ◽  
Far Eastern ◽  
North And South

Evaluation of previously undescribed collections of Late TriassicGryphaeafrom the North American Cordillera increases the temporal range and geographic distribution of the genus.Gryphaea(Gryphaea)arcuataeformisKiparisova,G.cf.G.(Gryphaea)keilhauiBöhm, and a new species,G.(Gryphaea)nevadensis, occur in lower Carnian to upper Norian strata from Alaska, British Columbia, Oregon, and Nevada. The distribution is mostly primary with respect to the Upper Triassic North American Craton, and requires long-distance larval dispersal along the latitude of far-eastern Panthalassa. Unlike most modern oysters, the distribution of these Triassic gryphaeids may have been restricted to cool and deeper water environments.An early Carnian age ofGryphaea(Gryphaea)arcuataeformisplaces this species as the oldest knownGryphaea. When combined with late Carnian and Norian occurrences from the North and South American Cordillera, these data indicate that a low-latitude origin for the genus cannot be overlooked. Gryphaeids survived the end-Triassic extinction event presumably by living in refugia.

Diversification of the North American Doellingeria-Eucephalus Clade (Astereae: Asteraceae) Inferred from Molecular and Morphological Evidence

2019 ◽  
Vol 44 (4) ◽  
pp. 930-942
Author(s):  
Geraldine A. Allen ◽  
Luc Brouillet ◽  
John C. Semple ◽  
Heidi J. Guest ◽  
Robert Underhill
Keyword(s):  
North American ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Sister Group ◽  
Morphological Evidence ◽  
South American ◽  
New Combinations ◽  
The North ◽  
Hybridization Event ◽  
Ancient Hybridization

Abstract—Doellingeria and Eucephalus form the earliest-diverging clade of the North American Astereae lineage. Phylogenetic analyses of both nuclear and plastid sequence data show that the Doellingeria-Eucephalus clade consists of two main subclades that differ from current circumscriptions of the two genera. Doellingeria is the sister group to E. elegans, and the Doellingeria + E. elegans subclade in turn is sister to the subclade containing all remaining species of Eucephalus. In the plastid phylogeny, the two subclades are deeply divergent, a pattern that is consistent with an ancient hybridization event involving ancestral species of the Doellingeria-Eucephalus clade and an ancestral taxon of a related North American or South American group. Divergence of the two Doellingeria-Eucephalus subclades may have occurred in association with northward migration from South American ancestors. We combine these two genera under the older of the two names, Doellingeria, and propose 12 new combinations (10 species and two varieties) for all species of Eucephalus.

RESOLVING SOURCE-TO-SINK DYNAMICS BY MULTI-PROXY DATA FROM THE NORTH AND SOUTH AMERICAN CONTINENTAL SEDIMENTARY ARCHIVES

2020 ◽  
Author(s):  
Barbara Carrapa ◽  
◽  
Andrea Stevens Goddard ◽  
Scott Meek ◽  
Peter G. DeCelles
Keyword(s):  
South American ◽  
Proxy Data ◽  
The North ◽  
Source To Sink ◽  
North And South

scholarly journals Balance Differences between North and South American Older Adults: A Cross-Sectional, Age and Sex Matched Study

2021 ◽  
Author(s):  
Matheus Almeida Souza ◽  
Daniel Goble ◽  
Paige Arney ◽  
Edgar Ramos Vieira ◽  
Gabriela Silveira-Nunes ◽  
...  
Keyword(s):  
Older Adults ◽  
High Risk ◽  
North American ◽  
Force Plate ◽  
South American ◽  
Risk Of Falling ◽  
Men And Women ◽  
Falls Risk ◽  
South Americans ◽  
North And South

This study aimed to characterize the risk of falling in low, moderate and high risk participants from two different geographical locations using a portable force-plate. A sample of 390 older adults from South and North America were matched for age, sex, height and weight. All participants performed a standardized balance assessment using a force plate. Participants were classified in low, moderate and high risk of falling. No differences were observed between South and North American men, nor comparing North American men and women. South American women showed the significantly shorter center of pressure path length compared to other groups. The majority of the sample was categorized as having low risk of falling (male: 65.69 % and female: 61.87 %), with no differences between men and women. Also, no differences were found between North vs. South Americans, nor for falls risk levels when male and female groups were compared separately. In conclusion, South American women had better balance compatible with the status of the 50-59 years’ normative age-range. The prevalence of low falls risk was ~ 61-65 % and the prevalence of moderate to high risk was ~ 16-19 %. The frequency of fall risk did not differ significantly between North and South Americans, nor between males and females.

Sign in / Sign up

Export Citation Format

Share Document