Genetic relationships in Abies (fir) of eastern United States: an electrophoretic study

1984 ◽  
Vol 62 (4) ◽  
pp. 609-616 ◽  
Author(s):  
Brian F. Jacobs ◽  
Charles R. Werth ◽  
Sheldon I. Guttman
Keyword(s):  
United States ◽  
Cluster Analysis ◽  
Genetic Relationships ◽  
Genetic Distances ◽  
Hybrid Origin ◽  
Eastern United States ◽  
Electrophoretic Study ◽  
Alternative Hypotheses ◽  
The Relationship ◽  
Cone Scale

Abies (fir) is widely considered to consist of two species in the eastern United States, A. balsamea (L.) Mill, and A. fraseri (Pursh.) Poir., distinguished by relative cone bract to subtending cone scale lengths and number of leaf hypodermal cells. Intermediate individuals have been recognized as A. balsamea var. phanerolepis Fern. An understanding of the relationship between the two putative species hinges on the interpretation of the intermediate. Two alternative hypotheses view the intermediate as either an interspecific hybrid or as an intraspecific variant. Twenty gene loci were electrophorctically analyzed in samples from 12 populations representing all three taxa. All populations shared similar complements of alleles at comparable frequencies for 13 polymorphic loci. Genetic distances among populations ranged from 0.10 to 0.0. Cluster analysis joined populations of A. fraseri with those representing A. balsamea var. phanerolepis at a distance of 0.03 and linked populations of A. balsamea with the other two taxa at 0.06. A hierarchical analysis of the three taxa, delimited by cluster analysis and bract exsertion, places A. balsamea var. phanerolepis intermediate between the two species. These data support a conspecifie status for all of eastern U.S. Abies with gene exchange between populations relatively unrestricted at last contact (≈ 10 000 years BP). Further, A. balsamea var. phenerolepis, while electrophoretically intermediate, is likely not of hybrid origin. Our results are consistent with those of recent studies which conclude that A. fraseri and A. balsamea are very closely related taxa of Pleistocene origin.

scholarly journals Relationships of Fire and Precipitation Regimes in Temperate Forests of the Eastern United States

2012 ◽  
Vol 16 (11) ◽  
pp. 1-15 ◽  
Author(s):  
Charles W. Lafon ◽  
Steven M. Quiring
Keyword(s):  
United States ◽  
Daily Precipitation ◽  
Precipitation Variability ◽  
Annual Precipitation ◽  
Moisture Regime ◽  
Fire Occurrence ◽  
Climate Variables ◽  
Eastern United States ◽  
Fire Activity ◽  
The Relationship

Abstract Fire affects virtually all terrestrial ecosystems but occurs more commonly in some than in others. This paper investigates how climate, specifically the moisture regime, influences the flammability of different landscapes in the eastern United States. A previous study of spatial differences in fire regimes across the central Appalachian Mountains suggested that intra-annual precipitation variability influences fire occurrence more strongly than does total annual precipitation. The results presented here support that conclusion. The relationship of fire occurrence to moisture regime is also considered for the entire eastern United States. To do so, mean annual wildfire density and mean annual area burned were calculated for 34 national forests and parks representing the major vegetation and climatic conditions throughout the eastern forests. The relationship between fire activity and two climate variables was analyzed: mean annual moisture balance [precipitation P − potential evapotranspiration (PET)] and daily precipitation variability (coefficient of variability for daily precipitation). Fire activity is related to both climate variables but displays a stronger relationship with precipitation variability. The southeastern United States is particularly noteworthy for its high wildfire activity, which is associated with a warm, humid climate and a variable precipitation regime, which promote heavy fuel production and rapid drying of fuels.

scholarly journals GENETIC RELATIONSHIPS BETWEEN NATIVE SHEEP BREEDS IN NIGERIA BASED ON MICROSATELLITE DNA POLYMORPHISMS.

2021 ◽  
Vol 27 ◽  
pp. 1-8
Author(s):  
O. ADEBAMBO ◽  
J. I. WILLAMS ◽  
S. BLOTT ◽  
B. URQUHART
Keyword(s):  
Genetic Relationship ◽  
Microsatellite Dna ◽  
Genetic Relationships ◽  
Genetic Distances ◽  
Dna Polymorphisms ◽  
Evolutionary Divergence ◽  
Microsatellite Dna Markers ◽  
Diversity Studies ◽  
High Degree ◽  
The Relationship

Genetic relationship among Nigeria's breeds of sheeps and crosses was studied using microsatellite DNA polymorphisms. DNA samples extracted from four Nigeria's breeds of sheeps (West African Dwarf,the balami, Uda and yankassa) and crosses were analysed using 30 microsatellite markers for diversity studies. Twenty of the makers were by the sheeps genome . Nineteen of the loci were polymorphic and were used to calculate genetic distances (Ds) between the based on allelefrequences of microsatellite. The phylogenetic relatioship between the breeds were similarly estimated. With the total number of loci studied, 285 alleles were generated and a high decree of heterozysity was recorded, (0.57 to 0.72), a relative high degree of relaibility could be placed on the tree topology with the relationship between breeds potraying a closer relationship between the yankassa and Uda (Ds 0.356). The genetic distance (Ds) was 0.432, 0.534 and 0.665 between the African Dwarf and the Yankassa, Uda and Balami respectively also indictating a closer relatioship between the Yankassa, and the WAD compared to the basically Northern breeds (Uda and Balami). This further confirms the evolutionary divergence of the breeds which makes them distint entitles. The data suggests that microsatellite DNA markers are useful tools for studying the genetic relationship among these sheeps breeds. The high polymorphic alleles could thus be exploited in breeds improvement and development.

The Relationship between the North Atlantic Oscillation and High-Wind Observations Across the Eastern United States 

2021 ◽  
Author(s):  
Sylvia Stinnett ◽  
Joshua Durkee ◽  
Joshua Gilliland ◽  
Victoria Murley ◽  
Alan Black ◽  
...  
Keyword(s):  
United States ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Eastern United States ◽  
High Wind ◽  
The North ◽  
The North Atlantic ◽  
Wind Events ◽  
The North Atlantic Oscillation ◽  
The Relationship

<p>The North Atlantic Oscillation (NAO) is a high-frequency oscillation that has known influences on the climatology of weather patterns across the eastern United States. This study explores the relationship between the daily North Atlantic Oscillation index with observed high-wind events from 391 first-order weather stations across the eastern U.S. from 1973-2015. These events were determined following typical National Weather Service high-wind criteria: sustained winds of at least 18 m•s-1 for at least 1 hour or a wind gust of at least 26 m•s-1 for any duration. Since research literature shows high-wind events are often connected to parent mid-latitude cyclone tracks, and since the NAO has been shown to influence these storm tracks, it is hypothesized that changes in NAO phases are connected to spatial shifts and frequencies in high-wind observations. Initial results show a preferred southwesterly direction during each NAO phase. Variance in high-wind directions appears to increase (decrease) during negative (positive) NAO phases. Further, the greatest spatial difference in the mean center of high-wind observations was between positive and negative NAO phases. Overall, these preliminary findings indicate changes in high-wind observations may be linked to NAO phases.</p>

An electrophoretic study of representatives of subgenus Diploxylon of Pinus

1989 ◽  
Vol 67 (6) ◽  
pp. 1750-1759 ◽  
Author(s):  
Roopa R. Karalamangala ◽  
Daniel L. Nickrent
Keyword(s):  
United States ◽  
Cluster Analysis ◽  
Phylogenetic Trees ◽  
Small Sample Size ◽  
The United States ◽  
Small Sample ◽  
Genetic Affinity ◽  
Electrophoretic Study ◽  
Isozyme Loci

Relationships among 14 taxa in subgenus Diploxylon of Pinus from Mexico and the United States were analyzed using 15 isozyme loci obtained from both frozen and fresh needle tissue. The phenogram obtained from cluster analysis of genetic distance values and phylogenetic trees implementing the distance Wagner procedure were in general agreement with classifications based on morphological features. Pinus leiophylla is genetically distinct from other species. Two groupings, one comprising P. oocarpa and P. pringlei and another comprising P. lawsonii and P. teocote, correspond to sections Serotinus and Teocote (sensu Martínez), respectively. Classification of the remaining eight taxa has varied, ranging from their placement in three, two, or only one section. Isozyme analysis resulted in a group that included P. cooperi, P. douglasiana, P. durangensis, P. michoacana, and P. montezumae, which suggests genetic affinity between Sections Pseudostrobus and Montezumae (sensu Martínez). This result corresponds more closely to the placement of these species in subsection Pseudostrobi. The distant relationship between P. engelmannii and the ponderosa pines may be anomalous (an artifact of small sample size) or may indicate greater genetic divergence than previously recognized.

Calculation of biomass trend, exploitation rate, and surplus production from survey and catch data

2001 ◽  
Vol 58 (3) ◽  
pp. 579-584 ◽  
Author(s):  
Ray Hilborn
Keyword(s):  
United States ◽  
Survey Data ◽  
Eastern United States ◽  
Stock Size ◽  
Surplus Production ◽  
Catch Data ◽  
Exploitation Rate ◽  
Alternative Hypotheses ◽  
History Of

If survey data and historical catches are available, it is possible to estimate the history of surplus production from a fishery as long as the scalar between the survey and absolute biomass can be estimated. Alternative hypotheses about present stock size correspond to alternative hypotheses about the scalar, so that by specifying an estimate of the current stock size or exploitation rate, the entire trend of surplus production can be calculated. An example, using monkfish (Lophius americanus) in the eastern United States, is given that shows quite robust conclusions to alternative assumptions about current stock size, and the analysis suggests that the surplus production from monkfish has been the highest during the period of lowest stock size.

scholarly journals Genetic Diversity of Seven Deciduous Azalea Species (Rhododendron spp. section Pentanthera) Native to the Eastern United States

2008 ◽  
Vol 133 (3) ◽  
pp. 374-382 ◽  
Author(s):  
Matthew Chappell ◽  
Carol Robacker ◽  
Tracie M. Jenkins
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Diversity ◽  
Interspecific Variation ◽  
Genetic Distances ◽  
Anthropogenic Activity ◽  
Group Method ◽  
Aflp Analysis ◽  
Eastern United States

Despite the ecologic and economic importance of native deciduous azaleas (Rhododendron L. section Pentanthera G. Don), our understanding of interspecific variation of North American deciduous azalea species comes principally from morphologic studies. Furthermore, little is known concerning intraspecific or interpopulation genetic variation. With ever-increasing loss and fragmentation of native azalea habitat in the eastern United States due to anthropogenic activity, it is imperative that an understanding of natural genetic variation among and within species and populations is acquired. The present study addresses questions of genetic diversity through the use of amplified fragment length polymorphism (AFLP) analysis. Twenty-five populations of seven species of native azalea were analyzed using three primer pairs that amplified a total of 417 bands. Based on analysis of molecular variance (AMOVA) and estimates of Nei's coefficients of gene diversity (H S, H T, and G ST), the majority of variation found in deciduous azalea occurs within populations. Variation both among species and among population was low, likely the effect of common ancestry as well as frequent introgression among members (and populations) of section Pentanthera. The latter was evident in four populations of R. prunifolium (Small) Millais and R. canescens (Michaux) Sweet that were highly related to R. austrinum (Small) Rehder and R. viscosum (L.) Torrey, respectively. Despite these outliers, most populations were grouped into species based on Nei's unbiased genetic distances viewed as an unweighted pair group method with arithmetic mean (UPGMA) phenogram. The significance of these results is discussed in relation to breeding in section Pentanthera.

scholarly journals Microsatellite Markers Developed from `Bluecrop' Reveal Polymorphisms in the Genus Vaccinium and Are Suitable for Cultivar Fingerprinting

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1122B-1122 ◽  
Author(s):  
Peter Boches ◽  
Lisa J. Rowland ◽  
Kim Hummer ◽  
Nahla V. Bassil
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Genetic Distance ◽  
Microsatellite Markers ◽  
Genetic Relationships ◽  
Distance Measures ◽  
Hybrid Origin ◽  
Pedigree Information ◽  
Species Relationships ◽  
Ssr Loci

Microsatellite markers for blueberry (Vaccinium L.) were created from a preexisting blueberry expressed sequence tag (EST) library of 1305 sequences and a microsatellite-enriched genomic library of 136 clones. Microsatellite primers for 65 EST-containing simple sequence repeats (SSRs) and 29 genomic SSR were initially tested for amplification and polymorphism on agarose gels. Potential usefulness of these SSRs for estimating species relationships in the genus was assessed through cross-species transference of 45 SSR loci and cluster analysis using genetic distance values from five highly polymorphic EST-SSR loci. Cross-species amplification for 45 SSR loci ranged from 17% to 100%, and was 83% on average in nine sections. Cluster analysis of 59 Vaccinium species based on genetic distance measures obtained from 5 EST-SSR loci supported the concept of V. elliotii Chapm. as a genetically distinct diploid highbush species and indicated that V. ashei Reade is of hybrid origin. Twenty EST-SSR and 10 genomic microsatellite loci were used to determine genetic diversity in 72 tetraploid V. corymbosum L. accessions consisting mostly of common cultivars. Unique fingerprints were obtained for all accessions analyzed. Genetic relationships, based on microsatellites, corresponded well with known pedigree information. Most modern cultivars clustered closely together, but southern highbush and northern highbush cultivars were sufficiently differentiated to form distinct clusters. Future use of microsatellites in Vaccinium will help resolve species relationships in the genus, estimate genetic diversity in the National Clonal Germplasm Repository (NCGR) collection, and confirm the identity of clonal germplasm accessions.

scholarly journals Genetic Variation and Virulence on Lr26 in Puccinia triticina

2004 ◽  
Vol 94 (6) ◽  
pp. 632-640 ◽  
Author(s):  
E. Kosman ◽  
E. Pardes ◽  
Y. Anikster ◽  
J. Manisterski ◽  
P. Ben. Yehuda ◽  
...  
Keyword(s):  
United States ◽  
Cluster Analysis ◽  
Genetic Variation ◽  
Molecular Markers ◽  
Geographical Origin ◽  
Genetic Relationships ◽  
Random Amplified Polymorphic Dna ◽  
Puccinia Triticina ◽  
The United States ◽  
Virulence Phenotype

The genetic relationships between isolates of Puccinia triticina virulent on wheat with the Lr26 resistance gene were studied. The diversity within and between isolates of P. triticina from Israel, Europe, and the United States was determined by virulence on near-isogenic Thatcher lines and by random amplified polymorphic DNA. According to the molecular markers, isolates that were virulent on Lr26 had diversity levels similar to those of Lr26 nonpathogenic isolates. Distances between subpopulations of isolates virulent and avirulent on Lr26 varied and were unrelated to the Lr26 virulence phenotype. Cluster analysis suggested four groups, three of which were closely associated with the geographical origin of the isolates—Israel, the United States, and Europe. All four groups included both Lr26 virulent and avirulent pathotypes. The results showed that Lr26 virulent rust pathotypes are as genetically dissimilar as the rest of the population. The cluster analysis showed that the rust population in Israel includes at least two different subpopulations, both of which contain Lr26 virulent and Lr26 avirulent isolates.

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