scholarly journals Population genetic structure of yellow starthistle (Centaurea solstitialis), a colonizing weed in the western United States

1997 ◽  
Vol 75 (9) ◽  
pp. 1470-1478 ◽  
Author(s):  
Mei Sun
Keyword(s):  
United States ◽  
Genetic Structure ◽  
Population Genetic ◽  
Gene Diversity ◽  
Polymorphic Locus ◽  
Allozyme Variation ◽  
Western United States ◽  
Centaurea Solstitialis ◽  
Yellow Starthistle ◽  
Marginal Population

Yellow starthistle (Centaurea solstitialis L.), a diploid annual native to the Mediterranean region, has rapidly colonized a variety of disturbed habitats in the western United States since its accidental introduction in the mid-19th century. Population genetic attributes were investigated in association with the species' colonizing success. Allozyme electrophoretic surveys were conducted for a total of 22 populations from California, Washington, and Idaho, including the southern and northern extremes of its distribution in the Pacific states. High levels of allozyme variation exist within populations, on average 43% of loci were polymorphic, with 2.88 alleles, a heterozygosity of 0.38, and gene diversity of 0.35 per polymorphic locus. At the species level, 56% of loci were polymorphic, with 2.85 alleles per locus, and the total gene diversity was 0.172. With the exception of a marginal population San Diego, the level of genetic diversity was similarly high in all regions. Lack of interpopulation genetic divergence (GST = 0.095) suggests that majority of the colonial populations were founded by a large number of genotypes and that high levels of gene flow may exist between local populations (Nm = 2.38). Information on genetic structure of the weed populations may aid our understanding of the species' colonizing ability in North America and is important for predicting the effectiveness of biological control program. Key words: allozyme variation, Centaurea solstitialis, population genetics, weed colonization, yellow starthistle.

Distribution of Yellow Starthistle (Centaurea solstitialis) and Russian Knapweed (Centaurea repens)

Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 315-327 ◽  
Author(s):  
Donald M. Maddox ◽  
Aubrey Mayfield ◽  
Noah H. Poritz
Keyword(s):  
United States ◽  
The United States ◽  
Economic Importance ◽  
Western United States ◽  
Centaurea Solstitialis ◽  
Yellow Starthistle ◽  
Russian Knapweed ◽  
Centaurea Repens ◽  
The World ◽  
Made In

The world distributions of yellow starthistle (Centaurea solstitialis L. ♯ CENSO) and Russian knapweed (Centaurea repens L. ♯ CENRE) are mapped based on information from world regional floras. A survey of weed specialists and herbaria was made in the United States, and the extent of the infestations and economic importance of these weeds was determined for the 48 contiguous states. Yellow starthistle currently occurs in 209 counties in 23 states and has apparently increased in abundance since 1970. Russian knapweed was reported in 412 counties in 21 states and does not seem to be spreading. Both of these weedy plant species are of greater economic importance in the western United States than in the east.

scholarly journals Factors Affecting Infection of Yellow Starthistle (Centaurea solstitialis) by Synchytrium solstitiale, Causal Agent of False Rust Disease

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 425-428 ◽  
Author(s):  
T. L. Widmer ◽  
F. Guermache
Keyword(s):  
United States ◽  
Classical Biological Control ◽  
The United States ◽  
Carthamus Tinctorius ◽  
Centaurea Solstitialis ◽  
Yellow Starthistle ◽  
Rust Disease ◽  
Invasive Weed ◽  
Factors Affecting ◽  
Centaurea Calcitrapa

Yellow starthistle (Centaurea solstitialis) is an annual invasive weed in the United States with Mediterranean origins. The expense of chemical control and the vast area of invasion make this weed an appropriate target for classical biological control. Observations of a field site in southern France revealed small orange galls on the leaves of yellow starthistle seedlings caused by the fungus Synchytrium solstitiale. Inoculation of yellow starthistle seedlings with a suspension of zoospores released from infected tissue resulted in infection. Ten days after inoculation, typical orange galls appeared on the exposed tissue. Preliminary host range testing showed up to 100% infection of C. solstitialis seedlings from both France and the United States and infection of Carthamus tinctorius, Centaurea americana, C. diffusa, C. rothrockii, C. squarrosa, and Helianthus annuus seedlings. No symptoms were observed on seedlings of Centaurea calcitrapa, C. maculosa, C. sulfurea, Cirsium californica, C. occidentale, Cynera cardunculus, and Taraxacum officinale. Zoospores were released in a pH range between 4.45 and 8.25 and optimally at temperatures between 5 and 15°C. Infection of yellow starthistle seedlings occurred after a minimum 1-h exposure to a zoospore suspension at 20°C.

Population genetic structure in duckweed (Lemna minor, Lemnaceae)

1996 ◽  
Vol 74 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Christopher T. Cole ◽  
Martin I. Voskuil
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic ◽  
Lemna Minor ◽  
Vegetative Reproduction ◽  
Low Frequency ◽  
Morphological Differentiation ◽  
Genotypic Diversity ◽  
Allozyme Variation ◽  
Low Levels

Allozyme variation in 11 Minnesota populations of Lemna minor L. was studied, using 11 enzyme systems, resolving 16 putative loci from 285 plants. Significant deviations from Hardy–Weinberg frequencies occurred in several populations that had excesses of heterozygotes at several loci. While genotypic diversity and evenness measures are similar to other vegetatively reproducing plants (D = 0.541, E = 0.607), very few multilocus genotypes per population were found (mean = 4.0). Substantial population structure was evident (FST = 0.407), apparently reflecting low levels of gene flow (Nm = 0.30) despite the capacity of this species for dispersal of plantlets. This low level of gene flow and apparent low frequency of sexual reproduction has produced substantial levels of genetic divergence among populations, despite an absence of morphological differentiation. Keywords: allozymes, genetic structure, hydrophily, Lemna, vegetative dispersal, vegetative reproduction.

scholarly journals Diverging Genetic Structure of Coexisting Populations of the Black Storm-Petrel and the Least Storm-Petrel in the Gulf of California

2020 ◽  
Vol 13 ◽  
pp. 194008292094917
Author(s):  
Misael D. Mancilla-Morales ◽  
Santiago Romero-Fernández ◽  
Araceli Contreras-Rodríguez ◽  
José J. Flores-Martínez ◽  
Víctor Sánchez-Cordero ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Mate Selection ◽  
Gulf Of California ◽  
Population Genetic ◽  
Life Histories ◽  
Gene Diversity ◽  
Isolation By Distance ◽  
Storm Petrel

Estimations on the influence of evolutionary and ecological forces as drivers of population gene diversity and genetic structure have been performed on a growing number of colonial seabirds, but many remain poorly studied. In particular, the population genetic structure of storm-petrels (Hydrobatidae) has been evaluated in only a few of the 24 recognized species. We assessed the genetic diversity and population structure of the Black Storm-Petrel ( Hydrobates melania) and the Least Storm-Petrel ( Hydrobates microsoma) in the Gulf of California. The two species were selected because they are pelagic seabirds with comparable ecological traits and breeding grounds. Recent threats such as introduced species of predators and human disturbance have resulted in a decline of many insular vertebrate populations in this region and affected many different aspects of their life histories (ranging from reproductive success to mate selection), with a concomitant loss of genetic diversity. To elucidate to what extent the population genetic structure occurs in H. melania and H. microsoma, we used 719 base pairs from the mitochondrial cytochrome oxidase c subunit I gene. The evaluation of their molecular diversity, genetic structure, and gene flow were performed through diversity indices, analyses of molecular and spatial variance, and isolation by distance (IBD) across sampling sites, respectively. The population genetic structure (via AMOVA and SAMOVA) and isolation by distance (pairwise p-distances and FST/1– FST (using ΦST) were inferred for H. microsoma. However, for H. melania evidence was inconclusive. We discuss explanations leading to divergent population genetic structure signatures in these species, and the consequences for their conservation.

scholarly journals Population structure of Opisthorchis felineus (Trematoda) and its second intermediate hosts — cyprinid fishes in the Ob-Irtysh focus of opisthorchiasis, based on allozyme data

2014 ◽  
Vol 51 (4) ◽  
pp. 309-317 ◽  
Author(s):  
O. Zhigileva ◽  
V. Ozhireľev ◽  
T. Stepanova ◽  
T. Moiseenko
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Allozyme Variation ◽  
Intermediate Hosts ◽  
Opisthorchis Felineus ◽  
Cyprinid Fishes ◽  
Low Levels

AbstractGenetic variability of West Siberian populations of Opisthorchis felineus and two species of cyprinid fish, its second intermediate hosts, was studied by isozyme analysis. Low levels of allozyme variation and genetic differentiation in O. felineus from the Ob-Irtysh focus of opisthorchiasis were detected. The proportion of polymorphic loci was 21.1 %, the average observed heterozygosity (Hobs) was 0.008, and expected heterozygosity (Hexp) was 0.052. For most loci in O. felineus deficit of heterozygotes (FIS = 0.7424) was observed. A comparison of population genetic structure of fish and parasites showed they were not congruent. Estimates of genetic differentiation of the parasite were smaller than for the fish — its intermediate host. Migration and population structure of the second intermediate hosts do not play an important role in formation of the population-genetic structure of O. felineus in the Ob-Irtysh focus of opisthorchiasis.

scholarly journals Phylogeography and population genetics of a widespread cold-adapted ant, Prenolepis imparis

2021 ◽  
Author(s):  
Maria Tonione ◽  
Ke Bi ◽  
Rob Dunn ◽  
Andrea Lucky ◽  
Neil Tsutsui
Keyword(s):  
United States ◽  
Gene Flow ◽  
Population Genetic ◽  
Late Quaternary ◽  
Western United States ◽  
Glacial Cycles ◽  
Cold Adapted ◽  
Contemporary Gene Flow ◽  
Demographic Patterns

Historical climate fluctuations have left genetic signatures on species and populations across North America. Here, we used phylogenetic and population genetic analyses from 1,402 orthologous sequences of 75 individuals obtained through sequencing of Ultraconserved Elements (UCEs) to identify population genetic structure and historical demographic patterns across the range of a widespread, cold-adapted ant, the winter ant, Prenolepis imparis. We relate the genomic patterns to those expected as a result of in situ diversification, maintained connectivity, or recent migration. We recovered five well-supported, genetically isolated clades across the distribution: 1) a basal lineage located in Florida, 2) populations across the southern United States, 3) populations that span the midwestern and northeastern United States, 4) populations from the western United States, and 5) populations in southwestern Arizona and Mexico. Using Bayesian clustering analysis in STRUCTURE and k-means clustering in ADEGENET, we investigated gene flow between these major genetic clades and did not find evidence of gene flow between clades. We did find evidence of localized structure with migration in the western United States clade. High support for five major geographic lineages and lack of evidence of contemporary gene flow indicate in situ diversification across the species’ range, probably influenced by glacial cycles of the late Quaternary.

Genetic variation in Armeria maritima in Iceland

Polar Record ◽  
2002 ◽  
Vol 38 (206) ◽  
pp. 219-224
Author(s):  
Marianne Philipp
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Gene Diversity ◽  
The Self ◽  
Self Incompatibility ◽  
Rare Alleles ◽  
Incompatibility System ◽  
Armeria Maritima

AbstractA comparison of the population genetic structure of Armeria maritima in Iceland with an earlier study in Denmark was undertaken. Ten populations were sampled in Iceland for isozyme analysis. Most populations showed Hardy-Weinberg proportions, but a higher number than statistically expected possessed too many homozygotes. This could indicate a breakdown of the self-incompatibility system in some cases. Statistically significant differences in allelic frequencies among populations were observed but no positive correlation between genetic distance and geographic position was found. Gene diversity in Iceland was lower than in Denmark although the alleles occurring in Iceland were the same as those found in Denmark. Missing alleles were those found with lowest frequency in Denmark. It is suggested that A. maritima in Iceland has immigrated from the southern part of the distribution post-glacially, leaving behind the rare alleles.

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