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 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 The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus)

2021 ◽  
Vol 15 (2) ◽  
pp. e0009139
Author(s):  
Maria Angenica F. Regilme ◽  
Thaddeus M. Carvajal ◽  
Ann–Christin Honnen ◽  
Divina M. Amalin ◽  
Kozo Watanabe
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Aedes Aegypti ◽  
Spatial Scale ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Mosquito Control ◽  
Genetic Admixture ◽  
Fine Spatial Scale ◽  
The Road

Dengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 359 adults and 17 larvae Ae. aegypti were collected from June to September 2017 in 13 sites across EB. North (N1-N8) and South (S1-S5) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 3 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.

scholarly journals Microgeographic Population Genetic Structure of Baylisascaris procyonis (Nematoda: Ascaroidae) in Western Michigan Indicates the Grand River Is a Barrier to Gene Flow

2015 ◽  
Vol 101 (6) ◽  
pp. 671 ◽  
Author(s):  
Christina A. Sarkissian ◽  
Sara K. Campbell ◽  
Guha Dharmarajan ◽  
Joseph Jacquot ◽  
L. Kristen Page ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Baylisascaris Procyonis ◽  
Grand River

scholarly journals Population Genetic Structure of Rhizoctonia oryzae-sativae from Rice in Latin America and Its Adaptive Potential to Emerge as a Pathogen on Urochloa Pastures

2017 ◽  
Vol 107 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Danilo A. dos Santos Pereira ◽  
Paulo C. Ceresini ◽  
Vanina L. Castroagudín ◽  
Lina M. Ramos-Molina ◽  
Edisson Chavarro-Mesa ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Reproductive System ◽  
Population Genetic ◽  
Upland Rice ◽  
Adaptive Potential ◽  
Rhizoctonia Oryzae ◽  
Hardy Weinberg Equilibrium ◽  
Two Populations ◽  
Brazilian Populations

The fungus Rhizoctonia oryzae-sativae is an important pathogen that causes the aggregated sheath spot disease on rice. In this study, we investigated the genetic structure of rice-adapted populations of R. oryzae-sativae sampled from traditional rice-cropping areas from the Paraíba Valley, São Paulo, Brazil, and from Meta, in the Colombian Llanos, in South America. We used five microsatellite loci to measure population differentiation and infer the pathogen’s reproductive system. Gene flow was detected among the three populations of R. oryzae-sativae from lowland rice in Brazil and Colombia. In contrast, a lack of gene flow was observed between the lowland and the upland rice populations of the pathogen. Evidence of sexual reproduction including low clonality, Hardy-Weinberg equilibrium within loci and gametic equilibrium between loci, indicated the predominance of a mixed reproductive system in all populations. In addition, we assessed the adaptive potential of the Brazilian populations of R. oryzae-sativae to emerge as a pathogen to Urochloa spp. (signalgrass) based on greenhouse aggressiveness assays. The Brazilian populations of R. oryzae-sativae were probably only incipiently adapted as a pathogen to Urochloa spp. Comparison between RST and QST showed the predominance of diversifying selection in the divergence between the two populations of R. oryzae-sativae from Brazil.

scholarly journals Absence of Population Genetic Structure Among Breeding Colonies of the Waved Albatross

The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 440-445 ◽  
Author(s):  
Kathryn P. Huyvaert ◽  
Patricia G. Parker
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Breeding Population ◽  
Genetic Structuring ◽  
Galapagos Archipelago ◽  
Phoebastria Irrorata ◽  
Waved Albatrosses

Abstract We used four variable microsatellite loci to examine the distribution of genetic variation and degree of genetic structuring among three subcolonies of Waved Albatrosses (Phoebastria irrorata). The breeding population of this species is almost entirely limited to the island of Española in the Galápagos Archipelago. Such strong philopatry could lead to population genetic structure among subcolonies on the island. Pairwise values of the FST analog, θ, calculated from microsatellite genotypes, were all less than 0.012, indicating little genetic differentiation and the presence of gene flow throughout the population.

Population genetic structure inMyrtus communisL. in a chronically fragmented landscape in the Mediterranean: can gene flow counteract habitat perturbation?

Plant Biology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 442-453 ◽  
Author(s):  
R. G. Albaladejo ◽  
L. F. Carrillo ◽  
A. Aparicio ◽  
J. F. Fernández-Manjarrés ◽  
J. P. González-Varo
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Fragmented Landscape ◽  
The Mediterranean
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