Population structure, fecundity and morphological characteristics of M. vollenhovenii (Herklots, 1857) on lower volta river basin channel, Ghana

Abstract Background Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances (Missouri, Iowa, Washington, Louisiana, and Tennessee (USA), and Quebec in Canada) of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) per locus ranged from 0.070 to 0.905, and the average polymorphic information content (PIC) was 0.535. The provenance ‘Was’ had a relatively low genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon’s information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931, respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, individuals distributed in the Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a small gene flow and high degree of genetic differentiation compared with the other provenances, and was classified into one group. There was a significant relationship between genetic distance and geographical distance. Conclusions P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals. Individuals reflecting population genetic information can be selected to build a core germplasm bank. Meanwhile, the results could provide theoretical support for the scientific management and efficient utilization of P. deltoides genetic resources, and promote the development of molecular marker-assisted breeding of poplar.

Download Full-text

Ancestry, population structure, and conservation genetics of Arctic grayling (Thymallus arcticus) in the upper Missouri River, USA

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f09-113 ◽

2009 ◽

Vol 66 (10) ◽

pp. 1758-1774 ◽

Cited By ~ 14

Author(s):

Douglas P. Peterson ◽

William R. Ardren

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

River Basin ◽

Genetic Relationships ◽

Missouri River ◽

Arctic Grayling ◽

Headwater Lakes ◽

Native Populations ◽

Thymallus Arcticus ◽

Two Populations

We genotyped Arctic grayling ( Thymallus arcticus ) at 10 microsatellite loci in 18 samples (n = 726) from Montana, Wyoming, and Saskatchewan to determine genetic relationships among native, captive, and naturalized populations in the upper Missouri River basin, to assess patterns in genetic diversity, and to infer recent demographic histories. Substantial genetic subdivision was observed among sample populations (global FST = 0.10). Canadian populations have been isolated from Missouri River populations long enough for mutation to cause genetic differences between regions (mean pairwise FST = 0.18, RST = 0.54). Within the Missouri River basin, most naturalized lacustrine populations traced their ancestry to Red Rock lakes. Two populations in headwater lakes within the Big Hole River watershed appear to be native. We found neither evidence for introgression of Canadian-origin grayling nor any effect of hatchery stocking in native populations. The native fluvial Big Hole River group was genetically distinct and most diverse (HE = 0.89), whereas native Madison River and Red Rock lakes populations exhibited lower genetic diversity (HE = 0.74 and 0.80, respectively) and evidence of recent bottlenecks. The existing Big Hole and Red Rock populations are at low abundance but do not appear to be at immediate risk of inbreeding depression (Ne = 207.7–228.2).

Download Full-text

High-Level Genetic Diversity but No Population Structure Inferred from Nuclear and Mitochondrial Markers of the Peritrichous Ciliate Carchesium polypinum in the Grand River Basin (North America)

Applied and Environmental Microbiology ◽

10.1128/aem.00178-09 ◽

2009 ◽

Vol 75 (10) ◽

pp. 3187-3195 ◽

Cited By ~ 28

Author(s):

E. Gentekaki ◽

D. H. Lynn

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Genetic Variation ◽

River Basin ◽

Large Subunit ◽

Population Level ◽

Nuclear Markers ◽

Mitochondrial Markers ◽

Intraspecific Genetic Variation ◽

Grand River

ABSTRACT Studies that assess intraspecific genetic variation in ciliates are few and quite recent. Consequently, knowledge of the subject and understanding of the processes that underlie it are limited. We sought to assess the degree of intraspecific genetic variation in Carchesium polypinum (Ciliophora: Peritrichia), a cosmopolitan, freshwater ciliate. We isolated colonies of C. polypinum from locations in the Grand River basin in Southwestern Ontario, Canada. We then used the nuclear markers—ITS1, ITS2, and the hypervariable regions of the large subunit rRNA—and an 819-bp fragment of the mitochondrial cytochrome c oxidase I gene (cox-1) to investigate the intraspecific genetic variation of C. polypinum and the degree of resolution of the above-mentioned markers at the population level. We also sought to determine whether the organism demonstrated any population structure that mapped onto the geography of the region. Our study shows that there is a high degree of genetic diversity at the isolate level, revealed by the mitochondrial markers but not the nuclear markers. Furthermore, our results indicate that C. polypinum is likely not a single morphospecies as previously thought.

Download Full-text

Population Structure in the Roundtail Chub (Gila robusta Complex) of the Gila River Basin as Determined by Microsatellites: Evolutionary and Conservation Implications

PLoS ONE ◽

10.1371/journal.pone.0139832 ◽

2015 ◽

Vol 10 (10) ◽

pp. e0139832 ◽

Cited By ~ 6

Author(s):

Thomas E. Dowling ◽

Corey D. Anderson ◽

Paul C. Marsh ◽

Michael S. Rosenberg

Keyword(s):

Population Structure ◽

River Basin ◽

Gila River ◽

Conservation Implications ◽

Roundtail Chub

Download Full-text

Fauna and population structure of springtails (Hexapoda, Collembola) in zonal forest-steppe biotopes of the Middle Volga River basin

Entomological Review ◽

10.1134/s0013873810040056 ◽

2010 ◽

Vol 90 (4) ◽

pp. 441-458

Author(s):

Yu. B. Shveenkova

Keyword(s):

Population Structure ◽

River Basin ◽

Forest Steppe ◽

Volga River ◽

Volga River Basin ◽

Middle Volga

Download Full-text

Population structure and reproductive biology of Astyanax gymnodontus (Characiformes: Characidae), a poorly known endemic fish of the Iguaçu River basin, Brazil

Revista de Biología Tropical ◽

10.15517/rbt.v64i1.18100 ◽

2016 ◽

Vol 64 (1) ◽

pp. 69 ◽

Cited By ~ 2

Author(s):

Matheus Tenorio Baumgartner ◽

Pedro Rogério Leandro da Silva ◽

Gilmar Baumgartner

Keyword(s):

Population Structure ◽

Sex Ratio ◽

River Basin ◽

Reproductive Biology ◽

Body Length ◽

Fish Species ◽

Energy Allocation ◽

Influence Area ◽

Endemic Fish ◽

Iguaçu River

Success in fish breeding depends on reproduction intensity, periodicity and the place where it occurs. Information about fish species reproduction is important to assist managers, and to determine conservation and management strategies. The fish assemblage of the Iguaçu River basin is already known for its high endemism, and despite this privilege, the large number of dams built along it, threat this particular biodiversity. Astyanax gymnodontus is an endemic fish species and studies on its population structure and reproductive biology are important, since they represent the first step for further community studies. Our objective was to evaluate some aspects of the population structure and reproductive biology of A. gymnodontus in the influence area of Salto Santiago dam, Iguaçu River, Paraná State, Brazil. Sampling was made monthly from July 2003 to June 2005, and bimonthly from July 2005 to March 2013, at five sites in the influence area of Salto Santiago dam. Fishes were collected using 10 m length gillnets with meshes ranging from 2.5 to 6.0 cm between non-adjacent knots and trammel nets with inner meshes of 6.0 cm between non-adjacent knots. Nets were arranged on surface, bottom and margins of each site, exposed for 24 h. Additional drags on littoral areas were performed from January to March and October to December from 2009 to 2011, with 50.0 m nets, 0.5 cm mesh size, for juveniles capture. We captured and analyzed 21 932 individuals, being 9 249 females and 12 683 males, representing 42.2 % and 57.8 %, respectively. The average body length was 8.8 cm for females and 8.3 cm for males. The average weight was 18.8 g for females and 16.0 g for males. Sex ratio calculated for the entire period was 1.8 males/female. Males were more abundant than females in 73.2 % of samples and significant differences were observed in 35.3 % of samples. The estimated length at first maturity (SL50) was 6.4 cm for females and 6.2 cm for males. We suggest that sexual differences in body length and weight, and sex ratio occurred as a result of sexual differences in energy allocation. Females spend more energy on body growth, which means more eggs production and higher fecundity. As an integrated response, males spend more energy on sperm production, in competition with other males, leading to a smaller body size. Differences in estimated SL50 might be an indicator of this sexual difference in energy allocation. The reproduction period was from September to February, with greater intensity at the beginning of this period, and the sites of highest reproductive intensity were those immediate downstream from dams, and therefore with more riverine characteristics.

Download Full-text

Cambarus franklini, a new crayfish (Decapoda: Cambaridae) from the Catawba River Basin in western North Carolina, USA

Zootaxa ◽

10.11646/zootaxa.4568.3.6 ◽

2019 ◽

Vol 4568 (3) ◽

pp. 520

Author(s):

MICHAEL A. PERKINS ◽

BRONWYN W. WILLIAMS ◽

WILLIAM T. RUSS

Keyword(s):

North Carolina ◽

River Basin ◽

Morphological Characteristics ◽

Species Group ◽

The South ◽

Double Row ◽

Western North Carolina ◽

Upper South ◽

C Complex ◽

A New Species

A new species of stream-dwelling crayfish, Cambarus franklini, the South Mountains crayfish, is described from the upper South Fork Catawba River basin in western North Carolina, USA using morphological and genetic data. Cambarus franklini was previously considered a member of the widespread and morphologically variable Cambarus species C complex and is morphologically most similar to an undiagnosed member of the group native to the upper Catawba River basin in NC. Cambarus franklini can be differentiated from this species group by several morphological characteristics including: lacking a well-defined double row of tubercles along the mesial margin of the palm, possessing a more weakly convergent and longer acumen, and conspicuous blue-green and red coloration, particularly throughout the telson and along the distal margins of the rami. This species is phylogenetically most similar to Cambarus johni, Cooper, 2006, another former member of the Cambarus species C group. Cambarus franklini has a limited geographic range (<100 km2) and is currently known only from the Henry and Jacob Fork watersheds in the South Mountains region of the Eastern Blue Ridge foothills.

Download Full-text