Genetic differentiation over a small spatial scale in the smooth newt (Lissotriton vulgaris)

2021 ◽  
pp. 61-69
Author(s):  
Zoltan Toth
Keyword(s):  
Genetic Variation ◽  
Spatial Scale ◽  
Population Biology ◽  
Breeding Habitat ◽  
Dispersal Ability ◽  
Small Spatial Scale ◽  
Genetic Population ◽  
Lissotriton Vulgaris ◽  
Natural Breeding ◽  
Allelic Differentiation

Understanding the distribution of genetic variation is central for both population biology and conservation genetics. Genetic population structure can be primarily affected by the species’ dispersal ability, which is assumed to be limited in many amphibians. In this study, we estimated allelic differentiation metrics and FST indices to investigate genetic variation among natural breeding ponds of smooth newts (Lissotriton vulgaris) over a small spatial scale. Based on six microsatellite loci, we found a small, but significant allelic differentiation among clusters of natural breeding ponds (i.e. ‘local regions’), which result was in line with the calculation of corresponding hierarchical FST values. Analysis of molecular variance also indicated significant between-region variation in the study area. Pairwise estimations showed that only the furthermost regions differed from each other in both differentiation measures, but this difference was not attributable to geographic distances between ponds. Our results provide evidence that hierarchical genetic structure can be characteristic to breeding ponds of smooth newts on a small spatial scale in their natural breeding habitat, but dispersal distance may be less limited than previously thought in these philopatric caudates.

scholarly journals Patterns of plant invasions at small spatial scale correspond with that at the whole country scale

2016 ◽  
Vol 19 (2) ◽  
pp. 983-998 ◽  
Author(s):  
Marcin K. Dyderski ◽  
Andrzej M. Jagodziński
Keyword(s):  
Spatial Scale ◽  
Plant Invasions ◽  
Small Spatial Scale

scholarly journals Determining Whether Geographic Origin and Potato Genotypes Shape the Population Structure of Phytophthora infestans in the Central Region of Colombia

2019 ◽  
Vol 109 (1) ◽  
pp. 145-154
Author(s):  
Sandra Catalina Chaves ◽  
María Camila Rodríguez ◽  
María Fernanda Mideros ◽  
Florencia Lucca ◽  
Carlos E. Ñústez ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Phytophthora Infestans ◽  
Central Region ◽  
Geographic Origin ◽  
Geographic Area ◽  
Potato Cultivars ◽  
Clonal Lineage ◽  
Host Genotype ◽  
Genetic Population

Pathogen variation plays an important role in the dynamics of infectious diseases. In this study, the genetic variation of 279 Phytophthora infestans isolates was assessed using a combination of 12 microsatellite simple-sequence repeat markers. Isolates were collected from 11 different potato cultivars in 11 different geographic localities of the central region of Colombia. The objective of this study was to determine whether populations were differentiated by host genotype or geographic origin. Within a single clonal lineage, EC-1, 76 genotypes were detected. An analysis of molecular variance attributed most of the variation to differences within host genotypes rather than among the host genotypes, suggesting that host cultivars do not structure the populations of the pathogen. Furthermore, the lack of a genetic population structure according to the host cultivar was confirmed by all of the analyses, including the Bayesian clustering analysis and the minimum spanning network that used the Bruvo genetic distance, which suggested that there are no significant barriers to gene flow for P. infestans among potato cultivars. According to the geographic origin, the populations of P. infestans were also not structured, and most of the variation among the isolates was attributed to differences within localities. Only some but not all localities in the north and west of the central region of Colombia showed some genetic differentiation from the other regions. The absence of sexual reproduction of this pathogen in Colombia was also demonstrated. Important insights are discussed regarding the genetic population dynamics of the P. infestans populations of the central region of Colombia that were provided by the results. In Colombia, there is a high genetic variation within the EC-1 clonal lineage with closely related genotypes, none dominant, that coexist in a wide geographic area and on several potato cultivars.

scholarly journals Seasonality and Small Spatial-Scale Variation of Chlorophyll a Fluorescence in Bryophyte Syntrichia ruralis [Hedw.] in Semi-Arid Sandy Grassland, Hungary

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 92 ◽  
Author(s):  
Ruchika ◽  
Zsolt Csintalan ◽  
Evelin Ramóna Péli
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quenching ◽  
Spatial Scale ◽  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Small Spatial Scale ◽  
Variation Trend ◽  
Fluorescence Parameters ◽  
Semi Arid ◽  
Sandy Grassland

Bryophytes face challenges due to global climate change which is leading to in-depth research in monitoring and studying their photosynthetic activity. The aim of this preliminary experiment was to study the seasonal variation trend in the chlorophyll a fluorescence parameters, Fv/Fm (ratio of variable to maximum fluorescence), photochemical fluorescence quenching (qP), photochemical quantum yield of photosystem II (ΦPS II), fluorescence quenching (qN), and non-photochemical quenching (NPQ), in the moss cushions of Syntrichia ruralis [Hedw.] collected from semi-arid sandy dunes for two slopes i.e., north-east (NE) and south-west (SW) direction. Our results showed a seasonal and small-spatial scale variation trend in all chlorophyll fluorescence parameters. These variations are due to different seasonal conditions referring to different degrees of environmental stress. ΦPS II and qP values were maximum in winter and in spring seasons while Fv/Fm, NPQ and qN were maximum in summer. Based on the different exposition of dunes, the SW slope showed increased values of the effective quantum yield of PS II and qP in comparison to the NE slope due to the optimal microclimate conditions for their expansion. These results may refer to the future changing in diversification and coverage of the Syntrichia species in semi-arid sandy grassland due to more effective metabolism in the beneficial microclimatic conditions.

scholarly journals In-situ severe breeding habitat intervention only achieves temporary success in reducing Batrachochytrium dendrobatidis infection

2020 ◽  
Vol 41 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Andrés Fernández-Loras ◽  
Luz Boyero ◽  
Jaime Bosch
Keyword(s):  
Batrachochytrium Dendrobatidis ◽  
Research Effort ◽  
Breeding Habitat ◽  
Habitat Manipulation ◽  
Breeding Sites ◽  
Breeding Habitats ◽  
The Common ◽  
Natural Breeding ◽  
Midwife Toad

Abstract Chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), is causing sharp declines in amphibian populations around the globe. A substantial research effort has been made to study the disease, including treatments against Bd, but most treatments have been applied to captive amphibians only. We report a study aimed at clearing wild populations of the Common Midwife toad Alytes obstetricans. We removed all larvae from natural breeding sites (cattle troughs) and conducted two types of severe breeding habitat manipulation (complete drying and fencing for the whole breeding season). While larval removal followed by drying was a successful method of Bd elimination, the effect was only temporary. Since terrestrial habits of adult A. obstetricans prevent them from infection, our findings suggest that, even in simple breeding habitats where all aquatic amphibian stages can be handled and extreme habitat intervention is possible, Bd cannot be eliminated without controlling other potential Bd reservoirs in the surroundings of breeding sites.

scholarly journals Population size, habitat fragmentation, and the nature of adaptive variation in a stream fish

2014 ◽  
Vol 281 (1790) ◽  
pp. 20140370 ◽  
Author(s):  
Dylan J. Fraser ◽  
Paul V. Debes ◽  
Louis Bernatchez ◽  
Jeffrey A. Hutchings
Keyword(s):  
Genetic Variation ◽  
Habitat Fragmentation ◽  
Population Size ◽  
Brook Trout ◽  
Small Populations ◽  
Adaptive Genetic Variation ◽  
Genetic Population ◽  
Fragmented Populations ◽  
Large Populations ◽  
Adaptive Differentiation

Whether and how habitat fragmentation and population size jointly affect adaptive genetic variation and adaptive population differentiation are largely unexplored. Owing to pronounced genetic drift, small, fragmented populations are thought to exhibit reduced adaptive genetic variation relative to large populations. Yet fragmentation is known to increase variability within and among habitats as population size decreases. Such variability might instead favour the maintenance of adaptive polymorphisms and/or generate more variability in adaptive differentiation at smaller population size. We investigated these alternative hypotheses by analysing coding-gene, single-nucleotide polymorphisms associated with different biological functions in fragmented brook trout populations of variable sizes. Putative adaptive differentiation was greater between small and large populations or among small populations than among large populations. These trends were stronger for genetic population size measures than demographic ones and were present despite pronounced drift in small populations. Our results suggest that fragmentation affects natural selection and that the changes elicited in the adaptive genetic composition and differentiation of fragmented populations vary with population size. By generating more variable evolutionary responses, the alteration of selective pressures during habitat fragmentation may affect future population persistence independently of, and perhaps long before, the effects of demographic and genetic stochasticity are manifest.

Gene flow maintains a large genetic difference in clutch size at a small spatial scale

Nature ◽  
2005 ◽  
Vol 433 (7021) ◽  
pp. 65-68 ◽  
Author(s):  
Erik Postma ◽  
Arie J. van Noordwijk
Keyword(s):  
Gene Flow ◽  
Spatial Scale ◽  
Clutch Size ◽  
Genetic Difference ◽  
Small Spatial Scale

Opposing selective pressures decouple pattern and process of parasitic infection over small spatial scale

Oikos ◽  
2015 ◽  
Vol 124 (11) ◽  
pp. 1511-1519 ◽  
Author(s):  
James E. Byers ◽  
Anna J. Malek ◽  
Lauren E. Quevillon ◽  
Irit Altman ◽  
Carolyn L. Keogh
Keyword(s):  
Spatial Scale ◽  
Parasitic Infection ◽  
Small Spatial Scale ◽  
Pattern And Process ◽  
Selective Pressures

Meiofauna constitute a considerable portion of invertebrate drift among moss-rich patches within a karst hydrosystem

Biologia ◽  
2014 ◽  
Vol 69 (3) ◽  
Author(s):  
Mirela Perić ◽  
Tvrtko Dražina ◽  
Maria Špoljar ◽  
Ines Radanović ◽  
Biserka Primc ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Spatial Scale ◽  
Early Summer ◽  
Small Scale ◽  
Invertebrate Drift ◽  
Flow Conditions ◽  
Small Spatial Scale ◽  
Minor Influence ◽  
Drift Density ◽  
A Minor

AbstractAiming to establish the most frequent invertebrate taxa in drift at the small spatial scale within a moss-rich karst tufa-precipitating hydrosystem, we sampled drift among microhabitats differing in substratum type and flow conditions along a tufa barrier-cascading lotic reach. Additionally, we addressed the question of the contribution and the potential significance of meiofauna within the overall invertebrate drift at the small spatial scale. During the study period, a total of 60 invertebrate taxa were recorded in the drift. Six of these taxa belonged to the annelid/arthropod meiofauna and they represented 35% of total drift density. Macroinvertebrates found in drift were represented mainly by larval insects. The composition of the most abundant taxa in total drift was as follows: Alona spp. (Cladocera 26.7%), Riolus spp. (Coleoptera: Elmidae 13.2%), Simulium spp. (Diptera: Simuliidae 12.2%), Enchytraeidae (Oligochaeta 10.4%), Hydrachnidia (6.3%), Orthocladinae (Diptera: Chironomidae 3.9%) and Naididae (Oligochaeta 3.6%). Faunal drift densities and amounts of transported particulate matter (PM) were highest at the fast-flowing sites located at the barriers and lowest at the slow-flowing sites within pools. Similarly to the seasonal amounts of transported PM, faunal drift was lowest in winter, and peaked in autumn and in late spring/early summer. Correlation between flow velocity and PM-faunal drift densities suggested a significant effect of the dislodged PM, though a minor influence of discharge and flow velocity on faunal drift. We suggest that the small-scale habitat heterogeneity and the respective feeding and refugial strategies of the fauna, as well as faunal passive dislodgement initiated by the shear forces of the flow were the most important drivers of observed drift patterns.

Genetic variation in a freshwater bryozoan: II: The effect of increasing spatial scale

2002 ◽  
Vol 154 (2) ◽  
pp. 293-309
Author(s):  
Tristan W. Hatton-Ellis ◽  
Andrew Hope ◽  
Leslie R. Noble ◽  
Beth Okamura
Keyword(s):  
Genetic Variation ◽  
Spatial Scale
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