Landscape genetic structure of Pinus banksiana: allozyme variation

2001 ◽  
Vol 79 (8) ◽  
pp. 871-878 ◽  
Author(s):  
Cuauhtemoc Saenz-Romero ◽  
Raymond P Guries ◽  
Andrew I Monk
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Pinus Banksiana ◽  
Allozyme Variation ◽  
Jack Pine ◽  
Genetic Distances ◽  
Jack Pine Forests ◽  
Forest Mosaic ◽  
Landscape Genetic

Many of Wisconsin's jack pine forests originated following fire or agricultural abandonment creating a forest mosaic fragmented by a history of disturbance and past land use. The extent and patterning of genetic diversity at a landscape scale (30 × 30 km) was investigated in 82 natural Pinus banksiana Lamb. (jack pine) stands in Wisconsin using 14 polymorphic allozymes. Most measures of genetic diversity and overall allelic frequencies varied little among these stands, and Reynolds' (coancestry) genetic distances were small (mean = 0.026). Genetic differentiation among stands was limited but significant ([Formula: see text]ST = 0.022). Gene flow (Nm) is extensive, estimated to be slightly more than 11 migrants per generation. Autocorrelation analysis provided evidence for a weak pattern of genetic structure at a few loci with a spatial scale of 8–15 km. However, when all loci were examined together the populations did not present a clear spatial pattern across the landscape, probably because of extensive gene flow among stands.Key words: jack pine, allozymes, genetic diversity, population differentiation, spatial autocorrelation, gene flow.

Landscape genetic structure of Pinus banksiana: allozyme variation

2001 ◽  
Vol 79 (8) ◽  
pp. 871-878 ◽  
Author(s):  
Cuauhtemoc Saenz-Romero ◽  
Raymond P. Guries ◽  
Andrew I. Monk
Keyword(s):  
Genetic Structure ◽  
Pinus Banksiana ◽  
Allozyme Variation ◽  
Landscape Genetic

scholarly journals Trade-Offs among Release Treatments in Jack Pine Plantations: Twenty-Five Year Responses

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 370
Author(s):  
Holly D. Deighton ◽  
Frederick Wayne Bell ◽  
Nelson Thiffault ◽  
Eric B. Searle ◽  
Mathew Leitch ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Boreal Forests ◽  
Pinus Banksiana ◽  
Vegetation Management ◽  
Jack Pine ◽  
Forest Diversity ◽  
Trade Offs ◽  
Jack Pine Forests ◽  
Stand Yield ◽  
Forest Managers

We assessed 27 indicators of plant diversity, stand yield and individual crop tree responses 25 years post-treatment to determine long-term trade-offs among conifer release treatments in boreal and sub-boreal forests. This research addresses the lack of longer-term data needed by forest managers to implement more integrated vegetation management programs, supporting more informed decisions about release treatment choice. Four treatments (untreated control, motor-manual brushsaw, single aerial spray, and complete competition removal) were established at two jack pine (Pinus banksiana Lamb.) sites in Ontario, Canada. Our results suggest that plant diversity and productivity in boreal jack pine forests are significantly influenced by vegetation management treatments. Overall, release treatments did not cause a loss of diversity but benefitted stand-scale yield and individual crop tree growth, with maximum benefits occurring in more intensive release treatments. However, none of the treatments maximized all 27 indicators studied; thus, forest managers are faced with trade-offs when choosing treatments. Research on longer term effects, ideally through at least one rotation, is essential to fully understand outcomes of different vegetation management on forest diversity, stand yield, and individual crop tree responses.

scholarly journals Population Genetic Structure and Habitat Connectivity for Jaguar (Panthera onca) Conservation in Central Belize.

2019 ◽  
Author(s):  
Angelica Menchaca ◽  
Natalia Rossi ◽  
Jeremy Froidevaux ◽  
Isabela Dias-freedman ◽  
Anthony Caragiulo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Genetic Connectivity ◽  
Suitable Habitat ◽  
Fine Scale ◽  
Panthera Onca ◽  
Wildlife Sanctuary ◽  
Landscape Permeability ◽  
Forest Reserve

Abstract Connectivity among jaguar (Panthera onca) populations will ensure natural gene flow and the long-term survival of the species throughout its range. Jaguar conservation efforts have focused primarily on connecting suitable habitat in a broad-scale. Accelerated habitat reduction, human-wildlife conflict, limited funding, and the complexity of jaguar behaviour have proven challenging to maintain connectivity between populations effectively. Here, we used non-invasive genetic sampling and individual-based conservation genetic analyses to assess genetic diversity and levels of genetic connectivity between individuals in the Cockscomb Basin Wildlife Sanctuary and the Maya Forest Corridor. We used expert knowledge and scientific literature to develop models of landscape permeability based on circuit theory with fine-scale landscape features as ecosystem types, distance to human settlements and roads to predict the most probable jaguar movement across central Belize. Results We used 12 highly polymorphic microsatellite loci to identify 50 individual jaguars. We detected high levels of genetic diversity across loci (HE= 0.61, HO= 0.55, and NA=9.33). Using Bayesian clustering and multivariate models to assess gene flow and genetic structure, we identified one single group of jaguars (K = 1). We identified critical areas for jaguar movement that fall outside the boundaries of current protected areas in central Belize. We detected two main areas of high landscape permeability in a stretch of approximately 18 km between Sittee River Forest Reserve and Manatee Forest Reserve that may increase functional connectivity and facilitate jaguar dispersal from and to Cockscomb Basin Wildlife Sanctuary. Our analysis provides important insights on fine-scale genetic and landscape connectivity of jaguars in central Belize, an area of conservation concern. Conclusions The results of our study demonstrate high levels of relatively recent gene flow for jaguars between two study sites in central Belize. Our landscape analysis detected corridors of expected jaguar movement between the Cockscomb Basin Wildlife Sanctuary and the Maya Forest Corridor. We highlight the importance of maintaining already established corridors and consolidating new areas that further promote jaguar movement across suitable habitat beyond the boundaries of currently protected areas. Continued conservation efforts within identified corridors will further maintain and increase genetic connectivity in central Belize.

scholarly journals Targeted Sequencing Suggests Wild-Crop Gene Flow Is Central to Different Genetic Consequences of Two Independent Pumpkin Domestications

2021 ◽  
Vol 9 ◽  
Author(s):  
Heather R. Kates ◽  
Fernando López Anido ◽  
Guillermo Sánchez-de la Vega ◽  
Luis E. Eguiarte ◽  
Pamela S. Soltis ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
Morphological Diversity ◽  
Cucurbita Maxima ◽  
Wild Progenitor ◽  
Breeding Potential ◽  
Trait Improvement ◽  
Wild Progenitors

Studies of domestication genetics enrich our understanding of how domestication shapes genetic and morphological diversity. We characterized patterns of genetic variation in two independently domesticated pumpkins and their wild progenitors to assess and compare genetic consequences of domestication. To compare genetic diversity pre- and post-domestication and to identify genes targeted by selection during domestication, we analyzed ∼15,000 SNPs of 48 unrelated accessions, including wild, landrace, and improved lines for each of two pumpkin species, Cucurbita argyrosperma and Cucurbita maxima. Genetic diversity relative to its wild progenitor was reduced in only one domesticated subspecies, C. argyrosperma ssp. argyrosperma. The two species have different patterns of genetic structure across domestication status. Only 1.5% of the domestication features identified for both species were shared between species. These findings suggest that ancestral genetic diversity, wild-crop gene flow, and domestication practices shaped the genetic diversity of two similar Cucurbita crops in different ways, adding to our understanding of how genetic diversity changes during the processes of domestication and how trait improvement impacts the breeding potential of modern crops.

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.

Intact genetic structure and high levels of genetic diversity in bottlenecked sockeye salmon (Oncorhynchus nerka) populations of the Fraser River, British Columbia, Canada

2000 ◽  
Vol 57 (10) ◽  
pp. 1985-1998 ◽  
Author(s):  
Ruth E Withler ◽  
Khai D Le ◽  
R John Nelson ◽  
Kristina M Miller ◽  
Terry D Beacham
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Allelic Diversity ◽  
Lower Proportion ◽  
Fraser River ◽  
Rare Alleles ◽  
Genetic Bottlenecks

Analysis of six microsatellite loci in 5800 sockeye salmon (Oncorhynchus nerka) from 29 Fraser River populations provided little evidence of genetic bottlenecks or mass straying in upper Fraser sockeye salmon resulting from reduced abundances following 1913-1914 rockslides in the Fraser canyon and successive decades of high exploitation. Upper Fraser populations were not characterized by a paucity of rare alleles, a sensitive indicator of populations in which effective size has been recently reduced. Heterozygosity and allelic diversity did not differ consistently between lower and upper Fraser populations. Throughout the watershed, early-migrating populations had lower allelic diversity and a lower proportion of rare alleles than did late-migrating ones. Genetic differentiation between upper and lower Fraser populations and heterogeneity among lower Fraser populations supported the suggestion that Fraser sockeye salmon are descendants of at least two postglacial "races." Variation among lakes within regions was the strongest component of genetic structure, accounting for five times the variation among populations within lakes and more than two times the variation among regions. Extensive historical transplants of eggs and juveniles apparently resulted in lit tle gene flow among regions, but three populations were reestablished or rebuilt as the result of more recent transplants.

scholarly journals Landscape genetic structure of Scirpus mariqueter reveals a putatively adaptive differentiation under strong gene flow in estuaries

2019 ◽  
Vol 9 (6) ◽  
pp. 3059-3074 ◽  
Author(s):  
Mei Yang ◽  
Chengyuan Xu ◽  
Pierre Duchesne ◽  
Qiang Ma ◽  
Ganqiang Yin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Scirpus Mariqueter ◽  
Landscape Genetic ◽  
Adaptive Differentiation

scholarly journals Genetic diversity and landscape genetic structure of otter (Lutra lutra) populations in Europe

2010 ◽  
Vol 11 (2) ◽  
pp. 583-599 ◽  
Author(s):  
Nadia Mucci ◽  
Johanna Arrendal ◽  
Hermann Ansorge ◽  
Michael Bailey ◽  
Michaela Bodner ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Lutra Lutra ◽  
Landscape Genetic

scholarly journals Spectrum of genetic diversity and networks of clonal organisms

2007 ◽  
Vol 4 (17) ◽  
pp. 1093-1102 ◽  
Author(s):  
Alejandro F Rozenfeld ◽  
Sophie Arnaud-Haond ◽  
Emilio Hernández-García ◽  
Víctor M Eguíluz ◽  
Manuel A Matías ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Genetic Structure ◽  
Small World ◽  
Clonal Plants ◽  
Posidonia Oceanica ◽  
Genetic Distances ◽  
Wide Range ◽  
Clonal Organisms ◽  
Genetic Structure And Diversity

Clonal reproduction characterizes a wide range of species including clonal plants in terrestrial and aquatic ecosystems, and clonal microbes such as bacteria and parasitic protozoa, with a key role in human health and ecosystem processes. Clonal organisms present a particular challenge in population genetics because, in addition to the possible existence of replicates of the same genotype in a given sample, some of the hypotheses and concepts underlying classical population genetics models are irreconcilable with clonality. The genetic structure and diversity of clonal populations were examined using a combination of new tools to analyse microsatellite data in the marine angiosperm Posidonia oceanica . These tools were based on examination of the frequency distribution of the genetic distance among ramets, termed the spectrum of genetic diversity (GDS), and of networks built on the basis of pairwise genetic distances among genets. Clonal growth and outcrossing are apparently dominant processes, whereas selfing and somatic mutations appear to be marginal, and the contribution of immigration seems to play a small role in adding genetic diversity to populations. The properties and topology of networks based on genetic distances showed a ‘small-world’ topology, characterized by a high degree of connectivity among nodes, and a substantial amount of substructure, revealing organization in subfamilies of closely related individuals. The combination of GDS and network tools proposed here helped in dissecting the influence of various evolutionary processes in shaping the intra-population genetic structure of the clonal organism investigated; these therefore represent promising analytical tools in population genetics.

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