scholarly journals Patterns of Fine-Scale Spatial Genetic Structure and Pollen Dispersal in Giant Sequoia (Sequoiadendron giganteum)

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Rainbow DeSilva ◽  
Richard S. Dodd
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Pollen Dispersal ◽  
Detailed Examination ◽  
Background Information ◽  
Long Distance ◽  
Giant Sequoia ◽  
Sequoiadendron Giganteum

Research Highlights: Patterns of dispersal shape the distribution and temporal development of genetic diversity both within and among populations. In an era of unprecedented environmental change, the maintenance of extant genetic diversity is crucial to population persistence. Background and Objectives: We investigate patterns of pollen dispersal and spatial genetic structure within populations of giant sequoia (Sequoiadendron giganteum). Materials and Methods: The leaf genotypes of established trees from twelve populations were used to estimate the extent of spatial genetic structure within populations, as measured by the Sp statistic. We utilized progeny arrays from five populations to estimate mating parameters, the diversity of the pollen pool, and characteristics of pollen dispersal. Results: Our research indicates that giant sequoia is predominantly outcrossing, but exhibits moderate levels of bi-parental inbreeding (0.155). The diversity of the pollen pool is low, with an average of 7.5 pollen donors per mother tree. As revealed by the Sp-statistic, we find significant genetic structure in ten of twelve populations examined, which indicates the clustering of related individuals at fine spatial scales. Estimates of pollen and gene dispersal indicate predominantly local dispersal, with the majority of pollen dispersal <253 m, and with some populations showing fat-tailed dispersal curves, suggesting potential for long-distance dispersal. Conclusions: The research presented here represent the first detailed examination of the reproductive ecology of giant sequoia, which will provide necessary background information for the conservation of genetic resources in this species. We suggest that restoration planting can mitigate potential diversity loss from many giant sequoia populations.

Analysis of the spatial genetic structure of Passiflora incarnata in recently disturbed sites

2005 ◽  
Vol 83 (4) ◽  
pp. 420-426 ◽  
Author(s):  
Rebecca T Tague ◽  
Stephanie A Foré
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Multilocus Genotype ◽  
Long Distance ◽  
Short Life Span ◽  
Successional Species ◽  
Passiflora Incarnata ◽  
Coefficient Of Coancestry

In early successional species, short life span and frequent spatial relocation may affect the distribution of genetic variation but the pattern may be altered by reproductive patterns. Passiflora incarnata L. (Passifloraceae), an early successional vine found throughout the southeastern United States, reproduces sexually and asexually through clonal sprouts. We examined the genetic structure of P. incarnata in recently disturbed habitats at three spatial scales: within a patch, among patches separated by 250 m, and between sites separated by 10 km. Genetic variation may be clumped at the scale of neighboring plants if stem resprouting is significant. In each patch, eleven arbitrarily selected plants and their four nearest neighbors were mapped and leaf samples were collected for genetic analysis. The multilocus genotype of each individual for seven polymorphic allozymes was determined. Potential clones were determined by estimating the probability of a second occurrence of each genotype and a multilocus coefficient of coancestry. Data indicated P. incarnata was reproducing primarily sexually. Most of the genetic variation was within a patch with little variation among patches. These data suggest that the genetic structure of this colonizing species was determined by founder effects interacting with long distance pollen movement.Key words: allozymes, passionflower, spatial, genetic structure, early colonizer, Passiflora incarnata.

Genetic diversity, spatial genetic structure and realised seed and pollen dispersal of Himatanthus drasticus (Apocynaceae) in the Brazilian savanna

2014 ◽  
Vol 15 (5) ◽  
pp. 1073-1083 ◽  
Author(s):  
Cristina Baldauf ◽  
Maísa Ciampi-Guillardi ◽  
Thaísa Jacinto Aguirra ◽  
Christiane Erondina Corrêa ◽  
Flavio Antonio Maës dos Santos ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Pollen Dispersal ◽  
Brazilian Savanna

scholarly journals Spatial genetic structure, genetic diversity and pollen dispersal in a harvested population of Astrocaryum aculeatum in the Brazilian Amazon

BMC Genetics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Santiago Linorio Ferreyra Ramos ◽  
Gabriel Dequigiovanni ◽  
Alexandre Magno Sebbenn ◽  
Maria Teresa Gomes Lopes ◽  
Paulo Yoshio Kageyama ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Pollen Dispersal ◽  
Brazilian Amazon ◽  
Astrocaryum Aculeatum

scholarly journals Global gene flow releases invasive plants from environmental constraints on genetic diversity

2020 ◽  
Vol 117 (8) ◽  
pp. 4218-4227 ◽  
Author(s):  
Annabel L. Smith ◽  
Trevor R. Hodkinson ◽  
Jesus Villellas ◽  
Jane A. Catford ◽  
Anna Mária Csergő ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Invasive Plants ◽  
Spatial Genetic Structure ◽  
Plantago Lanceolata ◽  
Research Network ◽  
Environmental Constraints ◽  
Long Distance ◽  
Precipitation Seasonality ◽  
The Impact

When plants establish outside their native range, their ability to adapt to the new environment is influenced by both demography and dispersal. However, the relative importance of these two factors is poorly understood. To quantify the influence of demography and dispersal on patterns of genetic diversity underlying adaptation, we used data from a globally distributed demographic research network comprising 35 native and 18 nonnative populations of Plantago lanceolata. Species-specific simulation experiments showed that dispersal would dilute demographic influences on genetic diversity at local scales. Populations in the native European range had strong spatial genetic structure associated with geographic distance and precipitation seasonality. In contrast, nonnative populations had weaker spatial genetic structure that was not associated with environmental gradients but with higher within-population genetic diversity. Our findings show that dispersal caused by repeated, long-distance, human-mediated introductions has allowed invasive plant populations to overcome environmental constraints on genetic diversity, even without strong demographic changes. The impact of invasive plants may, therefore, increase with repeated introductions, highlighting the need to constrain future introductions of species even if they already exist in an area.

Pollinators and pollen dispersal of Piper dilatatum (Piperaceae) on Barro Colorado Island, Panama

2007 ◽  
Vol 23 (5) ◽  
pp. 603-606 ◽  
Author(s):  
David W. Kikuchi ◽  
Eloisa Lasso ◽  
James W. Dalling ◽  
Nadav Nur
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Inbreeding Depression ◽  
Spatial Genetic Structure ◽  
Critical Role ◽  
Pollen Dispersal ◽  
Barro Colorado Island ◽  
Long Distance ◽  
Self Fertilization ◽  
Pollen And Seed Dispersal

The genus Piper is an important component of tropical forests worldwide. Many Piper species have been reported as self-compatible (Figueiredo & Sazima 2000), and many have the ability to reproduce asexually, forming clonal aggregations (Grieg 1993). Furthermore, the main dispersers of Piper (bats) transport whole infructescences to feeding roosts (Fleming & Heithaus 1981), tending to disperse closely related seeds in clumps. These characteristics of Piper biology are likely to result in populations with strongly marked spatial genetic structure, and raise the potential for inbreeding depression through self-fertilization. A few studies using allozymes to evaluate spatial genetic structure in Piper spp. support this view. These studies indicate that populations separated by more than 1 km are genetically distinct (high FST values; Wright 1943) and that for some species inbreeding could be substantial (high values of FIS and FIT; Heywood & Fleming 1986, Mariot et al. 2002). However, the contributions of limited pollen and seed dispersal to generating spatial genetic structure remain unknown. Estimates of seed dispersal probabilities by Carollia perspicillata (Phyllostomidae) bats on Barro Colorado Island (BCI), Panama, and at Santa Rosa, Costa Rica, indicate that Piper dispersers move most seeds 50–300 m from the parent plant, with occasional long-distance events of > 1 km (Fleming 1981, Thies 1998). However, no studies have assessed how far Piper flower visitors move pollen. If seed dispersal is limited, and clonal reproduction is common, then long-distance pollen transfer may play a critical role in preventing inbreeding depression in Piper populations.

scholarly journals The Patterns and Puzzles of Genetic Diversity of Endangered Freshwater Mussel Unio crassus Philipsson, 1788 Populations from Vistula and Neman Drainages (Eastern Central Europe)

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 119
Author(s):  
Adrianna Kilikowska ◽  
Monika Mioduchowska ◽  
Anna Wysocka ◽  
Agnieszka Kaczmarczyk-Ziemba ◽  
Joanna Rychlińska ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Scales ◽  
Freshwater Mussel ◽  
Its Region ◽  
Strong Relationship ◽  
Mantel Test ◽  
Freshwater Ecosystems ◽  
Hierarchical Organization ◽  
Anthropogenic Factors

Mussels of the family Unionidae are important components of freshwater ecosystems. Alarmingly, the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species identifies almost 200 unionid species as extinct, endangered, or threatened. Their decline is the result of human impact on freshwater habitats, and the decrease of host fish populations. The Thick Shelled River Mussel Unio crassus Philipsson, 1788 is one of the examples that has been reported to show a dramatic decline of populations. Hierarchical organization of riverine systems is supposed to reflect the genetic structure of populations inhabiting them. The main goal of this study was an assessment of the U. crassus genetic diversity in river ecosystems using hierarchical analysis. Different molecular markers, the nuclear ribosomal internal transcribed spacer ITS region, and mitochondrial DNA genes (cox1 and ndh1), were used to examine the distribution of U. crassus among-population genetic variation at multiple spatial scales (within rivers, among rivers within drainages, and between drainages of the Neman and Vistula rivers). We found high genetic structure between both drainages suggesting that in the case of the analyzed U. crassus populations we were dealing with at least two different genetic units. Only about 4% of the mtDNA variation was due to differences among populations within drainages. However, comparison of population differentiation within drainages for mtDNA also showed some genetic structure among populations within the Vistula drainage. Only one haplotype was shared among all Polish populations whereas the remainder were unique for each population despite the hydrological connection. Interestingly, some haplotypes were present in both drainages. In the case of U. crassus populations under study, the Mantel test revealed a relatively strong relationship between genetic and geographical distances. However, in detail, the pattern of genetic diversity seems to be much more complicated. Therefore, we suggest that the observed pattern of U. crassus genetic diversity distribution is shaped by both historical and current factors i.e. different routes of post glacial colonization and history of drainage systems, historical gene flow, and more recent habitat fragmentation due to anthropogenic factors.

scholarly journals Influence of environmental factors on the genetic variation of the aquatic macrophyte Ranunculus subrigidus on the Qinghai-Tibetan Plateau

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhigang Wu ◽  
Xinwei Xu ◽  
Juan Zhang ◽  
Gerhard Wiegleb ◽  
Hongwei Hou
Keyword(s):  
Genetic Diversity ◽  
Tibetan Plateau ◽  
Environmental Factors ◽  
Local Adaptation ◽  
Aquatic Macrophyte ◽  
Spatial Genetic Structure ◽  
Long Distance ◽  
Elevation Gradients ◽  
Mantel Tests ◽  
Genetic Patterns

Abstract Background Due to the environmental heterogeneity along elevation gradients, alpine ecosystems are ideal study objects for investigating how ecological variables shape the genetic patterns of natural species. The highest region in the world, the Qinghai-Tibetan Plateau, is a hotspot for the studies of evolutionary processes in plants. Many large rivers spring from the plateau, providing abundant habitats for aquatic and amphibious organisms. In the present study, we examined the genetic diversity of 13 Ranunculus subrigidus populations distributed throughout the plateau in order to elucidate the relative contribution of geographic distance and environmental dissimilarity to the spatial genetic pattern. Results A relatively low level of genetic diversity within populations was found. No spatial genetic structure was suggested by the analyses of molecular variance, Bayesian clustering analysis and Mantel tests. Partial Mantel tests and multiple matrix regression analysis showed a significant influence of the environment on the genetic divergence of the species. Both climatic and water quality variables contribute to the habitat heterogeneity of R. subrigidus populations. Conclusions Our results suggest that historical processes involving long-distance dispersal and local adaptation may account for the genetic patterns of R. subrigidus and current environmental factors play an important role in the genetic differentiation and local adaptation of aquatic plants in alpine landscapes.

scholarly journals Genomic variation in the American pika: signatures of geographic isolation and implications for conservation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kelly B. Klingler ◽  
Joshua P. Jahner ◽  
Thomas L. Parchman ◽  
Chris Ray ◽  
Mary M. Peacock
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Sierra Nevada ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Thermal Sensitivity ◽  
Genomic Variation ◽  
Genome Wide ◽  
A Genome ◽  
American Pika

Abstract Background Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. Results Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006–0.0009; θW = 0.0005–0.0007) relative to populations in California (π = 0.0014–0.0019; θW = 0.0011–0.0017) and the Rocky Mountains (π = 0.0025–0.0027; θW = 0.0021–0.0024), indicating substantial genetic drift in these isolated populations. Tajima’s D was positive for all sites (D = 0.240–0.811), consistent with recent contraction in population sizes range-wide. Conclusions Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.

Effects of seed dispersal, adult tree and seedling density on the spatial genetic structure of regeneration at fine temporal and spatial scales

2010 ◽  
Vol 7 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Fabrice Sagnard ◽  
Sylvie Oddou-Muratorio ◽  
Christian Pichot ◽  
Giovanni G. Vendramin ◽  
Bruno Fady
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Seedling Density ◽  
Adult Tree ◽  
Temporal And Spatial
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