scholarly journals Effective gene flow patterns across a fragmented landscape in southern Costa Rica for Symphonia globulifera (Clusiaceae); a species with mobile seed and pollen dispersers

2019 ◽  
Vol 67 (2SUPL) ◽  
pp. S95-S111 ◽  
Author(s):  
Wendy Solís-Hernández ◽  
Eric-J. Fuchs
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Costa Rica ◽  
Forest Fragmentation ◽  
Flow Patterns ◽  
Tropical Tree ◽  
Forest Fragment ◽  
Long Distance ◽  
Dispersal Vectors ◽  
Symphonia Globulifera

In tropical trees, forest fragmentation has been shown to affect mating and gene flow patterns. Mobile dispersal vectors should be less sensitive to fragmented landscapes and may ameliorate the genetic effects of forest fragmentation on plant populations. To test this hypothesis, we analyzed gene flow patterns in Symphonia globulifera, a tropical tree species with highly mobile pollinators and seed dispersers in the Osa Peninsula in southern Costa Rica. We used microsatellites to study genetic diversity and realized gene flow patterns between a continuous forest and a forest fragment. We found high levels of genetic diversity in adults and seedlings at both sites. Parentage analyses suggest near-neighbor matings and frequent long-distance gene flow events. Half the progeny beneath an adult was not sired by that tree and the majority of established seedlings were the result of long-distance gene dispersal. Gene flow from the forest into the fragment was more common than from the fragment into the continuous forests. Despite long distance gene flow events, seedling spatial genetic structure was stronger and extended further in the forest fragment likely due to limited seed dispersal. We conclude that fragmentation affects gene flow in this tropical tree and may compromise its genetic diversity in forest fragments even for a species with mobile pollen and seed vectors.

Genetic structure after forest fragmentation: a landscape ecology perspective on Acer saccharum

1992 ◽  
Vol 70 (8) ◽  
pp. 1659-1668 ◽  
Author(s):  
Stephanie A. Foré ◽  
R. James Hickey ◽  
John L. Vankat ◽  
Sheldon I. Guttman ◽  
Robert L. Schaefer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Forest Fragmentation ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Fragmented Landscape ◽  
Starch Gel Electrophoresis ◽  
Long Distance ◽  
Local Populations ◽  
Genetic Diversity And Structure

Fragmentation of large expanses of forests into small stands has isolated local populations of organisms. Sugar maple (Acer saccharum) was used to determine if the degree of forest fragment isolation affects genetic diversity and structure of local populations. Genetic data were collected from canopy (prefragmentation) and juvenile (postfragmentation) individuals in 15 woodlots. Genotypes were inferred from phenotypic enzyme patterns of seven enzymes representing eight loci extracted from cambium and resolved with starch gel electrophoresis. Analyses of allelic data indicated that genetic diversity was not significantly different between juvenile or canopy subdivisions, or between woodlots with low and high degrees of isolation. Genetic differentiation among woodlots was significantly greater for the canopy than for the juvenile subdivision. Estimates of gene flow indicate that postfragmentation gene flow rates are higher than prefragmentation rates. Apparently, sugar maple's high potential for long-distance gene flow is enhanced by altered wind flux across a fragmented landscape. The results also show that forest fragmentation does not always result in greater isolation of local populations. Key words: sugar maple, gene flow, conservation, isolation, allozymes.

scholarly journals Pollen-mediated gene flow ensures connectivity among spatially discrete sub-populations of Phalaenopsis pulcherrima, a tropical food-deceptive orchid

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhe Zhang ◽  
Stephan W. Gale ◽  
Ji-Hong Li ◽  
Gunter A. Fischer ◽  
Ming-Xun Ren ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Polynomial Regression ◽  
Genetic Erosion ◽  
Population Level ◽  
Hainan Island ◽  
Paternity Analysis ◽  
Genetic Structuring ◽  
Long Distance ◽  
High Genetic Diversity

Abstract Background Gene flow in plants via pollen and seeds is asymmetrical at different geographic scales. Orchid seeds are adapted to long-distance wind dispersal but pollinium transfer is often influenced by pollinator behavior. We combined field studies with an analysis of genetic diversity among 155 physically mapped adults and 1105 F1 seedlings to evaluate the relative contribution of pollen and seed dispersal to overall gene flow among three sub-populations of the food-deceptive orchid Phalaenopsis pulcherrima on Hainan Island, China. Results Phalaenopsis pulcherrima is self-sterile and predominantly outcrossing, resulting in high population-level genetic diversity, but plants are clumped and exhibit fine-scale genetic structuring. Even so, we detected low differentiation among sub-populations, with polynomial regression analysis suggesting gene flow via seed to be more restricted than that via pollen. Paternity analysis confirmed capsules of P. pulcherrima to each be sired by a single pollen donor, probably in part facilitated by post-pollination stigma obfuscation, with a mean pollen flow distance of 272.7 m. Despite limited sampling, we detected no loss of genetic diversity from one generation to the next. Conclusions Outcrossing mediated by deceptive pollination and self-sterility promote high genetic diversity in P. pulcherrima. Long-range pollinia transfer ensures connectivity among sub-populations, offsetting the risk of genetic erosion at local scales.

scholarly journals Genetic structure of Oryza glumaepatula wild rice populations and evidence of introgression from O. sativa in Costa Rica

2015 ◽  
Author(s):  
Eric J Fuchs ◽  
Allan Meneses Martínez ◽  
Amanda Calvo ◽  
Melania Muñoz ◽  
Griselda Arrieta-Espinoza
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Costa Rica ◽  
Genetic Structure ◽  
Wild Species ◽  
Wild Rice ◽  
Wild Rice Species ◽  
Genetic Diversity And Structure ◽  
Diversity Estimates ◽  
Oryza Glumaepatula

Wild crop relatives are an important source of genetic diversity for crop improvement. However, gene flow from cultivated species into wild species may prove detrimental. Introgression may lead to changes in wild species by incorporating alleles from domesticated species, which may increase the likelihood of extinction. The objective of the present study is to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated if there is evidence of introgression between wild rice and commercial varieties of O. sativa since it is cultivated commonly in close proximity to wild rice populations. Individuals from all known O. glumaepatula populations in Costa Rica were collected. With the aid of 455 AFLP markers, we characterized the genetic diversity and structure among seven populations in northern Costa Rica. Given the dominant nature of our markers, Bayesian estimates of genetic structure were used. We also compared genetic diversity estimates between O. glumaepatula individuals and O. sativa commercial rice. Our results show that O. glumaepatula populations in Costa Rica have moderately high levels of genetic diversity, comparable to those found in South American populations. This is likely a result of large population size. Despite the restricted distributions of this wild species, in Costa Rica most populations are composed of several thousand individuals, thus reducing the effects of drift on genetic diversity. Our results also found low but significant structure (\theta=0.03±0.001) among populations that are separated by ~10 Km within a single river. The position of the population along the river did not influence genetic diversity estimates or differences among populations. This river does not have a strong current and meadows or seeds may easily move upstream, thus homogenizing genetic diversity across populations regardless of river position. Ample gene flow through pollen, seeds or detached culms within the same river reduces genetic structure. A Bayesian structure analysis showed that individuals from two populations share a significant proportion of their genomes with O. sativa genome. These results suggest that the low levels of genetic structure found in these populations are likely the result of introgression from cultivated O. sativa populations. These results expose an important biohazard as recurrent hybridization may reduce genetic diversity of this wild rice species. Introgression may transfer commercial traits into the only populations of O. glumaepatula in Costa Rica, which in turn could alter genetic diversity and increase the likelihood of local extinction. These results have important implications for in situ conservation strategies of the only wild populations of O. glumaepatula in Costa Rica.

scholarly journals Evolutionary history of two cryptic species of Northern African jerboas

2019 ◽  
Author(s):  
Ana Filipa Moutinho ◽  
Nina Serén ◽  
Joana Paupério ◽  
Teresa Luísa Silva ◽  
Fernando Martínez-Freiría ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Cryptic Species ◽  
Evolutionary History ◽  
Demographic History ◽  
Habitat Specialization ◽  
Geographic Scale ◽  
Long Distance ◽  
Ecological Divergence ◽  
Geographic Population

Abstract Background Evidence suggests that complex paleoclimatic and geological events help shape species distributions, thus affecting their evolutionary history. In Sahara-Sahel, climatic oscillations shifted the desert extent during the Pliocene-Pleistocene interval, triggering the diversification of several species. Here, we investigated how these biogeographical and ecological events have shaped patterns of genetic diversity and divergence in African Jerboas, desert specialist species. We focused on two sister and cryptic species, Jaculus jaculus and J. hirtipes , where we (1) evaluated their genetic differentiation, (2) reconstructed their evolutionary and demographic history; (3) tested the level of gene flow between them, and (4) assessed their ecological niche divergence. Results The analyses based on 231 individuals sampled throughout North Africa, 8 sequence fragments (one mitochondrial and seven single copy nuclear DNA, including two candidate genes for fur coloration: MC1R and Agouti ), 6 microsatellite markers and ecological modelling revealed: (1) two distinct genetic lineages with overlapping distributions, in agreement with their classification as different taxa, J. jaculus and J. hirtipes , with (2) low levels of gene flow and strong species delimitation, (3) high genetic diversity but no apparent geographic population structure within species, suggesting long-distance migration between remote locations, and (4) low level of large-scale ecological divergence between the two taxa, suggesting species micro-habitat specialization. Conclusions Overall, our results suggest a speciation event that occurred during the Pliocene-Pleistocene transition. The contemporary distribution of genetic variation suggests ongoing population expansions, demonstrating the ability of these species for fast and long-range dispersal. Despite the largely overlapping distributions at a macrogeographic scale, our genetic results suggest that the two species remain reproductively isolated, as only negligible levels of gene flow were observed. The overlapping ecological preferences at a macro-geographic scale and the ecological divergence at the micro-habitat scale suggest that local adaptation may have played a crucial role in the speciation process of these species.

scholarly journals Genetic variation in the emblematic Puya raimondii (Bromeliaceae) from Huascarán National Park, Peru

2013 ◽  
Vol 13 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Claudia Teresa Hornung-Leoni ◽  
Victoria Sosa ◽  
June Simpson ◽  
Katia Gil
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Variability ◽  
National Park ◽  
Conservation Strategies ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Mountain Systems

Puya raimondii, the giant Peruvian and Bolivian terrestrial bromeliad, is an emblematic endemic Andean species well represented in Huascarán National Park in Peru. This park is the largest reserve of puna (high altitude plateau) vegetation. The objective of this study is to report on genetic variation in populations of P. raimondii from Huascarán and neighboring areas. AFLP profiles with four selective primer combinations were retrieved for 60 individuals from different zones. Genetic variability was estimated and a total of 172 bands were detected, of which 79.1% were polymorphic loci. The results showed genetic differentiation among populations, and gene flow. A cluster analysis showed that individuals of P. raimondii populations located in different mountain systems could be grouped together, suggesting long distance dispersal. Thus, conservation strategies for P. raimondii have to take into account exchange between populations located far apart in distance in order to preserve the genetic diversity of this showy species.

scholarly journals Especies crípticas Lutzomyia longipalpis (Diptera: Phlebotominae) y sus implicaciones en la en la transmisión de leishmaniasis en Panamá.

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Anayansi Valderrama Cumbrera ◽  
Mileyka Santos ◽  
Angélica Castro ◽  
José Dilermando Andrade Filho
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Costa Rica ◽  
Geographic Area ◽  
Lutzomyia Longipalpis ◽  
Dispersal Capacity ◽  
Principal Vector ◽  
Significant Differentiation ◽  
Vector Borne ◽  
Geographic Separation

<p><em>[Cryptic Species Lutzomyia longipalpis (Diptera: Phlebotominae) and its Implications in the Transmission of Leishmaniasis in Panama]</em></p><p><em>RESUMEN</em></p><p><em>Lutzomyia</em><em>longipalpis</em>es el principal vector de una importante enfermedad desatendida en América. La diversidad genética de este vector se estimó en la población colectada en dos áreas geográficas separadas por hasta 37 km. Analizamos la secuencia CB3-PDR / N1N-PDR de 22 individuos obteniendo un parámetro de: h = 0.43 y π = 0.0017 (Bo-na), h = 0.89, π = 0.004 (El Limón) con una diferenciación genética de kst = 0.03; p&gt; 0.05 entre ellos. Ocho haplotipos fueron detectados, de los cuales fue compartido. Se detectó una diferenciación significativa entre las poblaciones Panamá-Colombia (kst = 0.98), Panamá-Costa Rica (kst = 0.98) y Panamá-Brasil (kst = 0.72) bajo el modelo de aislamiento. Las inferencias genéticas de esta población pueden complementar la información de la capacidad de dispersión y brindar pistas importantes para comprender la ecología de <em>Lu</em>. <em>longiplapis</em>en Panamá.</p><p>ABSTRACT</p><p class="CuerpoA"><span class="Ninguno"><em><span lang="EN-US">Lutzomyia longipalpis</span></em></span><span class="Ninguno"><span lang="EN-US">is the main vector-borne of important neglected disease in America. The genetic diversity of this vector was estimated in population collected from two geographic area separated by up to </span></span><span class="Ninguno"><span lang="ES-TRAD">37</span></span><span class="Ninguno"><span lang="EN-US">km. We analyzed the sequence CB3-PDR/N1N-PDR of 22 individuals and the resulted of parameter was: h = 0.43 and π = 0.0017 (Bona), h = 0.89, π = 0.004 (El Limón) and genetic differentiation was kst = 0.03; p &gt; 0.05 among them. Eight haplotypes were detected, and one was shared. Significant differentiation was detected among populations Panama-Colombia (kst = 0.98), Panama-Costa Rica (kst = 0.98) and Panama-Brazil (kst = 0.72) and these were genetically isolated by distance. The existence of shared haplotypes among the populations suggests a gene flow despite the distance and geographic separation. Nevertheless, showed isolation it contrasted with individuals very distant.</span></span><span class="Ninguno"><span lang="EN-US">The genetic inferences of this population can supplement the information of dispersal capacity and provided important clues to understand the ecology of sandflies.</span></span></p>

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