scholarly journals Using molecular markers to investigate genetic diversity, mating system and gene flow of Neotropical trees

2018 ◽  
Vol 41 (2) ◽  
pp. 481-496 ◽  
Author(s):  
C. C. Vinson ◽  
E. Mangaravite ◽  
A. M. Sebbenn ◽  
T. A. Lander
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Gene Flow ◽  
Mating System ◽  
Neotropical Trees

scholarly journals Evolutionary dynamics of Cucurbita argyrosperma from the Mesoamerican domestication center using SSR molecular markers

2018 ◽  
Vol 53 (3) ◽  
pp. 287-297
Author(s):  
Daniela Priori ◽  
Daniel Zizumbo Villarreal ◽  
Víctor Manuel de Jesús Canché Ek ◽  
Verónica Limones-Briones ◽  
Rosa Lía Barbieri
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Gene Flow ◽  
Evolutionary Dynamics ◽  
High Gene Flow ◽  
Ssr Primers ◽  
Young Leaves ◽  
High Gene ◽  
Cultivated Populations ◽  
Human Selection

Abstract: The objective of this work was to evaluate the evolutionary dynamics of the wild-weedy-domestic gene pool of Cucurbita argyrosperma squash by estimating the levels of genetic diversity and gene flow in the putative area of its domestication. Nine populations were collected, and DNA was extracted from young leaves harvested separately from approximately 20 individuals in each population. The DNA fragments were amplified with eight pairs of SSR primers and separated by electrophoresis in 5% denaturing polyacrylamide gels. Genetic diversity and the amount of gene flow were estimated in the populations, and Bayesian grouping was used to determine the levels of gene infiltration and probability of ancestry. The ethnobotanical exploration indicated that the evolutionary dynamics in the area occurred under five different ecological scenarios. Eighty-seven alleles with 75% to 100% polymorphic loci were identified. The greater genetic diversity in the weedy-domestic populations may have been the product of recombination due to the high gene flow between these populations promoted by pollinators and human selection. There is high gene flow between the wild and cultivated populations of C. argyrosperma in its domestication centre, highlighting the importance of conserving and maintaining these genetic resources.

scholarly journals Maintaining their genetic distance; limited gene flow between widely hybridising species of Geum with contrasting mating systems

2017 ◽  
Author(s):  
Crispin Y. Jordan ◽  
Konrad Lohse ◽  
Frances Turner ◽  
Marian Thomson ◽  
Karim Gharbi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Mating System ◽  
Draft Genome ◽  
Sympatric Populations ◽  
Species Classification ◽  
Interspecific Gene Flow ◽  
System Transition ◽  
Tentative Evidence ◽  
Limited Gene Flow

AbstractMating system transition from outcrossing to selfing frequently gives rise to sister lineages with contrasting outcrossing rates. The evolutionary fate of such lineages depends on the extent to which they exchange genes. We measured gene flow between outcrossing Geum rivale and selfing G. urbanum, two sister species derived by mating system transition, which frequently hybridise. A draft genome was generated for G. urbanum and used to develop dd-RAD data scorable in both species. Coalescent analysis of RAD data from allopatric populations indicated that the two species diverged 2-3 Mya, and that long term gene flow between them has been very low (M=0.04). G. rivale showed greater genetic diversity in sympatry than allopatry, but genetic divergence between species was no lower in sympatry than allopatry, providing little evidence for recent introgression. Clustering of genotypes revealed that, apart from four early generation hybrids, individuals in sympatric populations fell into two genetically distinct groups with <1% admixture that corresponded exactly to their morphological species classification. Although our data suggest limited gene flow, we observed joint segregation of two putatively introgressed SNPs in G. urbanum populations that was associated with significant morphological variation; this provides tentative evidence for rare introduction of novel genetic diversity by interspecific gene flow. Our results indicate that despite frequent hybridisation, genetic exchange between G. rivale and G. urbanum has been very limited throughout their evolutionary history.

scholarly journals Ecological niche modelling and genetic diversity of Anomochloa marantoidea (Poaceae): filling the gaps for conservation in the earliest-diverging grass subfamily

2019 ◽  
Author(s):  
João P Silva Vieira ◽  
Alessandra S Schnadelbach ◽  
Frederic Mendes Hughes ◽  
Jomar G Jardim ◽  
Lynn G Clark ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Gene Flow ◽  
Ecological Niche ◽  
Natural Populations ◽  
Niche Modelling ◽  
Southern Bahia ◽  
Conservation Plan ◽  
New Occurrences

Abstract Anomochlooideae (Poaceae) represent the earliest-diverging extant lineage of grasses. One of the two genera is the monotypic Anomochloa, which is extremely rare and restricted to the Atlantic Forest of southern Bahia state in Brazil, where only two natural populations have been recorded to date. Knowledge of A. marantoidea is considered crucial to understanding evolutionary and diversification patterns in Poaceae. Despite this, knowledge of the biology and distribution of A. marantoidea remain incomplete, and thus the conservation of this poorly known species is problematic. We used niche modelling to estimate its current distribution and assess potential ranges in situ to explore new occurrences. In addition, genetic diversity and the factors that disrupt gene flow between populations of this species were estimated using molecular markers. Two new populations were documented; the modelled ecological niche indicates high climatic restriction, but also revealed suitable sites for the establishment of new populations. Genetic diversity is correlated to population size, and genetic structure analysis suggests recent fragmentation and low gene flow among the remaining populations, which exhibit high levels of inbreeding. These levels also indicate the capacity of A. marantoidea to respond favourably to selection and, thus, that a conservation plan could be designed to maintain the current genetic diversity.

Genetic Diversity, Mating System, and Reproductive Output of Restored Melaleuca acuminata Populations are Comparable to Natural Remnant Populations

2019 ◽  
Vol 37 (4) ◽  
pp. 222-232 ◽  
Author(s):  
Melissa A Millar ◽  
Janet M Anthony ◽  
David J Coates ◽  
Margaret Byrne ◽  
Siegfried L Krauss ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Reproductive Output

Genetic diversity and the mating system in a fragmented population of Tsoongiodendron odorum

2013 ◽  
Vol 20 (6) ◽  
pp. 676-684 ◽  
Author(s):  
Wang Xia ◽  
Wang Jing ◽  
Jiang Jinghu ◽  
Kang Ming
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Fragmented Population

Genetic Diversity of Basil (Ocimum spp. - Lamiaceae) Based on RAPD Markers and Volatile Oil Constituents

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 492f-493
Author(s):  
Roberto F. Vieira ◽  
James E. Simon ◽  
Peter Goldsbrough ◽  
Antonio Figueira
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Rapd Markers ◽  
Volatile Oil ◽  
Essential Oil Composition ◽  
Oil Composition ◽  
Traditional Medicines ◽  
The Tropics ◽  
High Degree ◽  
First Time

Essential oils extracted from basil (Ocimum spp.) by steam distillation are used to flavor foods, oral products, in fragrances, and in traditional medicines. The genus Ocimum contains around 30 species native to the tropics and subtropics, with some species naturalized and/or cultivated in temperate areas. Interand intraspecific hybridization have created significant confusion in the botanical systematics of this genus. Taxonomy of basil (O. basilicum) is also complicated by the existence of numerous varieties, cultivars, and chemotypes within the species that do not differ significantly in morphology. In this study we are using RAPD markers and volatile oil composition to characterize the genetic diversity among the most economically important Ocimum species. We hypothesize that the genetic similarity revealed by molecular markers will more accurately reflect the morphological and chemical differences in Ocimum than essential oil composition per se. Preliminary research using five Ocimum species, four undetermined species, and eight varieties of O. basilicum (a total of 19 accessions) generated 107 polymorphic fragments amplified with 19 primers. RAPDs are able to discriminate between Ocimum species, but show a high degree of similarity between O. basilicum varieties. The genetic distance between nine species and among 55 accessions within the species O. americanum, O. basilicum, O. campechianum, O. × citriodorum, O. gratissimum, O. kilimandscharium, O. minimum, O. selloi, and O. tenuiflorum will be analyzed by matrix of similarity and compared to the volatile oil profile. This research will for the first time apply molecular markers to characterize the genetic diversity of Ocimum associate with volatile oil constituent.

Genetic rescue by augmenting gene flow

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Inbreeding Coefficient ◽  
Outbreeding Depression ◽  
Genetic Rescue ◽  
Evolutionary Potential ◽  
Beneficial Effects ◽  
The Difference ◽  
Inbred Populations ◽  
Harmful Effects

Inbreeding is reduced and genetic diversity enhanced when a small isolated inbred population is crossed to another unrelated population. Crossing can have beneficial or harmful effects on fitness, but beneficial effects predominate, and the risks of harmful ones (outbreeding depression) can be predicted and avoided. For crosses with a low risk of outbreeding depression, there are large and consistent benefits on fitness that persist across generations in outbreeding species. Benefits are greater in species that naturally outbreed than those that inbreed, and increase with the difference in inbreeding coefficient between crossed and inbred populations in mothers and zygotes. However, benefits are similar across invertebrates, vertebrates and plants. There are also important benefits for evolutionary potential of crossing between populations.

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