scholarly journals High gene flow maintains genetic diversity following selection for high EPSPS copy number in the weed kochia (Amaranthaceae)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sara L. Martin ◽  
Leshawn Benedict ◽  
Wei Wei ◽  
Connie A. Sauder ◽  
Hugh J. Beckie ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Herbicide Resistance ◽  
Random Mating ◽  
Weed Species ◽  
Canadian Prairie ◽  
High Gene Flow ◽  
High Gene ◽  
Selection For

Abstract Kochia, a major weed species, has evolved resistance to four herbicide modes of action. Herbicide resistance appears to spread quickly, which could result in diminished standing genetic variation, reducing the ability of populations to adapt further. Here we used double digest restriction enzyme associated sequencing to determine the level of gene flow among kochia populations and whether selection for glyphosate resistance reduces genetic variation. Canadian Prairie populations show little to no genetic differentiation (FST = 0.01) and no correlation between genetic and geographic distance (r2 = − 0.02 p = 0.56), indicating high gene flow and no population structure. There is some evidence that kochia populations are genetically depauperate compared to other weed species, but genetic diversity did not differ between glyphosate susceptible and resistant populations or individuals. The inbreeding coefficients suggest there are 23% fewer heterozygotes in these populations than expected with random mating, and no variation was found within the chloroplast. These results indicate that any alleles for herbicide resistance can be expected to spread quickly through kochia populations, but there is little evidence this spread will reduce the species’ genetic variation or limit the species’ ability to respond to further selection pressure.

scholarly journals Going with the flow: analysis of population structure reveals high gene flow shaping invasion pattern and inducing range expansion of Mikania micrantha in Asia

2020 ◽  
Vol 125 (7) ◽  
pp. 1113-1126
Author(s):  
Achyut Kumar Banerjee ◽  
Zhuangwei Hou ◽  
Yuting Lin ◽  
Wentao Lan ◽  
Fengxiao Tan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Distance ◽  
Range Expansion ◽  
Mikania Micrantha ◽  
High Gene Flow ◽  
Genetic Pattern ◽  
High Gene

Abstract Background and Aims Mikania micrantha, a climbing perennial weed of the family Asteraceae, is native to Latin America and is highly invasive in the tropical belt of Asia, Oceania and Australia. This study was framed to investigate the population structure of M. micrantha at a large spatial scale in Asia and to identify how introduction history, evolutionary forces and landscape features influenced the genetic pattern of the species in this region. Methods We assessed the genetic diversity and structure of 1052 individuals from 46 populations for 12 microsatellite loci. The spatial pattern of genetic variation was investigated by estimating the relationship between genetic distance and geographical, climatic and landscape resistances hypothesized to influence gene flow between populations. Key Results We found high genetic diversity of M. micrantha in this region, as compared with the genetic diversity parameters of other invasive species. Spatial and non-spatial clustering algorithms identified the presence of multiple genetic clusters and admixture between populations. Most of the populations showed heterozygote deficiency, primarily due to inbreeding, and the founder populations showed evidence of a genetic bottleneck. Persistent gene flow throughout the invasive range caused low genetic differentiation among populations and provided beneficial genetic variation to the marginal populations in a heterogeneous environment. Environmental suitability was found to buffer the detrimental effects of inbreeding at the leading edge of range expansion. Both linear and non-linear regression models demonstrated a weak relationship between genetic distance and geographical distance, as well as bioclimatic variables and environmental resistance surfaces. Conclusions These findings provide evidence that extensive gene flow and admixture between populations have influenced the current genetic pattern of M. micrantha in this region. High gene flow across the invaded landscape may facilitate adaptation, establishment and long-term persistence of the population, thereby indicating the range expansion ability of the species.

scholarly journals Gender-based Genetic Variability of Ailanthus excelsa Roxb, Populations Using, RAPD, ISSR and SCoT Markers

2020 ◽  
pp. 75-83
Author(s):  
Shabnam Bano ◽  
Sumaiya Ansari ◽  
Meena Choudhary ◽  
U. K. Tomar
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Gene Diversity ◽  
Dna Amplification ◽  
Ailanthus Excelsa ◽  
High Gene Flow ◽  
Diversity Assessment ◽  
High Gene ◽  
Gender Based

Ailanthus excelsa Roxb. is an economically important and multipurpose dioecious tree species of India, mainly used for fodder and timber. Gender-based genetic diversity of five populations of two sites (Jodhpur, Rajasthan and Deesa, Gujarat) of A. excelsa was assessed. A total of 42 RAPD, 20 ISSR and 23 SCoT primers were screened for DNA amplification of 232 individuals. Out of which only 25 primers (13 RAPD, 6 ISSR and 6 SCoT) were found polymorphic. The SCoT markers were showed the highest value for PIC, MI, Rp value, Nei’s gene diversity and Shannon’s index, as compared with the other two markers. Female individuals in all five populations had slightly higher genetic diversity as compared with male individuals. A high level of genetic diversity (55%) was detected within the populations of male and female individuals. High gene flow (6.70) and low genetic differentiation (0.069) values were found between Jodhpur and Deesa sites. Principal component analysis for all populations were accounted for 48.7% of the genetic variation. The Mantel test showed significant correlation (R = 0.178, P = .01) between genetic and geographic distances. The present study showed that SCoT markers were best for genetic diversity assessment in A. excelsa over RAPD and ISSR markers. High gene flow and low genetic differentiation in A. excelsa indicates its poor population fragmentation despite long geographic distances.

scholarly journals Using population genetic tools to develop a control strategy for feral cats (Felis catus) in Hawai'i

2007 ◽  
Vol 34 (8) ◽  
pp. 587 ◽  
Author(s):  
Heidi Hansen ◽  
Steven C. Hess ◽  
David Cole ◽  
Paul C. Banko
Keyword(s):  
Genetic Diversity ◽  
Invasive Species ◽  
Population Genetics ◽  
Gene Flow ◽  
Population Genetic ◽  
Effective Control ◽  
Feral Cats ◽  
Genetic Tools ◽  
High Gene Flow ◽  
High Gene

Population genetics can provide information about the demographics and dynamics of invasive species that is beneficial for developing effective control strategies. We studied the population genetics of feral cats on Hawai‘i Island by microsatellite analysis to evaluate genetic diversity and population structure, assess gene flow and connectivity among three populations, identify potential source populations, characterise population dynamics, and evaluate sex-biased dispersal. High genetic diversity, low structure, and high number of migrants per generation supported high gene flow that was not limited spatially. Migration rates revealed that most migration occurred out of West Mauna Kea. Effective population size estimates indicated increasing cat populations despite control efforts. Despite high gene flow, relatedness estimates declined significantly with increased geographic distance and Bayesian assignment tests revealed the presence of three population clusters. Genetic structure and relatedness estimates indicated male-biased dispersal, primarily from Mauna Kea, suggesting that this population should be targeted for control. However, recolonisation seems likely, given the great dispersal ability that may not be inhibited by barriers such as lava flows. Genetic monitoring will be necessary to assess the effectiveness of future control efforts. Management of other invasive species may benefit by employing these population genetic tools.

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 Eco-evolutionary community turnover following environmental change

2018 ◽  
Author(s):  
Jesse R. Lasky
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Environmental Change ◽  
Community Dynamics ◽  
Environmental Gradients ◽  
Interspecific Variation ◽  
Community Response ◽  
High Gene Flow ◽  
High Gene ◽  
Response To Environmental Change

AbstractCo-occurring species often differ in intraspecific genetic diversity, which in turn can affect adaptation in response to environmental change. Specifically, the simultaneous evolutionary responses of co-occurring species to temporal environmental change may influence community dynamics. Local adaptation along environmental gradients combined with gene flow can promote genetic diversity of traits under selection within populations. Here I build off existing quantitative genetic theory to study community dynamics of locally adapted species in response to temporal environmental change. I show that species with greater gene flow have lower equilibrium population size due to maladaptive immigrant genotypes (migration load). However, following abrupt environmental change that leaves all species initially maladapted, high gene flow species adapt faster due to greater standing genetic diversity. As a result, communities may undergo a transient reversal in relative abundance, sometimes only after substantial lag periods. If constant temporal environmental change is applied, the community exhibits a shift toward stable dominance by species with intermediate gene flow. High gene flow species can sometimes increase abundance under environmental change if environmental change supresses superior competitor but lower gene flow species. The community dynamics observed here parallel the purely ecological successional dynamics following disturbances and are analogous to the transient benefit of hypermutator alleles under changing environments. My results demonstrate how interspecific variation in life history can have far-reaching impacts on eco-evolutionary community response to environmental change.

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