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 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.

Genetic structure and proposed conservation strategy for natural populations of Calycanthus chinensis Cheng et S.Y. Chang (Calycanthaceae)

2008 ◽  
Vol 88 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Chu-Chuan Fan ◽  
Nicola Pecchioni ◽  
Long-Qing Chen
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Genetic Distance ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Natural Populations ◽  
Population Level ◽  
Conservation Strategy ◽  
Information Index

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD

scholarly journals Genetic differentiation in spite of high gene flow in the dominant rainforest tree of southeastern Australia, Nothofagus cunninghamii

Heredity ◽  
2015 ◽  
Vol 116 (1) ◽  
pp. 99-106 ◽  
Author(s):  
C J Duncan ◽  
J R P Worth ◽  
G J Jordan ◽  
R C Jones ◽  
R E Vaillancourt
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Southeastern Australia ◽  
High Gene Flow ◽  
High Gene

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.

Genetic differentiation among 22 mature populations of green alder (Alnuscrispa) in central Quebec

1987 ◽  
Vol 17 (3) ◽  
pp. 219-227 ◽  
Author(s):  
J. Bousquet ◽  
W. M. Cheliak ◽  
M. Lalonde
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Polymorphic Locus ◽  
Green Alder ◽  
Apparent Homogeneity ◽  
Total Genetic Diversity ◽  
High Gene ◽  
Partial Isolation ◽  
Sexually Mature

Electrophoretically demonstrable diversity of 11 enzymes encoded by a total of 16 structural loci was analyzed in 22 sexually mature populations of Alnuscrispa (Ait.) Pursh (green alder, Betulaceae) in central Quebec. On average, 45% of the loci per population were polymorphic, with a mean of 2.39 alleles per polymorphic locus. Approximately 5% of the total genetic diversity resided among populations, with a mean genetic distance between populations of 0.01. Most populations thus appeared homogeneous, likely linked by high gene flow, as demonstrated by analysis of conditional average frequencies of alleles. Geoclimatic similarity among sites was also considered as a possible contributing factor to this apparent homogeneity. Heterogeneity of allele frequencies among populations was noted at seven loci. However, the presence of four populations that appeared to be more differentiated accounted for much of the observed heterogeneity. The early successional nature of this species and the partial isolation of these four populations seemed the most likely factors causing the observed differentiation.

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