Preliminary Investigation of Genetic Variation within and between Cultivated and Natural Populations of Banksia coccinea and Banksia menziesii

1998 ◽  
Vol 46 (4) ◽  
pp. 547 ◽  
Author(s):  
M. A. Rieger ◽  
M. Sedgley

The randomly amplified polymorphic DNA (RAPD) technique followed by analysis of molecular variance (AMOVA) was used to determine the level of variation within and between commercial plantations of Banksia coccinea R.Br. and B. menziesii R.Br. in South Australia and natural populations in Western Australia. For B. coccinea, the majority of variation was within populations (66.1%), while between all populations accounted for 20.8%. The variation between cultivated and natural populations was 13.2%. There was close clustering between the cultivated populations, which appeared to be most closely related to the inland natural populations. In contrast, the variation between cultivated and natural populations for B. menziesii was 0.4% with the majority of the variation within populations (93.2%) and 6.4% between all populations. The cultivated and natural populations formed a single cohesive cluster. These data indicate that the full range of natural genetic diversity of B. menziesii appears to occur in the cultivated plantations, but this was not the case for B. coccinea.

2018 ◽  
Vol 56 (3) ◽  
pp. 275
Author(s):  
Tran Thi Lieu ◽  
Dinh Thi Phong ◽  
Vu Thi Thu Hien

Keteleeria evelyniana Mast. is a big softwood species with high economic values. Therefore, the number of these trees are rapidly decreasing due to rampant exploitation as well as its habitat loss and recently, the species is considered vulnerablein Vietnam. In this study, we assessed the genetic variation among seventy K. evelyniana samples of three natural populations in Lam Dong, Dak Lak and Kon Tum using 16 microsatellite markers. The results showed that thirteen markers were polymorphic. A total 39 DNA fragments were amplified, among them, thirty – five were polymorphic (accounting for 89.74%). Among studied populations, the level of genetic diversity at Lam Dong (Na = 2.063; Ne = 1.730; Ap = 0.375; I = 0.558; Ho = 0.459 and He = 0.367) was the highest. Analysis of molecular variance (AMOVA) showed that the total level of molecular changes between populations was 34.65% and between individuals in the same population was 65.35%. Private alleles (Ap) and inbreeding values (Fis) of K. evelyniana species were founded of all three populations in Lam Dong, Dak Lak and Kon Tum (0.375 and -0.234; 0.188 and -0.065; 0.063 and -0.047, respectively). The gene flow (Nm) also occurred among the K. evelyniana populations with the average of Nm = 5.423. A dendrogram (UPGMA) constructed based on the similarity matrix of 70 K. evelyniana samples divided into two main groups with their genetic similarity coefficient ranged from 76.5% (Ke26 and Ke44) to 99% (Ke23 and Ke25). The obtained results indicated the importance of conserving the genetic resources of K. evelyniana species in Tay Nguyen.


2015 ◽  
Vol 37 (4) ◽  
pp. 984-992
Author(s):  
ELISA FERREIRA MOURA ◽  
MARIA DO SOCORRO PADILHA DE OLIVEIRA ◽  
DIEHGO TULOZA DA SILVA ◽  
LÍGIA CRISTINE GONÇALVES PONTES

ABSTRACT The aim of this study was to evaluate the genetic diversity and structure in the germoplasm of Oenocarpus mapora conserved at Eastern Amazon. Thus, 88 individuals were genotyped with five microsatellite loci. These individuals belong to 24 accessions that were sampled in eight sample places of three Brazilian Amazon states conserved at the Active Germplasm Bank (AGB) of Embrapa Eastern Amazon. All loci were polymorphic and they generated 85 alleles with an average of 17 alleles per loci. Total genetic diversity (HE) was 0.48. Sample places were considered genetically distinct, with ?p = 0.354. The analysis of molecular variance (AMOVA) identified that the genetic portion among areas was of 36.14% and within 63.86%. The Nei distances varied from 0.091 between Abaetetuba and Santo Antônio do Tauá, both in the state of Pará (PA), to 4.18, between Parintins, AM and Rio Branco, AC. By means of Bayesian analysis, it was identified nine clusters that compose the accessions of the germplasm bank, with different distributions among individuals. The study showed high fixation rates per sample area, which indicates that there may have been significant inbreeding or crossing among parental individuals. It suggests that future samples should be made of different plants in natural populations. Even though, it was verified that there is considerable genetic variation in the germplasm of O. mapora.


2011 ◽  
Vol 11 (3) ◽  
pp. 216-223 ◽  
Author(s):  
Liene Rocha Picanço Gomes ◽  
Maria Teresa Gomes Lopes ◽  
Jania Lilia da Silva Bentes ◽  
Willian Silva Barros ◽  
Pedro de Queiroz Costa Neto ◽  
...  

This study aimed to characterize the genetic diversity of buriti populations by AFLP (Amplified Fragment Length Polymorphism) markers. The analysis was performed in four populations used by traditional communities in the state of Amazonia (Bom Jesus do Anamã, Lauro Sodré, Santa Luzia do Buiçuzinho, and Esperança II). From each population 30 plants were randomly selected. To obtain the markers four primer combinations were used. The percentage of polymorphic loci was estimated, the molecular variance among and within populations analyzed and a dendrogram constructed. The primers detected 339 polymorphic loci ranging from 81.1 % to 91.1 % among populations. Analysis of molecular variance attributed 77.18 % to variation within and 22.8 % to variation between populations. The dendrogram indicated the formation of two groups, showing that the populations of Bom Jesus do Anamã and Lauro Sodré are genetically most similar and thet the genetic and geographical distances are not correlated.


2011 ◽  
Vol 18 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Fatemeh Mohammadzadeh ◽  
Hassan Monirifar ◽  
Jalal Saba ◽  
Mostafa Valizadeh ◽  
Ahmad Razban Haghighi ◽  
...  

Genetic diversity among and within 10 populations of Iranian alfalfa, from different areas of Azarbaijan, Iran was analyzed by screening DNA from seeds of individual plants and bulk samples. In individual study, 10 randomly amplified polymorphic DNA (RAPD) primers produced 156 polymorphic bands and a high level of genetic diversity was observed within populations. The averages of total and within population genetic diversity were 0.2349 and 0.1892, respectively. Results of analysis of molecular variance (AMOVA) showed the great genetic variation existed within populations (81.37%). These Results were in agreement with allogamous and polyploid nature of alfalfa. Cluster analysis was performed based on Nei’s genetic distances resulting in grouping into 3 clusters which could separate breeding population from other populations. Results of cluster analysis were in consistent with morphological and geographical patterns of populations. The results of bulk method were different from individual analysis. Our results showed that RAPD analysis is a suitable method to study genetic diversity and relationships among alfalfa populations.Keywords: Alfalfa; RAPD; Genetic diversity; Analysis of Molecular Variance; Cluster analysis.DOI: http://dx.doi.org/10.3329/bjpt.v18i2.9296Bangladesh J. Plant Taxon. 18: (2): 93-104, 2011 (December)


2010 ◽  
Vol 53 (5) ◽  
pp. 1037-1042 ◽  
Author(s):  
Sandra Aparecida Sahyun ◽  
Eduardo Augusto Ruas ◽  
Claudete de Fátima Ruas ◽  
Cristiano Medri ◽  
José Roberto Pinto de Souza ◽  
...  

Three populations of Maytenus aquifolium from Monte Alegre farm, Telemaco Borba county, Paraná, Brazil were analyzed by RAPD markers. A total of 13 primers were applied wich yielded 283 well amplified markers in all the studied populations (Mortandade, Vila Preta and Trinita), producing different values of gene diversity and polymorphic loci. The analysis of molecular variance (AMOVA) indicated that 21.77% of the genetic variation was among the population. Pairwise F ST analysis showed that the most divergent populations were closer geographically, demonstrating that other factors such as different soil types could explain this variation. Bayesian analysis for K number of clusters and the Principal Coordinate indicated that these three populations were highly structured, corroborating the high values found for the F ST and indicating that for conservation purposes all populations should be maintained.


2019 ◽  
Vol 36 (10) ◽  
pp. 2358-2374
Author(s):  
Nicolas Alcala ◽  
Amy Goldberg ◽  
Uma Ramakrishnan ◽  
Noah A Rosenberg

Abstract Natural populations display a variety of spatial arrangements, each potentially with a distinctive impact on genetic diversity and genetic differentiation among subpopulations. Although the spatial arrangement of populations can lead to intricate migration networks, theoretical developments have focused mainly on a small subset of such networks, emphasizing the island-migration and stepping-stone models. In this study, we investigate all small network motifs: the set of all possible migration networks among populations subdivided into at most four subpopulations. For each motif, we use coalescent theory to derive expectations for three quantities that describe genetic variation: nucleotide diversity, FST, and half-time to equilibrium diversity. We describe the impact of network properties on these quantities, finding that motifs with a high mean node degree have the largest nucleotide diversity and the longest time to equilibrium, whereas motifs with low density have the largest FST. In addition, we show that the motifs whose pattern of variation is most strongly influenced by loss of a connection or a subpopulation are those that can be split easily into disconnected components. We illustrate our results using two example data sets—sky island birds of genus Sholicola and Indian tigers—identifying disturbance scenarios that produce the greatest reduction in genetic diversity; for tigers, we also compare the benefits of two assisted gene flow scenarios. Our results have consequences for understanding the effect of geography on genetic diversity, and they can assist in designing strategies to alter population migration networks toward maximizing genetic variation in the context of conservation of endangered species.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2504 ◽  
Author(s):  
Katarzyna Bilska ◽  
Monika Szczecińska

BackgroundResearch into the protection of rare and endangered plant species involves genetic analyses to determine their genetic variation and genetic structure. Various categories of genetic markers are used for this purpose. Microsatellites, also known as simple sequence repeats (SSR), are the most popular category of markers in population genetics research. In most cases, microsatellites account for a large part of the noncoding DNA and exert a neutral effect on the genome. Neutrality is a desirable feature in evaluations of genetic differences between populations, but it does not support analyses of a population’s ability to adapt to a given environment or its evolutionary potential. Despite the numerous advantages of microsatellites, non-neutral markers may supply important information in conservation genetics research. They are used to evaluate adaptation to specific environmental conditions and a population’s adaptive potential. The aim of this study was to compare the level of genetic variation inPulsatilla patenspopulations revealed by neutral SSR markers and putatively adaptive ISJ markers (intron-exon splice junction).MethodsThe experiment was conducted on 14 Polish populations ofP. patensand threeP. patenspopulations from the nearby region of Vitebsk in Belarus. A total of 345 individuals were examined. Analyses were performed with the use of eight SSR primers specific toP. patensand three ISJ primers.ResultsSSR markers revealed a higher level of genetic variation than ISJ markers (He= 0.609,He= 0.145, respectively). An analysis of molecular variance (AMOVA) revealed that, the overall genetic diversity between the analyzed populations defined by parametersFSTand ΦPTfor SSR (20%) and ΦPTfor ISJ (21%) markers was similar. Analysis conducted in theStructureprogram divided analyzed populations into two groups (SSR loci) and three groups (ISJ markers). Mantel test revealed correlations between the geographic distance and genetic diversity of Polish populations ofP. patensfor ISJ markers, but not for SSR markers.ConclusionsThe results of the present study suggest that ISJ markers can complement the analyses based on SSRs. However, neutral and adaptive markers should not be alternatively applied. Neutral microsatellite markers cannot depict the full range of genetic variation in a population because they do not enable to analyze functional variation. Although ISJ markers are less polymorphic, they can contribute to the reliability of analyses based on SSRs.


2003 ◽  
Vol 51 (4) ◽  
pp. 393 ◽  
Author(s):  
M. W. McDonald ◽  
M. Rawlings ◽  
P. A. Butcher ◽  
J. C. Bell

Eucalyptus cladocalyx F.Muell. is a widely cultivated tree in dryland southern Australia. It is grown for firewood, timber production and as a windbreak and ornamental species. Natural populations of E. cladocalyx are endemic to South Australia where they occur in three disjunct regions. This study assessed the mating system and patterns of genetic diversity in natural populations of E. cladocalyx by using allozymes. Populations had relatively low levels of genetic diversity (HE = 0.148) and high levels of genetic divergence (θ = 0.26) among populations, similar to other regionally distributed eucalypts. Populations clustered into three distinct groups, which corresponded to its disjunct natural distribution. Genetic differentiation among populations and between regions was highly significant. Relatively high levels of inbreeding (tm = 0.57) were detected in natural populations of E.�cladocalyx. Outcrossing rates were highly variable among families, ranging from 0 to 100%. One-third of families from four populations had outcrossing rates that were not significantly different from zero. The origins of three commercially significant, cultivated stands of E. cladocalyx were also assessed. Allozyme profiles of cultivated stands from Wail and Lismore in western Victoria suggested origins in the Wirrabara region of the southern Flinders Ranges, while a cultivated stand of E. cladocalyx var. nana Hort. ex Yates had an allozyme profile consistent with origins in the Eyre Peninsula region. The results are discussed in relation to the species' morphological variation, biogeography and the implications for its domestication and conservation.


Parasitology ◽  
2002 ◽  
Vol 125 (7) ◽  
pp. S51-S59 ◽  
Author(s):  
J. CURTIS ◽  
R. E. SORENSEN ◽  
D. J. MINCHELLA

Blood flukes in the genus Schistosoma are important human parasites in tropical regions. A substantial amount of genetic diversity has been described in populations of these parasites using molecular markers. We first consider the extent of genetic variation found in Schistosoma mansoni and some factors that may be contributing to this variation. Recently, though, attempts have been made to analyze not only the genetic diversity but how that diversity is partitioned within natural populations of schistosomes. Studies with non-allelic molecular markers (e.g. RAPDs and mtVNTRs) have indicated that schistosome populations exhibit varying levels of gene flow among component subpopulations. The recent characterization of microsatellite markers for S. mansoni provided an opportunity to study schistosome population structure within a population of schistosomes from a single Brazilian village using allelic markers. Whereas the detection of population structure depends strongly on the type of analysis with a mitochondrial marker, analyses with a set of seven microsatellite loci consistently revealed moderate genetic differentiation when village boroughs were used to define parasite subpopulations and greater subdivision when human hosts defined subpopulations. Finally, we discuss the implications that such strong population structure might have on schistosome epidemiology.


Biologia ◽  
2014 ◽  
Vol 69 (3) ◽  
Author(s):  
Kadry Abdel Khalik ◽  
Magdy Abd El-Twab ◽  
Rasha Galal

AbstractGenetic diversity and phylogenetic analyses of 24 species, representing nine sections of the genus Galium (Rubiaceae), have been made using the Inter Simple Sequence Repeats (ISSR), Randomly Amplified Polymorphic DNA (RAPD), and combined ISSR and RAPD markers. Four ISSR primers and three RAPD primers generated 250 polymorphic amplified fragments. The results of this study showed that the level of genetic variation in Galium is relatively high. RAPD markers revealed a higher level of polymorphism (158 bands) than ISSR (92 bands). Clustering of genotypes within groups was not similar when RAPD and ISSR derived dendrograms were compared. Six clades can be recognized within Galium, which mostly corroborate, but also partly contradict, traditional groupings. UPGMA-based dendrogram showed a close relationship between members of section Leiogalium with G. verum and G. humifusum (sect. Galium), and G. angustifolium (sect. Lophogalium). Principal coordinated analysis, however, showed some minor differences with UPGMA-based dendrograms. The more apomorphic groups of Galium form the section Leiogalium clade including the perennial sections Galium, Lophogalium, Jubogalium, Hylaea and Leptogalium as well as the annual section Kolgyda. The remaining taxa of Galium are monophyletic.


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