scholarly journals Genetic structure and taxonomic position of Pinus uliginosa Neumann population from Wielkie Torfowisko Batorowskie in Stołowe Mts. (locus classicus)

2014 ◽  
Vol 64 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Anna Siedlewska ◽  
Wiesław Prus-Głowacki

Genetic structure of <i>Pinus uliginosa</i> Neumann from Wielkie Tor-fowisko Batorowskie peat-bog (<i>locus classicus</i>) was studied by means of isoenzyme variability and compared with genetic structure of <i>P. mugo</i> Turra from Tatra Mts and <i>P. sylvestris</i> populations from Klodzka Valley and Czersk. The level of genetic variability in the population of <i>P. uliginosa</i> (heterozygosity, genotypic polymorphism) was similar to that in populations of <i>P. mugo</i>, with an excess of homozygosity in relation to Hardy-Weinberg equilibrium. An average number of alleles per locus in population of <i>P. uliginosa</i> is the same as in the studied <i>P. sylvestris</i> populations, but the average number of genotypes is slightly lower. However, populations of <i>P. mugo</i> from montaneus stands in Tatra Mts. are characterized by a higher number of alleles per locus than that in <i>P. uliginosa</i> population.In populations of <i>P. mugo</i> from peat-bogs, a lower number of alleles and genotypes is noted than in <i>P. uliginosa</i> population. The coefficients of genetic similarity (Nei and Hedrick) show the distinctly separate character of <i>P. uliginosa</i> as compared to <i>P. sylvestris</i> and loose relationship of this taxon to <i>P. mugo</i>. Also the measure of genetic differentiation of populations (G<sub>ST</sub>) confirms the specificity of this pine taxon.

2008 ◽  
Vol 59 (3) ◽  
pp. 235 ◽  
Author(s):  
Alicia Slater Schultheis ◽  
Richard Marchant ◽  
Jane Margaret Hughes

In marine and freshwater invertebrate populations, microscale genetic differentiation or ‘genetic patchiness’ is thought to result from variation in the abundance and genetic composition of new recruits at a particular location. In the present study, the role of the adult emergence patterns in genetic patchiness was examined using mtDNA and two microsatellite loci to compare patterns of genetic differentiation in asynchronously (subtropical) and synchronously emerging (temperate) populations of the stone-cased caddisfly Tasimia palpata. A 550 base pair region of the mitochondrial cytochrome c oxidase subunit I gene (COI) was sequenced in at least 14 individuals from each population. Genetic structure was detected only at the reach scale in the subtropical populations and no genetic differentiation was detected in temperate populations. There were more deviations from Hardy–Weinberg equilibrium (HWE) in subtropical populations than in temperate populations where 44% and 12.5%, respectively, of tests for deviations from HWE were significant. Although distinct patterns of genetic structure and deviations from HWE were observed in the subtropical and temperate populations of T. palpata, no conclusive evidence was found to suggest that the differences are caused by differences in emergence patterns. We hypothesise that genetic patchiness must be caused by post-recruitment processes, most likely the preservation of oviposition ‘hotspots’ in subtropical streams.


2013 ◽  
Vol 43 (6) ◽  
pp. 978-984 ◽  
Author(s):  
Vanice Dias Oliveira ◽  
Allivia Rouse Carregosa Rabbani ◽  
Ana Veruska Cruz da Silva ◽  
Ana da Silva Lédo

This research had as objective to characterize genetically individuals of physic nut cultivated in experimental areas in Sergipe, Brazil by means of RAPD molecular markers. Leaves of 40 individuals were collected and DNA was isolated using CTAB 2% method. Were used 30 primers RAPD for DNA amplification, and this data was used to estimate the genetic similarity among the pairs of individuals, using Jaccard coefficient, and group them out for the UPGMA method. Also, the genetic structure and diversity of the populations were assessed using AMOVA. Of the 100 fragments generated, 29 of were polymorphic. A similarity average of 0.54 among the individuals was found and the amplitude similarities varied from 0.18 to 1.00. One of them (U5) was unit clusters and formed by the most divergent individuals. AMOVA indicated that there is more variation within (63%) the population. In conclusion, it was possible verify genetic variability in physic nut using RAPD markers at these experimental areas.


2017 ◽  
Vol 107 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Danilo A. dos Santos Pereira ◽  
Paulo C. Ceresini ◽  
Vanina L. Castroagudín ◽  
Lina M. Ramos-Molina ◽  
Edisson Chavarro-Mesa ◽  
...  

The fungus Rhizoctonia oryzae-sativae is an important pathogen that causes the aggregated sheath spot disease on rice. In this study, we investigated the genetic structure of rice-adapted populations of R. oryzae-sativae sampled from traditional rice-cropping areas from the Paraíba Valley, São Paulo, Brazil, and from Meta, in the Colombian Llanos, in South America. We used five microsatellite loci to measure population differentiation and infer the pathogen’s reproductive system. Gene flow was detected among the three populations of R. oryzae-sativae from lowland rice in Brazil and Colombia. In contrast, a lack of gene flow was observed between the lowland and the upland rice populations of the pathogen. Evidence of sexual reproduction including low clonality, Hardy-Weinberg equilibrium within loci and gametic equilibrium between loci, indicated the predominance of a mixed reproductive system in all populations. In addition, we assessed the adaptive potential of the Brazilian populations of R. oryzae-sativae to emerge as a pathogen to Urochloa spp. (signalgrass) based on greenhouse aggressiveness assays. The Brazilian populations of R. oryzae-sativae were probably only incipiently adapted as a pathogen to Urochloa spp. Comparison between RST and QST showed the predominance of diversifying selection in the divergence between the two populations of R. oryzae-sativae from Brazil.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Arsène Jacques Y. H. Fassinou ◽  
Come Z. Koukpo ◽  
Razaki A. Ossè ◽  
Fiacre R. Agossa ◽  
Roseric Azondékon ◽  
...  

Abstract Background Changes in the natural habitats of insect groups are determined the genetic polymorphisms between individuals. The objective of this study was to establish the genetic structure of the Anopheles coluzzii populations in four localities of Benin. Methods Insecticide surveys and larval sampling were conducted on 4 study localities, including Cotonou, Ketou, Zagnanado, and Sô-Ava. Molecular characterizations were performed on the Anopheles mosquitoes collected with the allelic and genotypic frequencies of kdr gene determined. The multiple comparison Chi square test for proportions was performed with R version 3.3.3. Next, the observed heterozygosity, expected heterozygosity, and indices of fixation, and genetic differentiation were estimated. Finally, the Hardy–Weinberg equilibrium (EHW) was determined to assess whether panmixia exists in the different populations of mosquitoes of the agroecological zones under study. Results Carbamates, pyrethroids, organophosphorus and organochlorines use have been reported in all localities except Sô-Ava. Anopheles coluzzii was strongly represented across all study localities. The L1014F allele was observed in the localities of Kétou, Cotonou and Zagnanado. Likewise, insecticide selection pressure of homozygous resistant individuals (L1014F/L1014F) was significantly higher in Kétou, Cotonou and Zagnanado (p value < 0.05). Surprisingly in Sô-Ava, a relatively high frequency of the L1014F allele despite the reported absence of pesticide use was observed. All mosquito populations were found to be deficient in heterozygosity across the study sites (FIS< 0). No genetic differentiation (FST< 0) was observed in the localities of Zagnanado and Kétou. Conclusion The survey on the use of insecticides showed that insecticide selection pressures differ across the investigated localities. It would be desirable to rotate or apply formulations of combined products with different modes of action. Doing so would enable a better management of resistant homozygous individuals, and mitigate the resistance effect of commonly used insecticides.


IAWA Journal ◽  
2004 ◽  
Vol 25 (4) ◽  
pp. 449-458 ◽  
Author(s):  
Oliver Dünisch ◽  
Carlos Bruno Reissmann ◽  
Afonso Oliszeski

In this study the wood anatomy of two leaf-morphotypes (“Yellow” and “Grey”) of Ilex paraguariensis St. Hil. (Aquifoliaceae) from South Brazil was compared with special attention to vessel attributes and a possible relationship of leaf morphology and wood structure. Sampling was carried out in a 15-year-old plantation in the state of Paraná, South Brazil. The anatomy of the juvenile and mature wood of five male and five female plants of each morphotype was investigated by light microscopy. In all plants the increment and the proportion of vessels decreased from pith to cambium, while vessel element length increased. Plants of the morphotype “Grey” had shorter vessel members (157–382 μm) and a lower number of bars per perforation plate (14–15) compared to the plants of the morphotype “Yellow” (vessel member length: 304–567 μm, bars: 22–24). No significant differences were found between the wood of male and female plants.


1989 ◽  
Vol 19 (11) ◽  
pp. 1371-1379 ◽  
Author(s):  
Monique Tremblay ◽  
Jean-Pierre Simon

The genetic structure of six marginal populations of white spruce (Piceaglauca (Moench) Voss) located at Richmond Gulf in the subarctic region of Nouveau-Québec, and one southern population located at Kuujjuaraapik (Poste-de-la-Baleine) were analyzed by acrylamide gel electrophoresis for seven enzyme systems. The analysis of 27 loci disclosed an average polymorphism of 76.2% and a level of heterozygosity of 0.319. Data based on Wright's; statistics: indicated a deficiency of heterozygotes for 60% of the loci, as calculated from the Hardy–Weinberg equilibrium. These results, coupled with the very low percentage of filled seeds in cones of all populations, suggest that a certain level of inbreeding or gene exchange among near-neighbour relatives influences the genetic structure of these populations. The genetic differentiation among populations is relatively high for a conifer [Formula: see text] and is not correlated with geographic distance. The age of trees, covering a period of 400 years affected by climatic changes, does not contribute to the genetic differentiation of the populations.


2012 ◽  
pp. 154-161
Author(s):  
Francisco Javier León ◽  
Fernando Rondón González ◽  
Clara Inés Vargas Castellanos ◽  
Myriam Oróstegui ◽  
Leonelo Bautista ◽  
...  

Introduction: In spite nearly 40% of the variability in blood pressure can be explained by genetic factors, the identifi­cation of genes associated to essential high blood pressure is difficult in populations where individuals have different genetic precedents; in these circumstances it is necessary to determinate whether the population is sub-structured because this can bias studies associated with this disease. Objectives: To determine the genetic structure of the population in Bucaramanga from genetic polymorphisms asso­ciated with the regulation of blood pressure: 448G>T, 679C>T y 1711C>T from the gene kinase 4 of the dopaminergic receptor linked to the protein G and Glu298Asp, -786T>C and the VNTR of the intron 4 of the gene of endothelial nitric oxide. Methodology: A sample of 552 unrelated individuals was studied through analysis of Restriction fragment length polymorphism. The allelic, haplotypic and genotypic frequencies were calculated, the Hardy-Weinberg equilibrium was determined and a molecular analysis of variance was performed to determine the genetic structure. Results: 38 Haplotypes were identified, with GCCTG4b as the most frequent (21.2%). The most diverse polymorphism was 448G>T with a frequency of 49.9% for heterozygous. The six polymorphisms were found in genetic equilibrium and genetic structure of populations was not evidenced (FST = 0,0038). Conclusion: The population studied does not present a genetic sub-structure and the polymorphisms analyzed were found in genetic equilibrium, this indicates that the population mixes randomly and there are no sub-groups capable of affecting the results of the association studies


2014 ◽  
Vol 67 (3-4) ◽  
pp. 269-274 ◽  
Author(s):  
Wiesław Prus-Głowacki ◽  
Ewa Bajus ◽  
Halina Ratyńska

Studies on taxonomic position of <em>Pinus uliginosa</em> Neumann, <em>P. uncinata</em> Ram. and <em>P. mugo</em> Turra, indicate a significant specificity of <em>P. uliginosa</em> population from Wielkie Torfowisko Batorowskie Peat Bog. <em>Pinus uncinata</em> in respect of genetic similarity is close to <em>Pinus mugo</em> Turra populations from the Tatra Mts. The time of divergence of <em>P. uliginosa</em> from the common ancestor, taking into account Nei's genetic distances, is twice as long as in the case of <em>Pinus uncinata</em>. In the view of the results the supposition that <em>Pinus uliginosa</em> from Wielkie Torfowisko Batorowskie Peat Bog is a marginal population of <em>P. uncinata</em> can be excluded, because of their significant difference in genetic structure. The presumable reasons of specificity of <em>P. uliginosa</em> population are disscused.


2018 ◽  
Vol 63 (No. 11) ◽  
pp. 462-472
Author(s):  
Anna Stachurska ◽  
Antoni Brodacki ◽  
Marta Liss

The objective of this study was to estimate the frequencies of alleles which produce coat colour in Polish Coldblood horse population, and to verify the hypothesis that coat colour is not considered in its selection. The analysis included 35 928 horses and their parents having been registered in the studbook over a half-century. Allele frequencies in Agouti (A), Extension (E), Dun (D), Roan (Rn), and Grey (G) loci, in parental and offspring generations, were estimated according to test matings and the square root of recessive phenotype frequency. The population structure is in Hardy–Weinberg equilibrium only at E locus and coat colour is regarded by breeders. Black horses are favoured. Higher E locus homozygosity in blacks than in bays makes it easier to obtain black foals. Dun-diluted, roan and grey coat colours are undesirable and the population has come to consist almost uniformly of basic coat colours. These results show the importance of studies on population genetic structure, which despite no formal criteria for breeding for colour, can considerably change through generations.


2021 ◽  
Author(s):  
Tirelo Bakae ◽  
Phetogo Ineeleng Monau ◽  
James Nsoso ◽  
Patrick Monametsi Kgwatalala

Abstract The study was performed to evaluate genetic variation on two Sanga type cattle found in Botswana; Tswana and Tuli using twelve microsatellite markers. All amplified loci were polymorphic with 75 and 77 alleles genotyped in the Tswana and Tuli populations, respectively. The total number of alleles per locus ranged from 2 (BM1818) to 10 (TGLA227) with total mean of 6.25 for Tswana and 6.43 for Tuli population. Almost all the markers showed high polymorphic information content (PIC) apart from BM1818 (0.375) and INTRA23 (0.393) which were moderately informative in Tswana population. Most of the markers were in Hardy-Weinberg equilibrium except for CSSRM60 and CSSM66 loci in Tswana population and ETH10, ETH225 and CSSM66 loci in Tuli population. A total of 103 unique alleles were genotyped across the two breeds with 49-shared, and 26 and 28 were unique to Tswana and Tuli populations, respectively. The expected heterozygosity (He) values were higher than the observed heterozygosity (Ho) in both populations; Tswana (He=0.7895±0.033 vs Ho=0.631±0.091) and Tuli (He=0.8123±0.033 vs Ho=0.556±0.021). The inbreeding coefficient was 0.200±0.002 and 0.332±0.001 in Tswana and Tuli populations, respectively. Analysis of molecular variance revealed 6.8% of the total genetic variation corresponding to differences between the two breeds and 93.2% within populations. The genetic identity between the two breeds was 56% and there were similar levels of multilocus heterozygosity and allelic diversity in the two breeds. The use of Tswana and Tuli breeds in a crossbreeding program is likely to result in minimal heterosis and therefore not recommended.


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