scholarly journals Genetic diversity of Betula nana in Sweden and conservation implications for protection of relict Polish populations

2021 ◽  
Vol 63 (3) ◽  
pp. 225-231
Author(s):  
Grażyna B. Dąbrowska ◽  
Henryk P. Dąbrowski ◽  
Iwona Szyp-Borowska

Abstract The natural range of the dwarf birch (Betula nana L.) includes the boreal, subarctic and arctic regions of Europe, Asia and North America, where it is relatively common. In Poland, it is a relict species occurring in fragmented populations. Using the random amplification of polymorphic DNA (RAPD) technique, we investigated the genetic diversity of the four Swedish populations representing a part of the continuous range of dwarf birch. With the knowledge of the level of genetic diversity of a population from a continuous distribution, we can assess the genetic status of polish populations and answer the question if habitat fragmentation and a decrease in population size lead to a loss in genetic diversity. Knowledge of genetic diversity is important for species conservation, especially to predict their ability to respond to environmental pressures. We found that the populations Abisko, Malbo, Gällivare and Storlien, which are located at the edge of the natural range of B. nana and occupy different habitats, are genetically diverse to varying degrees. The northern populations from Abisko and Gällivare showed a lower level of genetic polymorphism than the population from Malbo, the southernmost site of dwarf birch in Sweden. The data presented indicate higher genetic diversity existed within populations, whereas genetic differentiation between populations was lower. The high level of genetic differentiation within B. nana populations that were analysed in the present study may be explained by a limited capacity for dispersal among populations via both pollen and seeds. We found that the level of genetic diversity in one of the Polish populations of B. nana is comparable to that in areas in Scandinavia where populations are large and continuous. Based on these studies, we conclude that the “Linje” population has sufficient genetic resources.

2014 ◽  
Vol 61 (2) ◽  
Author(s):  
Małgorzata Czernicka ◽  
Jarosław Pławiak ◽  
Piotr Muras

Crosses between Betula nana and B. utilis 'Doorenbos' were undertaken in order to obtain interspecific hybrids which could be characterized by wide spreading stems, strong branching habit, decorative clear white bark and an interesting shape of purple leaves. The research purpose was to examine genetic diversity of the 16 F1 and F2 putative progenies by using the RAPD-PCR method and the ploidy analysis. A total of 242 RAPD markers were scored with 24 primers and 220 (90.9%) polymorphic bands were found. In the NJ dendrogram, cluster I consisted of the female parent--B. nana and 12 hybrids and cluster II grouped the male parent--B. utilis 'Doorenbos' with 4 hybrids (F2/2, F1/8, F1/7 and F2/1). The 2-D scaling by PCoA was in agreement with the similarity index, i.e. two hybrids (F1/8, F2/2) grouped with the male parent while others with female parent. Classification of the hybrid plants by chromosome counting demonstrated that 13 hybrids were confirmed with accurate chromosome counts as being diploid (2n=2x=28) and 3 plants (F1/7, F1/8, F2/2) as triploid with 42 chromosomes.


Author(s):  
Angélica Chávez-Cortázar ◽  
Ken Oyama ◽  
Maried Ochoa-Zavala ◽  
Martín Mata-Rosas ◽  
Emily Veltjen ◽  
...  

AbstractSpecial conservation efforts should be made for relict species, as they usually have small population sizes and restricted distributions, placing them in critical extinction risk. To achieve conservation, information about genetic diversity distribution is needed. Here, using nine nuclear microsatellites, we analyzed 23 populations of five recently described species of Magnolia distributed in Mexico, which were previously assigned to Magnolia dealbata. We aimed to determine the level of genetic diversity and the distribution of genetic variation and proposed conservation measures. Compared to other endemic and relict species, we found a moderate level of genetic diversity in most populations; however, we identified two populations with no genetic variation. Additionally, we found evidence of positive values of inbreeding likely due to geitonogamy. We found a strong population structure, low effective population size, and no evidence of bottlenecks. Patterns of genetic differentiation did not support the morphological distinction of five species, so we hypothesized that the gene pools may instead represent well-differentiated populations of a single species. We argue that the pattern of genetic differentiation is explained by the natural fragmentation of the cloud forests after glaciation events, and the effects of genetic drift in small populations poorly connected by gene flow. Despite the moderate levels of genetic diversity, special attention is needed to guarantee conservation, with emphasis on the populations in the central region of the country as well as the valuable populations identified in the southwestern region.


2019 ◽  
Vol 286 (1916) ◽  
pp. 20191989 ◽  
Author(s):  
M. C. Yates ◽  
E. Bowles ◽  
D. J. Fraser

Little empirical work in nature has quantified how wild populations with varying effective population sizes and genetic diversity perform when exposed to a gradient of ecologically important environmental conditions. To achieve this, juvenile brook trout from 12 isolated populations or closed metapopulations that differ substantially in population size and genetic diversity were transplanted to previously fishless ponds spanning a wide gradient of ecologically important variables. We evaluated the effect of genome-wide variation, effective population size ( N e ), pond habitat, and initial body size on two fitness correlates (survival and growth). Genetic variables had no effect on either fitness correlate, which was determined primarily by habitat (pond temperature, depth, and pH) and initial body size. These results suggest that some vertebrate populations with low genomic diversity, low N e , and long-term isolation can represent important sources of variation and are capable of maintaining fitness in, and ultimately persisting and adapting to, changing environments. Our results also reinforce the paramount importance of improving available habitat and slowing habitat degradation for species conservation.


2009 ◽  
Vol 159 (2) ◽  
pp. 237-244 ◽  
Author(s):  
M. CARMEN RODRIGUEZ-GACIO ◽  
JUAN DE JESÚS ◽  
MARÍA I. ROMERO ◽  
MARÍA T. HERRERA

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 155
Author(s):  
Kefena Effa ◽  
Sonia Rosenbom ◽  
Jianlin Han ◽  
Tadelle Dessie ◽  
Albano Beja-Pereira

Matrilineal genetic diversity and relationship were investigated among eight morphologically identified native Ethiopian horse populations using polymorphisms in 46 mtDNA D-loop sequences (454 base pairs). The horse populations identified were Abyssinian, Bale, Borana, Horro, Kafa, Kundido feral horses, Ogaden and Selale. Mitochondrial DNA D-loop sequences were characterized by 15 variable sites that defined five different haplotypes. All genetic diversity estimates, including Reynolds’ linearized genetic distance, genetic differentiation (FST) and nucleotide sequence divergence (DA), revealed a low genetic differentiation in native Ethiopian horse populations. However, Kundido feral and Borana domestic horses were slightly diverged from the rest of the Ethiopian horse populations. We also tried to shed some light on the matrilineal genetic root of native Ethiopian horses from a network constructed by combining newly generated haplotypes and reference haplotypes deposited in the GenBank for Eurasian type Turkish Anatolian horses that were used as a genetic conduit between Eurasian and African horse populations. Ninety-two haplotypes were generated from the combined Ethio-Eurasian mtDNA D-loop sequences. A network reconstructed from the combined haplotypes using Median-Joining algorithm showed that haplotypes generated from native Ethiopian horses formed separate clusters. The present result encourages further investigation of the genetic origin of native African horses by retrieving additional mtDNA sequences deposited in the GenBank for African and Eurasian type horses.


Heredity ◽  
2021 ◽  
Author(s):  
Yael S. Rodger ◽  
Alexandra Pavlova ◽  
Steve Sinclair ◽  
Melinda Pickup ◽  
Paul Sunnucks

AbstractConservation management can be aided by knowledge of genetic diversity and evolutionary history, so that ecological and evolutionary processes can be preserved. The Button Wrinklewort daisy (Rutidosis leptorrhynchoides) was a common component of grassy ecosystems in south-eastern Australia. It is now endangered due to extensive habitat loss and the impacts of livestock grazing, and is currently restricted to a few small populations in two regions >500 km apart, one in Victoria, the other in the Australian Capital Territory and nearby New South Wales (ACT/NSW). Using a genome-wide SNP dataset, we assessed patterns of genetic structure and genetic differentiation of 12 natural diploid populations. We estimated intrapopulation genetic diversity to scope sources for genetic management. Bayesian clustering and principal coordinate analyses showed strong population genetic differentiation between the two regions, and substantial substructure within ACT/NSW. A coalescent tree-building approach implemented in SNAPP indicated evolutionary divergence between the two distant regions. Among the populations screened, the last two known remaining Victorian populations had the highest genetic diversity, despite having among the lowest recent census sizes. A maximum likelihood population tree method implemented in TreeMix suggested little or no recent gene flow except potentially between very close neighbours. Populations that were more genetically distinctive had lower genetic diversity, suggesting that drift in isolation is likely driving population differentiation though loss of diversity, hence re-establishing gene flow among them is desirable. These results provide background knowledge for evidence-based conservation and support genetic rescue within and between regions to elevate genetic diversity and alleviate inbreeding.


2021 ◽  
Author(s):  
Guai-qiang Chai ◽  
Yizhong Duan ◽  
Peipei Jiao ◽  
Zhongyu Du ◽  
Furen Kang

Abstract Background:Elucidating and revealing the population genetic structure, genetic diversity and recombination is essential for understanding the evolution and adaptation of species. Ammopiptanthus, which is an endangered survivor from the Tethys in the Tertiary Period, is the only evergreen broadleaf shrub grown in Northwest of China. However, little is known about its genetic diversity and underlying adaptation mechanisms. Results:Here, 111 Ammopiptanthus individuals collected from fifteen natural populations in estern China were analyzed by means of the specific locus amplified fragment sequencing (SLAF-seq). Based on the single nucleotide polymorphisms (SNPs) and insertions and deletions (InDels) detected by SLAF-seq, genetic diversity and markers associated with climate and geographical distribution variables were identified. The results of genetic diversity and genetic differentiation revealed that all fifteen populations showed medium genetic diversity, with PIC values ranging from 0.1648 to 0.3081. AMOVA and Fst indicated that a low genetic differentiation existed among populations. Phylogenetic analysis showed that NX-BG and NMG-DQH of fifteen populations have the highest homology,while the genetic structure analysis revealed that these Ammopiptanthus germplasm accessions were structured primarily along the basis of their geographic collection, and that an extensive admixture occurred in each group. In addition, the genome-wide linkage disequilibrium (LD) and principal component analysis showed that Ammopiptanthus nanus had a more diverse genomic background, and all genetic populations were clearly distinguished, although different degrees of introgression were detected in these groups. Conclusion:Our study could provide guidance to the future design of association studies and the systematic utilization and protection of the genetic variation characterizing the Ammopiptanthus.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tian-Qi Shi ◽  
Hai-Mo Shen ◽  
Shen-Bo Chen ◽  
Kokouvi Kassegne ◽  
Yan-Bing Cui ◽  
...  

Malaria incidence has declined dramatically over the past decade and China was certified malaria-free in 2021. However, the presence of malaria in border areas and the importation of cases of malaria parasites are major challenges for the consolidation of the achievements made by China. Plasmodium vivax Duffy binding protein (PvDBP) performs a significant role in erythrocyte invasion, and is considered a promising P. vivax vaccine. However, the highly polymorphic region of PvDBP (PvDBP-II) impedes the development of blood-stage vaccine against P. vivax. In this study, we investigated the genetic diversity and natural selection of PvDBP-II among 124 P. vivax isolates collected from the China-Myanmar border (CMB) in Yunnan Province, China, during 2009–2011. To compare genetic diversity, natural selection, and population structure with CMB isolates, 85 pvdbp-II sequences of eastern Myanmar isolates were obtained from GenBank. In addition, global sequences of pvdbp-II were retrieved from GenBank to establish genetic differentiation relationships and networks with the CMB isolates. In total, 22 single nucleotide polymorphisms reflected in 20 non-synonymous and two synonymous mutations were identified. The overall nucleotide diversity of PvDBP-II from the 124 CMB isolates was 0.0059 with 21 haplotypes identified (Hd = 0.91). The high ratio of non-synonymous to synonymous mutations suggests that PvDBP-II had evolved under positive selection. Population structure analysis of the CMB and eastern Myanmar isolates were optimally grouped into five sub-populations (K = 5). Polymorphisms of PvDBP-II display that CMB isolates were genetically diverse. Mutation, recombination, and positive selection promote polymorphism of PvDBP-II of P. vivax population. Although low-level genetic differentiation in eastern Myanmar was identified along with the more effective malaria control measures, the complexity of population structure in malaria parasites has maintained. In conclusion, findings from this study advance knowledge of the understanding of the dynamic of P. vivax population, which will contribute to guiding the rational design of a PvDBP-II based vaccine.


ZooKeys ◽  
2021 ◽  
Vol 1055 ◽  
pp. 135-148
Author(s):  
Dongqi Liu ◽  
Feng Lan ◽  
Sicai Xie ◽  
Yi Diao ◽  
Yi Zheng ◽  
...  

To investigate the genetic effects on the population of Coreius guichenoti of dam constructions in the upper reaches of the Yangtze River, we analyzed the genetic diversity and population structure of 12 populations collected in 2009 and 2019 using mitochondrial DNA (mtDNA) control regions. There was no significant difference in genetic diversity between 2009 and 2019 (P > 0.05), but the population structure tended to become stronger. Genetic differentiation (FST) among five populations (LX, BB, YB, SF and JA) collected in 2009 was not significant (P > 0.05). However, some populations collected in 2019 were significantly differentiated (P < 0.05), indicating that the population structure has undergone change. A correlation analysis showed that the genetic diversity of the seven populations collected in 2019 was significantly negatively correlated with geographical height (r = −0.808, P = 0.028), indicating that the populations at high elevations were more vulnerable than those at low elevations. In order to prevent the further decrease of genetic diversity and population resources, some conservation and restoration suggestions, such as fish passage and artificial breeding, are put forward.


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