Marked differences in genetic diversity and differentiation between the centre and edge of the geographical range of Megaleranthis saniculifolia (Ranunculaceae), a Korean endemic species

2012 ◽  
Vol 60 (7) ◽  
pp. 582
Author(s):  
Ji Hee Jeong ◽  
Zin-Suh Kim

The amount and distribution of genetic diversity within and between Megaleranthis saniculifolia Ohwi populations were compared between the central and peripheral regions of the species distribution. Allozyme and ISSR markers were used for genetic analysis of six populations from the central region (DY) and five populations from the peripheral region (MJ). Genetic diversity was substantially higher in the DY region than in the MJ region. Relatively uniform homozygote excess at many loci in most populations indicated that M. saniculifolia was influenced by a substantial degree of inbreeding in both regions. The degree of differentiation between populations was remarkably higher in the MJ region than in the DY region. Cluster analysis showed a trend towards separation between regions, although populations in the MJ region exhibited a slightly different trend according to the markers. We conclude that genetic drift has been affecting the populations in the MJ region for a long time, on the basis of their low genetic diversity, high differentiation, U-shaped allele-frequency distribution, and fixation of alleles towards opposing frequencies (1 or 0) among populations. In contrast, the DY region maintained relatively stable populations, although evidence of a recent bottleneck was found in one population. Along with some practical measures for genetic conservation, we present an optimal sample size for ex situ conservation to secure as many common alleles as possible.

ZooKeys ◽  
2020 ◽  
Vol 941 ◽  
pp. 49-69
Author(s):  
Diana Ortíz-Gamino ◽  
Josefat Gregorio ◽  
Luis Cunha ◽  
Esperanza Martínez-Romero ◽  
Carlos Fragoso ◽  
...  

Pontoscolex corethrurus (Müller, 1857) is an invasive tropical earthworm, globally distributed. It reproduces through parthenogenesis, which theoretically results in low genetic diversity. The analysis of the population structure of P. corethrurus using molecular markers may significantly contribute to understanding the ecology and reproductive system of this earthworm species. This work assessed the genetic diversity and population structure of P. corethrurus with 34 polymorphic inter simple sequence repeat markers, covering four populations in tropical and temperate pastures from Veracruz State. Nuclear markers distinguished two genetic clusters, probably corresponding to two distinct genetic lineages. The number of clones detected in the AC population was lower than expected for a parthenogenetic species. Also, the apparent lack of differences in population structures related to the geographic region among the populations studied may indicate that human-mediated transference is prevalent in these areas. Still, most individuals apparently belong to lineage A, and only a few individuals seem to belong to the lineage B. Thus, the admixture signatures found among the four populations of P. corethrurus may have facilitated a successful invasion by directly increasing fitness. In summary, addressing the genetic variation of P. corethrurus with ISSR markers was a suitable approach, as it evidenced the genetic diversity and relationships in the populations evaluated.


Botany ◽  
2014 ◽  
Vol 92 (8) ◽  
pp. 579-587 ◽  
Author(s):  
Zhi-Yun Yang ◽  
Ting-Shuang Yi ◽  
Liang-Qin Zeng ◽  
Xun Gong

Aristolochia delavayi Franch. is an endangered species of the dry hot valleys of the Jinsha River, southwestern China. The genetic diversity and structure of the species and the occurrence of gene flow were investigated with eight inter-simple sequence repeat (ISSR) markers and four plastid loci (matK, trnL-trnT, rps4-trnT, and trnC-rpoB). The analysis of ISSR markers indicated that the genetic diversity of the species is relatively high (PPB = 84.71%). Similarly, a high gene diversity of HT = 0.833 was found based on the four plastid loci. It is possible that this species previously maintained a large effective population size and that the current relict distribution of the species is a result of large-scale fragmentation and habitat destruction. The origin of the species at approximately 3.407 million years ago and the ensuing intraspecific divergence are generally consistent with the history of two major glaciations in this region. Conservation measures are urgently needed to increase the genetic diversity and population size of this species through both in- and ex-situ action.


OCL ◽  
2021 ◽  
Vol 28 ◽  
pp. 3
Author(s):  
Meriem El Harfi ◽  
Jamal Charafi ◽  
Karim Houmanat ◽  
Hafida Hanine ◽  
Abdelghani Nabloussi

There is a need for sesame (Sesamum indicum L.) breeding in Morocco to release performant and adapted varieties, which requires a large genetic variability in the germplasm to be used. In this context, genetic diversity of sesame populations from different locations in Tadla area was investigated using ISSR (Inter Sequence Simple Repeats) markers as a simple method to reveal polymorphism among them. A total of 130 individuals representing 31 populations were sampled. Twenty-four ISSR primers were used for analysis of individuals representing the 31 different sesame populations grown in different agroclimatic zones of Tadla, accounting for 90% of sesame cultivation area in Morocco. Indeed, seven primers showed legible and reproducible genomic profiles with an interesting number of bands. A total of 57 bands were obtained with ISSR primers, of which 47 were polymorphic. PIC (Polymorphic Information Content) ranged from 0.002 to 0.350, showing that ISSR markers are informative and relevant for discriminating the populations evaluated. The similarity coefficient of ISSR data ranged from 0.509 to 1, with an average of 0.870. The results obtained showed that Moroccan sesame populations are characterized by a low genetic diversity, suggesting a genetic proximity among them. Therefore, new germplasm should be either introduced from diverse geographical origins or created through mutagenesis breeding in order to broaden the existing genetic variability.


2001 ◽  
Vol 29 ◽  
pp. 31-40 ◽  
Author(s):  
B. Moioli ◽  
A. Georgoudis ◽  
F. Napolitano ◽  
G. Catillo ◽  
S. Lucioli ◽  
...  

SummaryThe present study is a first step of a global project aiming at the estimation of the genetic distances and relationships among buffalo breeds and sub-populations and the investigation of the production potential and adaptability of different buffalo genotypes in various environments.Genetic diversity of Italian and Greek buffalo populations was estimated on the basis of allele frequencies at nine polymorphic microsatellite loci: CSSM43, CSSM38, DRB3, D21S4, CYP21, CSSM47, CSSM60, CSSM36 and CSSM33. The number of detected alleles per locus varied from two (D21S4) to thirteen (CSSM47). Allele frequency distribution was similar in the two populations, which have the same alleles at the highest frequency at all loci, except loci CSSM47 and CSSM60. Average gene diversity over all loci was 0.60. Across-loci average gene diversity increased with the number of alleles. Observed average heterozygosity was 0.167 and 0.177 in the Italian and Greek populations, respectively. The degree of differentiation between Italian and Greek buffalo was moderate and estimated at 0.021 ± 0.009.


2019 ◽  
Vol 17 (6) ◽  
pp. 536-544 ◽  
Author(s):  
Yves Bawin ◽  
Bart Panis ◽  
Samuel Vanden Abeele ◽  
Zhiying Li ◽  
Julie Sardos ◽  
...  

AbstractCrop wild relatives (CWRs) play a key role in crop breeding by providing beneficial trait characteristics for improvement of related crops. CWRs are more efficiently used in breeding if the plant material is genetically characterized, but the diversity in CWR genetic resources has often poorly been assessed. Seven seed collections of Musa balbisiana, an important CWR of dessert and cooking bananas, originating from three natural populations, two feral populations and two ex situ field collections were retrieved and their genetic diversity was quantified using 18 microsatellite markers to select core subsets that conserve the maximum genetic diversity. The highest genetic diversity was observed in the seed collections from natural populations of Yunnan, a region that is part of M. balbisiana's centre of origin. The seeds from the ex situ field collections were less genetically diverse, but contained unique variation with regards to the diversity in all seed collections. Seeds from feral populations displayed low genetic diversity. Core subsets that maximized genetic distance incorporated almost no seeds from the ex situ field collections. In contrast, core subsets that maximized allelic richness contained seeds from the ex situ field collections. We recommend the conservation and additional collection of seeds from natural populations, preferentially originating from the species' region of origin, and from multiple individuals in one population. We also suggest that the number of seeds used for ex situ seed bank regeneration must be much higher for the seed collections from natural populations.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7297 ◽  
Author(s):  
Hideyuki Ito ◽  
Miho Inoue-Murayama

We examined genetic diversity of the wild Tsushima leopard cat—a regional population of the Amur leopard cat—using microsatellite markers. In addition, we compared genetic diversity of the Tsushima leopard cat with that of the Korean population of Amur leopard cat. Although bias should be considered when applying cross-species amplification, the Tsushima leopard cat showed a lower index of molecular genetic diversity than did the Korean population. These results were consistent with those obtained using other genetic markers, such as mitochondrial DNA and Y chromosome sequences. This low genetic diversity of the wild Tsushima leopard cat may be derived from the founding population. Furthermore, our results suggest that the captive populations held in Japanese zoos may show extremely low genetic diversity, leading to difficulties in genetic management of the Tsushima leopard cat. Moreover, the two regional populations were clearly separated using these marker sets. In the present study, we demonstrated that the genetic diversity of the Tsushima leopard cat is extremely low compared with that of the continental regional population. Importantly, the Japanese captive population for ex situ conservation was derived from a founding population with extremely low genetic diversity; hence, we assume that both the captive and wild populations showed extremely low genetic diversities. Our findings emphasize the need to develop carefully considered management strategies for genetic conservation.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sakina Elshibli ◽  
Helena Korpelainen

Medemia argun is a wild, dioecious palm, adapted to the harsh arid environment of the Nubian Desert in Sudan and southern Egypt. There is a concern about its conservation status, since little is known about its distribution, abundance, and genetic variation. M. argun grows on the floodplains of seasonal rivers (wadis). The continuing loss of suitable habitats in the Nubian Desert is threatening the survival of this species. We analyzed the genetic diversity, population genetic structure, and occurrence of M. argun populations to foster the development of conservation strategies for M. argun. Genotyping-by-sequencing (GBS) analyses were performed using a whole-genome profiling service. We found an overall low genetic diversity and moderate genetic structuring based on 40 single-nucleotide polymorphisms (SNPs) and 9,866 SilicoDArT markers. The expected heterozygosity of the total population (HT) equaled 0.036 and 0.127, and genetic differentiation among populations/groups (FST) was 0.052 and 0.092, based on SNP and SilicoDArT markers, respectively. Bayesian clustering analyses defined five genetic clusters that did not display any ancestral gene flow among each other. Based on SilicoDArT markers, the results of the analysis of molecular variance (AMOVA) confirmed the previously observed genetic differentiation among generation groups (23%; p < 0.01). Pairwise FST values indicated a genetic gap between old and young individuals. The observed low genetic diversity and its loss among generation groups, even under the detected high gene flow, show genetically vulnerable M. argun populations in the Nubian Desert in Sudan. To enrich and maintain genetic variability in these populations, conservation plans are required, including collection of seed material from genetically diverse populations and development of ex situ gene banks.


2020 ◽  
Vol 126 (6) ◽  
pp. 1029-1038
Author(s):  
Bilal Muhammad Sharif ◽  
Concetta Burgarella ◽  
Fabien Cormier ◽  
Pierre Mournet ◽  
Sandrine Causse ◽  
...  

Abstract Background and Aims Inferring the diffusion history of many human-dispersed species is still not straightforward due to unresolved past human migrations. The centre of diversification and routes of migration of the autopolyploid and clonally propagated greater yam, Dioscorea alata, one of the oldest edible tubers, remain unclear. Here, we address yam demographic and dispersal history using a worldwide sample. Methods We characterized genome-wide patterns of genetic variation using genotyping by sequencing 643 greater yam accessions spanning four continents. First, we disentangled the polyploid and clonal components of yam diversity using allele frequency distribution and identity by descent approaches. We then addressed yam geographical origin and diffusion history with a model-based coalescent inferential approach. Key Results Diploid genotypes were more frequent than triploids and tetraploids worldwide. Genetic diversity was generally low and clonality appeared to be a main factor of diversification. The most likely evolutionary scenario supported an early divergence of mainland Southeast Asian and Pacific gene pools with continuous migration between them. The genetic make-up of triploids and tetraploids suggests that they have originated from these two regions before westward yam migration. The Indian Peninsula gene pool gave origin to the African gene pool, which was later introduced to the Caribbean region. Conclusions Our results are congruent with the hypothesis of independent domestication origins of the two main Asian and Pacific gene pools. The low genetic diversity and high clonality observed suggest a strong domestication bottleneck followed by thousands of years of widespread vegetative propagation and polyploidization. Both processes reduced the extent of diversity available for breeding, and this is likely to threaten future adaptation.


Author(s):  
Luiz Sergio Costa Duarte Filho ◽  
Edson Ferreira Da Silva ◽  
Danielson Ramos Ribeiro ◽  
Allison Vieira Da Silva ◽  
Iêda Ferreira De Oliveira

In order to assure and evaluate the genetic diversity, wild populations of Cotton (Gossypium mustelinum) were collected and evaluated from the coastal plain north of Pernambuco, Brazil. Such populations occur in urban areas in a state of real expansion and with imminent risks of extinction. As a result of these risks and the state of real expansion, aiming at the ex situ conservation of these genetic resources, branches of 66 plants were collected in three populations of G. mustelinum that are located in restinga vegetation in the localities of Ponta de Pedras and Bara of Catuama, both in the municipality of Goiana and in the locality Sossego Beach in the municipality Island of Itamaracá. The collected genotypes were inserted in a new Germplasm Bank (BAG) at the Federal Rural University of Pernambuco, after which a sample composed of 24 genotypes contained in the BAG was collected to perform genetic diversity studies using molecular markers of ISSR type. For the molecular analysis, 24 accesses with 4 ISSR primers were analyzed, which produced a total of 36 bands, with a mean of 1,52 alleles per amplified locus. The genetic dissimilarity values, calculated according to the complement of the Jaccard index, ranged from 0.000 to 0.080. The UPGMA method grouped the accesses into three groups. The UFRPE30, UFRPE42 and UFRPE45 accessions were more dissimilar and UFRPE-48, UFRPE-50, UFRPE-52, UFRPE-55, UFRPE60, UFRPE06, UFRPE28, UFRPE29, UFRPE1, UFRPE2, UFRPE17 the least dissimilar. The ISSR markers used in this study demonstrated efficiency in the detection of molecular polymorphisms, revealing genetic variability among the 24 accessions. Considering the results obtained in this work, it is possible to infer that there is considerable genetic variability among the accessions of cotton, demonstrating the importance of the markers in the analysis of variability of species not studied, such as (G. mustelinum).


2020 ◽  
Vol 190 (1) ◽  
pp. 384-395
Author(s):  
Michael Joseph Jowers ◽  
João Queirós ◽  
Rui Resende Pinto ◽  
Abdullahi H Ali ◽  
Mathew Mutinda ◽  
...  

Abstract The hirola antelope (Beatragus hunteri) is considered to be the most endangered antelope in the world. In the ex situ translocated population at Tsavo East National Park, calf mortality and the critically low population numbers might suggest low genetic diversity and inbreeding depression. Consequently, a genetic study of the wild population is pivotal to gain an understanding of diversity and differentiation within its range before designing future translocation plans to increase the genetic diversity of the ex situ population. For that purpose, we assessed 55 individuals collected across five localities in eastern Kenya, covering its entire natural range. We used the complete mitochondrial DNA control region and microsatellite genotyping to estimate genetic diversity and differentiation across its range. Nuclear genetic diversity was moderate in comparison to other endangered African antelopes, with no signals of inbreeding. However, the mitochondrial data showed low nucleotide diversity, few haplotypes and low haplotypic differentiation. Overall, the inferred low degree of genetic differentiation and population structure suggests a single population of hirola across the natural range. An overall stable population size was inferred over the recent history of the species, although signals of a recent genetic bottleneck were found. Our results show hope for ongoing conservation management programmes and that there is a future for the hirola in Kenya.


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