scholarly journals Multiple founder events explain the genetic diversity and structure of the model allopolyploid grass Brachypodium hybridum in the Iberian Peninsula hotspot

2019 ◽  
Author(s):  
Valeriia Shiposha ◽  
Isabel Marques ◽  
Diana López-Alvarez ◽  
Antonio J Manzaneda ◽  
Pilar Hernandez ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Iberian Peninsula ◽  
Diploid Species ◽  
Evolutionary Analysis ◽  
Multiple Origins ◽  
Model Complex ◽  
Genetic Diversity And Structure ◽  
Nuclear Ssr

Abstract Background and Aims It is accepted that contemporary allopolyploid species have originated recurrently, but very few cases have been documented using multiple natural formations of the same species. To extend our knowledge, we have investigated the multiple origins, genetic variation, and structure of the allotetraploid grass Brachypodium hybridum with respect to its progenitor diploid species B. distachyon (D genome) and B. stacei (S genome). For this, our primary focus is the Iberian Peninsula, an evolutionary hotspot for the genus Brachypodium. Methods We analysed 342 B. hybridum individuals from 36 populations using 10 nuclear SSR loci and two plastid loci. The B. hybridum genetic profiles were compared with those previously reported for B. stacei and B. distachyon. In addition, phylogenetic analysis of the plastid data was performed for a reduced subset of individuals. Key Results The nuclear SSR genetic analysis detected medium to high genetic diversity, with a strong south-to-north genetic structure cline, and a high selfing rate in B. hybridum. Comparative genetic analysis showed a close relatedness of current B. hybridum D allelic profiles with those of B. distachyon, but a lack of similarity with those of B. stacei, suggesting another B. stacei source for the B. hybridum S alleles. Plastid analysis detected three different bidirectional allopolyploidization events: two involved distinct B. distachyon-like ancestors and one involved a B. stacei-like ancestor. The Southeastern (SE) Iberian Peninsula B. hybridum populations were more genetically diverse and could have originated from at least two hybridization events whereas Northeaster-Northwestern (NE-NW) Iberian Peninsula B. hybridum populations were less diverse and may have derived from at least one hybridization event. Conclusions The genetic and evolutionary evidence support the plausible in situ origin of the SE and northern Iberian Peninsula B. hybridum allopolyploids from their respective local B. distachyon and unknown B. stacei ancestors. The untapped multiple origins and genetic variation detected in these B. hybridum populations opens the way to future evolutionary analysis of allopolyploid formation and genomic dominance and expression in the B. hybridum – B. distachyon – B. stacei grass model complex.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

scholarly journals Genetic analysis of silver-fir populations in the Beskids

2011 ◽  
Vol 72 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Leon Mejnartowicz
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Abies Alba ◽  
Genetic Distances ◽  
Silver Fir ◽  
Geographical Distance ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Rare Alleles

Twenty-eight isozymic loci were studied in the Beskid Mts., in four populations of common silver-fir (<em>Abies alba</em>): one in Beskid Makowski (BM) and three populations in Beskid Sądecki (BS). Their genetic variation and diversity were analyzed, and Nei's genetic distances between the populations were calculated. The results show that the geographical distance between the BM population and the three BS populations is reflected in genetic distances. The BM population is clearly distinct from the others. It has the lowest genetic diversity (<em>I</em> = <em>0.42</em>), percentage of polymorphic loci <em>(%PoL </em>= <em>64.29</em>) and number of rare alleles (<em>NoRa </em>= <em>5</em>). Besides, the BM population has the highest observed heterozygosity (<em>Ho </em>= <em>0.291</em>), which exceeds the expected heterozygosity (<em>He </em>= <em>0.254</em>), estimated on the basis of the Hardy-Weinberg Principle. On the contrary, BS populations are in the state of equilibrium, which is manifested, in similar values of <em>He </em>= <em>0.262 </em>and <em>Ho </em>= <em>0.264</em>.

scholarly journals Conservation genetics of the threatened plant species Physaria filiformis (Missouri bladderpod) reveals strong genetic structure and a possible cryptic species

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247586
Author(s):  
Christine E. Edwards ◽  
Brooke C. Tessier ◽  
Joel F. Swift ◽  
Burgund Bassüner ◽  
Alexander G. Linan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Plant Species ◽  
Genetic Drift ◽  
Rare Species ◽  
Ex Situ ◽  
Ouachita Mountains ◽  
Genetic Diversity And Structure ◽  
Genetic Clusters

Understanding genetic diversity and structure in a rare species is critical for prioritizing both in situ and ex situ conservation efforts. One such rare species is Physaria filiformis (Brassicaceae), a threatened, winter annual plant species. The species has a naturally fragmented distribution, occupying three different soil types spread across four disjunct geographical locations in Missouri and Arkansas. The goals of this study were to understand: (1) whether factors associated with fragmentation and small population size (i.e., inbreeding, genetic drift or genetic bottlenecks) have reduced levels of genetic diversity, (2) how genetic variation is structured and which factors have influenced genetic structure, and (3) how much extant genetic variation of P. filiformis is currently publicly protected and the implications for the development of conservation strategies to protect its genetic diversity. Using 16 microsatellite markers, we genotyped individuals from 20 populations of P. filiformis from across its geographical range and one population of Physaria gracilis for comparison and analyzed genetic diversity and structure. Populations of P. filiformis showed comparable levels of genetic diversity to its congener, except a single population in northwest Arkansas showed evidence of a genetic bottleneck and two populations in the Ouachita Mountains of Arkansas showed lower genetic variation, consistent with genetic drift. Populations showed isolation by distance, indicating that migration is geographically limited, and analyses of genetic structure grouped individuals into seven geographically structured genetic clusters, with geographic location/spatial separation showing a strong influence on genetic structure. At least one population is protected for all genetic clusters except one in north-central Arkansas, which should therefore be prioritized for protection. Populations in the Ouachita Mountains were genetically divergent from the rest of P. filiformis; future morphological analyses are needed to identify whether it merits recognition as a new, extremely rare species.

scholarly journals How diverse can rare species be on the margins of genera distribution?

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alice Backes ◽  
Geraldo Mäder ◽  
Caroline Turchetto ◽  
Ana Lúcia Segatto ◽  
Jeferson N Fregonezi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Habitat Loss ◽  
Evolutionary History ◽  
Founder Effects ◽  
Geographical Isolation ◽  
Genetic Diversity And Structure ◽  
Genetic Patterns

Abstract Different genetic patterns have been demonstrated for narrowly distributed taxa, many of them linking rarity to evolutionary history. Quite a few species in young genera are endemics and have several populations that present low variability, sometimes attributed to geographical isolation or dispersion processes. Assessing the genetic diversity and structure of such species may be important for protecting them and understanding their diversification history. In this study, we used microsatellite markers and plastid sequences to characterize the levels of genetic variation and population structure of two endemic and restricted species that grow in isolated areas on the margin of the distribution of their respective genera. Plastid and nuclear diversities were very low and weakly structured in their populations. Evolutionary scenarios for both species are compatible with open-field expansions during the Pleistocene interglacial periods and genetic variability supports founder effects to explain diversification. At present, both species are suffering from habitat loss and changes in the environment can lead these species towards extinction.

scholarly journals Development and characterization of microsatellite markers for two subspecies of Handroanthus chrysanthus

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Augusta Yadira Cueva-Agila ◽  
Carlos Manchego ◽  
Cristian Bastidas ◽  
Manuel Curto
Keyword(s):  
Genetic Diversity ◽  
South America ◽  
Genetic Analysis ◽  
Microsatellite Markers ◽  
High Throughput Sequencing ◽  
Biodiversity Loss ◽  
Important Species ◽  
Polymorphic Microsatellites ◽  
Genetic Diversity And Structure

Abstract An understanding of the genetic diversity and structure of plant species is essential in order to comprehend the degree of biodiversity loss and to develop successful restoration programs. Handroanthus is an important genus that presents one of the most valuable timbers of South America. Handroanthus chrysanthus is an important species distributed in Central and South America. Microsatellite markers are not previously developed for this species. Ten microsatellites for Handroanthus chrysanthus developed using high-throughput sequencing are presented here. The usefulness of these microsatellite loci for the genetic analysis of subspecies H. chrysanthus subsp. chrysanthus (distributed in coastal dry forests) and subspecies H. chrysanthus subsp. meridionalis (distributed in premontane moist forests) is analyzed. At least eight polymorphic microsatellites are useful for each subspecies, seven of which can be used in both subspecies.

Genetic variation within and among populations of Camelliajaponica (Theaceae) in Korea

1996 ◽  
Vol 26 (4) ◽  
pp. 537-542 ◽  
Author(s):  
Myong Gi Chung ◽  
Soon Suk Kang
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Pollen Dispersal ◽  
Island Populations ◽  
Generation Times ◽  
Genetic Diversity And Structure ◽  
Stump Sprouting ◽  
Ability To Regenerate ◽  
The Mean ◽  
High Level

The genetic diversity and structure of 17 Korean populations of Camelliajaponica L., a broad-leaved evergreen tree, was examined. Although most populations are restricted to several islands near the southern and southwestern coast of the Korean Peninsula, they maintain higher levels of genetic variation within populations than do long-lived, woody angiosperms. For example, 13 of 16 loci examined were polymorphic in at least one population, the mean number of alleles per locus was 2.63, and mean expected heterozygosity was 0.265. These values were comparable with those for continuously distributed, mainland populations of C. japonica in Japan. However, a considerably high level of heterozygote deficiency was observed in Korean populations of C. japonica (mean FIS = 0.202). About 13% of the total genetic variation was found among populations (GST = 0.129). Indirect estimates of the number of migrants per generation (1.69, calculated from FST; 2.14, calculated from the mean frequency of eight private alleles) indicate that gene flow among island populations is moderate. Factors contributing to the high levels of genetic diversity found in the entire species of C. japonica include long generation times, ability to regenerate by stump sprouting, predominant outcrossing induced by animal vectors, and occasional pollen dispersal by birds.

scholarly journals The Multiple Origins of Roe Deer Populations in Western Iberia and Their Relevance for Conservation

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2419
Author(s):  
Tânia Barros ◽  
Eduardo Ferreira ◽  
Rita Gomes Rocha ◽  
Gonçalo Brotas ◽  
Juan Carranza ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Nuclear Dna ◽  
Roe Deer ◽  
Capreolus Capreolus ◽  
Global Changes ◽  
Multiple Origins ◽  
Relict Population ◽  
Genetic Diversity And Structure ◽  
Genetic Clusters ◽  
Management And Conservation

The roe deer (Capreolus capreolus) is native and widespread in Europe and its phylogeography has been clarified in the last decades. Southern peninsulas are considered as reservoirs of genetic diversity and the source for the recolonization of Europe after the last glacial maximum. Even though roe deer populations have been genetically characterized, there is a major knowledge gap about the populations at the western edge of its distribution. To fill this caveat, and based on mitochondrial and nuclear DNA data, we aim to: (i) characterize the genetic diversity and structure of roe deer in western Iberia; (ii) clarify the origins and phylogeographical affinities of these populations, namely the relict population from Peneda Gerês National Park (PNPG, Portugal) and the likely allochthonous populations from central and south (CS) Portugal; (iii) discuss the implications of our findings for the management and conservation of the roe deer. Three major genetic clusters were inferred based on nuclear genotypes and were structured in a similar way as the three major mtDNA clades present in Iberia. Patterns inferred with nuclear markers confirmed PNPG as a relict population. Roe deer from CS Portugal share haplotypes with Central Europe rather than with other western Iberian populations, confirming its mainly allochthonous origin. Our results highlight western Iberia as a diversity hotspot for roe deer. We highlight the role of intraspecific genetic diversity as a source of resilience against ongoing global changes; the need for transboundary management and the importance of genetic data to inform management and conservation. When considered, repopulation or translocation measures should follow the IUCN Law of Reintroductions and meticulously conducted in order to preserve the genetic heritage of the species.

scholarly journals Genetic diversity and structure of Astrocaryum jauari (Mart.) palm in two Amazon river basins

2014 ◽  
Vol 14 (3) ◽  
pp. 166-173 ◽  
Author(s):  
Liliane D. Santos Oliveira ◽  
Santiago L. Ferreyra Ramos ◽  
Maria T. Gomes Lopes ◽  
Gabriel Dequigiovanni ◽  
Elizabeth Ann Veasey ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Microsatellite Loci ◽  
Plant Material ◽  
Spatial Genetic Structure ◽  
River Basins ◽  
Genetic Analyses ◽  
Main River ◽  
Genetic Diversity And Structure

Astrocaryum jauari is a non-domesticated palm that is exploited by poachers. Our objective was to investigate the organization of the geneticdiversity and structure of three A. jauari populations. The study was carried out in the state of Amazonas, between the municipalities of Coari and Manaus. Nine microsatellite loci were used for the genetic analyses. High genetic variation was found, with a mean number of alleles per locus varying from 3.9 to 4.4. The average observed heterozygosity, varying from 0.71 to 0.78, was higher than expected. No spatial genetic structure was detected, since only one cluster was observed. Our results indicate a possible dispersion strategy and suggest that conservation measures of this species should focus mainly on the populations found at the end of the main river (Solimões) where most of the plant material originating from the headwaters of the tributaries of this river is concentrated.

Sign in / Sign up

Export Citation Format

Share Document