scholarly journals Diversity and Cytogenomic Characterization of Wild Carrots in the Macaronesian Islands

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1954
Author(s):  
Guilherme Roxo ◽  
Mónica Moura ◽  
Pedro Talhinhas ◽  
José Carlos Costa ◽  
Luís Silva ◽  
...  

The Macaronesian islands constitute an enormous reservoir of genetic variation of wild carrots (subtribe Daucinae; Apiaceae), including 10 endemic species, but an accurate understanding of the diversification processes within these islands is still lacking. We conducted a review of the morphology, ecology, and conservation status of the Daucinae species and, on the basis of a comprehensive dataset, we estimated the genome size variation for 16 taxa (around 320 samples) occurring in different habitats across the Macaronesian islands in comparison to mainland specimens. Results showed that taxa with larger genomes (e.g., Daucus crinitus: 2.544 pg) were generally found in mainland regions, while the insular endemic taxa from Azores and Cabo Verde have smaller genomes. Melanoselinum decipiens and Monizia edulis, both endemic to Madeira Island, showed intermediate values. Positive correlations were found between mean genome size and some morphological traits (e.g., spiny or winged fruits) and also with habit (herbaceous or woody). Despite the great morphological variation found within the Cabo Verde endemic species, the 2C-values obtained were quite homogeneous between these taxa and the subspecies of Daucus carota, supporting the close relationship among these taxa. Overall, this study improved the global knowledge of DNA content for Macaronesian endemics and shed light into the mechanisms underpinning diversity patterns of wild carrots in the western Mediterranean region.

2021 ◽  
Vol 9 ◽  
Author(s):  
Miguel Brilhante ◽  
Guilherme Roxo ◽  
Sílvia Catarino ◽  
Patrícia dos Santos ◽  
J. Alfredo Reyes-Betancort ◽  
...  

The rich endemic flora of the Macaronesian Islands places these oceanic archipelagos among the top biodiversity hotspots worldwide. The radiations that have determined the evolution of many of these insular lineages resulted in a wealth of endemic species, many of which occur in a wide range of ecological niches, but show small distribution areas in each of them. Aeonium (Crassulaceae) is the most speciose lineage in the Canary Islands (ca. 40 taxa), and as such can be considered a good model system to understand the diversification dynamics of oceanic endemic floras. The present study aims to assess the genome size variation within Aeonium distribution, i.e., the Macaronesian archipelagos of Madeira, Canaries and Cabo Verde, and analyse it together with information on distribution (i.e., geography and conservation status), taxonomy (i.e., sections), morphological traits (i.e., growth-form), geological data (i.e., island's geological age), and environmental variables (i.e., altitude, annual mean temperature, and precipitation). Based on extensive fieldwork, a cytogeographic screening of 24 Aeonium species was performed. The conservation status of these species was assessed based on IUCN criteria. 61% of the taxa were found to be threatened (4% Endangered and 57% Vulnerable). For the first time, the genome size of a comprehensive sample of Aeonium across the Macaronesian archipelagos was estimated, and considerable differences in Cx-values were found, ranging from 0.984 pg (A. dodrantale) to 2.768 pg (A. gorgoneum). An overall positive correlation between genome size and conservation status was found, with the more endangered species having the larger genomes on average. However, only slight relationships were found between genome size, morphological traits, and environmental variables. These results underscore the importance of characterizing the cytogenomic diversity and conservation status of endemic plants found in Macaronesian Islands, providing, therefore, new data to establish conservation priorities.


Crop Science ◽  
2004 ◽  
Vol 44 (1) ◽  
pp. 261 ◽  
Author(s):  
A. Lane Rayburn ◽  
D. P. Biradar ◽  
R. L. Nelson ◽  
R. McCloskey ◽  
K. M. Yeater

2017 ◽  
Vol 4 (9) ◽  
pp. 170862 ◽  
Author(s):  
H. Ritchie ◽  
A. J. Jamieson ◽  
S. B. Piertney

Genome size varies considerably across taxa, and extensive research effort has gone into understanding whether variation can be explained by differences in key ecological and life-history traits among species. The extreme environmental conditions that characterize the deep sea have been hypothesized to promote large genome sizes in eukaryotes. Here we test this supposition by examining genome sizes among 13 species of deep-sea amphipods from the Mariana, Kermadec and New Hebrides trenches. Genome sizes were estimated using flow cytometry and found to vary nine-fold, ranging from 4.06 pg (4.04 Gb) in Paralicella caperesca to 34.79 pg (34.02 Gb) in Alicella gigantea . Phylogenetic independent contrast analysis identified a relationship between genome size and maximum body size, though this was largely driven by those species that display size gigantism. There was a distinct shift in the genome size trait diversification rate in the supergiant amphipod A. gigantea relative to the rest of the group. The variation in genome size observed is striking and argues against genome size being driven by a common evolutionary history, ecological niche and life-history strategy in deep-sea amphipods.


Genome ◽  
2016 ◽  
Vol 59 (6) ◽  
pp. 393-402 ◽  
Author(s):  
Nicholas W. Jeffery ◽  
Kristin Hultgren ◽  
Solomon Tin Chi Chak ◽  
T. Ryan Gregory ◽  
Dustin R. Rubenstein

Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony.


Caryologia ◽  
2015 ◽  
Vol 68 (2) ◽  
pp. 92-96 ◽  
Author(s):  
Oriane Hidalgo ◽  
Joan Vallès ◽  
Angel Romo ◽  
Miguel-Ángel Canela ◽  
Teresa Garnatje

2008 ◽  
Vol 276 (3-4) ◽  
pp. 209-217 ◽  
Author(s):  
Itayguara Ribeiro da Costa ◽  
Marcelo Carnier Dornelas ◽  
Eliana Regina Forni-Martins

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
C. P. Stelzer ◽  
J. Blommaert ◽  
A. M. Waldvogel ◽  
M. Pichler ◽  
B. Hecox-Lea ◽  
...  

Abstract Background Eukaryotic genomes are known to display an enormous variation in size, but the evolutionary causes of this phenomenon are still poorly understood. To obtain mechanistic insights into such variation, previous studies have often employed comparative genomics approaches involving closely related species or geographically isolated populations within a species. Genome comparisons among individuals of the same population remained so far understudied—despite their great potential in providing a microevolutionary perspective to genome size evolution. The rotifer Brachionus asplanchnoidis represents one of the most extreme cases of within-population genome size variation among eukaryotes, displaying almost twofold variation within a geographic population. Results Here, we used a whole-genome sequencing approach to identify the underlying DNA sequence differences by assembling a high-quality reference genome draft for one individual of the population and aligning short reads of 15 individuals from the same geographic population including the reference individual. We identified several large, contiguous copy number variable regions (CNVs), up to megabases in size, which exhibited striking coverage differences among individuals, and whose coverage overall scaled with genome size. CNVs were of remarkably low complexity, being mainly composed of tandemly repeated satellite DNA with only a few interspersed genes or other sequences, and were characterized by a significantly elevated GC-content. CNV patterns in offspring of two parents with divergent genome size and CNV patterns in several individuals from an inbred line differing in genome size demonstrated inheritance and accumulation of CNVs across generations. Conclusions By identifying the exact genomic elements that cause within-population genome size variation, our study paves the way for studying genome size evolution in contemporary populations rather than inferring patterns and processes a posteriori from species comparisons.


2015 ◽  
Vol 57 (1) ◽  
pp. 104-113
Author(s):  
Sandra Cichorz ◽  
Maria Gośka ◽  
Monika Rewers

AbstractSinceM. sinensisAnderss.,M. sacchariflorus(Maxim.) Hack. andM. ×giganteusJ.M.Greef & Deuter ex Hodk. and Renvoize have considerably the highest potential for biomass production amongMiscanthusAnderss. species, there is an urgent need to broaden the knowledge about cytological characteristics required for their improvement. In this study our objectives were to assess the genome size variation among eighteenMiscanthusaccessions, as well as estimation of the monoploid genome size (2C and Cx) of theM. sinensiscultivars, which have not been analyzed yet. The characterization of threeMiscanthusspecies was performed with the use of flow cytometry and analysis of the stomatal length. The triploid (2n = 3x = 57)M. sinensis‘Goliath’ andM. ×giganteusclones possessed the highest 2C DNA content (8.34 pg and 7.43 pg, respectively). The intermediate 2C-values were found in the nuclei of the diploid (2n = 2x = 38)M. sinensisaccessions (5.52–5.72 pg), whereas they were the lowest in the diploid (2n = 2x = 38)M. sacchariflorusecotypes (4.58–4.59 pg). The presented study revealed interspecific variation of nuclear DNA content (P<0.01) and therefore allowed for recognition of particular taxa, inter- and intraspecific hybrids and prediction of potential parental components. Moreover, intraspecific genome size variation (P<0.01) was observed inM. sinensiscultivars at 3.62%. The values of the stomatal size obtained for the triploidM. ×giganteus‘Great Britain’ (mean 30.70 μm) or ‘Canada’ (mean 29.67 μm) and diploidM. sinensis‘Graziella’ (mean 29.96 μm) did not differ significantly, therefore this parameter is not recommended for ploidy estimation.


1989 ◽  
Vol 53 (3) ◽  
pp. 173-182 ◽  
Author(s):  
Chara J. Ragland ◽  
John R. Gold

SummaryGenome sizes (nuclear DNA contents) were documented spectrophotometrically from individuals of each of nine species of the North American centrarchid (sunfish) genus Lepomis. The distributions of DNA values within and among the nine species were essentially normal and continuous, suggesting that changes in DNA quantity in Lepomis are small in amount, involve both gains and losses of DNA, and are cumulative and independent in effect. Significant differences in mean genome size were found between individuals within populations in all nine species and between species. Nested analysis of variance and comparisons of average genome size difference or distance between individuals drawn from different levels of taxonomic organization revealed that the majority of genome size divergence in Lepomis occurs above the hierarchical level of individuals within populations. The Lepomis data when compared to similar data from North American cyprinid fishes appear to suggest that: (i) genome size evolution in these fishes at least follows a continuous rather than a discontinuous mode; (ii) the general predictions of hypothetical models relating genome size variation as a function of organismal position along adaptive continua may be oversimplified, or not applicable to complex, higher eukaryotes; and (iii) changes in genome size in these fishes may be concentrated in speciation episodes.


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