Genetic diversity of three Aegla species (Decapoda, Anomura) revealed by AFLP and mtDNA markers

Crustaceana ◽  
2019 ◽  
Vol 92 (4) ◽  
pp. 445-462
Author(s):  
Bianca L. Zimmermann ◽  
Jober V. De Vargas Machado ◽  
Sandro Santos ◽  
Marlise L. Bartholomei-Santos
Keyword(s):  
Genetic Diversity ◽  
Distinct Species ◽  
Genetic Distances ◽  
Species Level ◽  
Taxonomic Resolution ◽  
Similar Species ◽  
Southern Brazil ◽  
Low Levels ◽  
Management And Conservation ◽  
Mtdna Markers

Abstract Representatives of the genus Aegla present a conserved morphology; thus, the increased use of molecular markers has raised many taxonomic issues. We used AFLP and mtDNA to investigate the genetic differentiation and phylogenetic relationships of morphologically similar species with overlapping distribution areas in southern Brazil: A. georginae, A. ludwigi, and A. platensis. While A. platensis is widely distributed, the critically endangered A. georginae and A. ludwigi have limited distributions. Although both markers showed populations with low levels of genetic variability, they differed markedly in revealing relationships between populations; according to AFLP, the genetic distances between A. platensis populations were as high as those between distinct species, a result not observed when considering mtDNA data. We emphasize that the use of multiple lines of evidence is necessary for defining correct levels of genetic diversity and a good species-level taxonomic resolution. Such features are essential for the management and conservation of Aegla species.

A karyological study of the genus Pnigalio Schrank (Hymenoptera: Eulophidae): Assessing the taxonomic utility of chromosomes at the species level

2011 ◽  
Vol 102 (1) ◽  
pp. 43-50 ◽  
Author(s):  
M. Gebiola ◽  
M. Giorgini ◽  
P. Navone ◽  
U. Bernardo
Keyword(s):  
Relative Length ◽  
Distinct Species ◽  
Species Level ◽  
Similar Species ◽  
Karyological Study ◽  
Centromeric Index ◽  
Interspecific Variability ◽  
Reciprocal Differences ◽  
Karyotype Structure

AbstractWe provide a karyological study of 12 species of the genus Pnigalio in an attempt to evaluate the taxonomic utility of karyotypes at the species level. For all species of Pnigalio examined the number of chromosome was 2n=12. Karyotype formulae presented mainly metacentric and submetacentric chromosomes, although a pair of acrocentrics or subtelocentrics, shorter than biarmed chromosomes, was present in some species. The analysis of karyotypes of Pnigalio showed frequent but not general interspecific variability of the chromosome traits. Although most of the studied species revealed concordance between morphological and karyological characters (centromeric index and relative length), two other categories have been identified: morphologically distinct species without reciprocal differences in karyotype structure, and morphologically similar species that strongly differ in chromosomal characters.

Genetic variation in the widespread Embothrium coccineum (Proteaceae) endemic to Patagonia: effects of phylogeny and historical events

2007 ◽  
Vol 55 (8) ◽  
pp. 809 ◽  
Author(s):  
Cintia P. Souto ◽  
Andrea C. Premoli
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Life History Traits ◽  
Glacial Refugia ◽  
Genetic Distances ◽  
Species Level ◽  
Historical Events ◽  
Adult Trees ◽  
Cold Tolerant ◽  
Parsimony Trees

Allozyme electrophoresis was used to measure and compare, with other members of the Proteaceae, levels and distribution of genetic diversity in Embothrium coccineum J.R.Forst., a widespread outcrossing species endemic of Andean Patagonian forests. We analysed variation at the species level by sampling 34 populations along its entire range of ~20° latitude. We tested the hypothesis of multiple Pleistocene refugia by phylogeographic methods. We resolved 16 isozyme loci assayed in 934 adult trees. At the species level, total genetic diversity (HT = 0.220) was similar to that of other outcrossed and widespread plant species. Genetic parameters (NA, PSS, HE) were not statistically different from other outcrossed but mostly range-restricted Proteaceae, reflecting a strong phylogenetic imprinting for species sharing life-history traits. Populations are genetically divergent among each other (FST = 0.202). The low correlation between geographic and genetic distances suggests separate histories, i.e. multiple glacial refugia for the cold-tolerant E. coccineum. Phylogeographic trees produced different topologies, although maximum likelihood and parsimony trees shared some elements. Both trees suggest a northern and central clade, and then a separate southern clade. Current processes such as gene flow and selection confound the historic signal. These results seem in contrast to many of the northern hemisphere post-glacial phylogeographic reconstructions which show clear historical tracks of northern range expansion from southern refugia. The present study highlights the importance of phylogenetic imprinting, life-history traits and historical events driving genetic diversity patterns in this widespread Proteaceae from southern South America.

Genetic variation in sand pine (Pinusclausa)

1996 ◽  
Vol 26 (2) ◽  
pp. 244-254 ◽  
Author(s):  
Kathleen C. Parker ◽  
J.L. Hamrick
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Genetic Distances ◽  
Species Level ◽  
Allozyme Diversity ◽  
Present Distribution ◽  
Genetic Bottlenecks ◽  
Florida Panhandle ◽  
Sand Pine

Pinusclausa (Chapm. ex Engelm.) Vasey ex Sarg. is a member of subsection Contortae that is restricted to Florida and the southern tip of Alabama. The present distribution of P. clausa is divided into two purported varieties: var. clausa in peninsular Florida and var. immuginata primarily in the Florida panhandle. We determined allozyme diversity and population genetic structure for 12 populations of var. clausa and 9 populations of var. immuginata. At the species level, 88% of the 26 loci examined were polymorphic. The genetic diversity maintained at both the species (Hes = 0.100) and population (Hep = 0.092) levels was low relative to most other pine species. Genetic differentiation among populations was also relatively low (GST = 0.054). Genetic distances between populations of the same variety (mean D = 0.006) were lower than genetic distances between populations of different varieties (mean D = 0.012). Although allele frequencies at individual loci differed significantly between the two varieties, each variety maintained nearly 99% of the genetic variation apparent at the species level (intervarietal differentiation, Gv = 0.014). The lower levels of genetic diversity in P. clausa may have resulted in part from genetic bottlenecks during periods of range retraction.

Reappraisal of the taxonomic status of Amphisbaena prunicolor (Cope 1885) and Amphisbaena albocingulata Boettger 1885 (Amphisbaenia: Amphisbaenidae)

Zootaxa ◽  
2012 ◽  
Vol 3550 (1) ◽  
pp. 1 ◽  
Author(s):  
RENATA PEREZ ◽  
SÍRIA RIBEIRO ◽  
MÁRCIO BORGES-MARTINS
Keyword(s):  
Intraspecific Variation ◽  
Taxonomic Status ◽  
Distinct Species ◽  
Colour Pattern ◽  
Similar Species ◽  
Unique Combination ◽  
Southern Brazil ◽  
Diagnostic Characters ◽  
Specific Rank

We revised the taxonomic status of Amphisbaena prunicolor and A. albocingulata, two taxa traditionally recognized assubspecies of A. prunicolor in the A. darwini complex. Despite some authors elevated both taxa to the specific rank, itstaxonomic decisions were made without specific commentaries and/or proper diagnostic characters. The comparison ofmorphological characters between the two taxa with other similar species, associated with A. darwini (A. darwini, A.heterozonata, A. munoai and A. trachura), revealed a unique combination of diagnostic characters. Amphisbaena pruni-color and A. albocingulata were considered distinct species, diagnosable by the presence of the postmalar row in A. pru-nicolor, absent in A. albocingulata and by the ventral colour pattern uniform (pale brown) in A. albocingulata andcheckerboard (brown-purplish and white) in A. prunicolor. We also provided a redescription of the two species, information on intraspecific variation in A. munoai and suggested the extension of the distribution of A. darwini to southern Brazil.

GENETIC RELATIONSHIPS AMONG CHORISTONEURA SPECIES (LEPIDOPTERA: TORTRICIDAE) IN NORTH AMERICA AS REVEALED BY ISOZYME STUDIES

1996 ◽  
Vol 128 (2) ◽  
pp. 245-262 ◽  
Author(s):  
G.T. Harvey
Keyword(s):  
New Species ◽  
Genetic Relationships ◽  
Distinct Species ◽  
Geographic Range ◽  
Genetic Distances ◽  
Species Level ◽  
Aspartate Transaminase ◽  
Polymorphic Loci ◽  
Wagner Trees ◽  
Better Than

AbstractAllozymes at several polymorphic loci were assayed in larval collections of 12 recognized species and two possible new species of Choristoneura and two species of Archips. Most of the 48 collections came from high density populations, and those of C. fumiferana, C. occidentalis, and C. pinus represented much of the geographic range of these species. Mean percentage heterozygosity ranged from 2.0 to 18.6%, based on nine polymorphic loci. Three loci are sex-linked in C. fumiferana, two in C. pinus and C. occidentalis and probably in some other members of the group. Allozymes of aspartate transaminase (AAT-1) were most varied among the species and permit identification of individual C. fumiferana in better than 95% of cases. Among the group of coniferophagous Choristoneura species genetic distances were small (max. Nei = 0.232); C. fumiferana was the most distinct species. Wagner trees based on modified Rogers’ distances supported the above conclusions but indicated that separations among C. biennis, C. orae, C. occidentalis, C. carnana, C. subretiniana, and the two new species of Choristoneura were very small and probably below the species level, based on the allozymes measured.

Genetic Diversity and Spread of Thiobencarb Resistant Early Watergrass (Echinochloa oryzoides) in California

Weed Science ◽  
2011 ◽  
Vol 59 (2) ◽  
pp. 195-201 ◽  
Author(s):  
Maria D. Osuna ◽  
Miki Okada ◽  
Riaz Ahmad ◽  
Albert J. Fischer ◽  
Marie Jasieniuk
Keyword(s):  
Genetic Diversity ◽  
Central Valley ◽  
Genetic Distances ◽  
Mantel Test ◽  
Rice Fields ◽  
Long Distance ◽  
Geographical Distances ◽  
Nuclear Microsatellite ◽  
Low Levels ◽  
Analytical Approaches

Resistance to the thiocarbamates has been selected in early watergrass populations within the rice-growing region of California. To elucidate the processes contributing to the spread of resistance among rice fields, we characterized the genetic diversity and differentiation of thiobencarb-resistant (R) and thiobencarb-susceptible (S) populations across the Central Valley using microsatellite markers. A total of 406 individuals from 22 populations were genotyped using seven nuclear microsatellite primer pairs. Three analytical approaches (unshared allele, Shannon–Weaver, and allelic-phenotype statistics) were used to assess genetic diversity and differentiation in the allohexaploid species. Low levels of genetic variation were detected within populations, consistent with other highly selfing species, with S populations tending to be more diverse than R populations.FSTvalues indicated that populations were genetically differentiated and that genetic differentiation was greater among S populations than R populations. Principal coordinate analysis generated two orthogonal axes that explained 88% of the genetic variance among early watergrass populations and differentiated populations by geographical region, which was associated with resistance phenotype. A Mantel test revealed that genetic distances between R populations were positively correlated with the geographical distances separating populations. Taken together, our results suggest that both short- and long-distance seed dispersal, and multiple local and independent evolutionary events, are involved in the spread of thiobencarb-resistant early watergrass across rice fields in the Sacramento Valley. In contrast, resistance was not detected in early watergrass populations in the San Joaquin Valley.

scholarly journals Genetic Diversity Among Some Walnut (Juglans regia L.) Genotypes by SSR Markers

2021 ◽  
Vol 13 (12) ◽  
pp. 6830
Author(s):  
Murat Guney ◽  
Salih Kafkas ◽  
Hakan Keles ◽  
Mozhgan Zarifikhosroshahi ◽  
Muhammet Ali Gundesli ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Plant Genetic Resources ◽  
Juglans Regia ◽  
Genetic Distances ◽  
Mean Value ◽  
Central Anatolia ◽  
Group Method ◽  
Arithmetic Average ◽  
Pair Group ◽  
Principal Coordinates

The food needs for increasing population, climatic changes, urbanization and industrialization, along with the destruction of forests, are the main challenges of modern life. Therefore, it is very important to evaluate plant genetic resources in order to cope with these problems. Therefore, in this study, a set of ninety-one walnut (Juglans regia L.) accessions from Central Anatolia region, composed of seventy-four accessions and eight commercial cultivars from Turkey, and nine international reference cultivars, was analyzed using 45 SSR (Simple Sequence Repeats) markers to reveal the genetic diversity. SSR analysis identified 390 alleles for 91 accessions. The number of alleles per locus ranged from 3 to 19 alleles with a mean value of 9 alleles per locus. Genetic dissimilarity coefficients ranged from 0.03 to 0.68. The highest number of alleles was obtained from CUJRA212 locus (Na = 19). The values of polymorphism information content (PIC) ranged from 0.42 (JRHR222528) to 0.86 (CUJRA212) with a mean PIC value of 0.68. Genetic distances were estimated according to the UPGMA (Unweighted Pair Group Method with Arithmetic Average), Principal Coordinates (PCoA), and the Structure-based clustering. The UPGMA and Structure clustering of the accessions depicted five major clusters supporting the PCoA results. The dendrogram revealed the similarities and dissimilarities among the accessions by identifying five major clusters. Based on this study, SSR analyses indicate that Yozgat province has an important genetic diversity pool and rich genetic variance of walnuts.

scholarly journals New Species and New Records of Sponge-Inhabiting Barnacles (Cirripedia, Balanidae, Acastinae) from Australia

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 290
Author(s):  
Andrew M. Hosie ◽  
Jane Fromont ◽  
Kylie Munyard ◽  
Diana S. Jones
Keyword(s):  
New Species ◽  
New Records ◽  
Morphological Characters ◽  
Genetic Distances ◽  
Similar Species ◽  
Diverse Group ◽  
Undescribed Species

The subfamily Acastinae contains a diverse group of barnacles that are obligate symbionts of sponges and alcyonacean and antipatharian corals. Integrating morphological and genetic (COI) data to compare against known species, this paper reports on nine species of sponge-inhabiting barnacles of the subfamily Acastinae, including three undescribed species (Acasta caveata sp. nov., Euacasta acutaflava sp. nov., and E. excoriatrix sp. nov.) and three species previously not recorded in Australian waters (A. sandwichi, Pectinoacasta cancellorum, and P. sculpturata). The new species are distinguished from similar species by a suite of morphological characters as well as genetic distances. A lectotype for Pectinoacasta cancellorum is designated. Sponge hosts were identified for all specimens where possible and are represented by 19 species from eight families and five orders.

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