scholarly journals Genomics-Based Phylogenetic and Population Genetic Analysis of Global Samples Confirms Halophila johnsonii Eiseman as Halophila ovalis (R.Br.) Hook.f.

2021 ◽  
Vol 8 ◽  
Author(s):  
Michelle Waycott ◽  
Kor-jent van Dijk ◽  
Ainsley Calladine ◽  
Eric Bricker ◽  
Ed Biffin

Halophila johnsonii is an endangered seagrass species that is restricted to the southeast coast of Florida, United States. Its taxonomic status has been called into question, in particular, given the close morphological and genetic similarity of H. johnsonii and the widely distributed and morphologically variable Halophila ovalis, which is largely restricted to the Indo-Pacific region. While a close relationship to H. ovalis is uncontroversial, it remains uncertain whether H. johnsonii represents a distinct lineage or is a recent introduction to the Florida region. Given the conservation status of H. johnsonii, distinguishing these alternatives has important implications for the management of the species and its habitat. Here, we develop molecular data sets for samples of H. johnsonii and H. ovalis including DNA sequences, genome-wide SNPs and microsatellites with the view to resolving the affinities of H. johnsonii with respect to the wider H. ovalis complex. Phylogenetic hypotheses based upon plastid (∼18000 bp) and low copy nuclear DNA (∼6500 bp) sequences derived from hybrid capture, along with 990 genome-wide ddRAD SNPs consistently resolved H. johnsonii within H. ovalis. Specifically, we found a close affinity between H. johnsonii and H. ovalis sampled from the east coast of Africa. In addition, Halophila specimens collected in Antigua, which are within the range of morphological variation typical for H. ovalis, are virtually identical to H. johnsonii and the East African H. ovalis samples based upon DNA sequence analyses and these group together using Bayesian clustering analyses of microsatellites and ddRAD SNPs. We conducted population genetic analyses using large number of H. johnsonii samples collected over a 17-year period. Genotypic data generated through microsatellites and ddRAD SNPs revealed genetic uniformity for all 132 H. johnsonii samples across the Indian River Lagoon, Florida, while samples of H. ovalis from Antigua shared the same genotype as H. johnsonii. We conclude that the lack of genetic diversity and the absence of sexual reproduction strongly indicates that the total range of H. johnsonii is actually one clone that is closely related to populations in Africa and Antigua and may be derived from a recent introduction from one of those regions.

2011 ◽  
Vol 59 (1) ◽  
pp. 206-224 ◽  
Author(s):  
Dorothy A. Steane ◽  
Dean Nicolle ◽  
Carolina P. Sansaloni ◽  
César D. Petroli ◽  
Jason Carling ◽  
...  

Zootaxa ◽  
2011 ◽  
Vol 2876 (1) ◽  
pp. 1 ◽  
Author(s):  
AURÉLIEN MIRALLES ◽  
JÖRN KÖHLER ◽  
FRANK GLAW ◽  
MIGUEL VENCES

The present paper constitutes a study on a taxonomically confusing group of closely related species belonging to the Malagasy skink genus Madascincus, currently encompassing the nominal species M. polleni, M. intermedius and M. stumpffi. Based on combined analyses of mitochondrial and nuclear DNA sequences (ND1 and RAG2 genes, respectively), and morphological examination, we provide evidence for the existence of at least four distinct evolutionary lineages within this complex: Madascincus stumpffi; Madascincus arenicola sp. nov. from northern Madagascar; and two cryptic species morphologically similar to the name-bearing types of M. polleni and M. intermedius. The two latter species, although genetically distinct, appear to be morphologically indistinguishable and their taxonomic status cannot be resolved until a better sampling will be available.


2015 ◽  
Vol 6 ◽  
Author(s):  
Pablo Orozco-terWengel ◽  
Mario Barbato ◽  
Ezequiel Nicolazzi ◽  
Filippo Biscarini ◽  
Marco Milanesi ◽  
...  

Zootaxa ◽  
2009 ◽  
Vol 2294 (1) ◽  
pp. 1-22 ◽  
Author(s):  
RAINER SONNENBERG ◽  
ECKHARD BUSCH

The phylogeny of the West African genus Archiaphyosemion was studied with mitochondrial and nuclear DNA sequences. The results of the combined dataset presented here did not support a monophyletic group. After the exclusion of the type species of the genus, A. guineense, the remaining species form a well-supported monophyletic group. Based on these molecular results and supported by morphological data, we suggest a new name for this group, Nimbapanchax, new genus. Additionally, based on a recent collection in Guinea, two new Nimbapanchax species were described. The taxon Nimbapanchax leucopterygius, new species, is described for a nothobranchiid fish formerly misidentified as Archiaphyosemion maeseni (Poll, 1941). Nimbapanchax melanopterygius, new species, is described from the Mount Nimba region in southeastern Guinea. Both new Nimbapanchax species are clearly distinguished from their congeners by the coloration pattern of adult males. The results of the DNA data support the assumption based on color pattern and morphological characters that the new described species are sister taxa. The type of Aphyosemion maeseni Poll, 1941 was reexamined and transferred to the genus Epiplatys, a decision based on diagnostic morphological characters.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Mulatu Geleta ◽  
Tomas Bryngelsson

DNA sequence data from the internal transcribed spacer of nuclear ribosomal DNA and eight chloroplast DNA regions were used to investigate haplotypic variation and population genetic structure of the Afroalpine giant lobelia,Lobelia rhynchopetalum.The study was based on eight populations sampled from two mountain systems in Ethiopia. A total of 20 variable sites were obtained, which resulted in 13 unique haplotypes and an overall nucleotide diversity (ND) of 0.281 ± 0.15 and gene diversity (GD) of 0.85 ± 0.04. Analysis of molecular variance (AMOVA) revealed a highly significant variation (P<0.001) among populations (FST), and phylogenetic analysis revealed that populations from the two mountain systems formed their own distinct clade with >90% bootstrap support. Each population should be regarded as a significant unit for conservation of this species. The primers designed for this study can be applied to anyLobeliaand other closely related species for population genetics and phylogenetic studies.


Phytotaxa ◽  
2017 ◽  
Vol 321 (2) ◽  
pp. 166 ◽  
Author(s):  
DAVY U. IKABANGA ◽  
TARIQ STÉVART ◽  
K. GUILLAUME KOFFI ◽  
FRANCK KAMENI MONTHÉ ◽  
ELIE C. NZIGOU DOUBINDOU ◽  
...  

Taxonomic classification based on morphology alone can prove difficult. This is the case of the polymorphic forest tree species Santiria trimera in Africa, whose classification has remained controversial for over a century. Studies combining chloroplast and nuclear DNA sequences show the existence of several phylogenetic clades in this taxon, with some occurring in sympatry in western Central Africa suggesting the existence of at least two species. By combining genetic and morphological markers, we aim to assess the species delimitation in the Santiria species complex. Morphological trait (trunk, leaflet, flower and fruit characteristics) analysis using 223 standing individuals and 103 herbarium samples were combined with genetic analyses using 479 individuals genotyped at eight microsatellite markers. Genetic clusters were identified using Bayesian assignment in order to delimit species following the Biological Species Concept and to identify distinctive characters from morphometric analyses in retrospect. Three genetic clusters were identified and found to occur in sympatry. The type of inflorescence and the colour of unripe fruit were the most discriminant morphological traits among those genetic clusters, while many quantitative traits showed overlapping distributions between genetic clusters and explain the difficulty encountered by previous botanists to resolve the taxonomy of Santiria. The combination of genetic and morphological data suggests the presence of three species within the taxon Santiria trimera from western Central Africa. This work should guide a taxonomic revision within the genus Santiria in Africa.


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