Morphological, phytochemical and molecular analyses define species limits in Eucalyptus magnificata (Myrtaceae) and lead to the discovery of a new rare species

2019 ◽  
Author(s):  
Timothy L. Collins ◽  
Rose L. Andrew ◽  
Jeremy J. Bruhl
Keyword(s):  
New England ◽  
Conservation Status ◽  
Strong Support ◽  
Full Description ◽  
Species Limits ◽  
Single Nucleotide ◽  
Test Species ◽  
Field Collection ◽  
Snp Data ◽  
Eastern Australia

Abstract. Eucalyptus magnificata L.A.S.Johnson & K.D.Hill is an endangered species endemic to the New England Tablelands Bioregion of eastern Australia, with taxonomic conflict regarding its recognition. Analyses of morphology, phytochemistry and genomic DNA were used to test species limits of E. magnificata. Morphometric and phytochemical phenetic analyses found distinct differences among E. magnificata, E. baueriana and a putative entity recognised during field collection, i.e. E. sp. Dalveen. Another putative entity, E. sp. Oxley, was morphologically and phytochemically intermediate between E. magnificata and E. conica. Phenetic analysis of single-nucleotide polymorphism (SNP) data supported the results from morphological and phytochemical analyses. The original circumscription of E. magnificata, as distinct from E. baueriana, was strongly corroborated. Eucalyptus magnificata was found to be restricted in distribution to the Macleay Gorges area south-east of Armidale. Multiple lines of evidence provided strong support for the recognition of E. sp. Dalveen as a separately evolving entity at a species level, here described as Eucalyptus dalveenica T.L.Collins, R.L.Andrew & J.J.Bruhl. A full description of the new species, a table distinguishing E. dalveenica from closely related taxa, and an identification key are provided. Distribution, habitat and conservation status are discussed.

Performance of a points-based scoring system for assessing species limits in birds

The Auk ◽  
2021 ◽  
Author(s):  
Joseph A Tobias ◽  
Paul F Donald ◽  
Rob W Martin ◽  
Stuart H M Butchart ◽  
Nigel J Collar
Keyword(s):  
Strong Support ◽  
Molecular Data ◽  
Sympatric Species ◽  
Global Scale ◽  
Training Set ◽  
Species Limits ◽  
Phenotypic Data ◽  
Fast Tracking ◽  
Extinction Rates ◽  
Phenotypic Divergence

AbstractSpecies are fundamental to biology, conservation, and environmental legislation; yet, there is often disagreement on how and where species limits should be drawn. Even sophisticated molecular methods have limitations, particularly in the context of geographically isolated lineages or inadequate sampling of loci. With extinction rates rising, methods are needed to assess species limits rapidly but robustly. Tobias et al. devised a points-based system to compare phenotypic divergence between taxa against the level of divergence in sympatric species, establishing a threshold to guide taxonomic assessments at a global scale. The method has received a mixed reception. To evaluate its performance, we identified 397 novel taxonomic splits from 328 parent taxa made by application of the criteria (in 2014‒2016) and searched for subsequent publications investigating the same taxa with molecular and/or phenotypic data. Only 71 (18%) novel splits from 60 parent taxa have since been investigated by independent studies, suggesting that publication of splits underpinned by the criteria in 2014–2016 accelerated taxonomic decisions by at least 33 years. In the evaluated cases, independent analyses explicitly or implicitly supported species status in 62 (87.3%) of 71 splits, with the level of support increasing to 97.2% when excluding subsequent studies limited only to molecular data, and reaching 100% when the points-based criteria were applied using recommended sample sizes. Despite the fact that the training set used to calibrate the criteria was heavily weighted toward passerines, splits of passerines and non-passerines received equally strong support from independent research. We conclude that the method provides a useful tool for quantifying phenotypic divergence and fast-tracking robust taxonomic decisions at a global scale.

scholarly journals Genome-Wide Patterns of Homozygosity Reveal the Conservation Status in Five Italian Goat Populations

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1510
Author(s):  
Salvatore Mastrangelo ◽  
Rosalia Di Gerlando ◽  
Maria Teresa Sardina ◽  
Anna Maria Sutera ◽  
Angelo Moscarelli ◽  
...  
Keyword(s):  
Conservation Status ◽  
Phenotypic Traits ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Local Populations ◽  
Genomic Technologies ◽  
Fitness Traits ◽  
Genome Wide ◽  
Breeding Schemes ◽  
Genomic Inbreeding

The application of genomic technologies has facilitated the assessment of genomic inbreeding based on single nucleotide polymorphisms (SNPs). In this study, we computed several runs of homozygosity (ROH) parameters to investigate the patterns of homozygosity using Illumina Goat SNP50 in five Italian local populations: Argentata dell’Etna (N = 48), Derivata di Siria (N = 32), Girgentana (N = 59), Maltese (N = 16) and Messinese (N = 22). The ROH results showed well-defined differences among the populations. A total of 3687 ROH segments >2 Mb were detected in the whole sample. The Argentata dell’Etna and Messinese were the populations with the lowest mean number of ROH and inbreeding coefficient values, which reflect admixture and gene flow. In the Girgentana, we identified an ROH pattern related with recent inbreeding that can endanger the viability of the breed due to reduced population size. The genomes of Derivata di Siria and Maltese breeds showed the presence of long ROH (>16 Mb) that could seriously impact the overall biological fitness of these breeds. Moreover, the results confirmed that ROH parameters are in agreement with the known demography of these populations and highlighted the different selection histories and breeding schemes of these goat populations. In the analysis of ROH islands, we detected harbored genes involved with important traits, such as for milk yield, reproduction, and immune response, and are consistent with the phenotypic traits of the studied goat populations. Finally, the results of this study can be used for implementing conservation programs for these local populations in order to avoid further loss of genetic diversity and to preserve the production and fitness traits. In view of this, the availability of genomic data is a fundamental resource.

scholarly journals Structural evolution of the early Permian Nambucca Block (New England Orogen, eastern Australia) and implications for oroclinal bending

Tectonics ◽  
2014 ◽  
Vol 33 (7) ◽  
pp. 1425-1443 ◽  
Author(s):  
Uri Shaanan ◽  
Gideon Rosenbaum ◽  
Pengfei Li ◽  
Paulo Vasconcelos
Keyword(s):  
New England ◽  
Structural Evolution ◽  
Early Permian ◽  
Eastern Australia ◽  
New England Orogen

scholarly journals A publicly available repository of ROH islands reveals signatures of selection in different livestock and pet species

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Wim Gorssen ◽  
Roel Meyermans ◽  
Steven Janssens ◽  
Nadine Buys
Keyword(s):  
Association Studies ◽  
Genome Wide Association Studies ◽  
Single Nucleotide ◽  
Future Studies ◽  
Snp Data ◽  
Animal Populations ◽  
Genome Wide ◽  
Starting Point ◽  
Different Populations ◽  
Signatures Of Selection

Abstract Background Runs of homozygosity (ROH) have become the state-of-the-art method for analysis of inbreeding in animal populations. Moreover, ROH are suited to detect signatures of selection via ROH islands and are used in other applications, such as genomic prediction and genome-wide association studies (GWAS). Currently, a vast amount of single nucleotide polymorphism (SNP) data is available online, but most of these data have never been used for ROH analysis. Therefore, we performed a ROH analysis on large medium-density SNP datasets in eight animal species (cat, cattle, dog, goat, horse, pig, sheep and water buffalo; 442 different populations) and make these results publicly available. Results The results include an overview of ROH islands per population and a comparison of the incidence of these ROH islands among populations from the same species, which can assist researchers when studying other (livestock) populations or when looking for similar signatures of selection. We were able to confirm many known ROH islands, for example signatures of selection for the myostatin (MSTN) gene in sheep and horses. However, our results also included multiple other ROH islands, which are common to many populations and not identified to date (e.g. on chromosomes D4 and E2 in cats and on chromosome 6 in sheep). Conclusions We are confident that our repository of ROH islands is a valuable reference for future studies. The discovered ROH island regions represent a unique starting point for new studies or can be used as a reference for future studies. Furthermore, we encourage authors to add their population-specific ROH findings to our repository.

Tracing the origins of hybrids through history: monstrous cultivars and Napoléon Bonaparte’s exiled paper daisies (Asteraceae; Gnaphalieae)

2021 ◽  
Author(s):  
Timothy L Collins ◽  
Jeremy J Bruhl ◽  
Alexander N Schmidt-Lebuhn ◽  
Ian R H Telford ◽  
Rose L Andrew
Keyword(s):  
Gene Flow ◽  
Phylogenetic Analyses ◽  
Strong Support ◽  
Napoleon Bonaparte ◽  
Snp Data ◽  
Cast Doubt ◽  
Molecular Phylogenetic ◽  
St Helena ◽  
New Evidence

Abstract Golden everlasting paper daisies (Xerochrysum, Gnaphalieae, Asteraceae) were some of the earliest Australian native plants to be cultivated in Europe. Reputedly a favourite of Napoléon Bonaparte and Empress Joséphine, X. bracteatum is thought to have been introduced to the island of St Helena in the South Atlantic during Napoléon’s exile there. Colourful cultivars were developed in the 1850s, and there is a widely held view that these were produced by crossing Xerochrysum with African or Asian Helichrysum spp. Recent molecular phylogenetic analyses and subtribal classification of Gnaphalieae cast doubt on this idea. Using single-nucleotide polymorphism (SNP) data, we looked for evidence of gene flow between modern cultivars, naturalized paper daisies from St Helena and four Xerochrysum spp. recorded in Europe in the 1800s. There was strong support for gene flow between cultivars and X. macranthum. Paper daisies from St Helena were genotypically congruent with X. bracteatum and showed no indications of ancestry from other species or from the cultivars, consistent with the continuous occurrence of naturalized paper daisies introduced by Joséphine and Napoléon. We also present new evidence for the origin of colourful Xerochrysum cultivars and hybridization of congeners in Europe from Australian collections.

scholarly journals Species Delimitation and Conservation in Taxonomically Challenging Lineages: The Case of Two Clades of Capurodendron (Sapotaceae) in Madagascar

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1702
Author(s):  
Carlos G. Boluda ◽  
Camille Christe ◽  
Aina Randriarisoa ◽  
Laurent Gautier ◽  
Yamama Naciri
Keyword(s):  
Conservation Status ◽  
The Other ◽  
Genetic Admixture ◽  
Putative Hybrid ◽  
Illegal Logging ◽  
Conservation Assessment ◽  
Protein Coding ◽  
Test Species ◽  
Species Complexes ◽  
Genetic Pools

Capurodendron is the largest endemic genus of plants from Madagascar, with around 76% of its species threatened by deforestation and illegal logging. However, some species are not well circumscribed and many of them remain undescribed, impeding a confident evaluation of their conservation status. Here we focus on taxa delimitation and conservation of two species complexes within Capurodendron: the Arid and Western complexes, each containing undescribed morphologies as well as intermediate specimens alongside well-delimited taxa. To solve these taxonomic issues, we studied 381 specimens morphologically and selected 85 of them to obtain intergenic, intronic, and exonic protein-coding sequences of 794 nuclear genes and 227 microsatellite loci. These data were used to test species limits and putative hybrid patterns using different approaches such as phylogenies, PCA, structure analyses, heterozygosity level, FST, and ABBA-BABA tests. The potential distributions were furthermore estimated for each inferred species. The results show that the Capurodendron Western Complex contains three well-delimited species, C. oblongifolium, C. perrieri, and C. pervillei, the first two hybridizing sporadically with the last and producing morphologies similar to, but genetically distinct from C. pervillei. The Arid Complex shows a more intricate situation, as it contains three species morphologically well-delimited but genetically intermixed. Capurodendron mikeorum nom. prov. is shown to be an undescribed species with a restricted distribution, while C. androyense and C. mandrarense have wider and mostly sympatric distributions. Each of the latter two species contains two major genetic pools, one showing interspecific admixture in areas where both taxa coexist, and the other being less admixed and comprising allopatric populations having fewer contacts with the other species. Only two specimens out of 172 showed clear genetic and morphological signals of recent hybridization, while all the others were morphologically well-delimited, independent of their degree of genetic admixture. Hybridization between Capurodendron androyense and C. microphyllum, the sister species of the Arid Complex, was additionally detected in areas where both species coexist, producing intermediate morphologies. Among the two complexes, species are well-defined morphologically with the exception of seven specimens (1.8%) displaying intermediate patterns and genetic signals compatible with a F1 hybridization. A provisional conservation assessment for each species is provided.

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