scholarly journals Conservation genomics of an Australian orchid complex with implications for the taxonomic and conservation status of Corybas dowlingii

2020 ◽  
Author(s):  
Natascha D. Wagner ◽  
Mark A. Clements ◽  
Lalita Simpson ◽  
Katharina Nargar

AbstractThis study assessed genomic diversity in an Australian species complex in the helmet orchids to clarify taxonomic delimitation and conservation status of the threatened species Corybas dowlingii, a narrow endemic from southeast Australia. Taxonomic delimitation between the three closely related species C. aconitiflorus, C. barbarae, and C. dowlingii has been mainly based on floral traits which exhibit varying degrees of overlap, rendering species delimitation in the complex difficult. Genomic data for the species complex was generated using double-digest restriction-site associated DNA (ddRAD) sequencing. Maximum likelihood, NeighborNet, and Bayesian structure analyses showed genetic differentiation within the species complex and retrieved genomic signatures consistent with hybridisation and introgression between C. aconitiflorus and C. barbarae, and an intermediate genetic position of C. dowlingii indicating a hybrid origin of the species. The genetic structure analysis showed varying levels of genetic admixture for several C. aconitiflorus, C. barbarae, and C. dowlingii samples, thus further corroborating the presence of hybridisation and introgression within the species complex. The taxonomic status of C. dowlingii D.L.Jones was revised to C. × dowlingii D.L.Jones stat. nov. to reflect its hybrid origin. The conservation status of C. × dowlingii was assessed based on key ecological and ethical aspects, and recommendations made regarding its conservation status in Australian conservation legislation.

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.


2020 ◽  
Vol 45 (3) ◽  
pp. 537-543
Author(s):  
Karinne Sampaio Valdemarin ◽  
Jair Eustáquio Quintino Faria ◽  
Fiorella Fernanda Mazine ◽  
Vinicius Castro Souza

Abstract—A new species of Eugenia from the Atlantic forest of Brazil is described and illustrated. Eugenia flavicarpa is restricted to the Floresta de Tabuleiro (lowland forests) of Espírito Santo state and is nested in Eugenia subg. Pseudeugenia. Considering all other species of the subgenus that occur in forest vegetation types of the Atlantic forest phytogeographic domain, Eugenia flavicarpa can be distinguished mainly by the combination of smooth leaves with indumentum on both surfaces, with two marginal veins, usually ramiflorous inflorescences, pedicels 4.5‐9.7 mm long, flower buds 3.5‐4 mm in diameter, and by the calyx lobes that are 2‐3 mm long with rounded to obtuse apices. Morphological analyses were performed to explore the significance of quantitative diagnostic features between the new species and the closely related species, Eugenia farneyi. Notes on the habitat, distribution, phenology, and conservation status of Eugenia flavicarpa are provided, as well as a key for all species of Eugenia subg. Pseudeugenia from forest vegetation of the Atlantic forest phytogeographic domain.


Author(s):  
Neil O. M. Ravenscroft

AbstractThe marsh fritillary Euphydryas aurinia is declining across Europe and is of high conservation interest. Its ecology has been defined and its conservation status assessed primarily from the affinities and populations of young caterpillars in the autumn, before hibernation and high winter mortality. The possibility that caterpillars of E. aurinia can overwinter more than once was investigated on the Isle of Islay, Scotland after caterpillars were found to occur at some locations in the spring despite a pre-hibernation absence. Closely-related species in North America and Northern Europe can prolong larval development by diapausing for a year as does E. aurinia in Scandinavia. Measurements of development and manipulations of distribution confirmed that some caterpillars do extend the life-cycle in Scotland and may occur in areas devoid of larvae in their first year. Caterpillars attempting this life-cycle develop slowly in spring, attain the normal penultimate spring instar and then enter diapause while other caterpillars are pupating. They moult just before diapause, construct highly cryptic webs and on emergence the following spring are 5–6 times heavier than larvae emerging in their first spring, or the equivalent of a month or so ahead. They attain a final, extra instar as larvae in their first spring reach the penultimate instar. Knowledge of this life-cycle is confined in the UK to Islay but its occurrence in this mild climate implies that it is more widespread.Implications for insect conservation Conditions that permit long diapause are probably precise and may not be reflected in recognised qualities of habitat. The species may also be present despite a perceived absence in autumn, the standard period for monitoring. Assessments of the prevalence of the life-cycle and its contribution to the persistence of E. aurinia are required. Populations of E. aurinia are known to fluctuate greatly and do occur below the observation threshold for long periods.


Phytotaxa ◽  
2015 ◽  
Vol 217 (2) ◽  
pp. 164 ◽  
Author(s):  
İlker Çinbilgel ◽  
özkan Eren ◽  
Hayri Duman ◽  
Mustafa Gökceoğlu

Pimpinella ibradiensis, an unusual new species found in the Toka Yayla (İbradı, Antalya) in southern Anatolia, is described and illustrated. Site conditions, synecology and conservation status of P. ibradiensis are considered. In light of the comparison with the other closely related four species, namely P. nephrophylla, P. flabellifolia, P. sintenisii and P. paucidentata, its similarity within the genus are discussed. P. ibradiensis is easly distinguished from its relatives by its white petals, presence of bracts and bracteoles, larger fruits (4–5.5 × 1–2 mm), and having serrulate basal leaves with 60–95 strongly cartilaginous teeth along margins. The geographical distribution of P. ibradiensis and closely related species are mapped and the identification key of those species is updated.


Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 139
Author(s):  
Marlien M. van der Merwe ◽  
Jia-Yee S. Yap ◽  
Peter D. Wilson ◽  
Helen T. Murphy ◽  
Andrew Ford

Maximising genetic diversity in conservation efforts can help to increase the chances of survival of a species amidst the turbulence of the anthropogenic age. Here, we define the distribution and extent of genomic diversity across the range of the iconic but threatened Acacia purpureopetala, a beautiful sprawling shrub with mauve flowers, restricted to a few disjunct populations in far north Queensland, Australia. Seed production is poor and germination sporadic, but the species occurs in abundance at some field sites. While several thousands of SNP markers were recovered, comparable to other Acacia species, very low levels of heterozygosity and allelic variation suggested inbreeding. Limited dispersal most likely contributed towards the high levels of divergence amongst field sites and, using a generalised dissimilarity modelling framework amongst environmental, spatial and floristic data, spatial distance was found to be the strongest factor explaining the current distribution of genetic diversity. We illustrate how population genomic data can be utilised to design a collecting strategy for a germplasm conservation collection that optimises genetic diversity. For this species, inclusion of all field sites will capture maximum genetic diversity for both in situ and ex situ conservation. Assisted cross pollination, within and between field sites and genetically structured groups, is recommended to enhance heterozygosity particularly at the most disjunct sites and further fragmentation should be discouraged to avoid loss of genetic connectivity.


Phytotaxa ◽  
2021 ◽  
Vol 521 (3) ◽  
pp. 219-226
Author(s):  
THIAGO COBRA E MONTEIRO ◽  
JOÃO RICARDO VIEIRA IGANCI ◽  
SILVIA T.S. MIOTTO ◽  
ANA PAULA FORTUNA-PEREZ

In the context of an ongoing taxonomic review of Adesmia subg. Adesmia ser. Bicolores, a new endangered species endemic to Rio Grande do Sul state, Brazil, is herein described. The new species present a long glandular ochraceous indumentum, flowers 10–15 mm long, and arilated seeds. Information about morphology, differences from closely related species, phenology, conservation status, and etymology are provided.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1702
Author(s):  
Carlos G. Boluda ◽  
Camille Christe ◽  
Aina Randriarisoa ◽  
Laurent Gautier ◽  
Yamama Naciri

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.


2021 ◽  
Vol 740 ◽  
Author(s):  
Filippo Di Giovanni ◽  
Pier Luigi Scaramozzino ◽  
Augusto Loni ◽  
Andrea Lucchi

Despite their importance as potential biological control agents, species of the campoplegine genus Campoplex Gravenhorst, 1829 are hard to identify. Previous works provided short descriptions or poor illustrations of crucial characters, meaning it is often impossible to distinguish closely related species. We provide illustrations to identify species of the Campoplex difformis group and redescriptions of and illustrations for C. difformis (Gmelin, 1790), C. capitator Aubert, 1960, C. dubitator Horstmann, 1985, C. formosanae Horstmann, 2012, and C. unicingulatus (Schmiedeknecht, 1909). In addition, the taxonomic status of C. difformis is clarified; a lectotype is designated for C. capitator in Aubert’s collection in Lausanne and the host record for this species on Ancylis mitterbacheriana (Denis & Schiffermüller, 1775) is queried; Campoplex corsicator Aubert, 1960 stat. nov. is removed from synonymy with Campoplex tibialis (Szépligeti, 1916) and redescribed.


2020 ◽  
Author(s):  
Naoki Osada ◽  
Kazunari Matsudaira ◽  
Yuzuru Hamada ◽  
Suchinda Malaivijitnond

AbstractThe role of sex-specific demography in hybridization and admixture of genetically diverged species and populations is essential to understand the mechanisms forming the genomic diversity of sexually reproducing organisms. In order to infer how sex-linked genetic loci have been differentiated undergoing frequent hybridization and admixture, we examined 17 whole-genome sequences of seven species of the genus Macaca, which shows frequent inter-specific hybridization and predominantly female philopatry. We found that hybridization and admixture were prevalent within these species. For three cases of suggested hybrid origin of species/subspecies, M. arctoides, M. fascicularis ssp. aurea, and Chinese M. mulatta, we examined the level of admixture of X chromosomes, which is less affected by male-biased migration than that of autosomes. In one case, we were able to determine that M. cyclopis and M. fuscata was genetically closer to Chinese M. mulatta than to the Indian M. mulatta, and the admixture level of Chinese M. mulatta and M. fuscata/cyclopis was more pronounced on the X chromosome than on autosomes. Since the mitochondrial genomes of Chinese M. mulatta, M. cyclopis, and M. fuscata were found to cluster together, and the mitochondrial genome of Indian M. mulatta is more distantly related, the observed pattern of genetic differentiation on X-chromosomal loci is consistent with the nuclear swamping hypothesis, in which strong, continuous male-biased introgression from the ancestral Chinese M. mulatta population to a population related to M. fuscata and M. cyclopis generated incongruencies between the genealogies of the mitochondrial and autosomal genomes.


Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 451-468 ◽  
Author(s):  
Malahat Taban ◽  
Masoud Sheidai ◽  
Zahra Noormohammadi ◽  
Narjes Azizi ◽  
Somayeh Ghasemzadeh-Baraki ◽  
...  

Helichrysum armenium and H. rubicundum are two medicinally important plants of Iran that are distributed in various regions of the country. They are extensively used by locals as medicinal plants and a great negative selection pressure is applied on them. Therefore, due to importance of these plant species, we performed a population genetic study in both species. For this study, we used 66 randomly collected plants from 24 geographical populations of Helichrysum armenium and H. rubicundu. These species had areas of overlap and contact and we found some intermediate plants that were included in our study too. UPGMA and MDS analyses revealed morphological separation of these closely related species and placed intermediate plants in an intermediate position. ISSR analysis revealed inter-population genetic diversity and K-Means clustering and STRUCTURE analyses revealed populations. Genetic stratification in both species. Genetic difference of the studied populations was not correlated to geographical distance. Triangle plot of Bayesian analysis and NeighborNet plot showed inter-specific gene flow. The studied populations showed plants with 2n = 2x = 14 and 2n = 4x = 28 chromosomes and differed significantly in their meiotic behavior. Therefore, a combination of genetic stratification, and genetic admixture as well as polyploidy and chromosomes structural changes, have played rule in Helichrysum diversification.


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