High genetic diversity and presence of genetic structure characterise the Corso-Sardinian endemics Ruta corsica and Ruta lamarmorae (Rutaceae)

SummaryCorsica and Sardinia form one of the ten areas with highest biodiversity in the Mediterranean and are considered one of the priority regions for conservation in Europe. In order to preserve the high levels of endemism and biological diversity at different hierarchical levels, knowledge of the evolutionary history and current genetic structure of Corso-Sardinian endemics is instrumental. Microsatellite markers were newly developed and used to study the genetic structure and taxonomic status of Ruta corsica and Ruta lamarmorae, rare endemics of Corsica and Sardinia, respectively, and previously considered a single species. Our analyses identified high levels of genetic variation within each species (P=0.883, He=0.543 for R. corsica; P=0.972, He=0.627 for R. lamarmorae). Intrinsic traits of the species (hermaphroditism, proterandry and polyploidy) and island-dependent factors (i.e. age, origin and history of the islands) might explain the detected high levels of genetic variation. We discovered differentiation between R. corsica and R. lamarmorae, and genetic structure within each species, which are consistent with the observation of low dispersal ability for both species. Our genetic results support the recent taxonomic classification of R. corsica and R. lamarmorae as separate species and suggest that they diverge at only few loci. One R. corsica population (SA) strongly differed from all other studied populations and appeared to be the product of hybridization between the two species in STRUCTURE analyses. Our results provide important insights for the conservation of the two rare endemics. Further genetic analyses are recommended for R. lamarmorae and for population SA (R. corsica).

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The genetic structure of the marine flatworm Stylochoplana pusilla (Rhabditophora: Polycladida) and its use of intertidal snails

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315420000570 ◽

2020 ◽

Vol 100 (5) ◽

pp. 713-717

Author(s):

Daishi Yamazaki ◽

Tomoki Aota ◽

Satoshi Chiba

Keyword(s):

Genetic Structure ◽

Population Level ◽

Mantle Cavity ◽

Dispersal Ability ◽

Snail Species ◽

High Genetic Diversity ◽

Local Populations ◽

History Of ◽

Invertebrate Taxon ◽

Intertidal Snail

AbstractAlthough marine phylogeographers have accumulated knowledge of the evolutionary history of various invertebrates, there is a large bias among the taxa regarding genetic data. The order Polycladida is a typical example for which little genetic information at population level is available. Here, we focused on the polyclad flatworm Stylochoplana pusilla, distributed in the Japanese Pacific coastal area. Stylochoplana pusilla is known to have commensal relationships with certain intertidal snails, using snails (mainly Monodonta confusa) as a refugee house. During low tide, S. pusilla hides in the mantle cavity of snails to protect themselves from desiccation and predation. Here, we investigated the genetic structure of S. pusilla using a mitochondrial Cytochrome Oxidase I marker and the species diversity of snails used by it. We found that S. pusilla has high genetic diversity of its populations. While S. pusilla showed a significant genetic differentiation among populations, it was relatively low. In addition, we also showed that S. pusilla used several intertidal snail species which inhabit various coastal environments. The present study suggests S. pusilla has sufficient dispersal ability to connect among its local populations. Also, the range of available snails for S. pusilla may help the connectivity among local populations. We provide important knowledge about this invertebrate taxon with a unique ecology, which has been insufficiently studied.

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Re-examination of the taxonomy of the Macrobrachium australiense Holthuis (Decapoda : Palaemonidae) species-complex: molecular evidence for a single species

Invertebrate Systematics ◽

10.1071/is03003 ◽

2004 ◽

Vol 18 (2) ◽

pp. 227 ◽

Cited By ~ 7

Author(s):

Nicholas P. Murphy ◽

John W. Short ◽

Christopher M. Austin

Keyword(s):

Genetic Relationships ◽

Mitochondrial Gene ◽

Taxonomic Status ◽

Single Species ◽

Gene Region ◽

Molecular Evidence ◽

Morphological Divergence ◽

Separate Species ◽

North West ◽

North East

The freshwater shrimp Macrobrachium australiense is distributed throughout the majority of inland, north-west, north-east and eastern drainages. Owing to the large amount of morphological divergence, both between and within catchments, this species has proven to be taxonomically difficult and, until recently, consisted of three separate species, each with subsequent subspecies. This study uses nucleotide sequences from the 16S rRNA mitochondrial gene region to investigate the genetic relationships between populations and confirm the taxonomic status of M. australiense. The results from sequencing an approximately 450-bp fragment from this gene region from M. australiense sampled from 12 locations across inland, eastern and northern Australia identified very little variation. The variation found between 16S M. australiense haplotypes is much less than that found between Macrobrachium species, indicating that it is in fact a single species. The results are concordant with a recent morphological revision of Australian species in which nominal taxa of the M. australiense complex were synonymised.

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Population Genetic Structure and Genetic Diversity in Twisted-Jaw Fish, Belodontichthys truncatus Kottelat & Ng, 1999 (Siluriformes: Siluridae), from Mekong Basin

International Journal of Zoology ◽

10.1155/2017/5976421 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Surapon Yodsiri ◽

Komgrit Wongpakam ◽

Adisak Ardharn ◽

Chadaporn Senakun ◽

Sutthira Khumkratok

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Demographic History ◽

Hydropower Plant ◽

Mekong River ◽

Demographic Expansion ◽

High Genetic Diversity ◽

History Analysis ◽

History Of ◽

Important Food Source

The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.

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Disappearing apple snails (Caenogastropoda: Ampullariidae) of Thailand: a comprehensive update of their taxonomic status and distribution

Journal of Molluscan Studies ◽

10.1093/mollus/eyaa015 ◽

2020 ◽

Vol 86 (4) ◽

pp. 290-305 ◽

Cited By ~ 2

Author(s):

Ting Hui Ng ◽

Supunya Annate ◽

Ekgachai Jeratthitikul ◽

Chirasak Sutcharit ◽

Yanin Limpanont ◽

...

Keyword(s):

Cryptic Species ◽

Taxonomic Status ◽

Intraspecific Diversity ◽

Human Consumption ◽

Conservation Action ◽

Separate Species ◽

High Genetic Diversity ◽

Geometric Morphometric ◽

Geometric Morphometric Analysis ◽

Species Taxonomy

ABSTRACT Ampullariidae include the largest of all freshwater snails and are of ecological, evolutionary and anthropogenic importance in Southeast Asia (SEA). Native ampullariids belonging to the genus Pila face various threats but are understudied, with their species taxonomy being confused and data on their distributions being scarce. We provide a comprehensive update on the nomenclature, status and distribution of Pila species in Thailand, based on DNA barcoding and geometric morphometric analysis of recently collected material. We confirm that at least five Pila species are extant in Thailand: Pila virescens, P. celebensis, P. turbinis, P. gracilis and P. pesmei. Pila celebensis, which has distinctive egg masses among all the known Southeast Asian Pila, appears to be sister to a clade comprising other SEA and some African Pila. Our results suggest that Pila may have dispersed into SEA on at least two separate occasions. Two singletons collected from northern and eastern Thailand may constitute separate species, but this requires further study. Intraspecific diversity of the mitochondrial cytochrome c oxidase subunit I gene was relatively high for P. celebensis, P. gracilis and P. pesmei (maximum uncorrected p-distances varied from 7% to 9%), and may include cryptic species. Conversely, P. virescens showed low intraspecific p-distances (c. 0%) among clades collected from different localities. This strongly suggests that introductions by humans may be the major cause of this pattern, and our own observations—we found that this species is being cultured and is commonly sold in markets for human consumption—are consistent with this. Pila turbinis was the rarest species, with live snails being collected from only two localities. Throughout Thailand, invasive confamilial Pomacea species appear to be replacing native Pila species, particularly in the Chao Phraya basin. While Thai Pila exhibit surprisingly high genetic diversity, with cryptic species likely being present, widespread invasive snails pose a major threat to their survival and urgent conservation action is needed.

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Phylogeography of the black fly Simulium aureohirtum (Diptera: Simuliidae) in Thailand

Genome ◽

10.1139/gen-2014-0103 ◽

2014 ◽

Vol 57 (8) ◽

pp. 411-417 ◽

Cited By ~ 4

Author(s):

Jiraporn Thaijarern ◽

Piyamas Nanork Sopaladawan ◽

Komgrit Wongpakam ◽

Pairot Pramual

Keyword(s):

Genetic Structure ◽

Demographic History ◽

High Genetic Diversity ◽

Black Fly ◽

History Of ◽

Living Organisms ◽

High Level ◽

Genetic Structure And Diversity ◽

Lineage Divergence ◽

Population Demographic

The black fly Simulium aureohirtum Brunetti (Diptera: Simuliidae) is geographically widespread and utilizes diverse habitats. Previous studies revealed high genetic diversity, suggesting that this species could be a species complex. In this study, we used mitochondrial cytochrome c oxidase II sequences to examine genetic structure and demographic history of S. aureohirtum in Thailand. High level of genetic variation was observed due to the existence of genetically divergent lineages (A, B, and C). Lineages A and C were geographically widespread, while lineage B was geographically restricted to the eastern part of Thailand. The geographic localization of lineage B suggested limitations in gene flow, which is most likely a result of ecologically different habitats. Large genetic differences between individuals of lineages A and C, but geographically sympatric distributions of the members of these lineages, are considered to represent an admixture of the populations that have evolved allopatrically. Historical environmental change during the Pleistocene glaciations is possibly the factor that drove the lineage divergence. Population demographic history analyses revealed recent population expansions in the three lineages dating back to the last glaciations. These observations further highlight the significance of the Pleistocene climatic change on current genetic structure and diversity of living organisms of the Southeast Asian mainland.

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Spintharus flavidus in the Caribbean – a 30 million year biogeographical history and radiation of a ‘widespread species’

10.7287/peerj.preprints.1332v1 ◽

2015 ◽

Author(s):

Austin Dziki ◽

Greta Binford ◽

Jonathan A Coddington ◽

Ingi Agnarsson

Keyword(s):

Single Species ◽

Caribbean Region ◽

Dispersal Ability ◽

Widespread Species ◽

Caribbean Islands ◽

Island Endemics ◽

Molecular Phylogenetic ◽

Limited Dispersal ◽

History Of ◽

The Caribbean

The Caribbean island biota is characterized by high levels of endemism, the result of an interplay between colonization opportunities on islands and effective oceanic barriers among them. A relatively small percentage of the biota is represented by ‘widespread species’, presumably taxa for which oceanic barriers are ineffective. Few studies have explored in detail the genetic structure of widespread Caribbean taxa. The cobweb spider Spintharus flavidus Hentz, 1850 (Theridiidae) is one of two described Spintharus species and is unique in being widely distributed from northern N. America to Brazil and throughout the Caribbean. As a taxonomic hypothesis, Spintharus “flavidus” predicts maintenance of gene flow among Caribbean islands, a prediction that seems contradicted by known S. flavidus biology, which suggests limited dispersal ability. As part of an extensive survey of Caribbean arachnids (project CarBio), we conducted the first molecular phylogenetic analysis of S. flavidus with the primary goal of testing the ‘widespread species’ hypothesis. Our results, while limited to three molecular loci, reject the hypothesis of a single widespread species. Instead this lineage seems to represent a radiation with at least 16 species in the Caribbean region. Nearly all are short range endemics with several distinct mainland groups and others being single island endemics. While limited taxon sampling, with a single specimen from S. America, constrains what we can infer about the biogeographical history of the lineage, clear patterns still emerge. Consistent with limited overwater dispersal, we find evidence for a single colonization of the Caribbean about 30 million years ago, coinciding with the timing of the GAARLandia landbridge hypothesis. In sum, S. “flavidus” is not a single species capable of frequent overwater dispersal, but rather a 30 my old radiation of single island endemics that provides preliminary support for a complex and contested geological hypothesis.

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The interacting effects of genetic variation in Geranium subg. Geranium (Geraniaceae) using scot molecular markers

Caryologia ◽

10.36253/caryologia-1079 ◽

2021 ◽

Vol 74 (3) ◽

pp. 141-150

Author(s):

Bo Shi ◽

Majid Khayatnezhad ◽

Abdul Shakoor

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Biological Diversity ◽

Isolation By Distance ◽

Morphological Characters ◽

Mantel Test ◽

Conservation Strategies ◽

High Genetic Diversity ◽

Information Index ◽

Narrow Endemic

One of the most crucial aspects of biological diversity for conservation strategies is genetic diversity, particularly in rare and narrow endemic species. Our study is the first attempt to utilize SCoT markers to check the genetic diversity in Iran. We used 115 plant samples. Our objectives were 1) to check genetic diversity among Geranium species 2) Genetic structure of the Geranium 3) Do the Geranium species exchange genes? 4) To detect isolation by distance among the Geranium species. We used traditional morphological and molecular methods to assess genetic diversity and genetic structure in the Geranium species. A total of 129 amplified polymorphic bands were generated across 13 Geranium species. The size of the amplified fragments ranged from 150 to 3000 bp. G. stepporum showed the highest values for the effective number of alleles (Ne = 1.30) and Shannon information index (I =0.35). Significant ANOVA results (P <0.01) showed differences in quantitative morphological characters in plant species. G. sylvaticum showed high genetic diversity. Mantel test showed a significant correlation (r = 0.17, p=0.0002) between genetic distance and geographical distance, so isolation by distance (IBD) occurred among the Geranium species. According to the SCoT markers analysis, G. kotschyi and G. dissectum had the lowest similarity, and the species of G. sylvaticum and G. pratense had the highest similarity. The present study revealed that a combination of morphological and SCoT methods could distinguish the species of Geranium.

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Taxonomic issues related to biological control prospects for the ragweed borer, Epiblema strenuana (Lepidoptera: Tortricidae)

Zootaxa ◽

10.11646/zootaxa.4729.3.3 ◽

2020 ◽

Vol 4729 (3) ◽

pp. 347-358

Author(s):

TODD M. GILLIGAN ◽

DONALD J. WRIGHT ◽

RICHARD L. BROWN ◽

BENNO A. AUGUSTINUS ◽

URS SCHAFFNER

Keyword(s):

Biological Control ◽

Host Range ◽

Biological Control Agent ◽

Feeding Habits ◽

Geographic Location ◽

Taxonomic Status ◽

Valid Species ◽

Separate Species ◽

Epiblema Strenuana ◽

History Of

The ragweed borer, Epiblema strenuana (Walker, 1863), has a long history of use as a biological control agent against important weed pests in the family Asteraceae. Recently, E. strenuana has been reported feeding on the invasive perennials Ambrosia confertiflora and A. tenuifolia in Israel. The geographic location of Israel has raised concern over the possibility that the moth may spread to areas such as Ethiopia where the oil-seed crop Guizotia abyssinica is cultivated, as this is a potential host for E. strenuana. However, the taxonomic status of E. strenuana and a current synonym, E. minutana (Kearfott, 1905) is unclear. These taxa have been treated as separate species in the past, and they potentially have different feeding habits and damage different parts of the plant. We analyzed DNA data and adult morphology and determined that E. minutana, stat. rev., is a valid species which we raise from synonymy with E. strenuana. Wing coloration, the shape of the female sterigma, and COI DNA barcodes are consistently different between the two species. We also determined that the species previously identified as E. strenuana in Israel is actually E. minutana. While detailed host range tests have been conducted on the E. strenuana populations released in Australia and China, the host range of E. minutana remains to be clarified. We discuss the history of biological control using E. strenuana and the implications for finding E. minutana in Israel. We also provide species redescriptions for E. strenuana and E. minutana and illustrate diagnostic characters.

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Genetic variation and genetic structure within metapopulations of two closely related selfing and outcrossing Zingiber species (Zingiberaceae)

AoB Plants ◽

10.1093/aobpla/plaa065 ◽

2020 ◽

Author(s):

Rong Huang ◽

Zong-Dian Zhang ◽

Yu Wang ◽

Ying-Qiang Wang

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

Genetic Structure ◽

Habitat Fragmentation ◽

Spatial Genetic Structure ◽

Full Range ◽

Breeding Systems ◽

Dispersal Ability ◽

Phylogenetic Distance ◽

Plant Populations

Abstract Habitat fragmentation strongly affects the genetic diversity of plant populations, and this has always attracted much research interest. Although numerous studies have investigated the effects of habitat fragmentation on the genetic diversity of plant populations, fewer studies have compared species with contrasting breeding systems while accounting for phylogenetic distance. Here, we compare the levels of genetic diversity and differentiation within and among subpopulations in metapopulations (at fine-scale level) of two closely related Zingiber species, selfing Zingiber corallinum and outcrossing Zingiber nudicarpum. Comparisons of the genetic structure of species from unrelated taxa may be confounded by the effects of correlated ecological traits or/and phylogeny. Thus, we possibly reveal the differences in genetic diversity and spatial distribution of genetic variation within metapopulations that relate to mating systems. Compared to outcrossing Z. nudicarpum, the subpopulation genetic diversity in selfing Z. corallinum was significantly lower, but the metapopulation genetic diversity was not different. Most genetic variation resided among subpopulations in selfing Z. corallinum metapopulations, while a significant portion of variation resided either within or among subpopulations in outcrossing Z. nudicarpum, depending on whether the degree of subpopulation isolation surpass the dispersal ability of pollen and seed. A stronger spatial genetic structure appeared within subpopulations of selfing Z. corallinum potentially due to restricted pollen flow and seed dispersal. In contrast, a weaker genetic structure was apparent in subpopulations of outcrossing Z. nudicarpum most likely caused by extensive pollen movement. Our study shows that high genetic variation can be maintained within metapopulations of selfing Zingiber species, due to increased genetic differentiation intensified primarily by the stochastic force of genetic drift among subpopulations. Therefore, maintenance of natural variability among subpopulations in fragmented areas is key to conserve the full range of genetic diversity of selfing Zingiber species. For outcrossing Zingiber species, maintenance of large populations is an important factor to enhance genetic diversity.

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