Genetic diversity and differentiation in the critically endangered orchid (Amitostigma hemipilioides): implications for conservation

AbstractThe gharial (Gavialis gangeticus) is a critically endangered crocodylian, endemic to the Indian subcontinent. The species has experienced severe population decline during the twentieth century owing to habitat loss, poaching, and mortalities in passive fishing. Its extant populations have largely recovered through translocation programmes initiated in 1975. Understanding the genetic status of these populations is crucial for evaluating the effectiveness of the ongoing conservation efforts. This study assessed the genetic diversity, population structure, and evidence of genetic bottlenecks of the two managed populations inhabiting the Chambal and Girwa Rivers, which hold nearly 80% of the global gharial populations. We used seven polymorphic nuclear microsatellite loci and a 520 bp partial fragment of the mitochondrial control region (CR). The overall mean allelic richness (Ar) was 2.80 ± 0.40, and the observed (Ho) and expected (He) heterozygosities were 0.40 ± 0.05 and 0.39 ± 0.05, respectively. We observed low levels of genetic differentiation between populations (FST = 0.039, P < 0.05; G’ST = 0.058, P < 0.05 Jost’s D = 0.016, P < 0.05). The bottleneck analysis using the M ratio (Chambal = 0.31 ± 0.06; Girwa = 0.41 ± 0.12) suggested the presence of a genetic bottleneck in both populations. The mitochondrial CR also showed a low level of variation, with two haplotypes observed in the Girwa population. This study highlights the low level of genetic diversity in the two largest managed gharial populations in the wild. Hence, it is recommended to assess the genetic status of extant wild and captive gharial populations for planning future translocation programmes to ensure long-term survival in the wild.

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Looking Back for the Future: Utilizing Sawfish Saws from Natural History Collections to Conserve the Critically Endangered Largetooth Sawfish (Pristis pristis)

Biodiversity Information Science and Standards ◽

10.3897/biss.2.25806 ◽

2018 ◽

Vol 2 ◽

pp. e25806

Author(s):

Annmarie Fearing ◽

Kelcee Smith ◽

Tonya Wiley ◽

Jeff Whitty ◽

Kevin Feldheim ◽

...

Keyword(s):

Genetic Diversity ◽

Natural History ◽

Mitochondrial Control Region ◽

Genetic Bottleneck ◽

Critically Endangered ◽

Past Century ◽

Term Survival ◽

Tissue Samples ◽

The Past ◽

Natural History Collections

The Critically Endangered (International Union for Conservation of Nature) largetooth sawfish, Pristispristis, was historically distributed in the tropical Pacific, Atlantic and Indian Oceans. Today, ‘viable’ populations are largely limited to northern Australia. Populations that have suffered from drastic declines in abundance, such as those experienced by P.pristis, are typically at risk of having reduced, or low, levels of genetic diversity. Previous research found that P.pristis in Australia have experienced a genetic bottleneck, but it is unclear whether this bottleneck is the result of contemporary declines over the last century, or if it is the result of historic processes. A direct way to assess whether this genetic bottleneck occurred relatively recently is to compare levels of genetic diversity in contemporary and historic populations. Sawfish saws that were taken as trophies over the past century can now be found in natural history collections around the world and can provide DNA from past sawfish populations. We collected tissue samples from 150 dried P.pristis saws found in both private and public natural history collections. Because DNA from natural history specimens tends to be highly degraded, we targeted ten small DNA fragments, ~150 base pairs each, to amplify and sequence the entire mitochondrial control region. These data will provide important baseline information about P.pristis that can be used to quantify any loss of genetic diversity over the past ~100 years and assess their long-term survival potential. If the levels of genetic diversity in contemporary populations are severely reduced from those of past populations, protecting remaining genetic diversity within and between viable populations should be a priority in conservation plans.

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Peer Review #2 of "Genetic diversity and structure of the critically endangered Artocarpus annulatus, a crop wild relative of jackfruit (A. heterophyllus) (v0.2)"

10.7287/peerj.9897v0.2/reviews/2 ◽

2020 ◽

Keyword(s):

Genetic Diversity ◽

Peer Review ◽

Critically Endangered ◽

Wild Relative ◽

Crop Wild Relative ◽

Genetic Diversity And Structure

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Low genetic diversity and limited genetic structure across the range of the critically endangered Mexican howler monkey ( Alouatta palliata mexicana )

American Journal of Primatology ◽

10.1002/ajp.23160 ◽

2020 ◽

Vol 82 (8) ◽

Cited By ~ 1

Author(s):

Adrián Melo‐Carrillo ◽

Jacob C. Dunn ◽

Liliana Cortés‐Ortiz

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Alouatta Palliata ◽

Critically Endangered ◽

Howler Monkey ◽

Low Genetic Diversity ◽

Alouatta Palliata Mexicana

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Genetic diversity in fragmented populations of the critically endangered spider orchid Caladenia huegelii: implications for conservation

Conservation Genetics ◽

10.1007/s10592-008-9651-9 ◽

2008 ◽

Vol 10 (5) ◽

pp. 1199-1208 ◽

Cited By ~ 32

Author(s):

Nigel D. Swarts ◽

Elizabeth A. Sinclair ◽

Siegfried L. Krauss ◽

Kingsley W. Dixon

Keyword(s):

Genetic Diversity ◽

Critically Endangered ◽

Fragmented Populations

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Genetic diversity of Astragalus nitidiflorus, a critically endangered endemic of SE Spain, and implications for its conservation

Biochemical Systematics and Ecology ◽

10.1016/j.bse.2011.03.005 ◽

2011 ◽

Vol 39 (3) ◽

pp. 175-182 ◽

Cited By ~ 24

Author(s):

María J. Vicente ◽

Francisco Segura ◽

Mayra Aguado ◽

Daniele Migliaro ◽

José A. Franco ◽

...

Keyword(s):

Genetic Diversity ◽

Critically Endangered ◽

Se Spain

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Population genetics and conservation of the critically endangered Clematis acerifolia (Ranunculaceae)

Canadian Journal of Botany ◽

10.1139/b05-097 ◽

2005 ◽

Vol 83 (10) ◽

pp. 1248-1256 ◽

Cited By ~ 5

Author(s):

J. López-Pujol ◽

F.-M. Zhang ◽

S. Ge

Keyword(s):

Genetic Diversity ◽

Population Genetic ◽

Critically Endangered ◽

Ex Situ ◽

Genetic Structuring ◽

Long Term Storage ◽

Hardy Weinberg Equilibrium ◽

Term Storage

Allozyme electrophoresis was used to evaluate the levels of genetic diversity and population genetic structure of the critically endangered Clematis acerifolia Maximowicz (Ranunculaceae), a narrow endemic species in China. On the basis of variation at 19 putative loci in nine populations covering the entire distribution of this species, low values of genetic diversity were detected (P = 20.5%, A = 1.27, and He = 0.072). A significant deficiency of heterozygotes was found in all populations. Most loci showed deviations from the Hardy–Weinberg equilibrium, probably as a result of population genetic structuring. The high genetic divergence among populations (FST = 0.273) can be interpreted as an effect of the extinction of local populations and genetic drift within extant populations, and has probably been enhanced by habitat fragmentation in recent decades. Threats to this species are mainly anthropogenic (road works, construction of holiday resorts, and extraction activities), although stochastic risks cannot be ignored. Therefore, to preserve extant genetic variation of C. acerifolia, in situ strategies, such as the preservation of its habitat or at least the most diverse populations, and ex situ measures, such as the collection and long-term storage of seeds, should be adopted.

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