scholarly journals Demographic and genetic structure of a severely fragmented population of the endangered hog deer (Axis porcinus) in the Indo-Burma biodiversity hotspot

2019 ◽  
Author(s):  
Sangeeta Angom ◽  
Chongpi Tuboi ◽  
Mirza Ghazanfar Ullah ◽  
Syed Ainul Hussain
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Polymorphic Information Content ◽  
Distance Sampling ◽  
Northeast India ◽  
Biodiversity Hotspot ◽  
Evolutionary Potential ◽  
Female Ratio ◽  
Management Regime ◽  
Rare Alleles

AbstractThe population of the globally endangered hog deer (Axis porcinus) has declined severely across its geographic range. Intensive monitoring of its demographic and genetic status is necessary. Northeast India is a stronghold of the species; however, in recent years the population has been getting fragmented, and it is vulnerable to extinction. We examined the demographic and genetic structure of a small hog deer population in the floating meadows of Keibul Lamjao National Park (KLNP), located on the western fringe of the Indo-Burma biodiversity hotspot for conservation planning. We used a double-observer distance sampling method to derive the hog deer abundance and population structure. We also derived the genetic diversity of the population through microsatellite screening and bottleneck detection. Our study revealed that the abundance of the deer in the park was 1.82–4.32 individuals/km2. The adult male to female ratio and fawn to doe ratio were 36.2 ± 1.9 males/100 females and 16.5 ± 0.4 fawns/100 females, respectively. The mean number of alleles at 23 loci was 2.70 ± 0.18, the observed heterozygosity (HO) ranged from 0.26 to 0.63 (mean 0.42 ± 0.02), the expected heterozygosity (HE) ranged from 0.23 to 0.73 (χ = 0.51 ± 0.03), and the polymorphic information content (PIC) ranged from 0.2 to 0.67 (χ = 0.43 ± 0.03). The observed allelic distribution reveals that the population has not encountered any genetic bottleneck in the recent past. Although the population is declining, it still retains some rare alleles, and the genetic diversity is 50%. This diversity will probably not affect the short-term population growth but may affect the evolutionary potential by limiting the selection flexibility. Conservation measures coupled with a scientifically sound management regime may help the persistence of the population in the region at a time when the population still retains rare alleles and maintains reproductive fitness.

Intact genetic structure and high levels of genetic diversity in bottlenecked sockeye salmon (Oncorhynchus nerka) populations of the Fraser River, British Columbia, Canada

2000 ◽  
Vol 57 (10) ◽  
pp. 1985-1998 ◽  
Author(s):  
Ruth E Withler ◽  
Khai D Le ◽  
R John Nelson ◽  
Kristina M Miller ◽  
Terry D Beacham
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Allelic Diversity ◽  
Lower Proportion ◽  
Fraser River ◽  
Rare Alleles ◽  
Genetic Bottlenecks

Analysis of six microsatellite loci in 5800 sockeye salmon (Oncorhynchus nerka) from 29 Fraser River populations provided little evidence of genetic bottlenecks or mass straying in upper Fraser sockeye salmon resulting from reduced abundances following 1913-1914 rockslides in the Fraser canyon and successive decades of high exploitation. Upper Fraser populations were not characterized by a paucity of rare alleles, a sensitive indicator of populations in which effective size has been recently reduced. Heterozygosity and allelic diversity did not differ consistently between lower and upper Fraser populations. Throughout the watershed, early-migrating populations had lower allelic diversity and a lower proportion of rare alleles than did late-migrating ones. Genetic differentiation between upper and lower Fraser populations and heterogeneity among lower Fraser populations supported the suggestion that Fraser sockeye salmon are descendants of at least two postglacial "races." Variation among lakes within regions was the strongest component of genetic structure, accounting for five times the variation among populations within lakes and more than two times the variation among regions. Extensive historical transplants of eggs and juveniles apparently resulted in lit tle gene flow among regions, but three populations were reestablished or rebuilt as the result of more recent transplants.

An evaluation of the genetic structure of seed sources and the maintenance of genetic diversity during establishment of two yellow box (Eucalyptus melliodora) seed-production areas

2015 ◽  
Vol 63 (5) ◽  
pp. 455 ◽  
Author(s):  
Linda M. Broadhurst ◽  
Graham Fifield ◽  
Bindi Vanzella ◽  
Melinda Pickup
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Seed Production ◽  
Significant Loss ◽  
Evolutionary Potential ◽  
Seed Collection ◽  
Seed Sources ◽  
Significant Difference ◽  
Genetic Bottlenecks ◽  
Production Areas

Vegetation clearing and land-use change have depleted many natural plant communities to the point where restoration is required. A major impediment to the success of rebuilding complex vegetation communities is having regular access to sufficient quantities of high-quality seed. Seed-production areas (SPAs) can help generate this seed, but these must be underpinned by a broad genetic base to maximise the evolutionary potential of restored populations. However, genetic bottlenecks can occur at the collection, establishment and production stages in SPAs, requiring genetic evaluation. This is especially relevant for species that may take many years before a return on SPA investment is realised. Two recently established yellow box (Eucalyptus melliodora A.Cunn. ex Schauer, Myrtaceae) SPAs were evaluated to determine whether genetic bottlenecks had occurred between seed collection and SPA establishment. No evidence was found to suggest that a significant loss of genetic diversity had occurred at this stage, although there was a significant difference in diversity between the two SPAs. Complex population genetic structure was also observed in the seed used to source the SPAs, with up to eight groups identified. Plant survival in the SPAs was influenced by seed collection location but not by SPA location and was not associated with genetic diversity. There were also no associations between genetic diversity and plant growth. These data highlighted the importance of chance events when establishing SPAs and indicated that the two yellow box SPAs are likely to provide genetically diverse seed sources for future restoration projects, especially by pooling seed from both SPAs.

scholarly journals Genetic structure and diversity among individuals of Copaifera langsdorffii Desf. from Mato Grosso, Brazilian Amazon, using ISSR markers

2021 ◽  
Vol 10 (16) ◽  
pp. e187101623025
Author(s):  
Daniele Paula Maltezo ◽  
Julliane Dutra Medeiros ◽  
Ana Aparecida Bandini Rossi
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Variability ◽  
Polymorphic Information Content ◽  
Issr Markers ◽  
Group Method ◽  
Mato Grosso ◽  
Copaifera Langsdorffii ◽  
Genetic Structure And Diversity ◽  
Issr Primers

The Amazon is the largest tropical forest in the world and is home to around 20% of all the biodiversity on the planet, among the species present in the Amazon is Copaifera langsdorffii, exploited mainly for the extraction of oil-resin and wood, often in ways incorrect, which can cause the loss of genetic variability. The aim of this study was to evaluate the genetic structure and diversity among individuals of C. langsdorffii located in Mato Grosso, Brazil, using ISSR markers. We sampled leaves from 27 adult individuals of C. langsdorffii, whose total genomic DNA was extracted. A total of 12 ISSR primers were used for the molecular characterization of the individuals. A grouping analysis was performed using the unweighted pair group method, Bayesian analysis and characterized by the genetic diversity. The genetic diversity among and within the groups was demonstrated by the AMOVA. As a result, 106 fragments were amplified and 98.11% were polymorphic. The polymorphic information content of each primer ranged from 0.45 to 0.81.  The dendrogram showed the formation of 4 distinct groups. The greatest genetic variability is found within the groups and not between them. The percentage of polymorphism, genetic dissimilarity values and genetic diversity indexes indicate that there is high genetic variability among Copaifera langsdorffii individuals, suggesting that ISSR primers were efficient in detecting polymorphism in this species and that the individuals have potential for compose programs aimed at the preservation of the species and the ability to integrate germplasm banks.

scholarly journals Range-wide neutral and adaptive genetic structure of an endemic herb from Amazonian Savannas

AoB Plants ◽  
2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Amanda R Silva ◽  
Luciana C Resende-Moreira ◽  
Carolina S Carvalho ◽  
Eder C M Lanes ◽  
Mabel P Ortiz-Vera ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Extinction Risk ◽  
Clustering Methods ◽  
Effective Population ◽  
Evolutionary Potential ◽  
Management Actions ◽  
Temperature And Precipitation ◽  
Population Sizes ◽  
Genetic Clustering

Abstract Conserving genetic diversity in rare and narrowly distributed endemic species is essential to maintain their evolutionary potential and minimize extinction risk under future environmental change. In this study we assess neutral and adaptive genetic structure and genetic diversity in Brasilianthus carajensis (Melastomataceae), an endemic herb from Amazonian Savannas. Using RAD sequencing we identified a total of 9365 SNPs in 150 individuals collected across the species’ entire distribution range. Relying on assumption-free genetic clustering methods and environmental association tests we then compared neutral with adaptive genetic structure. We found three neutral and six adaptive genetic clusters, which could be considered management units (MU) and adaptive units (AU), respectively. Pairwise genetic differentiation (FST) ranged between 0.024 and 0.048, and even though effective population sizes were below 100, no significant inbreeding was found in any inferred cluster. Nearly 10 % of all analysed sequences contained loci associated with temperature and precipitation, from which only 25 sequences contained annotated proteins, with some of them being very relevant for physiological processes in plants. Our findings provide a detailed insight into genetic diversity, neutral and adaptive genetic structure in a rare endemic herb, which can help guide conservation and management actions to avoid the loss of unique genetic variation.

scholarly journals Genetic Diversity of Orobanche crenata Populations in Ethiopia Using Microsatellite Markers

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Gashaw Belay ◽  
Kassahun Tesfaye ◽  
Aladdin Hamwieh ◽  
Seid Ahmed ◽  
Tiegist Dejene ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Distance ◽  
Faba Bean ◽  
Polymorphic Information Content ◽  
Hot Spot ◽  
Molecular Techniques ◽  
Orobanche Crenata ◽  
Parasitic Weed ◽  
South Gondar

Orobanche crenata is a parasitic weed that causes considerable yield losses on food legumes in Ethiopia and the Mediterranean region. Understanding the genetic diversity of Orobanche crenata using molecular techniques generate useful information in managing the weed through resistance breeding. This study aimed at assessing the genetic diversity of O. crenata populations collected from major faba bean growing areas of Ethiopia. A total of 96 samples were collected from the Orobanche-infested faba bean farmer field. The genetic diversity of the population was studied using 30 O. cumana SSR markers. The results showed that 11 SSRs were functional and transferable markers to study the diversity of O. crenata populations. The average number of alleles, gene diversity, heterozygosity, and polymorphic information content values for the SSR loci were 9.6, 0.82, 0.38, and 0.80, respectively. The pairwise genetic similarity analysis showed the lowest genetic distance between samples collected from South Gondar and South Wollo (0.12) while the highest genetic distance (0.48) was found between South Gondar and North Wollo. The analysis of molecular variance result indicated that the variation among individuals was a major source of genetic variation (55%) followed by within individuals (43%) and among populations (2%) variation. The output of population genetic structure analysis indicated the presence of two major groups irrespective of the area of collection or region of origin. Besides, the outcome of the spatial autocorrelation computation indicated a significant and positive genetic correlation between samples collected under a 28 km radius. In general, the absence of geographic region based genetic structure presumably demonstrates the expansion of the parasitic weed between farming sites upon its recent introduction to the country. Thus, the clear absence of population differentiation warrants screening faba bean population in hot spot area.

scholarly journals Genetic structure of the carp population (Cyprinus carpio carpio) grown in the aquaculture in the Republic of Belarus

2021 ◽  
Vol 65 (1) ◽  
pp. 68-75
Author(s):  
V. A. Lemesh ◽  
V. Yu. Ageyets ◽  
A. Yu. Nosova ◽  
V. N. Kipen ◽  
N. I. Tsar ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Cyprinus Carpio ◽  
Microsatellite Loci ◽  
High Genetic Diversity ◽  
Total Percentage ◽  
Cyprinus Carpio Carpio ◽  
Rare Alleles ◽  
The Republic ◽  
High Level

In this study, we presented a panel of 14 microsatellite loci (MFW1, MFW2, MFW6, MFW9, MFW10, MFW11, MFW13, MFW16, MFW20, MFW24, MFW26, MFW28, MFW29 and Cid0909), with which we studied the genetic structure of Cyprinus carpio carpio of the breed “Izobelinsky” in the Republic of Belarus. Four offshoots of carp were included in the study: two mirrory (“Smes’ zerkal’naya”, “Tri prim”) and two scaly (“Smes’ cheshujchataya”, “Stolin XVIII”).As a result, it was found that the carp breed “Izobelinsky” exhibits a high level of in-breed genetic variability. In the studied microsatellite loci, 231 alleles were identified, 62 % of the total number of alleles were rare alleles with a frequency of occurrence of less than 5.0 %. The number of effective alleles (Ne) at the loci ranged from 3.082 (MFW10) to 9.754 (MFW26). The Shannon biodiversity index (I) was 2.082 ± 0.075. The highest value of the expected heterozygosity index (He) was noted for the MFW26 locus (0.897), the lowest – for the MFW10 locus (0.676).The greatest genetic diversity is characteristic of the scaly carp “Smes’ cheshujchataya” and “Stolin XVIII”. The highest total percentage of rare alleles was determined for fishes from “Stolin XVIII”. The minimum values of this parameter were found for specimens of the carp “Smes’ zerkal’naya” and “Tri prim”.The results of this study indicate a fairly high genetic diversity of four offshoots of the carp breed “Izobelinsky”, which was established using the marker loci optimally selected for analysis. This makes it possible to differentiate the layering among themselves.

scholarly journals Genetic Diversity of a Natural Population of Akebia trifoliata (Thunb.) Koidz and Extraction of a Core Collection Using Simple Sequence Repeat Markers

2021 ◽  
Vol 12 ◽  
Author(s):  
Yicheng Zhong ◽  
Yue Wang ◽  
Zhimin Sun ◽  
Juan Niu ◽  
Yaliang Shi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Simple Sequence Repeat ◽  
Core Collection ◽  
Polymorphic Information Content ◽  
Germplasm Conservation ◽  
Sequence Repeat ◽  
Information Index ◽  
Molecular Identity ◽  
Simple Sequence

Understand genetic diversity and genetic structure of germplasm is premise of germplasm conservation and utilization. And core collection can reduce the cost and difficulty of germplasm conservation. Akebia trifoliata (Thunb.) Koidz is an important medicinal, fruit and oil crop, particularly in China. In this study, 28 simple sequence repeat (SSR) markers were used to assess the genetic diversity and genetic structure of 955 A. trifoliata germplasms, determine their molecular identity and extract a core collection. The genetic diversity of the 955 germplasms was moderately polymorphic. The average number of alleles (Na), observed heterozygosity (HO), expected heterozygosity (HE), Shannon’s information index (I∗), and polymorphic information content (PIC) were 3.71, 0.24, 0.46, 0.81, and 0.41, respectively. Four subpopulations were identified, indicating a weak genetic structure. A 955 germplasms could be completely distinguished by the characters of s28, s25, s74, s89, s68, s30, s13, s100, s72, s77, and s3. And each germplasm’s molecular identity was made up of eleven characters. The core collection was composed of 164 germplasms (17.2% of 955 total germplasms in the population) and diversity parameters differed significantly from those of a random core collection. These results have implications for germplasm conservation. At the same time, based on the results, the 955 germplasm could be better used and managed.

Genetic diversity and genetic structure of the rare and endangered species, Primula ranunculoides

2014 ◽  
Vol 21 (5) ◽  
pp. 601-609
Author(s):  
Wang Deyun ◽  
Peng Jie ◽  
Chen Yajing ◽  
Lü Guosheng ◽  
Zhang Xiaoping ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Endangered Species ◽  
Rare And Endangered Species ◽  
Rare And Endangered

Genetic rescue by augmenting gene flow

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Inbreeding Coefficient ◽  
Outbreeding Depression ◽  
Genetic Rescue ◽  
Evolutionary Potential ◽  
Beneficial Effects ◽  
The Difference ◽  
Inbred Populations ◽  
Harmful Effects

Inbreeding is reduced and genetic diversity enhanced when a small isolated inbred population is crossed to another unrelated population. Crossing can have beneficial or harmful effects on fitness, but beneficial effects predominate, and the risks of harmful ones (outbreeding depression) can be predicted and avoided. For crosses with a low risk of outbreeding depression, there are large and consistent benefits on fitness that persist across generations in outbreeding species. Benefits are greater in species that naturally outbreed than those that inbreed, and increase with the difference in inbreeding coefficient between crossed and inbred populations in mothers and zygotes. However, benefits are similar across invertebrates, vertebrates and plants. There are also important benefits for evolutionary potential of crossing between populations.

scholarly journals The Patterns and Puzzles of Genetic Diversity of Endangered Freshwater Mussel Unio crassus Philipsson, 1788 Populations from Vistula and Neman Drainages (Eastern Central Europe)

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 119
Author(s):  
Adrianna Kilikowska ◽  
Monika Mioduchowska ◽  
Anna Wysocka ◽  
Agnieszka Kaczmarczyk-Ziemba ◽  
Joanna Rychlińska ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Scales ◽  
Freshwater Mussel ◽  
Its Region ◽  
Strong Relationship ◽  
Mantel Test ◽  
Freshwater Ecosystems ◽  
Hierarchical Organization ◽  
Anthropogenic Factors

Mussels of the family Unionidae are important components of freshwater ecosystems. Alarmingly, the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species identifies almost 200 unionid species as extinct, endangered, or threatened. Their decline is the result of human impact on freshwater habitats, and the decrease of host fish populations. The Thick Shelled River Mussel Unio crassus Philipsson, 1788 is one of the examples that has been reported to show a dramatic decline of populations. Hierarchical organization of riverine systems is supposed to reflect the genetic structure of populations inhabiting them. The main goal of this study was an assessment of the U. crassus genetic diversity in river ecosystems using hierarchical analysis. Different molecular markers, the nuclear ribosomal internal transcribed spacer ITS region, and mitochondrial DNA genes (cox1 and ndh1), were used to examine the distribution of U. crassus among-population genetic variation at multiple spatial scales (within rivers, among rivers within drainages, and between drainages of the Neman and Vistula rivers). We found high genetic structure between both drainages suggesting that in the case of the analyzed U. crassus populations we were dealing with at least two different genetic units. Only about 4% of the mtDNA variation was due to differences among populations within drainages. However, comparison of population differentiation within drainages for mtDNA also showed some genetic structure among populations within the Vistula drainage. Only one haplotype was shared among all Polish populations whereas the remainder were unique for each population despite the hydrological connection. Interestingly, some haplotypes were present in both drainages. In the case of U. crassus populations under study, the Mantel test revealed a relatively strong relationship between genetic and geographical distances. However, in detail, the pattern of genetic diversity seems to be much more complicated. Therefore, we suggest that the observed pattern of U. crassus genetic diversity distribution is shaped by both historical and current factors i.e. different routes of post glacial colonization and history of drainage systems, historical gene flow, and more recent habitat fragmentation due to anthropogenic factors.

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