scholarly journals The genetic diversity and population structure of two endemic Amazonian quillwort (Isoetes L.) species

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10274 ◽  
Author(s):  
Mirella Pupo Santos ◽  
João V.S. Rabelo Araujo ◽  
Arthur V. Sant’anna Lopes ◽  
Julio Cesar Fiorio Vettorazzi ◽  
Marcela Santana Bastos Boechat ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Geographical Location ◽  
Inter Simple Sequence Repeat ◽  
Shannon Index ◽  
Conservation Strategies ◽  
Amazon Forest ◽  
Mass Extinctions ◽  
Effective Conservation

Background Two endemic lycophyte species Isoetes cangae and Isoetes serracarajensis have been recently described in the State of Pará in the Amazon forest located in northern Brazil. Isoetes L. has survived through three mass extinctions. Plants are considered small-sized, heterosporous, and can display a great diversity of physiological adaptations to different environments. Thus, the current study aimed to estimate the genetic variation of the populations of I. cangae and I. serracarajensis to generate information about their different mechanisms for survival at the same geographical location that could point to different reproductive, adaptative and dispersal strategies and should be considered for effective conservation strategies. Methods The genetic diversity and population structure of I. cangae and I. serracarajensis were investigated using Inter Simple Sequence Repeat (ISSR) molecular markers. Total genomic DNA was isolated, and the genetic diversity parameters were calculated. Results The sixteen primers produced 115 reproducible bands, 87% of which were polymorphic. A high level of polymorphic loci (81.74% and 68.48%) and a high Shannon index (Sh = 0.376 and 0.289) were observed for I. cangae and I. serracarajensis, respectively. The coefficient of genetic differentiation between population areas (GST) showed a higher value in I. serracarajensis (0.5440). Gene flow was higher in I. cangae (1.715) and lower in I. serracarajensis populations (0.419). Overall, the results further show that I. serracarajensis and I. cangae are two species with considerable genetic variation and that these differences may reflect their habitats and modes of reproduction. These results should be considered in the development of effective conservation strategies for both species.

scholarly journals High Genetic Diversity and Low Differentiation in Michelia shiluensis, an Endangered Magnolia Species in South China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 469 ◽  
Author(s):  
Yanwen Deng ◽  
Tingting Liu ◽  
Yuqing Xie ◽  
Yaqing Wei ◽  
Zicai Xie ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Human Disturbance ◽  
Haplotype Diversity ◽  
Conservation Strategy ◽  
Ex Situ ◽  
Conservation Strategies ◽  
High Genetic Diversity ◽  
Cpdna Markers

Research Highlights: This study is the first to examine the genetic diversity of Michelia shiluensis (Magnoliaceae). High genetic diversity and low differentiation were detected in this species. Based on these results, we discuss feasible protection measures to provide a basis for the conservation and utilization of M. shiluensis. Background and Objectives: Michelia shiluensis is distributed in Hainan and Guangdong province, China. Due to human disturbance, the population has decreased sharply, and there is thus an urgent need to evaluate genetic variation within this species in order to identify an optimal conservation strategy. Materials and Methods: In this study, we used eight nuclear single sequence repeat (nSSR) markers and two chloroplast DNA (cpDNA) markers to assess the genetic diversity, population structure, and dynamics of 78 samples collected from six populations. Results: The results showed that the average observed heterozygosity (Ho), expected heterozygosity (He), and percentage of polymorphic loci (PPL) from nSSR markers in each population of M. shiluensis were 0.686, 0.718, and 97.92%, respectively. For cpDNA markers, the overall haplotype diversity (Hd) was 0.674, and the nucleotide diversity was 0.220. Analysis of markers showed that the genetic variation between populations was much lower based on nSSR than on cpDNA (10.18% and 77.56%, respectively, based on an analysis of molecular variance (AMOVA)). Analysis of the population structure based on the two markers shows that one of the populations (DL) is very different from the other five. Conclusions: High genetic diversity and low population differentiation of M. shiluensis might be the result of rich ancestral genetic variation. The current decline in population may therefore be due to human disturbance rather than to inbreeding or genetic drift. Management and conservation strategies should focus on maintaining the genetic diversity in situ, and on the cultivation of seedlings ex-situ for transplanting back to their original habitat.

AFLP analyses of genetic variation of Eupatorium adenophorum (Asteraceae) populations in China

2009 ◽  
Vol 89 (1) ◽  
pp. 119-126 ◽  
Author(s):  
W. K. Huang ◽  
F. H. Wan ◽  
J. Y. Guo ◽  
B. D. Gao ◽  
B. Y. Xie ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Amplified Fragment Length Polymorphism ◽  
Shannon Index ◽  
Eupatorium Adenophorum ◽  
Data Set

The Eupatorium adenophorum is one of the most widespread invasive alien species in China. In the present study, the genetic variation and population structure of this species were analyzed using amplified fragment length polymorphism (AFLP) markers. Nine primer pairs were selected for the analysis and 685 bands were produced, among which 474 bands were polymorphic (PPB = 69.2%). Diversity levels within populations were relatively high (mean expected heterozygosity = 0.188, mean Shannon index = 0.296). Regression analysis showed a significant positive relationship between Shannon genetic diversity and altitude (R2 = 0.31). However, there was a negative correlation between Shannon genetic diversity and latitude (R2 = 0.16), as well as between Shannon genetic diversity and longitude (R2 = 0.45). Cluster analysis grouped the majority of the weed populations into three main clusters that corresponded with the geographic regions. At the regional level, the AMOVA indicated that about 70% of the variations in the data set were from genotypic variations within populations, 13.3% of the variations were due to regional differences, and the remaining 16.6% were due to differences among populations within the provincial regions. The results imply that most individuals tested in the present study should have been produced through seeds, and the process of colonization resulted in progressive loss of genetic diversity from the southwest to the northeast of China. Key words: Amplified fragment length polymorphism, invasive species, Eupatorium adenophorum, diversity, genetic variation, population structure

scholarly journals Genetic diversity by ISSR of two endemic quillworts (Isoetes L.) species from Amazon Iron Rocky Outcrops, Isoetes cangae e I. serracarajensis

2019 ◽  
Author(s):  
Mirella Pupo Santos ◽  
João Victor da Silva Rabelo Araújo ◽  
Arthur Vinícius de Sant’anna Lopes ◽  
Julio Cesar Fiorio Vettorazzi ◽  
Rodrigo Nunes da Fonseca ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Species Conservation ◽  
Principal Component ◽  
Shannon Index ◽  
Conservation Strategies ◽  
Amazon Forest ◽  
The North ◽  
Species Specific ◽  
High Level ◽  
Issr Molecular Markers

AbstractTwo lycophytes endemic species have been recently described at the State of Pará, in the Amazon forest located in the North of Brazil. Genetic diversity and population structure of Isoetes cangae and I. serracarajensis were investigated through ISSR molecular markers. These analyses aim to establish strategies for future attempts for species conservation. From sixteen primers, 115 gel bands were identified from which 87% were polymorphic. A high level of polymorphic loci (81,74 % e 68,48 %) and a high Shannon index for intra populational genetic diversity was observed for each species (Sh=0.376 e 0.289) I. cangae and I. serracarajensis, respectively. The largest genetic diversity of both species relies in their own populations. The coefficient of genetic differentiation between population areas (GST) was higher in I. serracarajensis (0.5440) than in I. cangae (0.2250). Gene flow was high between I. cangae populations (1.7142) and very low in I. serracarajensis (0.4190). Principal Component Analysis (PCoA) showed that individual plants were allocated into species-specific and population groups. Overall, the results further show that I. serracarajensis (0.5440) and I. cangae are two species with considerable genetic variation. These results should be considered for effective conservation strategies of both species.

scholarly journals Patterns of Genetic Diversity and Structure at Fine Scale of an Endangered Moroccan Endemic Tree (Argania spinosa L. Skeels) Based on ISSR Polymorphism

2015 ◽  
Vol 43 (2) ◽  
pp. 528-535 ◽  
Author(s):  
Jamila MOUHADDAB ◽  
Naima AIT AABD ◽  
Hafid ACHTAK ◽  
Fouad MSANDA ◽  
Abdelaziz ZAHIDI ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Polymorphic Locus ◽  
Natural Habitat ◽  
Geographical Location ◽  
Inter Simple Sequence Repeat ◽  
Conservation Strategies ◽  
Argania Spinosa ◽  
Genetic Diversity And Structure ◽  
In The Wild ◽  
High Level

The preservation of the diversity of endangered populations of argan trees, in their natural habitat, is a crucial step toward their conservation. The aim of the present study was to evaluate the genetic diversity of the argan trees in the wild, and to establish a phylogenetic map using DNA fingerprints. The ultimate goal was to develop a core set that would represent the existing diversity in the whole germplasm. In regard to this, 200 samples of Argania spinosa individual trees were collected from 10 different provenances in the region of Essaouira (Morocco). The genetic variation between and within these argan trees was investigated using previously described Inter-Simple Sequence Repeat markers. These markers generated a total of 149 fragments, in which 148 (99.33%) were polymorphic. The samples collected in the ‘Ouled Lhaj’ provenance showed the lowest diversity (% of polymorphic locus P=48.32%; genetic diversity Nei h=0.153; allelic richness A=1.483), compared to those collected in the ‘Mramer’ provenance (%P=68.46%; h=0.233; A=1.685). Also, the results showed a high level of genetic differentiation among provenances (AMOVA=44%, Gst=0.40), and a limited gene flow (Nm=0.73) between the provenances. In addition, these data suggested a low correlation between the genetic diversity of the tree and their respective geographical location in relation to the proximity to the littoral. Finally, a core collection of 13 genotypes that represent the essential of the detected diversity was established. The distribution pattern of this genetic diversity provides an important baseline data for the conservation strategies of argan tree species in the wild.

Geographic patterns of genetic variation and population structure in Pinus aristata, Rocky Mountain bristlecone pine

2012 ◽  
Vol 42 (1) ◽  
pp. 23-37 ◽  
Author(s):  
Anna W. Schoettle ◽  
Betsy A. Goodrich ◽  
Valerie Hipkins ◽  
Christopher Richards ◽  
Julie Kray
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Bark Beetles ◽  
Climatic Factors ◽  
Rocky Mountain ◽  
Conservation Strategies ◽  
Restricted Gene Flow ◽  
Populations At Risk ◽  
Bristlecone Pine ◽  
Pinus Aristata

Pinus aristata Engelm., Rocky Mountain bristlecone pine, has a narrow core geographic and elevational distribution, occurs in disjunct populations, and is threatened by rapid climate change, white pine blister rust, and bark beetles. Knowledge of genetic diversity and population structure will help guide gene conservation strategies for this species. Sixteen sites across four mountain ranges in the core distribution of P. aristata were sampled and genetic diversity was assessed with 21 isozyme loci. Low species and population level genetic diversity (He = 0.070 and 0.062, respectively) occurred with moderate among-population differentiation (FST = 0.131). Genetic diversity correlated with longitude, latitude, and elevation and a strong mountain island effect may contribute to substructuring and isolation. Using multiple complementary analyses, sampled trees were assigned to three genetic lineages that varied in diversity and admixture and were associated with different climatic factors. The distribution of genetic diversity and substructuring of P. aristata may be an outcome of a combination of restricted gene flow due to geographic and phenological isolation, random processes of genetic drift, life history traits, natural selection, and postglacial migrations. The combination of low genetic diversity, moderate population isolation, and a protracted regeneration dynamic puts populations at risk for extirpation by novel stresses.

Genetic diversity and population structure of the rice false smut pathogen Ustilaginoidea virens in Sichuan-Chongqing region

Plant Disease ◽  
2021 ◽  
Author(s):  
Anfei Fang ◽  
Zhuangyuan Fu ◽  
Zexiong Wang ◽  
Yuhang Fu ◽  
Yubao Qin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Recombination ◽  
Resistance Breeding ◽  
Ustilaginoidea Virens ◽  
Breeding Lines ◽  
Rice False Smut ◽  
Geographical Populations ◽  
False Smut

Rice false smut caused by Ustilaginoidea virens is currently one of the most devastating fungal diseases of rice panicles worldwide. In this study, two novel molecular markers derived from SNP-rich genomic DNA fragments and a previously reported molecular marker were used for analyzing the genetic diversity and population structure of 167 U. virens isolates collected from nine areas in Sichuan-Chongqing region, China. A total of 62 haplotypes were identified, and a few haplotypes with high frequency were found and distributed in two to three areas, suggesting gene flow among different geographical populations. All isolates were divided into six genetic groups. The groups Ⅰ and Ⅵ were the largest including 61 and 48 isolates, respectively. The pairwise FST values showed significant genetic differentiation among all compared geographical populations. AMOVA showed that intergroup genetic variation accounted for 40.17% of the total genetic variation, while 59.83% of genetic variation came from intragroup. The UPGMA dendrogram and population structure revealed that the genetic composition of isolates collected from ST (Santai), NC (Nanchong), YC (Yongchuan), and WS (Wansheng) dominated by the same genetic subgroup was different from those collected from other areas. In addition, genetic recombination was found in a few isolates. These findings will help to improve the strategies for rice false smut management and resistance breeding, such as evaluating breeding lines with different isolates or haplotypes at different elevations and landforms.

scholarly journals Consequences of geographical habitats on population structure and genetic diversity in Campanula spp.

2010 ◽  
Vol 1 (1) ◽  
pp. 5 ◽  
Author(s):  
Matteo Caser ◽  
Valentina Scariot ◽  
Paul Arens
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Binding Site ◽  
Geographical Location ◽  
Nucleotide Binding ◽  
Nonparametric Test ◽  
Nucleotide Binding Site ◽  
Gene Profiling ◽  
R Gene ◽  
Nbs Profiling

Characterization of populations by means of DNA techniques provides a tool for precise identification and a quantitative estimate of genetic diversity, crucial in evaluation of genetic fragmentation within and among populations. NBS profiling are PCR-based approaches that sample genetic variation in resistance genes (R-gene), and R gene analogs (RGA). To date, myb patterns have not been used for evaluating genetic diversity in other species. NBS primers are homologous to the conserved sequences in the Nucleotide-Binding-Site of the NBS-LRR class of R-genes. A total of 12 populations from five Campanula species (C. barbata L., C. latifolia L., C. rapunculoides L., C. spicata L. and C. trachelium L.), autochthonous of the West Italian Alps, were genotyped via nucleotide-binding site (NBS) and myb gene profiling. The selected markers produced a total of 361 bands, showing high levels of polymorphism. Genetic diversity among and within species and population structure was evaluated by different statistical analyses performed using TREECON software, Mantel Nonparametric Test, NTSYS package, AMOVA and STRUCTURE. The correlation between genetic variability and geographical location suggests that the five Campanula species have been subjected to long-term evolutionary processes consistent with the natural fragmentation of continuous mountains areas.

scholarly journals How diverse can rare species be on the margins of genera distribution?

AoB Plants ◽  
2019 ◽  
Vol 11 (4) ◽  
Author(s):  
Alice Backes ◽  
Geraldo Mäder ◽  
Caroline Turchetto ◽  
Ana Lúcia Segatto ◽  
Jeferson N Fregonezi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Habitat Loss ◽  
Evolutionary History ◽  
Founder Effects ◽  
Geographical Isolation ◽  
Genetic Diversity And Structure ◽  
Genetic Patterns

Abstract Different genetic patterns have been demonstrated for narrowly distributed taxa, many of them linking rarity to evolutionary history. Quite a few species in young genera are endemics and have several populations that present low variability, sometimes attributed to geographical isolation or dispersion processes. Assessing the genetic diversity and structure of such species may be important for protecting them and understanding their diversification history. In this study, we used microsatellite markers and plastid sequences to characterize the levels of genetic variation and population structure of two endemic and restricted species that grow in isolated areas on the margin of the distribution of their respective genera. Plastid and nuclear diversities were very low and weakly structured in their populations. Evolutionary scenarios for both species are compatible with open-field expansions during the Pleistocene interglacial periods and genetic variability supports founder effects to explain diversification. At present, both species are suffering from habitat loss and changes in the environment can lead these species towards extinction.

scholarly journals Genome-Wide SNP Analysis Reveals the Population Structure and the Conservation Status of 23 Italian Chicken Breeds

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1441
Author(s):  
Filippo Cendron ◽  
Francesco Perini ◽  
Salvatore Mastrangelo ◽  
Marco Tolone ◽  
Andrea Criscione ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Conservation Status ◽  
Geographical Area ◽  
Snp Array ◽  
Local Economy ◽  
Conservation Strategies ◽  
Snp Analysis ◽  
Runs Of Homozygosity ◽  
Chicken Breeds

The genomic variability of local Italian chicken breeds, which were monitored under a conservation plan, was studied using single nucleotide polymorphisms (SNPs) to understand their genetic diversity and population structure. A total of 582 samples from 23 local breeds and four commercial stocks were genotyped using the Affymetrix 600 K Chicken SNP Array. In general, the levels of genetic diversity, investigated through different approaches, were lowest in the local chicken breeds compared to those in the commercial stocks. The level of genomic inbreeding, based on runs of homozygosity (FROH), was markedly different among the breeds and ranged from 0.121 (Valdarnese) to 0.607 (Siciliana). In all breeds, short runs of homozygosity (ROH) (<4 Mb in length) were more frequent than long segments. The patterns of genetic differentiation, model-based clustering, and neighbor networks showed that most breeds formed non-overlapping clusters and were clearly separate populations, which indicated the presence of gene flow, especially among breeds that originated from the same geographical area. Four genomic regions were identified as hotspots of autozygosity (islands) among the breeds, where the candidate genes are involved in morphological traits, such as body weight and feed conversion ratio. We conclude that the investigated breeds have conserved authentic genetic patterns, and these results can improve conservation strategies; moreover, the conservation of local breeds may play an important role in the local economy as a source of high-quality products for consumers.

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