scholarly journals Assessment of Genetic Diversity and Population Structure of the Endangered Astragalus exscapus subsp. transsilvanicus through DNA-Based Molecular Markers

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2732
Author(s):  
Katalin Szabo ◽  
Doru Pamfil ◽  
Alexandru Sabin Bădărău ◽  
Monica Hârţa

Astragalus exscapus L. subsp. transsilvanicus (Schur) Nyár. (Fabaceae) is a rare plant endemic to the Transylvanian Plateau, represented by 24 identified populations. Limited information on the genetic variation and population structure is available, which obstructs efficient measures for conservation strategy. The present study aimed to analyze the genetic diversity and population structure of eight populations of A. exscapus subsp. transsilvanicus revealed by sequence-related amplified polymorphism (SRAP) markers. A total of 164 bands were amplified, 96.7% of which (159) were polymorphic. Nei’s gene diversity index (He) was estimated to be 0.228 at the population level and 0.272 at the subspecies level. The genetic differentiation among populations (Gst) was 0.165, which indicated a low proportion of total genetic diversity. The analysis of molecular variance (AMOVA) indicated that 17% of the total variation of A. exscapus subsp. transsilvanicus is found among the populations, while 83% was found within the populations. A UPGMA dendrogram, principal coordinate analysis, and the STRUCTURE software grouped the populations into two clusters uncorrelated with the provenience of the 125 individuals, which might be attributed to fragmentation processes, insect pollination, population size, and specific environmental conditions of the habitats.

2008 ◽  
Vol 88 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Chu-Chuan Fan ◽  
Nicola Pecchioni ◽  
Long-Qing Chen

Calycanthus chinensis Cheng et S.Y. Chang, a tertiary relic species in China, is a shade-loving and deciduous bush withan elegant shape and beautiful flower of high ornamental value. It was widely planted in gardens and miniature scapes in China.The objective of this study was to characterize the genetic variation and structure in the three extant populations of the species, in order to provide useful information for a future conservation strategy. Twenty-two of 120 RAPD primers were selected and a total of 257 stable and clear DNA fragments were scored. Calycanthus chinensis showed a lower level of genetic diversity. At the population level, the percentage of polymorphic loci, Nei's gene diversity and Shannon’s information index were 40.9%, 0.1641 and 0.2386, respectively; while at the species level, the corresponding values were 59.1%, 0.2097 and 0.3123, respectively. The estimates of genetic differentiation based on Shannon’s information index (0.2360), Nei’s gene diversity (0.2175) and AMOVA (24.94%) were very similar, and significantly higher than the average genetic differentiation reported in outcrossed spermatophyte. So it suggested high genetic differentiation emerged among populations of C. chinensis. Genetic relationships among populations were assessed by Nei’s standard genetic distance, which suggested that the Tiantai population was genetically distinct from the other two populations. Moreover, the genetic distance was significantly correlated with geographical distance among populations (r = 0.997, t > t0.05). The gene flow (Nm) was 0.8994, indicating that gene exchange among populations was restricted. A conservation strategy was proposed based on the low gene flow and habitat deterioration, which are contributing to the endangered status of this species. Key words: Genetic diversity, endangered plant, population genetics, RAPD


2020 ◽  
Vol 50 (3) ◽  
pp. 204-212
Author(s):  
Stalin Juan Vasquez GUIZADO ◽  
Muhammad Azhar NADEEM ◽  
Fawad ALI ◽  
Muzaffer BARUT ◽  
Ephrem HABYARIMANA ◽  
...  

ABSTRACT Rosewood, Aniba rosaeodora is an endangered species in Amazon forests and its natural stands have been heavily depleted due to over-exploitation for the cosmetic industry. This study aimed to investigate the genetic diversity and population structure of 90 rosewood accessions from eight localities in the Peruvian Amazon through 11 Inter Simple Sequence Repeats (ISSR) primers. The ISSR primers produced a sum of 378 bands, of which 375 (99.2%) were polymorphic, with an average polymorphism information content (PIC) value of 0.774. The mean effective number of alleles (Ne), Shannon informative index (I), gene diversity (He) and total gene diversity (Ht) were 1.485, 0.294, 0.453 and 0.252, respectively. Analysis of molecular variance (AMOVA) showed the presence of maximum variability within populations (88%). The Structure algorithm, neighbor joining and principal coordinate analysis (PCoA) grouped the 90 rosewood accessions into three main populations (A, B and C). Diversity indices at the inter-population level revealed a greater genetic diversity in population A, due to higher gene flow. The neighbor-joining analysis grouped populations A and B, while population C was found to be divergent at the inter population level. We concluded that population A reflects higher genetic diversity and should be prioritized for future management and conservation plans.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yusen Shen ◽  
Jiansheng Wang ◽  
Ranjan K. Shaw ◽  
Huifang Yu ◽  
Xiaoguang Sheng ◽  
...  

Broccoli (Brassica oleracea var. italica) is one of the most important and nutritious vegetables widely cultivated in China. In the recent four decades, several improved varieties were bred and developed by Chinese breeders. However, the efforts for improvement of broccoli are hindered by limited information of genetic diversity and genetic relatedness contained within the available germplasms. This study evaluated the genetic diversity, genetic relationship, population structure, and fingerprinting of 372 accessions of broccoli representing most of the variability of broccoli in China. Millions of SNPs were identified by whole-genome sequencing of 23 representative broccoli genotypes. Through several stringent selection criteria, a total of 1,167 SNPs were selected to characterize genetic diversity and population structure. Of these markers, 1,067 SNPs were genotyped by target sequencing (GBTS), and 100 SNPs were genotyped by kompetitive allele specific PCR (KASP) assay. The average polymorphism information content (PIC) and expected heterozygosity (gene diversity) values were 0.33 and 0.42, respectively. Diversity analysis revealed the prevalence of low to moderate genetic diversity in the broccoli accessions indicating a narrow genetic base. Phylogenetic and principal component analyses revealed that the 372 accessions could be clustered into two main groups but with weak groupings. STRUCTURE analysis also suggested the presence of two subpopulations with weak genetic structure. Analysis of molecular variance (AMOVA) identified 13% variance among populations and 87% within populations revealing very low population differentiation, which could be attributed to massive gene flow and the reproductive biology of the crop. Based on high resolving power, a set of 28 KASP markers was chosen for DNA fingerprinting of the broccoli accessions for seed authentication and varietal identification. To the best of our knowledge, this is the first comprehensive study to measure diversity and population structure of a large collection of broccoli in China and also the first application of GBTS and KASP techniques in genetic characterization of broccoli. This work broadens the understanding of diversity, phylogeny, and population structure of a large collection of broccoli, which may enhance future breeding efforts to achieve higher productivity.


HortScience ◽  
2016 ◽  
Vol 51 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Haiying Zhang ◽  
Jianguang Fan ◽  
Shaogui Guo ◽  
Yi Ren ◽  
Guoyi Gong ◽  
...  

Watermelon belongs to the genus Citrullus. There have been continuing interests in breeding of watermelon for economic benefits, but information on the scope and utilization of genetic variations in Citrullus is still limited. The present study was conducted in 2012–13, to evaluate the genetic diversity and population structure of the 1197 line watermelon collection maintained by the Beijing Vegetable Research Center (BVRC), which belongs to seven Citrullus species including Citrullus naudinianus, Citrullus colocynthis, Citrullus rehmii, Citrullus ecirrhosus, Citrullus amarus, Citrullus mucosospermus, and Cirullus lanatus subsp. vulgaris. Twenty-three highly informative microsatellite markers evenly distributed in the watermelon genome were used to assess genetic diversity in this collection. The markers detected on an average of 6.05 alleles per locus with the average value of polymorphism information content (PIC) at 0.49. A high level of gene diversity [Nei’s gene diversity index (Nei) = 0.56] and a low observed heterozygosity (Ho = 0.10) were revealed within the collection. Structure analysis grouped the 1197 accessions into two main populations (Pop I and Pop II) and an admixture group. Pop I contained 450 accessions from C. lanatus subsp. vulgaris (446) and C. mucosospermus (4). Pop II comprised 465 accessions, 379 of which belonged to C. lanatus subsp. vulgaris and 86 to C. naudinianus (3), C. ecirrhosus (2), C. rehmii (2), C. colocynthis (11), C. amarus (58), and C. mucosospermus (10). The remaining 282 accessions were classified as an admixture group. The two main populations were further subdivided into four subgroups. The groupings were consistent with the estimation of F statistics (Fst) and Nei’s genetic distances in collections. We confirmed the distinct genetic backgrounds between American and East Asian ecotypes. Subsequently, we defined a core set consisting of 130 accessions including 47 from Pop I, 68 from Pop II, and 15 from the Admixture group. This core set was able to capture all 133 alleles detected by 23 simple sequence repeats (SSRs) in 1197 accessions. These results will facilitate efficient use of genetic variations in Citrullus in watermelon breeding and help optimization of accessions in genomewide association studies.


2019 ◽  
Vol 47 (4) ◽  
pp. 1308-1315
Author(s):  
Peng-Li ZHENG ◽  
Jian-Ru CHENG ◽  
Long-Qing CHEN ◽  
Ming-Qin ZHOU

Investigation on the level and pattern of genetic diversity of 10 natural populations of the endangered species Fraxinus hupehensis using inter-simple sequence repeat (ISSR) markers was crucial for understanding the structure of the population and assessing the best genetic protection strategies. A total of 180 polymorphic bands with the polymorphic rate of 100.00% were amplified by 14 primers. The genetic diversity at population level (Percentage of polymorphic loci, PPL=64.06; Nei’s gene diversity index, h=0.1519; Shannon’s information index, I=0.2434) was lower than that at species level (PPL= 100.00%, h=0.1833, I=0.3041). Analysis of molecular variance (AMOVA) demonstrated the low level of the genetic variation occurred between the populations (16.05%). This also can be corroborated by the gene flow (Nm 2.424) and the coefficient of gene differentiation (Gst=0.1710) among populations. Cluster analysis based on the unweighted pair group method with arithmetic averages (UPGMA) revealed four groups for 10 populations according to Nei’s genetic identity and seven categories for the 196 individuals according to SM values. Furthermore, the endangered mechanism and genetic structure of F. hupehensis were discussed, and appropriate targeted protection measures were proposed based on these findings.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


2006 ◽  
Vol 4 (2) ◽  
pp. 108-116 ◽  
Author(s):  
A.A. Jaradat ◽  
M. Shahid

Isozyme data were used to assess genetic diversity within and among a subdivided population of the salt-tolerant Batini barley landrace. Population diversity and its components were estimated on the basis of 12 isozymes scored on 450 single plants representing seven subpopulations. Two principal components, based on mean gene diversity, Shannon's diversity index, percentage polymorphic loci, genetic identity and genetic distance among subpopulations accounted for 91.7% of total variation and separated the subpopulations into four distinct groups. Contributions to total diversity by individual subpopulations were partitioned into intra- and inter-population components. The level of population differentiation indicates that a large percentage of total genetic diversity was apportioned within subpopulations. The presence of valuable genetic diversity in this landrace was confirmed.


2015 ◽  
Vol 15 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Hedia Bourguiba ◽  
Mohamed-Amine Batnini ◽  
Lamia Krichen ◽  
Neila Trifi-Farah ◽  
Jean-Marc Audergon

North Africa enclosed original apricot genetic resources with the cohabitation of grafting and seed-propagated accessions. In this study, we assessed the genetic diversity and population structure of 183 apricot accessions using 24 microsatellite markers distributed evenly in the Prunus genome. A total of 192 alleles and a high level of gene diversity (0.593) were detected among the whole panel. Genetic structure analysis revealed the presence of four genetic clusters. We also found that both geographical origin and mode of propagation are important factors structuring genetic diversity in apricot species. Results confirmed the presence of gene exchange between the northern and southern countries of the Mediterranean Basin. Subsequently, a core collection of 98 accessions based on M (maximization) strategy showing 99.47% of allele retention ratio was constructed. No significant differences for Shannon's information index and Nei's diversity index were observed between the core and entire collections. Our results provide an effective aid for future germplasm preservation and conservation strategies as well as genetic association studies development in relation to phenotypic data.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12024
Author(s):  
Wei-Hong Sun ◽  
De-Qiang Chen ◽  
Rebeca Carballar-Lejarazu ◽  
Yi Yang ◽  
Shuang Xiang ◽  
...  

Background Understanding plant genetic diversity is important for effective conservation and utilization of genetic resources. Euscaphis japonica (Thunb.) Dippel, is a monotypic species with high phenotypic diversity, narrow distribution, and small population size. In this study, we estimated the genetic diversity and population structure of E. japonica using nine natural populations and inter-simple sequence repeat (ISSR) markers. Our results could provide a theoretical reference for future conservation and utilization of E. japonica. Results We obtained a total of 122 DNA bands, of which 121 (99.18%) were polymorphic. The average number of effective alleles (Ne = 1.4975), Nei’s gene diversity index (H = 0.3016), and Shannon’s information index (I = 0.4630) revealed that E. japonica possessed a high level of genetic diversity. We observed that E. japonica consisted of both deciduous and evergreen populations. UPGMA tree showed that the evergreen and deciduous E. japonica form a sister group. There is little genetic differentiation among geographic populations based on STRUCTURE analysis. The Dice’s similarity coefficient between the deciduous and evergreen populations was low, and the Fst value was high, indicating that these two types of groups have high degree of differentiation. Conclusion Rich genetic diversity has been found in E. japonica, deciduous E. japonica and evergreen E. japonica populations, and genetic variation mainly exists within the population. The low-frequency gene exchange between deciduous and evergreen populations may be the result of the differentiation of deciduous and evergreen populations. We suggest that in-situ protection, seed collection, and vegetative propagation could be the methods for maintenance and conservation of E. japonica populations.


2019 ◽  
Vol 11 (3) ◽  
pp. 467-474
Author(s):  
Bolaji Zuluqurineen SALIHU ◽  
Olamide Ahmed FALUSI ◽  
Adeyinka Olufemi ADEPOJU ◽  
Ibrahim Wasiu AROLU ◽  
Oladipupo Yusuf DAUDU ◽  
...  

Castor oil plant (Ricinus communis L.) is an important oil crop with little research attention in Nigeria. In the present research, extent of genetic diversity among 20 Nigerian castor genotypes was determined using morphological descriptors and molecular markers. The genotypes were laid out on a randomized complete block design with three replicated plots. Molecular genotyping of the genotypes was carried out using genomic Simple Sequence Repeats (SSR). The genotypes revealed high divergence in seed colour, seed shape, seed mottle, seed caruncle and seed sizes. Seedling establishment varied from 70.18% (in Acc. 006) to 93.25% (Acc. 001) with average mean of 81.53%. Raceme length ranged from 15.90 cm to 29.54 cm with population mean of 20.80 cm. The highest seed yield (1222.98 kg/ha) was recorded in Acc. 001 and the least (611.46 kg/ha) was observed in Acc. 006. Seed oil content varied between 32.15% in Acc. 042 and 54.03% in Acc. 006. Agglomerative cluster dendrogram constructed from morphological data showed random distribution of the genotypes into three cluster groups irrespective of the sources/collection points. The genetic diversity based on SSR Marker Analysis revealed high average expected heterozygosity (0.74), Polymorphic information content (0.68), Nei’s gene diversity index (0.72) and Shannon's Information index (1.43). The dendrogram constructed from molecular data grouped the twenty genotypes into three groups at coefficient of 0.34. From these findings, it showed that the twenty genotypes evaluated are divergent in nature and they could serve as good genetic material for castor breeding in Nigeria.


2012 ◽  
Vol 4 (3) ◽  
pp. 757-767 ◽  
Author(s):  
M. M. Hassan ◽  
A. K. M. Shamsuddin ◽  
M. M. Islam ◽  
K. Khatun ◽  
J. Halder

Information on the patterns of genetic variation and population structure is essential for rational use and efficient management of germplasms. It helps in monitoring germplasm and can also be used to predict potential genetic gains. Therefore, in the present study genetic diversity of 59 rice genotypes were assessed using 8 simple sequence repeat (SSR) primers. By the DNA profiling, a total of 114 alleles were detected. Allele number per/locus ranged from 9 to 27, with an average of 14.25. Average polymorphism information content (PIC) value was 0.857 with lowest 0.767 to highest 0.857. Mean gene diversity over all SSR loci was 0.870 with a range from 0.792 to 0.948. Fst values for each locus varied from 0.071 to 0.262. Genetic distance between the variety pair ranged from 0.33 to 1.0. The lowest genetic distance was found between Rajashili and Kumragori (2). Cluster and principal coordinate analysis (PCoA) analysis revealed similar pattern of variation. Marker RM11300 was found most polymorphic and robust among the accessions and can be widely used for rice germplasm characterization. The exclusive variability and unique feature of germplasm found in this study can be a gateway for both domestic and global rice improvement.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i3.10416 J. Sci. Res. 4 (3), 757-767 (2012)


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