IMPROVED SSRs-BASED GENETIC DIVERSITY ASSESSMENT OF COCONUTS (COCOS NUCIFERA L) ALONG THE COAST OF KENYA

ABSTRACTCoconut is the most important cash crop along the Coast of Kenya, yet its genetic diversity has not been fully established. A genetic diversity study of 48 coconut genotypes that were collected along the Coast of Kenya was conducted with 13 polymorphic short sequence repeats (SSRs) markers. SSR analysis was performed using GeneMapper while data analysis was done with PowerMarker and DARwin softwares.The results revealed a total of 68 alleles ranging from 2 to 11 per locus with a mean of 5.23 per marker. Gene diversity and polymorphic information content (PIC) ranged between 0.41 to 0.83 and 0.33 to 0.79, respectively. A neighbour-joining dendrogram grouped the genotypes into three major clusters containing distinct sub-clusters. This study underscored that capillary electrophoresis is a more accurate and informative technique for SSRs allele scoring than agarose gels, which was reported in a previous study with the same SSRs markers and coconut genotypes in Kenya. The clusters observed forms the basis to isolate conservation blocks, which are the key to establishing a genebank, since there is no documented coconut genebank for ex-situ conservation in Kenya.

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Morphological Characterization and Genetic Diversity Analysis of a Tunisian Durum Wheat (Triticum Turgidum Var. Durum) Collection

10.21203/rs.3.rs-51248/v1 ◽

2020 ◽

Author(s):

Maroua Ouaja ◽

Bochra Amina Bahri ◽

Lamia Aouini ◽

Sahbi Ferjaoui ◽

Maher Medini ◽

...

Keyword(s):

Genetic Diversity ◽

Durum Wheat ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Morphological Characterization ◽

Genetic Variations ◽

Mantel Test ◽

Ex Situ ◽

The South ◽

Population Structure Analysis

Abstract Background: Tunisia is a center of genetic diversity of durum wheat and has a large number of abandoned old local landraces. An accurate investigation and characterization of the morphological and genetic features of these landraces would allow their rehabilitation and use for practical and beneficial purposes. In this context, a collection of 304 local accessions of durum wheat, collected from five regions and three climatic zones of central and southern Tunisia, was studied. Results: Morphological characterization was carried out using 12 spike-related traits and rendered a mean Shannon-Weaver Index (H') of 0.80 indicating the presence of a high level of polymorphism among accessions. Based on these traits 11 local landraces, namely Mahmoudi, Azizi, Jneh Khotifa, Mekki, Biskri, Taganrog, Biada, Badri, Richi, Roussia and Souri were identified. Spike length (H’=0.98) and shape (H’=0.86) with grains size (H’=0.94), form (H’=0.87) and color (H’=0.86) were the most polymorphic morphological traits. The genetic diversity was assessed using 10 SSR markers, with a polymorphic information content (PIC) of 0.69. Levels of genetic diversity were generally high, with a Shannon's Information Index (I) of 0.62 and a gene diversity (He) of 0.35. In addition, population structure analysis distinguished 11 genetic groups resulted from STRUCTURE and Mantel test showed a significant correlation between genetic and morphological distances. Analysis of molecular variance (AMOVA) showed high genetic variations within regions (81%) and wheat subpopulations (41%) showing a considerable amount of admixture between landraces realized by farmers; as well as a moderate (19%) and high (59%) genetic variations among regions and wheat subpopulations, indicating practices of selection pressure conducted by farmers. The Mahmoudi landrace showed spike densities significantly different between the center to the south of Tunisia; notably loose spikes with open glumes in the south and compact ones in the center, which may represent an adaptation form for tolerance to high temperature. Conclusion: Overall, this study highlights the genetic richness of local resources for better in situ or ex situ conservation and for their subsequent use in plant breeding programs.

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Morphological characterization and Genetic diversity analysis of a Tunisian durum wheat (Triticum turgidum var. durum) collection

10.21203/rs.3.rs-51248/v2 ◽

2020 ◽

Author(s):

Maroua Ouaja ◽

Bochra Amina Bahri ◽

Lamia Aouini ◽

Sahbi Ferjaoui ◽

Maher Medini ◽

...

Keyword(s):

Genetic Diversity ◽

Durum Wheat ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Morphological Characterization ◽

Genetic Variations ◽

Ex Situ ◽

Morphological Identification ◽

The South ◽

Population Structure Analysis

Abstract Background: Tunisia is a center of genetic diversity of durum wheat and has a large number of abandoned old local landraces. An accurate investigation and characterization of the morphological and genetic features of these landraces would allow their rehabilitation and use for practical and beneficial purposes. In this context, a collection of 304 local accessions of durum wheat, collected from five regions and three climatic zones of central and southern Tunisia, was studied. Results: Morphological characterization was carried out using 12 spike-related traits and rendered a mean Shannon-Weaver Index (H') of 0.80 indicating the presence of a high level of polymorphism among accessions. Based on these traits 11 local landraces, namely Mahmoudi, Azizi, Jneh Khotifa, Mekki, Biskri, Taganrog, Biada, Badri, Richi, Roussia and Souri were identified. Spike length (H’=0.98) and shape (H’=0.86) with grains size (H’=0.94), form (H’=0.87) and color (H’=0.86) were the most polymorphic morphological traits. The genetic diversity was assessed using 10 SSR markers, with a polymorphic information content (PIC) of 0.69. Levels of genetic diversity were generally high, with a Shannon's Information Index (I) of 0.62 and a gene diversity (He) of 0.35. In addition, population structure analysis distinguished 11 genetic subpopulations significantly correlated with the morphological identification. Analysis of molecular variance (AMOVA) showed high genetic variations within regions (81%) and within wheat subpopulations (41%) reflecting a considerable amount of admixture between landraces. The moderate (19%) and high (59%) genetic variations among regions and among wheat subpopulations observed highlighted farmers selection practices . Furthermore, Mahmoudi landrace showed spike densities significantly different between the center to the south of Tunisia; notably loose spikes with open glumes in the south and compact ones in the center, which may represent an adaptation form for tolerance to high temperature. Conclusion: Overall, this study underlined the genetic richness of local resources for better in situ or ex situ conservation and for their subsequent use in plant breeding programs.

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Molecular diversity analysis in hexaploid wheat (Triticum aestivum L.) and two Aegilops species (Aegilops crassa and Aegilops cylindrica) using CBDP and SCoT markers

Journal of Genetic Engineering and Biotechnology ◽

10.1186/s43141-021-00157-8 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Ghazal Ghobadi ◽

Alireza Etminan ◽

Ali Mehras Mehrabi ◽

Lia Shooshtari

Keyword(s):

Genetic Diversity ◽

Triticum Aestivum ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Crop Improvement ◽

Wild Relatives ◽

Resolving Power ◽

Start Codon ◽

Aegilops Cylindrica ◽

Aegilops Crassa

Abstract Background Evaluation of genetic diversity and relationships among crop wild relatives is an important task in crop improvement. The main objective of the current study was to estimate molecular variability within the set of 91 samples from Triticum aestivum, Aegilops cylindrica, and Aegilops crassa species using 30 CAAT box–derived polymorphism (CBDP) and start codon targeted (SCoT) markers. Results Fifteen SCoT and Fifteen CBDP primers produced 262 and 298 fragments which all of them were polymorphic, respectively. The number of polymorphic bands (NPB), polymorphic information content (PIC), resolving power (Rp), and marker index (MI) for SCoT primers ranged from 14 to 23, 0.31 to 0.39, 2.55 to 7.49, and 7.56 to 14.46 with an average of 17.47, 0.34, 10.44, and 5.69, respectively, whereas these values for CBDP primers were 15 to 26, 0.28 to 0.36, 3.82 to 6.94, and 4.74 to 7.96 with a mean of 19.87, 0.31, 5.35, and 6.24, respectively. Based on both marker systems, analysis of molecular variance (AMOVA) indicated that the portion of genetic diversity within species was more than among them. In both analyses, the highest values of the number of observed (Na) and effective alleles (Ne), Nei’s gene diversity (He), and Shannon’s information index (I) were estimated for Ae. cylindrica species. Conclusion The results of cluster analysis and population structure showed that SCoT and CBDP markers grouped all samples based on their genomic constitutions. In conclusion, the used markers are very effective techniques for the evaluation of the genetic diversity in wild relatives of wheat.

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Assessment of Genetic Diversity of Promising Castor Been (Ricinus communis L.) Genotypes in Nigeria

Notulae Scientia Biologicae ◽

10.15835/nsb11310346 ◽

2019 ◽

Vol 11 (3) ◽

pp. 467-474

Author(s):

Bolaji Zuluqurineen SALIHU ◽

Olamide Ahmed FALUSI ◽

Adeyinka Olufemi ADEPOJU ◽

Ibrahim Wasiu AROLU ◽

Oladipupo Yusuf DAUDU ◽

...

Keyword(s):

Genetic Diversity ◽

Diversity Index ◽

Gene Diversity ◽

Ricinus Communis ◽

Polymorphic Information Content ◽

Block Design ◽

Genetic Material ◽

Morphological Data ◽

Research Attention ◽

Ricinus Communis L

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.

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Assessment of Genetic Diversity and Population Structure of Some Soft and Hard Wheat Varieties Based on SSR Marker

Science Journal of University of Zakho ◽

10.25271/sjuoz.2020.8.3.732 ◽

2020 ◽

Vol 8 (3) ◽

pp. 80-87

Author(s):

Yousif M. Fattah ◽

Nergiz N. Tayib

Keyword(s):

Genetic Diversity ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Triticum Aestivum L ◽

Wheat Varieties ◽

Discriminating Power ◽

Triticum Spp ◽

Cultivated Species ◽

The Common ◽

Diversity Studies

Wheat (Triticum spp.) is one of the most important cereal crops in Iraq and the world. It includes many species and varieties. The two major cultivated species of wheat are, durum wheat (Tritium durum Desf.) which is tetraploid (2n= 28) and the common wheat (Triticum aestivum L.) which is hexaploid (2n = 42). Ten wheat varieties from both species were examined using ten Simple sequence repeat (SSR) markers (WMC17, WMC20, WMC21, WMC24, WMC25, WMC48, WMC50, WMC283, Xgwm11 and Xgwm626). Various genetic parameters were calculated using Power Marker V3.25 software. A total of 156 alleles were detected in both species. The gene diversity in wheat varieties from both species collectively varied from 0.85 to 1.00, which indicates considerable genetic diversity in the examined varieties. All markers used in this study were highly informative and the polymorphic information content (PIC) values were higher than 0.50 in all loci. Hence all markers are considered useful for genetic diversity studies in wheat’s populations. The dendrogram separated the populations into two main clades and many subgroups. Azadi variety was simplicifolious. This study confirms the discriminating power of SSR typing and its usefulness for comparison within hard and soft wheat populations.

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Molecular characterization of wheat (Triticum aestivum L.) genotypes through SSR markers

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v37i3.12082 ◽

2012 ◽

Vol 37 (3) ◽

pp. 389-398 ◽

Cited By ~ 3

Author(s):

S Islam ◽

MS Haque ◽

RM Emon ◽

MM Islam ◽

SN Begum

Keyword(s):

Genetic Diversity ◽

Triticum Aestivum ◽

Genetic Distance ◽

Microsatellite Markers ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Allelic Diversity ◽

Triticum Aestivum L ◽

Allele Number ◽

Average Gene

A study was undertaken to examine the genetic diversity of 12 wheat (Triticum aestivum L.) genotypes, using 4 simple sequence repeats (SSRs). A total of 10 alleles were found. Allele number per locus ranged from 2 to 4 with an average of 2.5. The polymorphic information content (PIC) values ranged from 0.2755 to 0.5411 with an average of 0.3839. The average gene diversity over all SSR loci for the 12 wheat genotypes was 0.4688, ranging from 0.3299 to 0.6042. Cluster analysis based on microsatellite allelic diversity discriminated the varieties into different clusters. Genetic diversity was the highest between variety Gourab and Akbar as well as Gourab and BAW-1064, showing a genetic distance value of 0.4697. The genetic distance was lowest between Balaka and Aghrani as well as Triticale and BAW-1036. Positive correlations were found between gene diversity, number of alleles, the allele size range and the types of repeat motif of microsatellite markers. It was found from this study that microsatellite markers could characterize and discriminate all of the genotypes. More primers should be used for saturation of different regions in further studies. Bangladesh J. Agril. Res. 37(3): 389-398, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12082

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Genetic diversity, population structure and association analysis in coconut (Cocos nucifera L.) germplasm using SSR markers

Plant Genetic Resources ◽

10.1017/s1479262117000119 ◽

2017 ◽

Vol 16 (2) ◽

pp. 156-168 ◽

Cited By ~ 6

Author(s):

S. Geethanjali ◽

J. Anitha Rukmani ◽

D. Rajakumar ◽

P. Kadirvel ◽

P.L. Viswanathan

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Association Analysis ◽

Gene Diversity ◽

Cocos Nucifera ◽

Germplasm Collection ◽

Yield Component ◽

Chromosome 1 ◽

Genetic Structuring ◽

Model Based Clustering

AbstractA world-wide coconut germplasm collection (79 genotypes) was analyzed for genetic diversity and population structure based on 48 simple sequence repeat (SSR) loci. The genotypes displayed moderately high amount of genetic diversity, which was strongly structured according to geographical origins. Number of SSR alleles ranged from 2 to 7 with an average of 4.1 per locus. Gene diversity (expected heterozygosity) estimates ranged from 0.162 to 0.811 with a mean of 0.573. Polymorphism information content values ranged from 0.149 to 0.785 with an average of 0.522. Hierarchical clustering analysis grouped the genotypes into two major clusters with two sub-groups in each, which corresponded with the geographic origins. The first cluster comprised of ‘Tall’ genotypes originated from Indo-Atlantic and South Asia regions. The second cluster comprised mostly of ‘Dwarf’ genotypes and some Tall genotypes which originated from Indo-Pacific and South-East Asia regions. Model-based clustering by STRUCTURE analysis also supported the presence of clear genetic structuring in the collection with two major populations (K = 2) and four sub-populations (K = 4). The proportion of SSR locus-pairs in linkage disequilibrium was low (2.4%). Association analysis in a subset of 44 genotypes detected a single SSR locus, CnCir73 (chromosome 1) putatively associated with fruit yield component traits, which corresponded with a previously mapped quantitative trait locus in coconut.

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AFLP and SSR analysis of genetic diversity among landraces of bread wheat (Triticum aestivum L. em. Thell) from different geographic regions

Australian Journal of Agricultural Research ◽

10.1071/ar05015 ◽

2005 ◽

Vol 56 (7) ◽

pp. 691 ◽

Cited By ~ 15

Author(s):

B. J. Stodart ◽

M. Mackay ◽

H. Raman

Keyword(s):

Genetic Diversity ◽

Middle East ◽

Bread Wheat ◽

Ssr Markers ◽

North Africa ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Triticum Aestivum L ◽

Southern Europe ◽

Germplasm Collections

A set of 44 bread wheat landraces was used to determine the efficacy of 16 amplifed fragment length polymorphism (AFLP) primers and 63 wheat simple sequence repeat (SSR) markers in identifying polymorphisms between accessions. The SSR markers detected approximately 10 alleles per locus with a mean gene diversity (Hz) of 0.63, whereas AFLP primers identified approximately 147 fragments per primer with a mean gene diversity of 0.25. A set of 54 SSR markers and 11 AFLP primers was identified as highly polymorphic (polymorphic information content (PIC) ≥ 0.5 and 0.3 for SSR and AFLP, respectively), and suitable for molecular characterisation of germplasm. Principle coordinate analysis suggested that the AFLP and SSR loci could be used to discriminate among accessions collected from North Africa and southern Europe from those collected from the Middle East. Both marker types indicate that accessions from North Africa and southern Europe, the Middle East, and southern and eastern Asia are genetically diverse. The results indicate the usefulness of the molecular markers to assess genetic diversity present within germplasm collections.

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Detection of genetic divergence among Putative Ethyl Methane Sulfonate Mutants of Super Basmati using Microsatellite Markers

10.21203/rs.3.rs-34720/v1 ◽

2020 ◽

Author(s):

Kiran Hameed ◽

Bushra Sadia ◽

Madiha Habib ◽

Zia ul Qamar ◽

Faisal Saeed Awan

Keyword(s):

Genetic Diversity ◽

Base Pair ◽

Polymorphic Information Content ◽

Rice Cultivar ◽

Ethyl Methane ◽

Allele Number ◽

Methane Sulphonate ◽

Ssrs Markers ◽

Mutagenic Effects ◽

Selection Of

Abstract Mutation is a resource of generating genetic diversity in crop plant for breeding as well as genetic analysis. Ethyl Methane Sulphonate (EMS) is frequently applied chemical agents in plants. The present study was completed to investigate the mutagenic effects of different concentration of EMS on yield contributing traits of super basmati. The seeds of rice cultivar (Super basmati) were mutagenized with different doses from 0-2% v/v of EMS with difference of 0.25% for determination LD50. The treated and non-treated plants were observed under different agronomic parameters. A total of 48 putative EMS mutants of super basmati were selected randomly to analyze genetic diversity using 25 SSR primers. These markers were located on twelve chromosomes of rice. SSRs analysis revealed that abroad level of genetic diversity was existed among mutants of super basmati. A sum of 91 alleles was identified of which 82 alleles were originated to be polymorphic and the rest of nine alleles were discovered as monomorphic. The range of allele number was 2-10 with mean of 3.64 alleles/locus. The value of polymorphic information content (PIC) was from 0.039 (RM5) to 0.878 (RM44) with mean of 0.439 for each locus. All mutants differentiated from each other in more than two set of primers due to presence or absence of unique bands on chromosomes at definite base pair. The size base pair range was 75-1000bp. Dendrogram located mutant indices into four major groups. Phylogenic analyses exposed 40-96% similarity. It is concluded that EMS induced genetic variability and SSRs markers (RM44, RM154, RM1, RM252, RM334, RM487, RM110 and RM257) could be employed for the selection of rice mutants throughout molecular breeding program.

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Genetic Diversity and Population Structure of Endangered Catfish Rita rita (Hamilton, 1822) Revealed by Heterologous DNA Microsatellite Markers

Asian Fisheries Science ◽

10.33997/j.afs.2021.34.2.007 ◽

2021 ◽

Vol 34 (2) ◽

Author(s):

MUHAMMAD FORHAD ALI ◽

◽

MD. RAFIQUL ISLAM SARDER ◽

MOHAMMAD MATIUR RAHMAN ◽

MD. FAZLUL AWAL MOLLAH ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Gene Diversity ◽

Polymorphic Information Content ◽

Genetic Difference ◽

Information Index ◽

Hardy Weinberg Equilibrium ◽

High Gene ◽

High Level ◽

Dna Microsatellite

Genetic information is essential for conservation and future aquaculture development of the endangered catfish Rita rita (Hamilton, 1822). Two hundred catfish, R. rita, 50 from four rivers, the Old Brahmaputra, Jamuna, Meghna and Kangsa were collected and analysed to evaluate the genetic diversity and population structure using five microsatellite primers (Cba06-KUL, Cba08-KUL, Cba09-KUL, Phy03-KUL and Phy07-KUL). Four of the five amplified loci were found polymorphic (P95) in all the populations and 46 alleles were recorded with 9 to 14 alleles per locus. Differences were observed in the total number of alleles ranging from 41 to 44, effective number of alleles from 29.96 to 37.46, observed heterozygosity from 0.57 to 0.76, Shannon’s information index from 2.09 to 2.30 and polymorphic information content from 0.84 to 0.88 among the four populations. Results exposed the highest levels of genetic diversity in the Meghna population while the lowest in the Kangsa population of R. rita. All the populations were significantly deviated (P < 0.001) from the Hardy-Weinberg equilibrium for all the loci. Nei’s genetic distance between populations ranged 0.007 to 0.017 with low overall genetic difference FST = 0.011 and high gene flow Nm = 24.333, indicating that R. rita populations were not subdivided. This study revealed a high level of gene diversity with deficiency in genetic heterogeneity in all the populations of R. rita, emphasising natural management, conservation and rehabilitation measures of this species.

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