scholarly journals Assessing the Genetic Diversity and Population Structure of a Tunisian Melon (Cucumis melo L.) Collection Using Phenotypic Traits and SSR Molecular Markers

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1121
Author(s):  
Hela Chikh-Rouhou ◽  
Najla Mezghani ◽  
Sameh Mnasri ◽  
Neila Mezghani ◽  
Ana Garcés-Claver
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Phenotypic Diversity ◽  
Diversity Index ◽  
Polymorphic Information Content ◽  
Crop Improvement ◽  
Molecular Data ◽  
Mantel Test ◽  
Phenotypic Traits ◽  
Genetic Diversity And Structure

The assessment of genetic diversity and structure of a gene pool is a prerequisite for efficient organization, conservation, and utilization for crop improvement. This study evaluated the genetic diversity and population structure of 24 Tunisian melon accessions, by using 24 phenotypic traits and eight microsatellite (SSR) markers. A considerable phenotypic diversity among accessions was observed for many characters including those related to agronomical performance. All the microsatellites were polymorphic and detected 30 distinct alleles with a moderate (0.43) polymorphic information content. Shannon’s diversity index (0.82) showed a high degree of polymorphism between melon genotypes. The observed heterozygosity (0.10) was less than the expected heterozygosity (0.12), displaying a deficit in heterozygosity because of selection pressure. Molecular clustering and structure analyses based on SSRs separated melon accessions into fivegroups and showed an intermixed genetic structure between landraces and breeding lines belonging to the different botanical groups. Phenotypic clustering separated the accessions into two main clusters belonging to sweet and non-sweet melon; however, a more precise clustering among inodorus, cantalupensis, and reticulatus subgroups was obtained using combined phenotypic–molecular data. The discordance between phenotypic and molecular data was confirmed by a negative correlation (r = −0.16, p = 0.06) as revealed by the Mantel test. Despite these differences, both markers provided important information about the diversity of the melon germplasm, allowing the correct use of these accessions in future breeding programs. Together they provide a powerful tool for future agricultural and conservation tasks.

scholarly journals Genetic Diversity and Population Structure of 93 Rice Cultivars (Lines) (Oryza Sativa Xian Group) in Qinba in China by 3 Types of Genetic Markers

2021 ◽  
Author(s):  
Yu Zhang ◽  
Yewen Wang ◽  
Peijiang Li ◽  
Yuexing Wang ◽  
Shimao Zheng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Markers ◽  
Ssr Markers ◽  
Diversity Index ◽  
Indica Rice ◽  
Mantel Test ◽  
Phenotypic Traits ◽  
Phenotypic Analysis

Abstract Background: The Qinba region is the transition region between Indica and Japonica varieties in China. It has a long history of Indica rice planting of more than 7000 years and is also a planting area for fine-quality Indica rice. The aims of this study are to explore different genetic markers applied to the analysis population structure, genetic diversity, selection and optimization of molecular markers of Indica rice, thus providing more information for the protection and utilization on germplasm resources of Indica rice. Methods: 15 phenotypic traits, a core set of 48 SSR markers as well as SNPs data obtained by genotyping-by-sequencing (GBS, NlaIII and MseI digestion, referred to as SNPs-NlaIII and SNPs-MseI, respectively) for this panel of 93 samples using the Illumina HiSeq2000 sequencing platform, were employed to explore the genetic diversity and population structure of 93 samples.Results: The average of coefficient of variation (CV) and diversity index (He) were 29.72% and 1.83 ranging from 3.07% to 137.43%, and from 1.45 to 2.03, respectively. The correlation coefficient between 15 phenotypic traits ranged from 0.984 to -0.604. The first four PCs accounted for 70.693% phenotypic variation based on phenotypic analysis. A total of 379 alleles were obtained using SSR markers, encompassing an average of 8.0 alleles per primer. Polymorphic bands (PPB) and polymorphism information content (PIC) was 88.65% and 0.77, respectively. The Mantel test showed that the correlation between the genetic distance matrix based on SNPs-NlaIII and SNPs-MseI was the largest (R2=0.88), and that based on 15 phenotypic traits and SSR was the smallest (R2=0.09). The 93 samples could be clustered into two subgroups by 3 types of genetic markers. Molecular variance analysis revealed that the genetic variation was 2% among populations and 98% within populations (the Nm was 0.16), Tajima’s D value was 1.66, the FST between the two populations was 0.61 based on 72,824 SNPs. Conclusions: The population genetic variation explained by SNPs was larger than that explained by SSRs. The gene flow of 93 samples used in this study was larger than that of naturally self-pollinated crops, which may be caused by long-term breeding selection of Indica rice in the Qinba region. The genetic structure of the 93 samples was simple and lacked rare alleles.

scholarly journals Genetic Diversity and Population Structure of 93 Rice Cultivars (Lines) (Oryza Sativa Xian Group) in Qinba in China By 3 Types of Genetic Markers

2022 ◽  
Author(s):  
Yu Zhang ◽  
Qiaoqiao He ◽  
Xixi Zhou ◽  
Yewen Wang ◽  
Peijiang Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Genetic Markers ◽  
Ssr Markers ◽  
Diversity Index ◽  
Indica Rice ◽  
Mantel Test ◽  
Phenotypic Traits ◽  
Phenotypic Analysis

Abstract Background: The Qinba region is the transition region between Indica and Japonica varieties in China. It has a long history of Indica rice planting of more than 7000 years and is also a planting area for fine-quality Indica rice. The aims of this study are to explore different genetic markers applied to the analysis population structure, genetic diversity, selection and optimization of molecular markers of Indica rice, thus providing more information for the protection and utilization on germplasm resources of Indica rice. Methods: 15 phenotypic traits, a core set of 48 SSR markers as well as SNPs data obtained by genotyping-by-sequencing (GBS, NlaIII and MseI digestion, referred to as SNPs-NlaIII and SNPs-MseI, respectively) for this panel of 93 samples using the Illumina HiSeq2000 sequencing platform, were employed to explore the genetic diversity and population structure of 93 samples.Results: The average of coefficient of variation (CV) and diversity index (He) were 29.72% and 1.83 ranging from 3.07% to 137.43%, and from 1.45 to 2.03, respectively. The correlation coefficient between 15 phenotypic traits ranged from 0.984 to -0.604. The first four PCs accounted for 70.693% phenotypic variation based on phenotypic analysis. A total of 379 alleles were obtained using SSR markers, encompassing an average of 8.0 alleles per primer. Polymorphic bands (PPB) and polymorphism information content (PIC) was 88.65% and 0.77, respectively. The Mantel test showed that the correlation between the genetic distance matrix based on SNPs-NlaIII and SNPs-MseI was the largest (R2=0.88), and that based on 15 phenotypic traits and SSR was the smallest (R2=0.09). The 93 samples could be clustered into two subgroups by 3 types of genetic markers. Molecular variance analysis revealed that the genetic variation was 2% among populations and 98% within populations (the Nm was 0.16), Tajima’s D value was 1.66, the FST between the two populations was 0.61 based on 72,824 SNPs. Conclusions: The population genetic variation explained by SNPs was larger than that explained by SSRs. The gene flow of 93 samples used in this study was larger than that of naturally self-pollinated crops, which may be caused by long-term breeding selection of Indica rice in the Qinba region. The genetic structure of the 93 samples was simple and lacked rare alleles.

scholarly journals Genetic and phenotypic diversity of selected Kenyan mung bean (Vigna radiata L. Wilckzek) genotypes

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jedidah Wangari Mwangi ◽  
Oduor Richard Okoth ◽  
Muchemi Peterson Kariuki ◽  
Ngugi Mathew Piero
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Phylogenetic Tree ◽  
Mung Bean ◽  
Phenotypic Diversity ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Phenotypic Traits ◽  
Breeding Programs ◽  
Population Structure Analysis

Abstract Background Mung bean is a pulse crop principally grown in the tropic and subtropic parts of the world for its nutrient-rich seeds. Seven mung beans accessions from Eastern Kenya were evaluated using thirteen phenotypic traits. In addition, 10 SSR markers were used to determine their genetic diversity and population structure. This aimed at enhancing germplasm utilization for subsequent mung bean breeding programs. Results Analysis of variance for most of the phenology traits showed significant variation, with the yield traits recording the highest. The first three principal components (PC) explained 83.4% of the overall phenotypic variation, with the highest (PC1) being due to variation of majority of the traits studied such as pod length, plant height, and seeds per pod. The dendogram revealed that the improved genotypes had common ancestry with the local landraces. The seven mung beans were also genotyped using 10 microsatellite markers, eight of which showed clear and consistent amplification profiles with scorable polymorphisms in all the studied genotypes. Genetic diversity, allele number, and polymorphic information content (PIC) were determined using powermarker (version 3.25) and phylogenetic tree constructed using DARWIN version 6.0.12. Analysis of molecular variance (AMOVA) was calculated using GenALEx version 6.5. A total of 23 alleles were detected from the seven genotypes on all the chromosomes studied with an average of 2.875 across the loci. The PIC values ranged from 0.1224 (CEDG056) to 0.5918 (CEDG092) with a mean of 0.3724. Among the markers, CEDG092 was highly informative while the rest were reasonably informative except CEDG056, which was less informative. Gene diversity ranged from 0.1836 (CEDG050) to 0.5102 (CDED088) with an average of 0.3534. The Jaccards dissimilarity matrix indicated that genotypes VC614850 and N26 had the highest level of dissimilarity while VC637245 and N26 had lowest dissimilarity index. The phylogenetic tree grouped the genotypes into three clusters as revealed by population structure analysis (K = 3), with cluster III having one unique genotype (VC6137B) only. AMOVA indicated that the highest variation (99%) was between individual genotype. In addition, marker traits association analysis revealed 18 significant associations (P < 0.05). Conclusion These findings indicate sufficient variation among the studied genotypes that can be considered for germplasm breeding programs.

scholarly journals Cross Species/Genera Transferability of SSR Markers, Genetic Diversity and Population Structure Analysis in Gladiolus (Gladiolus × grandiflorus L.) Genotypes

2021 ◽  
Author(s):  
Varun Hiremath ◽  
Kanwar Pal Singh ◽  
Neelu Jain ◽  
Kishan Swaroop ◽  
Pradeep Kumar Jain ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Ssr Markers ◽  
Structure Analysis ◽  
Genetic Relationships ◽  
Crop Improvement ◽  
Test Analysis ◽  
Average Value ◽  
Population Structure Analysis ◽  
Genetic Diversity And Structure

Abstract Genetic diversity and structure analysis using molecular markers is necessary for efficient utilization and sustainable management of gladiolus germplasm. Genetic analysis of gladiolus germplasm using SSR markers is largely missing due to scarce genomic information. In the present investigation, we report 66.66% cross transferability of Gladiolus palustris SSRs whereas 48% of Iris EST-SSRs were cross transferable across the gladiolus genotypes used in the study. A total of 17 highly polymorphic SSRs revealed a total 58 polymorphic loci ranging from two to six in each locus with an average of 3.41 alleles per marker. PIC values ranged from 0.11 to 0.71 with an average value of 0.48. Four SSRs were selectively neutral based on Ewens-Watterson test. Analysis of genetic structure of 84 gladiolus genotypes divided whole germplasm into two subpopulations. 35 genotypes were assigned to subpopulation 1 whereas 37 to subpopulation 2 and rest of the genotypes recorded as admixture. Analysis of molecular variance indicated maximum variance (53.59%) among individuals within subpopulations whereas 36.55% of variation observed among individuals within total population. Least variation (9.86%) was noticed between two subpopulations. Moderate (FST = 0.10) genetic differentiation of two subpopulations was observed. Grouping pattern of population structure was consistent with UPGMA dendrogram based on simple matching dissimilarity coefficient (ranged from 01.6 to 0.89) and PCoA. Genetic relationships assessed among the genotypes of respective clusters assist the breeders in selecting desirable parents for crossing. SSR markers from present study can be utilized for cultivar identification, conservation and sustainable utilization of gladiolus genotypes for crop improvement.

scholarly journals Genetic diversity and population structure of sweet orange [Citrus sinensis (L.) Osbeck] germplasm of India revealed by SSR and InDel markers

2022 ◽  
Author(s):  
Prasanth Tej Kumar Jagannadham ◽  
Thirugnanavel Anbalagan ◽  
Devendra Y Upadhyay ◽  
Snehal A. Kamde ◽  
Prafulla R. Jalamkar ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Citrus Sinensis ◽  
Sweet Orange ◽  
Polymorphic Information Content ◽  
Citrus Fruit ◽  
Molecular Data ◽  
Expected Heterozygosity ◽  
Indel Markers ◽  
Population Structure Analysis

Sweet orange (Citrus sinensis (L.) Osbeck) is an important commercial citrus fruit crop, cultivated in India and across the world. In India most of the cultivated sweet orange species were introduced varieties. In this study, we used two molecular markers, SSR and InDels, to understand the genetic diversity and population structure of seventy-two sweet orange genotypes. Genetic parameters consisted of a total number of alleles, a number of polymorphic alleles (effective alleles); genetic diversity (G.D.), expected heterozygosity (He), and the polymorphic information content (PIC) were calculated based on molecular data. Two dendrograms were constructed based on the InDels and SSR. In both the cases, they formed three major clusters showing various degrees of variations with respect to members of the clusters. Population structure analysis revealed the presence of two distinct subpopulations. Therefore, in order to address various challenges and develop sweet orange varieties with desirable traits, there is a need to broaden the genetic base of sweet orange through the intensive collection in the northeastern region. These results of intraspecific genetic variability of the collections will dictate the path for the sweet orange breeding and conservation programs in India.

scholarly journals Genetic diversity of natural populations of Taxus wallichiana var. mairei

2021 ◽  
Author(s):  
Qianqian Luo ◽  
Fengqing Li ◽  
Longhua Yu ◽  
Liyun Wang ◽  
Gangbiao Xu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Diversity Index ◽  
Polymorphic Information Content ◽  
Natural Populations ◽  
Mantel Test ◽  
Jiangxi Province ◽  
Timber Species ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Taxus Wallichiana

Abstract Maire yew (Taxus wallichiana var. mairei (Lemée H. Léveillé.) L. K. Fu et Nan Li) is a rare and endangered tree species, and it is also a precious timber species in China. We used 13 microsatellites to assess the genetic diversity and differentiation of 665 Maire yew samples from 18 natural populations. A total of 291 alleles were detected. The average number of alleles (Na=22.39), expected heterozygosity (He=0.74), polymorphic information content (PIC = 0.86) and Shannon diversity index (I = 1.66) of the loci indicated a high level of genetic diversity in natural Maire yew populations. Moreover, gene flow was more active among populations (Nm=1.62) than within populations. Among the 18 populations, the Xinfeng population in Jiangxi Province has the highest genetic diversity. Although each of the studied populations should be protected from further deforestation and agricultural expansion, the Xinfeng population deserves the highest conservation priority. The results based on analysis of molecular variance showed that genetic variation occurred mainly within populations (84.90%; P < 0.001), which indicated that the degree of genetic differentiation of the natural populations of Maire yew was low. Based on UPGMA, the 18 populations were categorized into 4 groups. A Mantel test showed that there was no significant correlation between standard genetic distance and geographical distance or altitude differences among the populations. The genetic clustering results also indicated that the genetic relationship followed a north to south clustered trend. The information presented here forms the basis for the development of genetic guidelines for appropriate conservation programs.

scholarly journals Genetic Diversity and Molecular Characterization of Worldwide Prairie Grass (Bromus catharticus Vahl) Accessions Using SRAP Markers

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2054
Author(s):  
Limei Yi ◽  
Zhixiao Dong ◽  
Yu Lei ◽  
Junming Zhao ◽  
Yanli Xiong ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Production Systems ◽  
Polymorphic Information Content ◽  
Distance Matrix ◽  
Molecular Data ◽  
Mantel Test ◽  
Grass Species ◽  
Srap Marker ◽  
Discrimination Power ◽  
Prairie Grass

Prairie grass (Bromus catharticus Vahl) is an important grass species that could be used in the production systems of certified seed and high-quality forage for grazing ruminants. In the present research, a sequence-related amplified polymorphism (SRAP) marker was employed to detect the genetic variability and structure of 80 prairie grass accessions from all over the world. Altogether, 460 reliable bands were amplified from 47 SRAP primer pairs with 345 (75%) polymorphic bands. The average values of discrimination power (DP) and polymorphic information content (PIC) were 0.753 and 0.317, respectively. Both the UPGMA clustering and PCoA analyses grouped the 80 accessions into five clusters, whereas the STRUCTURE analysis showed that 80 prairie grass accessions possessed three genetic memberships (K = 3). The results of the Mantel test showed that the distance matrix has a moderately positive correlation between the morphological and molecular data sets (r = 0.524). A poor genetic differentiation (Fst = 0.045) was discovered among the six geo-groups of accessions. Besides, the highest intragroup genetic diversity was found in the North America group (He = 0.335). This study provides a genetic structure and diversity case for prairie grass, and supplies new clues for the study and utilization of prairie grass.

Latitudinal structured populations of the Mexican wild squash Cucurbita argyrosperma subsp. sororia revealed by microsatellite markers

2017 ◽  
Vol 68 (9) ◽  
pp. 850 ◽  
Author(s):  
Francisco J. Balvino-Olvera ◽  
Karman F. Sánchez-Gómez ◽  
Jorge Arturo Lobo ◽  
Germán Avila-Sakar ◽  
Rogelio Cruz-Reyes ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Crop Improvement ◽  
Group Testing ◽  
Mantel Test ◽  
Structured Populations ◽  
Fixation Index ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Mexican Pacific ◽  
Genetic Diversity And Structure

Crop wild relatives represent an important agronomic resource for crop improvement and biodiversity conservation. The wild squash Cucurbita argyrosperma subsp. sororia. (Cucurbitaceae) has been considered the wild ancestor of cultivated forms of C. argyrosperma. In order to characterise the geographic patterns of genetic variation in this wild cucurbit and to identify priority areas for conservation, we analysed the genetic diversity and structure of natural populations along the Mexican Pacific coast. By using 14 polymorphic microsatellites, we genotyped 378 individuals sampled from 61 locations. Standard population genetics analyses and group testing were conducted on the genotypes with the aid of principal coordinate analysis and Bayesian analysis. Overall, we found an average of 12.3 alleles per locus and an expected heterozygosity of 0.756. We found greater genetic diversity in southern populations. The fixation index was 0.113, suggesting a mixed mating system. The Mantel test revealed a minor distance effect on genetic differentiation between individuals (r = 0.321). Finally, we found three main groups of populations arranged in a mostly latitudinal pattern, from Sinaloa (north-west) to Oaxaca–Guerrero (south-east). The greater genetic diversity and heterogeneity among southern populations (Guerrero–Oaxaca), suggests that this region is an important centre of diversity of this wild squash with important implications for conservation.

scholarly journals ISSR markers and morphometry determine genetic diversity and population structure in Hedera helix L.

2021 ◽  
Author(s):  
Abdul Shakoor ◽  
Gul Zaib ◽  
Fang Zhao ◽  
Wuyang Li ◽  
Xincan Lan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Similarity ◽  
Diversity Index ◽  
Morphological Characteristics ◽  
Principal Component ◽  
Mantel Test ◽  
Hedera Helix ◽  
Plant Populations ◽  
High Genetic Diversity

Hedera helix L. is an invasive, but medicinally important plant. In Iran, there is no available study on the H. helix population to reveal the genetic diversity and population structure. Fifty-six individual plants belonging to nine geographical populations were collected in four provinces of Iran. High genetic diversity, polymorphisms, and a Shannon diversity index of 0.269 were detected in Mazandaran, Kandovan (Population 3). Analysis of the molecular variance indicated 40% of total genetic variation of the whole population was present in the subpopulation. A high genetic similarity (0.922) between plant Populations 5 (Kermanshah; Islamabad) and 6 (Kermanshah; Paveh) was noted. On the other hand, a low genetic similarity was observed between plant Populations 1 (Tehran; Darband) and 8 (Ardabil; Hur). The Mantel test revealed a correlation between the genetic and geographical distances. Furthermore, it demonstrated the isolation mechanism responsible for the population structure in the H. helix plant populations. The principal component analysis explained the majority of the variation in the morphological characteristics. Three components explained 87% of the variation, and the first component explained 60% of the variation. For instance, the leaf morphology showed a correlation of &gt; 0.7 between leaf morphological and floral characters. The plant leaves and quantitative flower characteristics separated the plant populations according to the differences in length. The current results have implications for plant conservation and management.

scholarly journals Genetic diversity and fragmentation of Aspidosperma quebracho-blanco (Apocynaceae) natural habitats, conservation issues in Chaco forest and savanna biomes

2021 ◽  
Vol 9 (1) ◽  
pp. 115-129
Author(s):  
Thomáz S. Guerreiro Botelho ◽  
Gecele Matos Paggi ◽  
Maria Ana Farinaccio
Keyword(s):  
Genetic Diversity ◽  
Polymorphic Information Content ◽  
Natural Habitat ◽  
Mantel Test ◽  
Shannon Index ◽  
Conservation Strategies ◽  
Conservation Units ◽  
Natural Habitats ◽  
High Genetic Diversity ◽  
Genetic Diversity And Structure

The present study analyses the first data on genetic diversity of A. quebracho-blanco with the fragmentation of its natural habitat, supporting conservation strategies such as the definition of priority areas for conservation. DNA was extracted from 25 individuals of five populations of A. quebracho-blanco from Argentina, Paraguay, and Brazil. Six ISSR primers were used to characterize the genetic diversity and structure of this species. The genotypes were grouped according to a distance matrix, considering the genetic diversity indices of Nei (He), Shannon (H’), polymorphic information content (PIC), and heterozygosis (H). The populations showed an average genetic diversity that ranged from 0.09 to 0.15 for the Shannon index and from 0.19 to 0.31 for the Nei index; the Mantel test was not significant (r2 = 0.25, P = 0.106). The results obteined for the sampled populations reveal that conservation units are indispensable for conserving the species genetic resources. In addition, it would be essential to construct a germplasm bank for the Cordoba (Argentina) population, which is a population with high genetic diversity in a region of lower fragmentation compared to other regions evaluated, to ensure the conservation of A. quebracho-blanco.

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