scholarly journals DIVERSITY AND POPULATION STRUCTURE OF LOCAL AND EXOTIC LABLAB PURPUREUS ACCESSIONS IN KENYA AS REVEALED BY MICROSATELLITE MARKERS

2021 ◽  
pp. 8
Author(s):  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Diversity ◽  
Crop Improvement ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Lablab Purpureus ◽  
Geographic Origins ◽  
Sub Saharan ◽  
Wild Accessions

Lablab purpureus is an important pulse crop in some parts of sub-Saharan Africa and Asia but has largely remained underutilized. Understanding the genetic diversity is prerequisite for genetic improvement and utilization of this leguminous crop. The relationships of the local lablab genotypes and those collected from other diverse geographic origins including the wild accessions remain unknown in Kenya. The study was undertaken to determine genetic diversity and population structure of germplasm accessions collected from Kenya and other global regions. Eight simple sequence repeat primer pairs were used to genotype the 189 lablab accessions. A total of 39 alleles were revealed by eight SSR with an average of 4.88 alleles per polymorphic loci. The average PIC was 0.42. The gene diversity among the accessions ranged from 0.26 to 0.52 with an average of 0.38, indicating moderate genetic diversity. Germplasm collected from Kenya showed a moderate genetic diversity of 0.36. Higher genetic diversity (He<0.5) was detected within the Ethiopian and South Africa populations. Analysis of molecular variance (AMOVA) revealed that 94% of the allele diversity was attributed to individuals within populations while only 6% was distributed among the populations. The Bayesian model-based Structure method and Principal coordinate analysis (PCoA) scatter plot clustered the accessions into three groups with germplasms collected from Kenya showing distribution among all the three groups. The wild accessions clustered mainly with those from Southern and Eastern Africa confirming earlier suggestions that lablab is of African origin. The results of this study are discussed in light of the crop improvement of this crop.

scholarly journals Genetic diversity and population structure of early and extra-early maturing maize germplasm adapted to sub-Saharan Africa

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Baffour Badu-Apraku ◽  
Ana Luísa Garcia-Oliveira ◽  
César Daniel Petroli ◽  
Sarah Hearne ◽  
Samuel Adeyemi Adewale ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Inbred Lines ◽  
Snp Markers ◽  
Rapid Expansion ◽  
Sub Saharan Africa ◽  
Heterotic Groups ◽  
Breeding Programs ◽  
Early Maturing ◽  
Sub Saharan

Abstract Background Assessment and effective utilization of genetic diversity in breeding programs is crucial for sustainable genetic improvement and rapid adaptation to changing breeding objectives. During the past two decades, the commercialization of the early and extra-early maturing cultivars has contributed to rapid expansion of maize into different agro-ecologies of sub-Saharan Africa (SSA) where maize has become an important component of the agricultural economy and played a vital role in food and nutritional security. The present study aimed at understanding the population structure and genetic variability among 439 early and extra-early maize inbred lines developed from three narrow-based and twenty-seven broad-based populations by the International Iinstitute of Tropical Agriculture Maize Improvement Program (IITA-MIP). These inbreds were genotyped using 9642 DArTseq-based single nucleotide polymorphism (SNP) markers distributed uniformly throughout the maize genome. Results About 40.8% SNP markers were found highly informative and exhibited polymorphic information content (PIC) greater than 0.25. The minor allele frequency and PIC ranged from 0.015 to 0.500 and 0.029 to 0.375, respectively. The STRUCTURE, neighbour-joining phylogenetic tree and principal coordinate analysis (PCoA) grouped the inbred lines into four major classes generally consistent with the selection history, ancestry and kernel colour of the inbreds but indicated a complex pattern of the genetic structure. The pattern of grouping of the lines based on the STRUCTURE analysis was in concordance with the results of the PCoA and suggested greater number of sub-populations (K = 10). Generally, the classification of the inbred lines into heterotic groups based on SNP markers was reasonably reliable and in agreement with defined heterotic groups of previously identified testers based on combining ability studies. Conclusions Complete understanding of potential heterotic groups would be difficult to portray by depending solely on molecular markers. Therefore, planned crosses involving representative testers from opposing heterotic groups would be required to refine the existing heterotic groups. It is anticipated that the present set of inbreds could contribute new beneficial alleles for population improvement, development of hybrids and lines with potential to strengthen future breeding programs. Results of this study would help breeders in formulating breeding strategies for genetic enhancement and sustainable maize production in SSA.

scholarly journals Genetic Diversity, Population Structure and Species Delimitation of Trialeurodes vaporariorum (greenhouse whitefly)

2016 ◽  
Author(s):  
J. M. Wainaina ◽  
P. De Barro ◽  
L. Kubatko ◽  
M. A. Kehoe ◽  
J. Harvey ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Species Delimitation ◽  
Posterior Probability ◽  
Haplotype Diversity ◽  
Trialeurodes Vaporariorum ◽  
Sub Saharan Africa ◽  
Coi Gene ◽  
Greenhouse Whitefly ◽  
Sub Saharan

AbstractGenetic diversity within Trialeurodes vaporariorum (Westwood, 1856) remains largely unexplored, particularly within regions of Sub-Saharan Africa. In this study, T. vaporariorum samples were obtained from three locations in Kenya: Katumani, Kiambu and Kajiado counties. DNA extraction, PCR and Sanger sequencing were carried out on ~750 bp fragment of the mitochondria cytochrome c oxidase I (COI) gene from individual whiteflies. In addition, global populations were assessed and 19 haplotypes were identified, with three main haplotypes (Hp_19, Hp_10, Hp_011) circulating within Kenya. Measures of genetic diversity among T. vaporariorum populations resulted in haplotype diversity of 0.411, nucleotide diversity 0.00096, and Tajima’s D -0. 30315, (P>0.10). Analysis of population structure across global sequences using Structurama indicated one population globally, with posterior probability of 0.72. Bayesian and maximum likelihood phylogenetic analysis gave support for two clades (Clade I = an admixed global population and Clade II = subset of Kenyan and 1 Greek sequence). Species delimitation between the two clades was assessed by four parameters; posterior probability, Kimura’s two parameter (K2P), Rodrigo’s P (Randomly distinct) and Rosenberg’s reciprocal monophyly (P(AB). The two clades within the phylogenetic tree showed evidence of distinctness based on; Kimura two parameters (K2P) (p = -1.21E-01), Rodrigo’s P (RD) (p =0.05) and Rosenberg’s P(AB) (p = 2.3E -13). Overall, low genetic diversity within the Kenyan samples is a likely indicator of recent population expansion and colonization with this region and plausible signs of species complex formation in Sub-Saharan Africa.

scholarly journals Genetic Diversity and Population Structure of Soybean Lines Adapted to Sub-Saharan Africa Using Single Nucleotide Polymorphism (SNP) Markers

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 604
Author(s):  
Subhash Chander ◽  
Ana Luísa Garcia-Oliveira ◽  
Melaku Gedil ◽  
Trushar Shah ◽  
Gbemisola Oluwayemisi Otusanya ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Single Nucleotide Polymorphism ◽  
Population Structure ◽  
Polymorphic Information Content ◽  
Snp Markers ◽  
Sub Saharan Africa ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Or Groups ◽  
Sub Saharan

Soybean productivity in sub-Saharan Africa (SSA) is less than half of the global average yield. To plug the productivity gap, further improvement in grain yield must be attained by enhancing the genetic potential of new cultivars that depends on the genetic diversity of the parents. Hence, our aim was to assess genetic diversity and population structure of elite soybean genotypes, mainly released cultivars and advanced selections in SSA. In this study, a set of 165 lines was genotyped with high-throughput single nucleotide polymorphism (SNP) markers covering the complete genome of soybean. The genetic diversity (0.414) was high considering the bi-allelic nature of SNP markers. The polymorphic information content (PIC) varied from 0.079 to 0.375, with an average of 0.324 and about 49% of the markers had a PIC value above 0.350. Cluster analysis grouped all the genotypes into three major clusters. The model-based STRUCTURE and discriminant analysis of principal components (DAPC) exhibited high consistency in the allocation of lines in subpopulations or groups. Nonetheless, they presented some discrepancy and identified the presence of six and five subpopulations or groups, respectively. Principal coordinate analysis revealed more consistency with subgroups suggested by DAPC analysis. Our results clearly revealed the broad genetic base of TGx (Tropical Glycine max) lines that soybean breeders may select parents for crossing, testing and selection of future cultivars with desirable traits for SSA.

scholarly journals Genetic Diversity and Population Structure of Serbian Barley (Hordeum vulgare L.) Collection during a 40-Year Long Breeding Period

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Ljiljana Brbaklić ◽  
Dragana Trkulja ◽  
Sanja Mikić ◽  
Milan Mirosavljević ◽  
Vojislava Momčilović ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Hordeum Vulgare ◽  
Crop Improvement ◽  
Genetic Erosion ◽  
Breeding Period ◽  
Phenotypic Variance ◽  
Hordeum Vulgare L ◽  
Phenotypic Data ◽  
Breeding Material

Determination of genetic diversity and population structure of breeding material is an important prerequisite for discovering novel and valuable alleles aimed at crop improvement. This study’s main objective was to characterize genetic diversity and population structure of a collection representing a 40-year long historical period of barley (Hordeum vulgare L.) breeding, using microsatellites, pedigree, and phenotypic data. The set of 90 barley genotypes was phenotyped during three growing seasons and genotyped with 338 polymorphic alleles. The indicators of genetic diversity showed differentiation changes throughout the breeding periods. The population structure discriminated the breeding material into three distinctive groups. The principal coordinate analysis grouped the genotypes according to their growth habit and row type. An analysis of phenotypic variance (ANOVA) showed that almost all investigated traits varied significantly between row types, seasons, and breeding periods. A positive effect on yield progress during the 40-year long breeding period could be partly attributed to breeding for shorter plants, which reduced lodging and thus provided higher yield stability. The breeding material revealed a considerable diversity level based on microsatellite and phenotypic data without a tendency of genetic erosion throughout the breeding history and implied dynamic changes in genetic backgrounds, providing a great gene pool suitable for further barley improvement.

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

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.

scholarly journals Africa and the wider world: creole communities in the Atlantic and Indian Oceans

Tempo ◽  
2017 ◽  
Vol 23 (3) ◽  
pp. 465-481
Author(s):  
Malyn Newitt
Keyword(s):  
Technology Transfer ◽  
Indian Ocean ◽  
World Economy ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Cultural Appropriation ◽  
The World ◽  
African Slaves ◽  
The Indian Ocean ◽  
Sub Saharan

Abstract: Portuguese creoles were instrumental in bringing sub-Saharan Africa into the intercontinental systems of the Atlantic and Indian Ocean. In the Atlantic Islands a distinctive creole culture emerged, made up of Christian emigrants from Portugal, Jewish exiles and African slaves. These creole polities offered a base for coastal traders and became politically influential in Africa - in Angola creating their own mainland state. Connecting the African interior with the world economy was largely on African terms and the lack of technology transfer meant that the economic gap between Africa and the rest of the world inexorably widened. African slaves in Latin America adapted to a society already creolised, often through adroit forms of cultural appropriation and synthesis. In eastern Africa Portuguese worked within existing creolised Islamic networks but the passage of their Indiamen through the Atlantic created close links between the Indian Ocean and Atlantic commercial systems.

scholarly journals Resource frontiers and agglomeration economies: The varied logics of transnational land-based investing in Southern and Eastern Africa

AMBIO ◽  
2022 ◽  
Author(s):  
Dilini Abeygunawardane ◽  
Angela Kronenburg García ◽  
Zhanli Sun ◽  
Daniel Müller ◽  
Almeida Sitoe ◽  
...  
Keyword(s):  
Spatial Data ◽  
Large Scale ◽  
Agglomeration Economies ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Track Record ◽  
Level Data ◽  
Forestry Investments ◽  
Sub Saharan ◽  
Investment Location

AbstractActor-level data on large-scale commercial agriculture in Sub-Saharan Africa are scarce. The peculiar choice of transnational investing in African land has, therefore, been subject to conjecture. Addressing this gap, we reconstructed the underlying logics of investment location choices in a Bayesian network, using firm- and actor-level interview and spatial data from 37 transnational agriculture and forestry investments across 121 sites in Mozambique, Zambia, Tanzania, and Ethiopia. We distinguish four investment locations across gradients of resource frontiers and agglomeration economies to derive the preferred locations of different investors with varied skillsets and market reach (i.e., track record). In contrast to newcomers, investors with extensive track records are more likely to expand the land use frontier, but they are also likely to survive the high transaction costs of the pre-commercial frontier. We highlight key comparative advantages of Southern and Eastern African frontiers and map the most probable categories of investment locations.

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.

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