Population Structure And Diversity Among Improved Cowpea Varieties From Senegal Based On Microsatellite Markers

Author(s):  
◽  
◽  
◽  

Cowpea (Vigna unguiculata) is used in West Africa for both human consumption and animal feeding. Despite its importance, the production of the crop is hampered by biotic and abiotic constraints. To overcome these constraints, the Senegalese Institute of Agricultural Research (ISRA) has set up a breeding program since 1960 leading to the release of productive varieties. Information of the genetic diversity for these varieties could improve the effectiveness of further breeding programs. The objectives of this study was to assess the genetic diversity and the population structure of 11 cowpea improved varieties from ISRA collection. Twelve (12) polymorphic microsatellite markers were used and the analysis of genotypic data showed a total of 39 alleles ranging from 2 (SSR6288, SSR6311 and SSR6827) to 6 (SSR6807) per locus. Polymorphism rate ranged from 8.33% (Mougne and Kelle) to 58.33% (Mouride) with an average of 31.06%. Intra varietal genetic diversity was very weak (0.012 to 0.091). The genetic similarity revealed that Melakh and Pakau varieties were genetically the closest while Bambey 21 and Sam were the most distant. These results are confirmed by the dendrogram, which also showed that Thieye, Leona, Kelle, Sam, Mougne and Yacine varieties have a higher genetic stability than Lisard, Melakh, Pakau, Mouride and Bambey 21. Eighty-seven percent (87%) of the total variability was attributed to inter varietal variability while 17% was due to intra varietal variation. These results provide a better knowledge of genetic resources of cowpea varieties released and held by ISRA and constitute important input for further cowpea breeding programs.

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 281 ◽  
Author(s):  
Fu-Mei Liu ◽  
Ning-Nan Zhang ◽  
Xiao-Jin Liu ◽  
Zeng-Jiang Yang ◽  
Hong-Yan Jia ◽  
...  

Dalbergia odorifera T. Chen (Fabaceae) is a woody tree species indigenous to Hainan Island in China. Due to its high medicinal and commercial value, this tree species has been planted over 3500 ha2 in southern China. There is an urgent need for improvement of the D. odorifera germplasm, however, limited information on germplasm collection, conservation, and assessment of genetic resources is available. Therefore, we have built a database of 251 individuals collected across the whole of southern China, which included 42 wild trees and 210 cultivated trees, with the following objectives. (1) Evaluate genetic diversity and population structure of the database using 19 microsatellite markers and (2) develop a core collection for improvement and breeding programs. Totally, the 19 microsatellite markers harbored 77 alleles across the database with the polymorphic information content (PIC) ranging from 0.03 to 0.66. Medium genetic diversity level was inferred by Nei’s gene diversity (0.38), Shannon’s information index (0.65), and observed (0.33) and expected heterozygosity (0.38). Structure analysis showed that four was the optimum cluster size using the model-based Bayesian procedure, and the 251 D. odorifera individuals were grouped into five populations including four pure ones (RP1-4) and one mixed one (MIX) based on their maximum membership coefficients. Among these populations, the expected heterozygosity varied from 0.30 (RP3) to 0.38 (RP4). Analysis of molecular variance (AMOVA) showed 11% genetic variation existed among populations, and moderate population differentiation was inferred by the matrix of pairwise Fst (genetic differentiation among populations), which was in the range of 0.031 to 0.095. Moreover, a core collection of 31 D. odorifera individuals including six wild and 25 cultivated trees was developed, which was only 12.4% of the database but conserved the whole genetic diversity. The results of this study provided additional insight into the genetic structure of the large D. odorifera germplasm, and the core collection will be useful for the efficient and sustainable utilization of genetic resources, as well as efficient improvement in breeding programs.


2019 ◽  
Vol 37 (2) ◽  
pp. 152-160
Author(s):  
Rafaela de Jesus ◽  
Gabriel do N Santos ◽  
Andressa S Piccin ◽  
Thiago WA Balsalobre ◽  
Fernando C Sala ◽  
...  

ABSTRACT Peppers of the genus Capsicum are of great socioeconomic importance, being pungency trait their main attraction. Pungency characterization, genetic distance estimates and population structure analysis of the accessions belonging to germplasm banks are important for parent selection which allows to obtain superior progenies. Therefore, the aims of this study were: i) evaluate 81 accessions of the Capsicum spp. Germplasm Bank of Universidade Federal de São Carlos (BGC-UFSCar) with molecular markers linked to pungency; ii) estimate the genetic diversity among accessions of the BGC-UFSCar using microsatellite markers (SSR); and iii) evaluate the efficiency of these markers in the distinction among species of Capsicum spp. We noticed that pun11 and SNP molecular markers were efficient in predicting the pungent phenotype of BGC-UFSCar accessions in 84.85% and 95.59%, respectively. From a total of 13 amplified microsatellite markers, seven were polymorphic and efficient to discriminate species of Capsicum genus, both through genetic diversity analysis and population structure analysis, which showed three subpopulations. The molecular markers used in this study are useful tools for breeding programs since they were able to characterize and discriminate Capsicum spp. species at DNA level. Information obtained with molecular markers can assist in the selection of contrasting parents for future breeding programs.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Grimar Abdiel Perez ◽  
Pumipat Tongyoo ◽  
Julapark Chunwongse ◽  
Hans de Jong ◽  
Anucha Wongpraneekul ◽  
...  

AbstractThis study explored a germplasm collection consisting of 112 Luffa acutangula (ridge gourd) accessions, mainly from Thailand. A total of 2834 SNPs were used to establish population structure and underlying genetic diversity while exploring the fruit characteristics together with genetic information which would help in the selection of parental lines for a breeding program. The study found that the average polymorphism information content value of 0.288 which indicates a moderate genetic diversity for this L. acutangula germplasm. STRUCTURE analysis (ΔK at K = 6) allowed us to group the accessions into six subpopulations that corresponded well with the unrooted phylogenetic tree and principal coordinate analyses. When plotted, the STRUCTURE bars to the area of collection, we observed an admixed genotype from surrounding accessions and a geneflow confirmed by the value of FST = 0.137. AMOVA based on STRUCTURE clustering showed a low 12.83% variation between subpopulations that correspond well with the negative inbreeding coefficient value (FIS =  − 0.092) and low total fixation index (FIT = 0.057). There were distinguishing fruit shapes and length characteristics in specific accessions for each subpopulation. The genetic diversity and different fruit shapes in the L. acutangula germplasm could benefit the ridge gourd breeding programs to meet the demands and needs of consumers, farmers, and vegetable exporters such as increasing the yield of fruit by the fruit width but not by the fruit length to solve the problem of fruit breakage during exportation.


Author(s):  
Workia Ahmed ◽  
Tileye Feyissa ◽  
Kassahun Tesfaye ◽  
Sumaira Farrakh

Abstract Background Date palm tree (Phoenix dactylifera L.) is a perennial monocotyledonous plant belonging to the Arecaceae family, a special plant with extraordinary nature that gives eminent contributions in agricultural sustainability and huge socio-economic value in many countries of the world including Ethiopia. Evaluation of genetic diversity across date palms at DNA level is very important for breeding and conservation. The result of this study could help to design for genetic improvement and develop germplasm introduction programmes of date palms mainly in Ethiopia. Results In this study, 124 date palm genotypes were collected, and 10 polymorphic microsatellite markers were used. Among 10 microsatellites, MPdCIR085 and MPdCIR093 loci showed the highest value of observed and expected heterozygosity, maximum number of alleles, and highest polymorphic information content values. A total of 112 number of alleles were found, and the mean number of major allele frequency was 0.26, with numbers ranging from 0.155 (MPdCIR085) to 0.374 (MPdCIR016); effective number of alleles with a mean value of 6.61, private alleles ranged from 0.0 to 0.65; observed heterozygosity ranged from 0.355 to 0.726; expected heterozygosity varied from 0.669 to 0.906, polymorphic information content with a mean value of 0.809; fixation index individuals relative to subpopulations ranged from 0.028 for locus MPdCIR032 to 0.548 for locus MPdCIR025, while subpopulations relative to total population value ranged from − 0.007 (MPdCIR070) to 0.891 (MPdCIR015). All nine accesstions, neighbour-joining clustering analysis, based on dissimilarity coefficient values were grouped into five major categories; in population STRUCTURE analysis at highest K value, three groups were formed, whereas DAPC separated date palm genotypes into eight clusters using the first two linear discriminants. Principal coordinate analysis was explained, with a 17.33% total of variation in all populations. Generally, the result of this study revealed the presence of allele variations and high heterozygosity (> 0.7) in date palm genotypes. Conclusions Microsatellites (SSR) are one of the most preferable molecular markers for the study of genetic diversity and population structure of plants. In this study, we found the presence of genetic variations of date palm genotypes in Ethiopia; therefore, these genetic variations of date palms is important for crop improvement and conservation programmes; also, it will be used as sources of information to national and international genbanks.


2020 ◽  
Vol 27 (7) ◽  
pp. 1699-1709
Author(s):  
Rekha Sharma ◽  
Sonika Ahlawat ◽  
Himani Sharma ◽  
Ved Prakash ◽  
Shilpa ◽  
...  

2017 ◽  
Vol 71 ◽  
pp. 87-96 ◽  
Author(s):  
Muhammad Amjad Nawaz ◽  
Seung Hwan Yang ◽  
Hafiz Mamoon Rehman ◽  
Faheem Shehzad Baloch ◽  
Jeong Dong Lee ◽  
...  

Author(s):  
R. H. Sammour ◽  
M. A. Karam ◽  
Y. S. Morsi ◽  
R. M. Ali

Abstract The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.


BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Sirlene Viana de Faria ◽  
Leandro Tonello Zuffo ◽  
Wemerson Mendonça Rezende ◽  
Diego Gonçalves Caixeta ◽  
Hélcio Duarte Pereira ◽  
...  

Abstract Background The characterization of genetic diversity and population differentiation for maize inbred lines from breeding programs is of great value in assisting breeders in maintaining and potentially increasing the rate of genetic gain. In our study, we characterized a set of 187 tropical maize inbred lines from the public breeding program of the Universidade Federal de Viçosa (UFV) in Brazil based on 18 agronomic traits and 3,083 single nucleotide polymorphisms (SNP) markers to evaluate whether this set of inbred lines represents a panel of tropical maize inbred lines for association mapping analysis and investigate the population structure and patterns of relationships among the inbred lines from UFV for better exploitation in our maize breeding program. Results Our results showed that there was large phenotypic and genotypic variation in the set of tropical maize inbred lines from the UFV maize breeding program. We also found high genetic diversity (GD = 0.34) and low pairwise kinship coefficients among the maize inbred lines (only approximately 4.00 % of the pairwise relative kinship was above 0.50) in the set of inbred lines. The LD decay distance over all ten chromosomes in the entire set of maize lines with r2 = 0.1 was 276,237 kb. Concerning the population structure, our results from the model-based STRUCTURE and principal component analysis methods distinguished the inbred lines into three subpopulations, with high consistency maintained between both results. Additionally, the clustering analysis based on phenotypic and molecular data grouped the inbred lines into 14 and 22 genetic divergence clusters, respectively. Conclusions Our results indicate that the set of tropical maize inbred lines from UFV maize breeding programs can comprise a panel of tropical maize inbred lines suitable for a genome-wide association study to dissect the variation of complex quantitative traits in maize, mainly in tropical environments. In addition, our results will be very useful for assisting us in the assignment of heterotic groups and the selection of the best parental combinations for new breeding crosses, mapping populations, mapping synthetic populations, guiding crosses that target highly heterotic and yielding hybrids, and predicting untested hybrids in the public breeding program UFV.


Sign in / Sign up

Export Citation Format

Share Document