Genetic diversity of safflower (Carthamus tinctorius L.) germplasm as revealed by SSR markers

2015 ◽  
Vol 15 (1) ◽  
pp. 1-11 ◽  
Author(s):  
B. Usha Kiran ◽  
N. Mukta ◽  
P. Kadirvel ◽  
K. Alivelu ◽  
S. Senthilvel ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Seed Yield ◽  
Edible Oils ◽  
Agronomic Traits ◽  
Allelic Variation ◽  
Fatty Acid Content ◽  
Bootstrap Support ◽  
Oilseed Crop ◽  
Core Subset

Safflower is a multi-purpose oilseed crop, primarily known for good quality oil containing highest polyunsaturated fatty acid content (>80%) among edible oils. In this study, a core subset of 148 safflower accessions representing 15 countries, predominantly of Indian origin, was evaluated for agronomic traits and characterized for genetic diversity, population structure and linkage disequilibrium (LD) using 44 simple sequence repeat (SSR) loci across 11 linkage groups to enable its utilization in breeding and genetic mapping purposes. The collection had substantial variation for seed yield-related traits. SSR allelic variation was low as indicated by average number of alleles (3.6) per locus, gene diversity (0.314) and polymorphism information content (0.284). Cluster analysis (neighbour-joining tree) revealed five major genotypic groups with very low bootstrap support. STRUCTURE analysis showed recognizable population structure; based on membership coefficients ( ≥ 0.75), 52% accessions were classified into four populations (K= 4) and the remaining 48% accessions into admixture group. High Fst values (0.30–0.48) suggested that the populations were substantially differentiated. Analysis of molecular variance results showed that maximum of genetic variation (85%) was explained between individuals within the population suggesting that the population structure was only weak. About 1.9% of SSR locus pairs were in LD, which appeared to be low. High phenotypic variation, mild population structure and low level of LD among unlinked loci suggested that the core subset can be explored for association mapping of seed yield components in safflower.

scholarly journals Genetic diversity and population structure of a mini-core subset from the world cowpea (Vigna unguiculata (L.) Walp.) germplasm collection

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Christian Fatokun ◽  
Gezahegn Girma ◽  
Michael Abberton ◽  
Melaku Gedil ◽  
Nnanna Unachukwu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Vigna Unguiculata ◽  
Germplasm Collection ◽  
Core Subset ◽  
The World

scholarly journals Genetic Diversity, Linkage Disequilibrium and Population Structure of Bulgarian Bread Wheat Assessed by Genome-Wide Distributed SNP Markers: From Old Germplasm to Semi-Dwarf Cultivars

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1116
Author(s):  
Vladimir Aleksandrov ◽  
Tania Kartseva ◽  
Ahmad M. Alqudah ◽  
Konstantina Kocheva ◽  
Krasimira Tasheva ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Linkage Disequilibrium ◽  
Bread Wheat ◽  
Clustering Algorithm ◽  
Agronomic Traits ◽  
Gene Diversity ◽  
Geographic Region ◽  
Snp Markers ◽  
Genetic Diversity And Structure

Genetic diversity and population structure are key resources for breeding purposes and genetic studies of important agronomic traits in crops. In this study, we described SNP-based genetic diversity, linkage disequilibrium and population structure in a panel of 179 bread wheat advanced cultivars and old accessions from Bulgaria, using an optimized wheat 25K Infinium iSelect array. Out of 19,019 polymorphic SNPs, 17,968 had а known chromosome position on the A (41%), B (42%) and D (11%) genome, and 6% were not assigned to any chromosome. Homoeologous group 4, in particular chromosome 4D, was the least polymorphic. In the total population, the Nei’s gene diversity was within the range 0.1-0.5, and the polymorphism information content ranged from 0.1 to 0.4. Significant differences between the old and modern collections were revealed with respect to the linkage disequilibrium (LD): the average values for LD (r2), the percentage of the locus pairs in LD and the LD decay were 0.64, 16% and 3.3 for the old germplasm, and 0.43, 30% and 4.1 for the modern releases, respectively. Structure and k-means clustering algorithm divided the panel into three groups. The old accessions formed a distinct subpopulation. The cluster analysis further distinguished the modern releases according to the geographic region and genealogy. Gene exchange was evidenced mainly between the subpopulations of contemporary cultivars. The achieved understanding of the genetic diversity and structure of the Bulgarian wheat population and distinctiveness of the old germplasm could be of interest for breeders developing cultivars with improved characteristics. The obtained knowledge about SNP informativeness and the LD estimation are worthwhile for selecting markers and for considering the composition of a population in association mapping studies of traits of interest.

scholarly journals Assessment of the genetic diversity and population structure of groundnut germplasm collections using phenotypic traits and SNP markers: Implications for drought tolerance breeding

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259883
Author(s):  
Seltene Abady ◽  
Hussein Shimelis ◽  
Pasupuleti Janila ◽  
Shasidhar Yaduru ◽  
Admire I. T. Shayanowako ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Drought Tolerance ◽  
Agronomic Traits ◽  
Snp Markers ◽  
Phenotypic Traits ◽  
Environment Interaction ◽  
Optimum Conditions ◽  
Pod Yield ◽  
Germplasm Collections

Profiling the genetic composition and relationships among groundnut germplasm collections is essential for the breeding of new cultivars. The objectives of this study were to assess the genetic diversity and population structure among 100 improved groundnut genotypes using agronomic traits and high-density single nucleotide polymorphism (SNP) markers. The genotypes were evaluated for agronomic traits and drought tolerance at the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT)/India across two seasons. Ninety-nine of the test genotypes were profiled with 16363 SNP markers. Pod yield per plant (PY), seed yield per plant (SY), and harvest index (HI) were significantly (p < 0.05) affected by genotype × environment interaction effects. Genotypes ICGV 07222, ICGV 06040, ICGV 01260, ICGV 15083, ICGV 10143, ICGV 03042, ICGV 06039, ICGV 14001, ICGV 11380, and ICGV 13200 ranked top in terms of pod yield under both drought-stressed and optimum conditions. PY exhibited a significant (p ≤ 0.05) correlation with SY, HI, and total biomass (TBM) under both test conditions. Based on the principal component (PC) analysis, PY, SY, HSW, shelling percentage (SHP), and HI were allocated in PC 1 and contributed to the maximum variability for yield under the two water regimes. Hence, selecting these traits could be successful for screening groundnut genotypes under drought-stressed and optimum conditions. The model-based population structure analysis grouped the studied genotypes into three sub-populations. Dendrogram for phenotypic and genotypic also grouped the studied 99 genotypes into three heterogeneous clusters. Analysis of molecular variance revealed that 98% of the total genetic variation was attributed to individuals, while only 2% of the total variance was due to variation among the subspecies. The genetic distance between the Spanish bunch and Virginia bunch types ranged from 0.11 to 0.52. The genotypes ICGV 13189, ICGV 95111, ICGV 14421, and ICGV 171007 were selected for further breeding based on their wide genetic divergence. Data presented in this study will guide groundnut cultivar development emphasizing economic traits and adaptation to water-limited agro-ecologies, including in Ethiopia.

scholarly journals Helicobacter pylori: Clonal Population Structure and Restricted Transmission within Families Revealed by Molecular Typing

2000 ◽  
Vol 38 (10) ◽  
pp. 3646-3651 ◽  
Author(s):  
Shan-Rui Han ◽  
Hans-Christoph E. Zschausch ◽  
Heinz-Georg W. Meyer ◽  
Thomas Schneider ◽  
Michael Loos ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Population Structure ◽  
Molecular Typing ◽  
Allelic Variation ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Chromosomal Dna ◽  
H Pylori

Helicobacter pylori infects up to 50% of the human population worldwide. The infection occurs predominantly in childhood and persists for decades or a lifetime. H. pylori is believed to be transmitted from person to person. However, tremendous genetic diversity has been reported for these bacteria. In order to gain insight into the epidemiological basis of this phenomenon, we performed molecular typing of H. pylori isolates from different families. Fifty-nine H. pylori isolates from 27 members of nine families were characterized by using restriction fragment length polymorphism analysis of five PCR-amplified genes, by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA, and byvacA and cagA genotyping. The 16S rRNA gene exhibited little allelic variation, as expected for a unique bacterial species. In contrast, the vacA, flaA,ureAB, and lspA-glmM genes were highly polymorphic, with a mean genetic diversity of 0.83, which exceeds the levels recorded for all other bacterial species. In conjunction with PFGE, 59 H. pylori isolates could be differentiated into 21 clonal types. Each individual harbored only one clone, occasionally with a clonal variant. Identical strains were always found either between siblings or between a mother and her children. Statistical analysis revealed clonality of population structure in all isolates. The results of this study suggest the possible coexistence of a large array of clonal lineages that are evolving in each individual in isolation from one another. Transmission appears to occur primarily from mother to child and perhaps between siblings.

scholarly journals Mating type distribution, genetic diversity and population structure of Ascochyta rabiei, the cause of Ascochyta blight of chickpea in western Iran

2021 ◽  
Vol 60 (1) ◽  
pp. 3-11
Author(s):  
Somayeh FARAHANI ◽  
Reza TALEBI ◽  
Mojdeh MALEKI ◽  
Rahim MEHRABI ◽  
Homayoun KANOUNI
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Mating Type ◽  
Allelic Variation ◽  
Ascochyta Blight ◽  
Ascochyta Rabiei ◽  
Type Distribution ◽  
Western Iran ◽  
Population Structure Analysis ◽  
Geographical Regions

Ascochyta blight (caused by Ascochyta rabiei) is an important disease of chickpea. Mating type distribution, genetic diversity and population structure A. rabiei isolates from western Iran, using specific matting type primers, and ISSR and SSR molecular markers. Two mating types were identified, with the 57% of isolates belonging to MAT1-1. Ten ISSR markers produced 78 polymorphic bands with an average polymorphism information content (PIC) value of 0.33. Seven SSR markers showed high allelic variation (four to seven alleles) with the average PIC value of 0.61. The generated dendrogram using neighbor joining approach with ISSR and SSR marker data grouped isolates in three clusters. Combined dendrogram and model-based population structure analysis divided the isolates into two distinct populations. No significant correlation was found between geographical origins of isolates and their genetic diversity patterns, although the isolates from North Kermanshah and Kurdistan were closely grouped, and most of isolates from Lorestan and Kermanshah were clustered in a separate group. This relative spatial correlation between geographical locations and A. rabiei grouping indicated high genetic diversity within populations and no significant gene flow between distinctly geographical regions. This suggests the nece0ssity of continuous monitoring of A. rabiei populations in order to design effective chickpea breeding strategies to control the disease.

scholarly journals Genetic Diversity, Population Structure and Marker-Trait Association for 100-Seed Weight in International Safflower Panel Using SilicoDArT Marker Information

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 652 ◽  
Author(s):  
Fawad Ali ◽  
Muhammad Azhar Nadeem ◽  
Muzaffer Barut ◽  
Ephrem Habyarimana ◽  
Hassan Javed Chaudhary ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Seed Weight ◽  
Mixed Linear Model ◽  
Oilseed Crop ◽  
Trait Association ◽  
Information Index ◽  
Expected Heterozygosity ◽  
Two Populations ◽  
100 Seed Weight

Safflower is an important oilseed crop mainly grown in the arid and semi-arid regions of the world. The aim of this study was to explore phenotypic and genetic diversity, population structure, and marker-trait association for 100-seed weight in 94 safflower accessions originating from 26 countries using silicoDArT markers. Analysis of variance revealed statistically significant genotypic effects (p < 0.01), while Turkey samples resulted in higher 100-seed weight compared to Pakistan samples. A Constellation plot divided the studied germplasm into two populations on the basis of their 100-seed weight. Various mean genetic diversity parameters including observed number of alleles (1.99), effective number of alleles (1.54), Shannon’s information index (0.48), expected heterozygosity (0.32), and unbiased expected heterozygosity (0.32) for the entire population exhibited sufficient genetic diversity using 12232 silicoDArT markers. Analysis of molecular variance (AMOVA) revealed that most of the variations (91%) in world safflower panel are due to differences within country groups. A model-based structure grouped the 94 safflower accessions into populations A, B, C and an admixture population upon membership coefficient. Neighbor joining analysis grouped the safflower accessions into two populations (A and B). Principal coordinate analysis (PCoA) also clustered the safflower accessions on the basis of geographical origin. Three accessions; Egypt-5, Egypt-2, and India-2 revealed the highest genetic distance and hence might be recommended as candidate parental lines for safflower breeding programs. The mixed linear model i.e., the Q + K model, demonstrated that two DArTseq markers (DArT-45483051 and DArT-15672391) had significant association (p < 0.01) for 100-seed weight. We envisage that identified DArTseq markers associated with 100-seed weight will be helpful to develop high-yielding cultivars of safflower through marker-assisted breeding in the near future.

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