scholarly journals Linkage disequilibrium patterns, population structure and diversity analysis in a worldwide durum wheat collection including Argentinian genotypes

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Pablo Federico Roncallo ◽  
Adelina Olga Larsen ◽  
Ana Laura Achilli ◽  
Carolina Saint Pierre ◽  
Cristian Andrés Gallo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Linkage Disequilibrium ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Snp Array ◽  
Low Frequency ◽  
Germplasm Collection ◽  
Climate Change Scenarios ◽  
Allelic Variants

Abstract Background Durum wheat (Triticum turgidum L. ssp. durum Desf. Husn) is the main staple crop used to make pasta products worldwide. Under the current climate change scenarios, genetic variability within a crop plays a crucial role in the successful release of new varieties with high yields and wide crop adaptation. In this study we evaluated a durum wheat collection consisting of 197 genotypes that mainly comprised a historical set of Argentinian germplasm but also included worldwide accessions. Results We assessed the genetic diversity, population structure and linkage disequilibrium (LD) patterns in this collection using a 35 K SNP array. The level of polymorphism was considered, taking account of the frequent and rare allelic variants. A total of 1547 polymorphic SNPs was located within annotated genes. Genetic diversity in the germplasm collection increased slightly from 1915 to 2010. However, a reduction in genetic diversity using SNPs with rare allelic variants was observed after 1979. However, larger numbers of rare private alleles were observed in the 2000–2009 period, indicating that a high reservoir of rare alleles is still present among the recent germplasm in a very low frequency. The percentage of pairwise loci in LD in the durum genome was low (13.4%) in our collection. Overall LD and the high (r2 > 0.7) or complete (r2 = 1) LD presented different patterns in the chromosomes. The LD increased over three main breeding periods (1915–1979, 1980–1999 and 2000–2020). Conclusions Our results suggest that breeding and selection have impacted differently on the A and B genomes, particularly on chromosome 6A and 2A. The collection was structured in five sub-populations and modern Argentinian accessions (cluster Q4) which were clearly differentiated. Our study contributes to the understanding of the complexity of Argentinian durum wheat germplasm and to derive future breeding strategies enhancing the use of genetic diversity in a more efficient and targeted way.

scholarly journals Genetic variation and population structure in China summer maize germplasm

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guoping Shu ◽  
Gangqiang Cao ◽  
Niannian Li ◽  
Aifang Wang ◽  
Fang Wei ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Linkage Disequilibrium ◽  
Germplasm Collection ◽  
Genotyping By Sequencing ◽  
Inbred Lines ◽  
Summer Maize ◽  
Heterotic Groups ◽  
Breeding Germplasm

AbstractMaize (Zea mays L.) germplasm in China Summer maize ecological region (CSM) or central corn-belt of China is diverse but has not been systematically characterized at molecular level. In this study, genetic variation, genome diversity, linkage disequilibrium patterns, population structure, and characteristics of different heterotic groups were studied using 525,141 SNPs obtained by Genotyping-By-Sequencing (GBS) for 490 inbred lines collected from researchers at CSM region. The SNP density is lower near centromere, but higher near telomere region of maize chromosome, the degree of linkage disequilibrium (r2) vary at different chromosome regions. Majority of the inbred lines (66.05%) show pairwise relative kinship near zero, indicating a large genetic diversity in the CSM breeding germplasm. Using 4849 tagSNPs derived from 3618 haplotype blocks, the 490 inbred lines were delineated into 3 supergroups, 6 groups, and 10 subgroups using ADMIXTURE software. A procedure of assigning inbred lines into heterotic groups using genomic data and tag-SNPs was developed and validated. Genome differentiation among different subgroups measured by Fst, and the genetic diversity within each subgroup measured by GD are both large. The share of heterotic groups that have significant North American germplasm contribution: P, SS, IDT, and X, accounts about 54% of the CSM breeding germplasm collection and has increased significantly in the last two decades. Two predominant types of heterotic pattern in CSM region are: M-Reid group × TSPT group, and X subgroup × Local subgroups.

scholarly journals Genetic diversity and linkage disequilibrium using SNP (KASP) and AFLP markers in a worldwide durum wheat (Triticum turgidum L. var durum) collection

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218562 ◽  
Author(s):  
Pablo Federico Roncallo ◽  
Valeria Beaufort ◽  
Adelina Olga Larsen ◽  
Susanne Dreisigacker ◽  
Viviana Echenique
Keyword(s):  
Genetic Diversity ◽  
Linkage Disequilibrium ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Aflp Markers

scholarly journals The Global Durum Wheat Panel (GDP): An International Platform to Identify and Exchange Beneficial Alleles

2020 ◽  
Vol 11 ◽  
Author(s):  
Elisabetta Mazzucotelli ◽  
Giuseppe Sciara ◽  
Anna M. Mastrangelo ◽  
Francesca Desiderio ◽  
Steven S. Xu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Snp Array ◽  
Tetraploid Wheat ◽  
Breeding Program ◽  
Fixation Index ◽  
Breeding Programs ◽  
Genetic Clusters ◽  
Modern Breeding

Representative, broad and diverse collections are a primary resource to dissect genetic diversity and meet pre-breeding and breeding goals through the identification of beneficial alleles for target traits. From 2,500 tetraploid wheat accessions obtained through an international collaborative effort, a Global Durum wheat Panel (GDP) of 1,011 genotypes was assembled that captured 94–97% of the original diversity. The GDP consists of a wide representation of Triticum turgidum ssp. durum modern germplasm and landraces, along with a selection of emmer and primitive tetraploid wheats to maximize diversity. GDP accessions were genotyped using the wheat iSelect 90K SNP array. Among modern durum accessions, breeding programs from Italy, France and Central Asia provided the highest level of genetic diversity, with only a moderate decrease in genetic diversity observed across nearly 50 years of breeding (1970–2018). Further, the breeding programs from Europe had the largest sets of unique alleles. LD was lower in the landraces (0.4 Mbp) than in modern germplasm (1.8 Mbp) at r2 = 0.5. ADMIXTURE analysis of modern germplasm defined a minimum of 13 distinct genetic clusters (k), which could be traced to the breeding program of origin. Chromosome regions putatively subjected to strong selection pressure were identified from fixation index (Fst) and diversity reduction index (DRI) metrics in pairwise comparisons among decades of release and breeding programs. Clusters of putative selection sweeps (PSW) were identified as co-localized with major loci controlling phenology (Ppd and Vrn), plant height (Rht) and quality (gliadins and glutenins), underlining the role of the corresponding genes as driving elements in modern breeding. Public seed availability and deep genetic characterization of the GDP make this collection a unique and ideal resource to identify and map useful genetic diversity at loci of interest to any breeding program.

scholarly journals Genetic diversity and population structure of ridge gourd (Luffa acutangula) accessions in a Thailand collection using SNP markers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Grimar Abdiel Perez ◽  
Pumipat Tongyoo ◽  
Julapark Chunwongse ◽  
Hans de Jong ◽  
Anucha Wongpraneekul ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Germplasm Collection ◽  
Snp Markers ◽  
Fixation Index ◽  
Breeding Programs ◽  
Total Fixation ◽  
Unrooted Phylogenetic Tree ◽  
Luffa Acutangula ◽  
Selection Of

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.

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 Genotypic Characterization of the U.S. Peanut Core Collection

2020 ◽  
Vol 10 (11) ◽  
pp. 4013-4026
Author(s):  
Paul I. Otyama ◽  
Roshan Kulkarni ◽  
Kelly Chamberlin ◽  
Peggy Ozias-Akins ◽  
Ye Chu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Core Collection ◽  
Regional Distribution ◽  
Country Of Origin ◽  
Snp Array ◽  
Germplasm Collection ◽  
Genotypic Diversity ◽  
Cultivated Peanut ◽  
Food And Feed ◽  
Genetic Clustering

Cultivated peanut (Arachis hypogaea) is an important oil, food, and feed crop worldwide. The USDA peanut germplasm collection currently contains 8,982 accessions. In the 1990s, 812 accessions were selected as a core collection on the basis of phenotype and country of origin. The present study reports genotyping results for the entire available core collection. Each accession was genotyped with the Arachis_Axiom2 SNP array, yielding 14,430 high-quality, informative SNPs across the collection. Additionally, a subset of 253 accessions was replicated, using between two and five seeds per accession, to assess heterogeneity within these accessions. The genotypic diversity of the core is mostly captured in five genotypic clusters, which have some correspondence with botanical variety and market type. There is little genetic clustering by country of origin, reflecting peanut’s rapid global dispersion in the 18th and 19th centuries. A genetic cluster associated with the hypogaea/aequatoriana/peruviana varieties, with accessions coming primarily from Bolivia, Peru, and Ecuador, is consistent with these having been the earliest landraces. The genetics, phenotypic characteristics, and biogeography are all consistent with previous reports of tetraploid peanut originating in Southeast Bolivia. Analysis of the genotype data indicates an early genetic radiation, followed by regional distribution of major genetic classes through South America, and then a global dissemination that retains much of the early genetic diversity in peanut. Comparison of the genotypic data relative to alleles from the diploid progenitors also indicates that subgenome exchanges, both large and small, have been major contributors to the genetic diversity in peanut.

scholarly journals Evaluation of linkage disequilibrium, population structure, and genetic diversity in the U.S. peanut mini core collection

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Paul I. Otyama ◽  
Andrew Wilkey ◽  
Roshan Kulkarni ◽  
Teshale Assefa ◽  
Ye Chu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Linkage Disequilibrium ◽  
Core Collection ◽  
Mini Core Collection ◽  
The U.S
Sign in / Sign up

Export Citation Format

Share Document