scholarly journals Teak genetic diversity in Ghana shows a narrow base for further breeding and a need for improved international collaboration for provenance exchange.

2021 ◽  
Vol 2 (4) ◽  
pp. 44-54
Author(s):  
Tieme H V Wanders ◽  
James N Ofori ◽  
Alexander Amoako ◽  
Maarten Postuma ◽  
Cornelis A M Wagemaker ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
South America ◽  
International Collaboration ◽  
Genetic Basis ◽  
Genotyping By Sequencing ◽  
Provenance Trial ◽  
Forest Reserve ◽  
Nagoya Protocol ◽  
Narrow Base

We evaluated the genetic diversity of teak provenances at a newly established provenance trial with 52 provenances collected from Africa, South America and Asia in Tain II Forest Reserve in Central Ghana. This provenance collection / trial was established to widen the genetic basis for Teak establishment in West Africa. Using Genotyping by Sequencing (GBS) we analysed the genetic diversity of these provenances.  Results of the study revealed that, although acquired from  a wide geographical range, most  Teak provenances in the trial belong to only two distinct groups that are closely related. The implication of this finding is that, for breeding, a wider range of provenances are needed from the original Teak distribution areas and more specifically from Southern India. We conclude that urgent protection of older existing sources of genetic variation in Teak  as well as an improvement  of international collaboration under the Nagoya protocol with countries with  native teak populations is necessary.

scholarly journals Comparing the Effectiveness of Exome Capture Probes, Genotyping by Sequencing and Whole-Genome Re-Sequencing for Assessing Genetic Diversity in Natural and Managed Stands of Picea abies

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1185
Author(s):  
Helena Eklöf ◽  
Carolina Bernhardsson ◽  
Pär K. Ingvarsson
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Picea Abies ◽  
Norway Spruce ◽  
Large Scale ◽  
Genotyping By Sequencing ◽  
Complexity Reduction ◽  
Exome Capture ◽  
Genome Wide ◽  
Targeted Capture

Conifer genomes are characterized by their large size and high abundance of repetitive material, making large-scale genotyping in conifers complicated and expensive. One of the consequences of this is that it has been difficult to generate data on genome-wide levels of genetic variation. To date, researchers have mainly employed various complexity reduction techniques to assess genetic variation across the genome in different conifer species. These methods tend to capture variation in a relatively small subset of a typical conifer genome and it is currently not clear how representative such results are. Here we take advantage of data generated in the first large-scale re-sequencing effort in Norway spruce and assess how well two commonly used complexity reduction methods, targeted capture probes and genotyping by sequencing perform in capturing genome-wide variation in Norway spruce. Our results suggest that both methods perform reasonably well for assessing genetic diversity and population structure in Norway spruce (Picea abies (L.) H. Karst.). Targeted capture probes were slightly more effective than GBS, likely due to them targeting known genomic regions whereas the GBS data contains a substantially greater fraction of repetitive regions, which sometimes can be problematic for assessing genetic diversity. In conclusion, both methods are useful for genotyping large numbers of samples and they greatly reduce the cost involved with genotyping a species with such a complex genome as Norway spruce.

scholarly journals Genotyping-by-sequencing reveals the effects of riverscape, climate and interspecific introgression on the genetic diversity and local adaptation of the endangered Mexican golden trout (Oncorhynchus chrysogaster)

2018 ◽  
Author(s):  
Marco A. Escalante ◽  
Charles Perrier ◽  
Francisco J. García-De León ◽  
Arturo Ruiz-Luna ◽  
Enrique Ortega-Abboud ◽  
...  
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Genetic Variation ◽  
Local Adaptation ◽  
Population Genomics ◽  
Landscape Heterogeneity ◽  
Genotyping By Sequencing ◽  
Anthropogenic Factors ◽  
Nucleotide Polymorphisms ◽  
Evolutionary Potential

AbstractHow environmental and anthropogenic factors influence genetic variation and local adaptation is a central issue in evolutionary biology. The Mexican golden trout (Oncorhynchus chrysogaster), one of the southernmost native salmonid species in the world, is susceptible to climate change, habitat perturbations and the competition and hybridization with exotic rainbow trout (O. mykiss). The present study aimed for the first time to use genotyping-by-sequencing to explore the effect of genetic hybridization with O. mykiss and of riverscape and climatic variables on the genetic variation among O. chrysogaster populations. Genotyping-by-sequencing (GBS) was applied to generate 9767 single nucleotide polymorphisms (SNPs), genotyping 272 O. chrysogaster and O. mykiss. Population genomics analyses were combined with landscape ecology approaches into a riverine context (riverscape genetics). The clustering analyses detected seven different genetic groups (six for O. chrysogater and one for aquaculture O. mykiss) and a small amount of admixture between aquaculture and native trout with only two native genetic clusters showing exotic introgression. Latitude and precipitation of the driest month had a significant negative effect on genetic diversity and evidence of isolation by river resistance was detected, suggesting that the landscape heterogeneity was preventing trout dispersal, both for native and exotic individuals. Moreover, several outlier SNPs were identified as potentially implicated in local adaptation to local hydroclimatic variables. Overall, this study suggests that O. chrysogater may require conservation planning given i) exotic introgression from O. mykiss locally threatening O. chrysogater genetic integrity, and ii) putative local adaptation but low genetic diversity and hence probably reduced evolutionary potential especially in a climate change context.

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 Population Structure of Asian and European Common Wheat Accessions Based on Genotyping-By-Sequencing

2019 ◽  
Author(s):  
Xiu Yang ◽  
Ling Xi ◽  
Binwen Tan ◽  
Wei Zhu ◽  
Lili Xu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Common Wheat ◽  
Diversity Index ◽  
Genotyping By Sequencing ◽  
Cost Effective ◽  
Wheat Breeding ◽  
Snp Markers ◽  
Next Generation Sequencing Technology

Abstract Background Availability of information on the genetic diversity and population structure of germplasm facilitates its use in wheat breeding programs. Recently, with the development of next-generation sequencing technology, genotyping-by-sequencing (GBS) has been used as a high-throughput and cost-effective molecular tool for examination of the genetic diversity of wheat breeding lines. In this study, GBS was used to characterize a population of 180 accessions of common wheat originating from Asia and Europe between the latitudes 30° and 45°N.Results In total, 24,767 high-quality single-nucleotide polymorphism (SNP) markers were used for analysis of genetic diversity and population structure. The B genome contained the highest number of SNPs, followed by the A and D genomes. The polymorphism information content ranged from 0.1 to 0.4, with an average of 0.26. The distribution of SNPs markers on the 21 chromosomes ranged from 243 on chromosome 4D to 2,337 on chromosome 3B. Structure and cluster analyses divided the panel of accessions into two subgroups (G1 and G2). G1 principally consisted of European and partial Asian accessions, and G2 comprised mainly accessions from the Middle East and partial Asia. Molecular analysis of variance showed that the genetic variation was greater within groups (99%) than between groups (1%). Comparison of the two subgroups indicated that G1 and G2 contained a high level of genetic diversity. The genetic diversity of G2 was higher as indicated by the Shannon’s information index ( I ) = 0.512, diversity index ( h ) = 0.334, observed heterozygosity ( H o ) = 0.226, and unbiased diversity index (uh) = 0.338.Conclusion The present results will not only help breeders to understand the genetic diversity of wheat germplasm on the Eurasian continent between the latitudes of 30° and 45°N, but also provide valuable information for wheat genetic improvement through introgression of novel genetic variation in this region.

scholarly journals Genomic assessment of white clover and perennial ryegrass genetic resources

2020 ◽  
Vol 82 ◽  
pp. 27-34
Author(s):  
Marty J. Faville ◽  
Andrew G. Griffiths ◽  
Abdul Baten ◽  
Mingshu Cao ◽  
Rachael Ashby ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
New Zealand ◽  
Iberian Peninsula ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Eastern Mediterranean ◽  
Genetic Relationships ◽  
Genotyping By Sequencing ◽  
Phenotypic Characterisation

Forage resources conserved in genebanks, such as the Margot Forde Germplasm Centre (MFGC; PalmerstonNorth), are reservoirs of genetic diversity important for the development of cultivars adapted to abiotic stresses and environmental constraints. Genomic tools, including genotyping-by-sequencing (GBS), can support identification of manageable subsets (core collections) that are genetically representative of these large germplasm collections, for phenotypic characterisation. We used GBS to generate SNP (single nucleotide polymorphism) profiles for 172 white clover (WC) and 357 perennial ryegrass (PRG) MFGC-sourced accessions and estimated genetic relationships amongst accessions. In WC, accessions aligned along an east-west transect from Kazakhstan to Spain, identifying major diversity in Caucasus/Central Asia and Iberian Peninsula. A key feature was the reduced diversity present in New Zealand (NZL) accessions. Similarly, for PRG, most NZL accessions coalesced as one group, distinct from large clusters associated with the Iberian Peninsula, Italy and eastern Mediterranean/Caucasian region. These results emphasise the relatively narrow genetic diversity in NZL WC and PRG, and the broad extent of largely unexploited global diversity. Capturing global genetic variation incore collections will support pre-breeding programmes to mobilise novel genetic variation into New  Zealand-adapted genetic backgrounds, enabling development of cultivars with non-traditional traits including enhancedclimate resilience and environmental performance.

scholarly journals Using Genome-Wide SNP Discovery and Genotyping to Reveal the Main Source of Population Differentiation inNothofagus dombeyi(Mirb.) Oerst. in Chile

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Rodrigo Hasbún ◽  
Jorge González ◽  
Carolina Iturra ◽  
Glenda Fuentes ◽  
Diego Alarcón ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Woody Species ◽  
Genotyping By Sequencing ◽  
Snp Markers ◽  
Nucleotide Polymorphisms ◽  
Evolutionary Forces ◽  
Genome Wide ◽  
Diversity Studies ◽  
Nothofagus Dombeyi

Within a woody plant species, environmental heterogeneity has the potential to influence the distribution of genetic variation among populations through several evolutionary processes. In some species, a relationship between environmental characteristics and the distribution of genotypes can be detected, showing the importance of natural selection as the main source of differentiation.Nothofagus dombeyi(Mirb.) Oerst. (Nothofagaceae) is an endemic tree species occurring both in Chile and in Argentina temperate forests. Postglacial history has been studied with chloroplast DNA and evolutionary forces shaping genetic variation patterns have been analysed with isozymes but fine-scale genetic diversity studies are needed. The study of demographic and selection histories inNothofagus dombeyirequires more informative markers such as single nucleotide polymorphisms (SNP). Genotyping-by-Sequencing tools now allow studying thousands of SNP markers at reasonable prices in nonmodel species. We investigated more than 10 K SNP loci for signatures of local adaptation and showed that interrogation of genomic resources can identify shifts in genetic diversity and putative adaptive signals in this nonmodel woody species.

scholarly journals Contrasting gene flow at different spatial scales revealed by genotyping-by-sequencing in Isocladus armatus, a massively colour polymorphic New Zealand marine isopod

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5462 ◽  
Author(s):  
Sarah J. Wells ◽  
James Dale
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
New Zealand ◽  
Genetic Basis ◽  
Marine Organism ◽  
Spatial Scales ◽  
Genotyping By Sequencing ◽  
Population Connectivity ◽  
Larval Phase ◽  
Island Populations

Understanding how genetic diversity is maintained within populations is central to evolutionary biology. Research on colour polymorphism (CP), which typically has a genetic basis, can shed light on this issue. However, because gene flow can homogenise genetic variation, understanding population connectivity is critical in examining the maintenance of polymorphisms. In this study we assess the utility of genotyping-by-sequencing to resolve gene flow, and provide a preliminary investigation into the genetic basis of CP in Isocladus armatus, an endemic New Zealand marine isopod. Analysis of the genetic variation in 4,000 single nucleotide polymorphisms (SNPs) within and among populations and colour morphs revealed large differences in gene flow across two spatial scales. Marine isopods, which lack a pelagic larval phase, are typically assumed to exhibit greater population structuring than marine invertebrates possessing a biphasic life cycle. However, we found high gene flow rates and no genetic subdivision between two North Island populations situated 8 km apart. This suggests that I. armatus is capable of substantial dispersal along coastlines. In contrast, we identified a strong genetic disjunction between North and South Island populations. This result is similar to those reported in other New Zealand marine species, and is congruent with the presence of a geophysical barrier to dispersal down the east coast of New Zealand. We also found some support for a genetic basis to colouration evidenced by positive FST outlier tests, with two SNPs in particular showing strong association to the expression of a striped morph. Our study provides one of the first population genomic studies of a marine organism in New Zealand, and suggests that genotyping-by-sequencing can be a good alternative to more traditional investigations based on traditional markers such as microsatellites. Our study provides a foundation for further development of a highly tractable system for research on the evolutionary maintenance of CP.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

scholarly journals Genetic Diversity of Purple Passion Fruit, Passiflora edulis f. edulis, Based on Single-Nucleotide Polymorphism Markers Discovered through Genotyping by Sequencing

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 144
Author(s):  
Nohra Castillo Rodríguez ◽  
Xingbo Wu ◽  
María Isabel Chacón ◽  
Luz Marina Melgarejo ◽  
Matthew Wohlgemuth Blair
Keyword(s):  
Genetic Diversity ◽  
Single Nucleotide Polymorphism ◽  
Genotyping By Sequencing ◽  
Passion Fruit ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Passiflora Edulis ◽  
Tropical Fruit ◽  
Commercial Cultivars ◽  
Purple Passion Fruit

Orphan crops, which include many of the tropical fruit species used in the juice industry, lack genomic resources and breeding efforts. Typical of this dilemma is the lack of commercial cultivars of purple passion fruit, Passiflora edulis f. edulis, and of information on the genetic resources of its substantial semiwild gene pool. In this study, we develop single-nucleotide polymorphism (SNP) markers for the species and show that the genetic diversity of this fruit crop has been reduced because of selection for cultivated genotypes compared to the semiwild landraces in its center of diversity. A specific objective of the present study was to determine the genetic diversity of cultivars, genebank accession, and landraces through genotyping by sequencing (GBS) and to conduct molecular evaluation of a broad collection for the species P. edulis from a source country, Colombia. We included control genotypes of yellow passion fruit, P. edulis f. flavicarpa. The goal was to evaluate differences between fruit types and compare landraces and genebank accessions from in situ accessions collected from farmers. In total, 3820 SNPs were identified as informative for this diversity study. However, the majority distinguished yellow and purple passion fruit, with 966 SNPs useful in purple passion fruits alone. In the population structure analysis, purple passion fruits were very distinct from the yellow ones. The results for purple passion fruits alone showed reduced diversity for the commercial cultivars while highlighting the higher diversity found among landraces from wild or semi-wild conditions. These landraces had higher heterozygosity, polymorphism, and overall genetic diversity. The implications for genetics and breeding as well as evolution and ecology of purple passion fruits based on the extant landrace diversity are discussed with consideration of manual or pollinator-assisted hybridization of this species.

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