| Literature DB >> 30325667 |
Michael Halewood1, Isabel Lopez Noriega1, Dave Ellis2, Carolina Roa3, Mathieu Rouard4, Ruaraidh Sackville Hamilton5.
Abstract
This article describes how CGIAR centers and partners are using genomic sequence information to promote the conservation and sustainable use of crop genetic diversity, and to generate and share benefits derived from those uses. The article highlights combined institutional, and benefit-sharing-related challenges that need to be addressed to support expanded use of digital sequence information in agricultural research and development.Entities:
Keywords: benefit-sharing; conservation; genomic sequence information; sustainable use
Mesh:
Substances:
Year: 2018 PMID: 30325667 PMCID: PMC6204560 DOI: 10.1089/bio.2018.0043
Source DB: PubMed Journal: Biopreserv Biobank ISSN: 1947-5543 Impact factor: 2.300
Molecular Markers for Diversity Characterization and Breeding Applications
| RFLPs | Different sizes of alleles associated with restriction fragments generated by enzymes (endonucleases) | Medium | Genetics, e.g., to find where a specific gene lies on a chromosome; gene flow; phylogenetic studies | First applied DNA marker for genotyping; useful in construction of genetic linkage maps | Requires |
| RAPDs | Different sizes of alleles based on length of short primers complementary to randomly targeted DNA in multiple locations | High | Diversity, e.g., closely related species; gene mapping | Cheap; technically and time-wise low demanding; produces large no. of bands that can be characterized individually | Low reproducibility; mainly dominant; difficult to analyze; difficult to automate; cross-study comparisons are difficult |
| AFLPs | Differences in length of selectively amplified restriction fragments generated by endonucleases | High | Diversity and genetics, e.g., population structure studies; evaluation and characterization of animal and plant resources | Large numbers of markers can be generated | Low reproducibility |
| SSRs | Simple sequence repeats in tandem from 1–6 nucleotides in length | High | Diversity, genetics, and breeding, e.g., to distinguish closely related genotypes (population studies); linkage disequilibrium studies (i.e., association of a disease-causing locus and a marker) | Highly informative (large no. of alleles, high heterozygosity); codominant; easy to isolate; low ascertainment bias | High mutation rate; complex mutation behavior; not abundant enough; difficult to automate; cross-study comparisons require special preparation |
| SNPs | Single nucleotide mutation at a specific place (locus) in a DNA sequence | High | Diversity, genetics, and breeding, e.g., genetic variation in different species and breeds | Low mutation rate; high abundance; easy to type; high potential for automation; cross-study comparisons easy | Substantial heterogeneity rate among sites; expensive to isolate; low information content of a single SNP |
| GBS | Sequences of the ends of all resulting DNA restriction fragments produced by a frequent cutter enzyme; generates large no. of SNPs | High | Genetic map construction; SNP genotyping in a variety of species and populations useful for breeding, plant genetics, and germplasm characterization | Useful for high diversity and large genome species; cost-effective for genomic-assisted breeding; high automation; technically easier to use and less demanding than RADseq | Management and analysis of large amount of data; proprietary technology |
| DArTseq | Works on a genome complexity reduction concept—selection of genome with predominantly active genes (target low copy sequences) | High | High-resolution mapping and detailed genetic dissection of traits; phylogeography (in animals); genetic relatedness of species; species origin studies | Reduction complexity methods are simple and cheaper than other GBS-based methods; high reproducibility; high heterozygotes representation | Management and analysis of large amount of data; single source for proprietary technology |
| RADseq | Sequences of short regions (50–150 bases) flanking each and all restriction sites for a given endonuclease | High (uncovers 100 s–1000 s polymorphic genetic markers in a subset of genome) | Population differentiation and selection studies; phylogeography; ecological and evolutionary genomics; linkage mapping | Relatively low cost (greater no. of samples) and simple; greater coverage per locus; no prior genomic information required | Bias due to allele dropout, PCR duplicates, and variance in depth of coverage among loci (all of the former vary according the RADseq method used) |
AFLP, amplified fragment length polymorphism; DArTseq, diversity arrays technology sequencing; GBS, genotyping by sequencing; RADseq, restriction site-associated DNA sequencing; RAPD, randomly amplified polymorphic DNA; RFLP, restriction fragment length polymorphism; SNP, single nucleotide polymorphism; SSR, simple sequence repeat.

Dendogram of the CIP diversity reference core set of landrace cultivated potato (Papa nativa) based on genetic data from the SolCAP 12K SNP array. Colored lines in the dendogram denote different potato species. Bar below the dendogram denotes ploidy level (CIP data, unpublished). CIP, International Potato Center; SNP, single nucleotide polymorphism.

Three-dimensional PCA graph showing the distribution of Mexican wheat landrace groups based on genetic markers. There were a total of 15 groups—each represented by a different color—that correspond to different Mexican states. PC1, PC2, and PC3 contribute 10.5%, 8.2% and 6.9% of the total variation, respectively. Source: Vikram et al.[25] PCA, principal component analysis.

Overview of the SNP-Seek Database[d] that enables queries concerning 3024 sequenced rice accessions, and the MGIS information system[e] that facilitates exploration of allelic gene diversity in a panel of banana (Musa spp.) accessions.