Articles written in Journal of Genetics
Volume 91 Issue 1 April 2011 pp 111-117 Review Article
Most traits of interest to medical, agricultural and animal scientists show continuous variation and complex mode of inheritance. DNA-based markers are being deployed to analyse such complex traits, that are known as quantitative trait loci (QTL). In conventional QTL analysis, F2, backcross populations, recombinant inbred lines, backcross inbred lines and double haploids from biparental crosses are commonly used. Introgression lines and near isogenic lines are also being used for QTL analysis. However, such populations have major limitations like predominantly relying on the recombination events taking place in the F1 generation and mapping of only the allelic pairs present in the two parents. The second generation mapping resources like association mapping, nested association mapping and multiparent intercross populations potentially address the major limitations of available mapping resources. The potential of multiparent intercross populations in gene mapping has been discussed here. In such populations both linkage and association analysis can be conductted without encountering the limitations of structured populations. In such populations, larger genetic variation in the germplasm is accessed and various allelic and cytoplasmic interactions are assessed. For all practical purposes, across crop species, use of eight founders and a fixed population of 1000 individuals are most appropriate. Limitations with multiparent intercross populations are that they require longer time and more resource to be generated and they are likely to show extensive segregation for developmental traits, limiting their use in the analysis of complex traits. However, multiparent intercross population resources are likely to bring a paradigm shift towards QTL analysis in plant species.
Volume 100 All articles Published: 2 June 2021 Article ID 0038
High-throughput genotyping has become more convenient and cost-effective due to recent advancements in next-generation sequencing (NGS) techniques. Numerous approaches exploring sequencing advances for genotyping have been developed over the past decade, which includes different variants of genotyping-by-sequencing (GBS), and restriction-site associated DNA sequencing (RAD-seq). Most of these methods are based on the reduced representation of the genome, which ultimately reduces the cost of sequencing by many folds. However, continuously lowering the cost of sequencing makes it more convenient to use whole genome-based approaches. In this regard, skim sequencing, where low coverage whole-genome sequencing is used for the identification of large numbers of polymorphic markers cost-effectively. In the present review, we have discussed recent technological advancements, applicability, and challenges of skim sequencing-based genotypic approaches for crop improvement programmes. Skim sequencing is being extensively used for genotyping indiverse plant species and has a wide range of applications, particularly in quantitative trait loci (QTL) mapping, genomewide association studies (GWAS), fine genetic map construction, and identification of recombination and gene conversion events in various breeding programmes. The cost-effectiveness, simplicity, and genomewide coverage will increase the application of skims sequencing-based genotyping. The article summarizes the protocol, uses, bioinformatics tools, its application, and future prospects of skim sequencing in crop improvement.
Volume 100, 2021
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