Genotype by Sequencing Method and Its Application for Crop Improvement (A Review)

Genotype by sequencing (GBS) is a next generation sequencing based method that takes advantage of reduced representation to enable genotyping of large numbers of individuals at a large number of SNP markers. It is relatively straightforward, robust, and cost-effective method to reduce problems in crop caused by a large genome size, reduced representation libraries are produced using a restriction enzyme that targets genomic regions while multiplexing with barcodes reduces the cost for individual sample. Several types of molecular markers, such as single nucleotide polymorphism (SNP), have been identified and effectively used in plant breeding. The application of next-generation sequencing (NGS) technologies has led to remarkable advances in whole genome sequencing, which provides ultra- throughput sequences to revolutionize plant genotyping and breeding. The GBS approach includes the digestion of genomic DNA with restriction enzymes followed by the ligation of barcode adapter, PCR amplification and sequencing of the amplified DNA pool on a single lane of flow cells. GBS has been successfully used in implementing genome-wide association study (GWAS), genomic diversity study, QTL mapping, genetic linkage analysis, molecular marker discovery and genomic selection under a large scale of plant breeding programs. GBS will have broad application in genomics-assisted plant breeding programs