Overview on domestication, breeding, genetic gain and improvement of tuber quality traits of potato using fast forwarding technique (GWAS): A review

Tuber quality is the subject of great interest among the processing industry and consumers worldwide. Being a polygenic trait, its enhancement requires a systematic understanding of their genetic complexity. Molecular genetics offered valuable solutions to the challenging endeavours of slow genetic gains in conventional potato breeding. With the advent of linkage maps, molecular markers and availability of next-generation sequencing (NGS) platforms, the plant breeding programmes worldwide have achieved faster genetic gain due to marker-assisted selection (MAS). Linkage mapping detects QTLs in biparental population; alternatively, genomic and phenotypic differences can be identified by extensive genotyping and phenotyping of a germplasm panel depicting natural biological diversity to reveal QTLs, in other words, marker-trait associations. Due to advancements in the fields of genome sequencing and bioinformatics, researchers have preferred to use the genome-wide association mapping (GWAS) method for detecting QTLs due to its higher resolution. In potato, GWAS identified causative allele(s)/loci and provides reliable platform for the development of diagnostic SNP markers by employing Infinium SolCAP SNP array. Later, KASP validation markers can be developed to be used as selection markers in order to bred improved cultivars. The current review focuses on recently used approaches for genetic analyses (linkage mapping or association mapping) regarding potato tuber quality traits, provides comprehensive knowledge about breeding, genetic gain, basic genetic and statistical GWAS concepts and subsequently highlights the genetic discoveries using GWAS and KASP markers.