Advances in the application of molecular markers for the genetic improvement and breeding of fruit crops: A comprehensive review

Molecular marker technologies have transformed the breeding of fruit crops by making it possible to select accurately, characterize the genome, and genetically enhance. Advances in genomics resources and technology have facilitated development and application of molecular markers such as RFLPs, RAPDs, SNPs, and SSRs to effectively identify better genotypes, evaluate genetic diversity, map quantitative trait loci (QTLs), and expedite marker-aided selection (MAS). Fruit crops are challenging owing to their long juvenility, heterozygous nature of fruit breeders, and polygenic nature of most of the economical characters. Up to now, there have been two major challenges in this regard. A detailed review of the recent progress in application of molecular markers for genetic improvement of fruit crops with respect to marker development, functional genomics, QTL mapping, genome-wide association studies (GWAS) and genomic selection (GS) is presented. Results–Selected case studies in major fruit crops including mango, apple, citrus, grape, and banana are discussed, emphasizing their success stories in addressing key traits of yield, quality, and stress tolerance.