Vol. 11, Issue 7 (2022)

Author(s):
Shikha Jain, Shikha Saini, Koppula Satya Sai Kumar, Shubham Jagga, Poonam Maurya, Vinay Kumar and Bhargav Kiran

Abstract:
The domesticated apple (Malus × domestica Borkh.) is the main fruit crop of temperate regions of the world. The genetic improvement of apple can be done through various techniques including introduction, selection, hybridization, mutation and molecular techniques (genomics). Genetic improvement of fruit quality includes external fruit appearance, such as color, shape, and size, as well as internal traits such as aroma, texture, crispiness, and juiciness. Over the past ten years, apple genomic resources have been created, leading to the sequencing of the "Golden Delicious" genome with a genome size of 742.3Mbp. The creation of public databases such as the GDR (Genome Database for Rosaceae), NCBI, and the European HIDRAS Apple Breed offer excellent opportunities for improved collaboration between breeders and bioinformatics researchers. Genomics studies include structural, functional and comparative genomics. Although structural genomics was mainly based on microscopic research of chromosomes, it has now become a driving force in apple breeding research since the development of DNA marker technologies at the end of the 20^th to the beginning of the 21st centuries. Apple now has access to a wide range of genomic materials, including whole genome sequences, various ESTs, numerous molecular markers, and high-density genetic maps. These resources have been used for sequencing, Quantitative Trait Loci (QTL) mapping, and marker assisted selection (MAS). The availability of whole genome sequence has provided new opportunities to explore the genetic basis of fruit quality traits.