Genes and markers: Application in banana crop improvement

Abstract

Banana is one of the most economically important horticultural crops. Its improvement is a big challenge to breeders due to complex genomic nature and lack of advanced knowledge of its genetics. In the recent years, banana scientists around the globe have made considerable progress in its improvement through gene identification and subsequently its transformation into cultivars and have developed trait-linked markers to speed up the selection process in the cross-breeding program. Two genomes of the diploid banana Musa acuminata (A genome) and Musa balbisiana (B genome) have been sequenced and made publicly available. This facilitated the identification of agronomically important trait-linked genes and studies on their function, mode of inheritance, evolution and development of gene-linked markers, the landmark of the gene on the chromosome. Identification and characterization of important genes is the key to any breeding program. In bananas, several genes associated with disease resistance and fruit quality have been isolated, and their molecular characterization reported. Several molecular markers have been developed, including RAPD, ISSR, AFLP, DArT, and SSR, for the genomic group identification, estimation of genetic stability of somaclonal variation, disease-resistant cultivar identification, etc,. This chapter summarizes the progress of the application of agronomically important gene and molecular markers in banana breeding programs around the world.