Bridging molecular genetics and genomics for cotton fiber quality improvement

AbstractUpland cotton (Gossypium hirsutum L.) is the main source of natural fiber for the textile industry. Cotton fibers are unicellular trichomes that emerge from the epidermal cells of the seed. In cultivated cotton species, seed trichomes differentiate into two distinct types, spinnable lint, and short fuzz. The main priority for cotton growers is fiber yield, whereas the textile industry also demands better fiber quality characteristics, such as length, uniformity, strength, maturity, and optimal fineness. However, it is a major challenge for breeders to improve fiber quality while maintaining yield, because of the observed negative correlation between yield and fiber quality traits. Recent technical advances in sequencing and bioinformatics have facilitated the assembly of reference quality genomes of multiple cotton species, bringing a new era for cotton genomics. Available genomic resources will help genetically dissect the agronomic and fiber quality traits of cotton and identify gene variants that can be used for cotton improvement through breeding or biotechnology. Here, we review recent progress in the sequencing of genomes of cotton species and approaches in molecular genetics and genomics for the improvement of cotton fiber quality traits. We discuss progress in the understanding of each stage of cotton fiber development and the remaining challenges.