DefinePK

Abstract

Since its first use in 6000 BC, cotton (genus Gossypium) has become a major natural textile in the global market. Modern tools such as web databases, microsatellite databases, and comparative QTL resources have been developed to evaluate the consequences of human dispersal and selection on different strains of Gossypium. Out of the fifty species of Gossypium, only four have been domesticated, leading to significant changes in lint percentage (40%), fibre length (22%), and boll size. The biggest challenge with domestication is the lack of genetic variety. This is particularly evident in Gossypium hirsutum L. upland cotton cultivars compared to Pima and Egyptian cotton cultivars of Gossypium barbadense. The latter possess a higher degree of genetic diversity due to the introduction of G. hirsutum genes into G. barbadense cultivars. Including genes from all types of Gossypium in cultivated cotton species is very important. The use of genome-wide markers such as Simple Sequence Repeat (SSR), Restriction Fragment Length Polymorphism (RFLP), Amplified Fragment Length Polymorphism (AFLP), and Random Amplified Polymorphic DNA (RAPD) enabled the discovery of 16,162 public SSRs and 312 mapped RFLP sequences. These markers were further employed to study various plant traits reported in 26 mapping populations. These included qualitative traits such as fiber quality, yield, leaf and flower shape, trichome density and placement, disease protection, and quantitative traits such as quantitative trait loci (QTLs). After a suitable comparison of the mapped populations, 432 QTLs were associated with 3,475 loci within 11 mapping groups. Furthermore, a meta-analysis of over 1,000 QTLs derived from backcross and hybrid inbred line populations with the same parents revealed the most accurate meta-clusters for fiber color, fineness, and length. The cotton genome has undergone enrichment by incorporating genes obtained from distantly related organisms via diverse transformation techniques.