A review of genetic mechanisms of early maturity in cotton (Gossypium hirsutum L.)

Abstract

Early maturity is an important target of cotton (Gossypium hirsutum L.) breeding programs. The selection and popularization of early-maturing cotton cultivars have significantly alleviated the problem of optimizing farmland cropping systems when planting cotton and cereals. However, breeding early-maturity cotton with high yields and high-quality crops is sharply constrained by the genetic complexity of the early-maturity trait. Despite the use of modern biotechnological tools, the exact genetic mechanisms underlying early maturity are still not fully understood. Here, we systematically summarize the progress made in understanding the genetic mechanisms responsible for early maturity using the classical quantitative inheritance model, the major gene–polygene mixed inheritance model, quantitative trait locus (QTL) mapping, gene cloning and functional analyses. We also discuss the phenotypic selection strategy in breeding early-maturing cotton cultivars, the application of related QTLs and functional genomic research. We suggest selecting for early-maturity indicators, especially flower and boll period, in early generations but selecting yield percentage before frost continuously among generations. The stable QTLs and related markers involved in early maturity can be used efficiently in breeding programs, and QTL fine-mapping, interaction and omics studies should be performed, along with the mining and in-depth functional analyses of novel genes. Such research will offer new perspectives on the practical breeding and functional genomics of early-maturity cotton.