Advances and new insights in naturally colored cotton breeding and research

Cotton is the world's most important fiber crop, and naturally colored cotton (NCC) is an important kind of environmental friendly material. The NCC described here refers to that the cotton fiber itself can synthesize pigments and present colors. NCC has gone through domestication and traditional breeding era in history. Due to the bottlenecks faced by NCC such as low fiber yield, poor quality, narrow color spectrum and unstable color, coupled with the advent of the industrialization era, the practical application of NCC has entered into a trough period. However, NCC has the advantages of environmentally friendly, antimicrobial and flame retardant, and researchers gradually resume the study of colored cotton from the breeding and physiological and biochemical perspectives. Especially with the arrival of the era of cotton functional genome, important research progresses have been made in the genetic study and genetic engineering of NCC. This study was focused on the metabolic pathways, genetic regulatory models and research highlights of NCC, which will provide new ideas for molecular design breeding of NCC, and realize the creation of high-yield, fine-quality and color-diverse NCC.