Current status of genetic engineering in cotton (Gossypium hirsutum L): an assessment

Cotton is considered as the foremost commercially important fiber crop and is deemed as the backbone of the textile industry. The productivity of cotton crop, worldwide, is severely hampered by the occurrence of pests, weeds, pathogens apart from various environmental factors. Several beneficial agronomic traits, viz., early maturity, improved fiber quality, heat tolerance, etc. have been successfully incorporated into cotton varieties employing conventional hybridization and mutation breeding. Crop losses, due to biotic factors, are substantial and may be reduced through certain crop protection strategies. In recent years, pioneering success has been achieved through the adoption of modern biotechnological approaches. Genetically engineered cotton varieties, expressing Bacillus thuringiensis cry genes, proved to be highly successful in controlling the bollworm complex. Various other candidate genes responsible for resistance to insect pests and pathogens, tolerance to major abiotic stress factors such as temperature, drought and salinity, have been introduced into cotton via genetic engineering methods to enhance the agronomic performance of cotton cultivars. Furthermore, genes for improving the seed oil quality and fiber characteristics have been identified and introduced into cotton cultivars. This review provides a brief overview of the various advancements made in cotton through genetic engineering approaches.