A comparative study of transgenic cotton development, impacts, challenges and prospects with respect to China and Africa

Abstract

Cotton is grown in about 101 countries with about 10 countries including China contributing highest quantity. Africa contributes less than 5% to the global demand for cotton. Processing of cotton generate so many businesses for the rural people of China and Africa. Like other cotton producing continents, the majorly cultivated species of cotton in China and Africa is Gossypium hirsutisms Gh (Upland Cotton) and is mostly grown by the smallholder farmers using crop rotation with few large plantations. China and Africa climate condition encourage pest growth which brings about pest attack on cotton followed by yield losses. Effort towards solving this problem was based on integration of transgenic cotton into cotton farming. It has been found that Bacillus thuringiensis strains produce crystal (Cry) and cytolytic (Cyt) toxins at the beginning of sporulation and during the stationary growth phase. These crystals are aggregate of proteins encoded by Cry genes and they have insecticidal properties. The Bt Cry genes have been isolated and used to transform cotton seed thus, the term Bt cotton/transgenic cotton which now have in built Cry gene to resist insect attack. In cotton, Bt gene is mostly expressed in the green parts of plant compared to the non-green parts and in the young plants compared to the older plants. This work therefore focused on cotton farming, the Bt crystal, Bt gene, methods of transformation of cotton with Bt gene, Bt gene expression level, resistances, mode of action, limitations and possible recommendations with respect to its use in China and Africa.