and Pakistan. Although cultivated since antiquity, it was the invention of the cotton gin that so lowered the cost of production that led to its widespread use, and it is the most widely used natural fiber cloth in clothing today.
There are four commercially-grown species of cotton, including Gossypium hirsutum, also known as upland cotton, which makes up 90% of the world production of cotton. Current estimates for world production are about 25 million tons annually, accounting for 2.5% of the world's arable land. China is the world's largest producer of cotton, but most of this is used domestically. The United States has been the largest exporter for many years.
There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis andgenetic worth.
The goal of a commercial cotton breeding program is to develop new, unique, and superior cotton cultivars. The breeder initially selects and crosses two or more parental lines, followed by generation advancement and selection, thus producing many new genetic combinations. The breeder can theoretically generate billions of different genetic combinations via this procedure. The breeder has no direct control over which genetic combinations will arise in the limited population size which is grown. Therefore, two breeders will never develop the same line having the same traits.
Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic, and soil conditions, and further selections are then made, during and at the end of the growing season.