Gossypium hirsutum
Gossypium hirsutum
Gossypium hirsutum is a plant of the genus cotton (Gossypium ). It is native to tropical America and is now widely grown for the production of cotton fibers.
Description
Gossypium hirsutum is a perennial shrub that reaches a height of 1.5 to 2 m. In cultivation the plant is considered as one year and then 60 to 150 cm high. The shoot axis is green, sometimes reddish crowded, she is busy with simple hairs that fall off over time. The leaves are three-lobed, rarely five-lobed, the uppermost sometimes unlobed. The leaf lobes are broadly triangular and end long drawn out. The sheet is 5 to 10 cm long, the width is slightly greater than the length. The leaf base is cordate, the petiole is 3-10 (14 ) cm long. The petiole and the leaf surface is hairy, the upper surface sparsely. The stipules are 0.5 to 1 cm long, they fall off soon.
The flowers appear singly in the leaf axils. The flower stems are 1 to 1.5 inches long, they are extended to fruit maturity at 2.5 cm. The outer calyx consists of three non- fused bracts. They are 2-4 cm long and 1.5 to 3 cm broad, hairy, heart-shaped front with seven to nine pointed prongs at the base. The bowl-shaped calyx has five lobes ciliated. The petals are white to yellowish, reddish when fading. They measure 4 to 5.5 cm in length with 3.5 to 4.5 cm wide, they are inversely - ovate. The Columna is 1 to 2 cm long. The capsule fruit is three-to five-piece, oval, beaked front. It is 3 to 4 cm long and 2-3 cm wide. The oval seeds are 0.3 to 0.5 cm in size. They are surrounded by long white fibers, and light gray, short, firmly adhering fibers.
Dissemination
Gossypium hirsutum is native to tropical America, possibly from Mexico. It is cultivated in the tropics and subtropics worldwide. The four-time set of chromosomes of Gossypium hirsutum derived from two different types of output ( Allopolyploidy ). However, a part of the chromosome set is similar to the American types, the second part of the African species. When the intersection of the two parental species took place is unclear: It was suggested a date prior to the separation of Africa and South America (in 60-100 million years ago ), or a replacement with the people a few hundred years ago. However, molecular genetic studies suggest an age of Gossypium hirsutum 1-2 million years ago; such as the replacement of the now spatially separated on different continents output types took place is unclear.
Use
Gossypium hirsutum is the main supplier of cotton fibers. About 90 % of world cotton production based on G. hirsutum. The first cultivation probably took place on the Yucatán peninsula, and from there it spread to Central America, the Caribbean to the north of South America. Early breeding changes relate primarily to the reduction of dormancy and rapid, unaffected by photoperiodism bloom.