Muhammad Usman1, Muhammad Zeeshan1, Eman Mehrab1 and Samyka Marium and Muhammad Kashif Shahzad Sarwar *2
1 Department of Botany, University of Agriculture Faisalabad 2* Cotton Research Station, Ayub agricultural Research Institute, Faisalabad
*Corresponding author: jatdhelvi@gmail.com
The wild races of Gossypium hirsutum is a tetraploid perennial plant and follows short day photoperiodism for flowerings. But upland cotton, which is cultivated in most parts of world, insensitive to photoperiodism. The flowering or reproductive stage in Gossypium hirsutum’s life cycle is important for cotton fiber formation. However, upland cotton is insensitive to the process of photoperiodism but its critical to understand the floral transition process, structure of cotton flower at microscopic level and effect of environmental factors on its flowerings so that it may help scientists in several other processes like speed breeding or to develop good varieties of cotton because fruiting is next stage of flowerings in cotton plant. Many circadian clock genes in cotton plant express according to sunlight duration, temperature, age, and hormonal changes. Cotton flowers at a certain age. Several genes, such as circadian clock genes in cotton leaves, control flowering circumstances such sunshine length, temperature, and more. Phloem transports reproductive signals from cotton leaves to shoot apex. Floral identity genes activate floral identity organ genes that generate cotton flower parts. The photoperiodism in Arabidopsis thialiana, which is considered as model plant also help to understand the photoperiodism in cotton at microscopic and genetic level.