Cotton Leaf Curl Virus: A Threat to Pakistan Cotton
Feb 15, 2019
Spread of cotton leaf curl virus (CLCuV) in cotton growing areas of Punjab cause immense losses in cotton production in Pakistan. It appeared in epidemic form in 1998, but became serious from 1992-93. Studies to combat this problem centres around the characterization of virus, its vector (whitefly), alternate host and the causative environmental factors. In our surveys, it was found that the incidence and severity of the disease varied from place to place, developing hot spots under certain environmental conditions that we tried to analyze. The nature of this virus was studied through molecular characterization. Studies were undertaken to develop cultivars resistant to the virus. A technique for the field evaluation of the breeding material on a large scale was developed which helped to screen for resistance to the disease. This helped to show that this disease is controlled by a single dominant gene. A series of resistant cotton strains have been developed since then, that save the crop from the onslaught of the virus. Two resistant cultivars, CIM – 1100 and CIM – 448, have already been approved for general cultivation. Future behaviour of the virus is being monitored.