Present status of cotton leaf curl virus disease (CLCUVD): a major threat to cotton production

Cotton is a major cash crop cultivated throughout the world for fiber, feed, fuel and food. Globally, it ranked 1st for fiber and 2nd among the oilseed crops. It is cultivated in around 60 countries of the world with an approximate production of 119.8 million bales annually. During its life cycle, cotton is exposed to about 75 destructive diseases from sowing till harvesting. These stresses are responsible for about 50% yield losses annually with a worth of $ 50 billion in the world. Among them, Cotton leaf curl virus disease (CLCuVD) is one of the significant factors responsible for yield reduction worldwide. This disease is caused by cotton leaf cur virus which is mainly acquired and transmitted by the vector Whitefly (Bemisia tabaci). This virus belongs to the family Geminiviridae and genus Begomovirus. Geminiviruses consist of small circular, single stranded DNA encapsidated in a twinned icosahedral pattern. These are either monopartite or bipartite. Bipartite begomoviruses are composed of circular single stranded DNA-A and DNA-B, both these components are essential for the infection in New World while some bipartite begomoviruses are also present in Old World, but differences are still present. Monopartite begomoviruses are composed of circular single stranded DNA-A and satellite molecules (DNA α-satellite and β-satellite), these are essential components for the severity of disease in the Old World. Efforts are underway to develop new strategies to protect the cotton plants against CLCuVD and its viral causal agents. This review helps the reader to better understand the biology of Cotton leaf curl virus (CLCuV), its behavior/interaction with the host Whitefly as well as recent developments being made for the control of cotton leaf curl disease.