An overview of Cotton LeAf CurL virus DiseAse, persistAnt ChALLeng for Cotton proDuCtion

Iqbal, M., M. NaeeM, U. azIz, J. afzal and M. alaM KhaN, 2014. an overview of cotton leaf curl virus disease, persistant challeng for cotton production. Bulg. J. Agric. Sci., 20: 405-415 Cotton leaf curl virus (ClCuV) disease is crucial threat for cotton production in Pakistan. ClCuV belongs to genus Begomovirus of Geminiviridae family and is transmitted by Bemisia tabaci. Drastic reduction in yield was observed during 199495 and 2007-08 due to this disease. however in 1996-1997 ClCuD resistant varieties such as CIM 1100, CIM 448, CIM 446, MNh 554 and Vh 53 were evolved but in 2006-07 with the development of recombinant specie (Cotton leaf Curl burewala virus) having sequence derived from ClCuMuV and ClCuKoV, disease spread in epidemic form breaking all of the available resistance in Gossypium hirsutum l. germplasm. The resistant sources against the new species of ClCuV are Gossypium herbaceum and Gossypium arboreum and eight wild diploid species which can be used to transfer resistant gene in upland cotton. Owing to unavailability of resistant varieties losses due to this disease can be minimized by adopting certain management strategies like early sowing, balanced use of fertilizer and eradication of host plants from field. Utilization of advanced bio-techniques such as marker assisted selection, RNai and DNai based genetic resistance may prove to be fruitful for the control of the disease. In this review article we have tried to cover all aspects of cotton leaf curl disease and losses caused by this disease. Cotton leaf curl virus causes severe reduction in cotton production. Development of cotton leaf curl virus resistant varieties can diminish the damages of this disease. balanced use of fertilizers and eradication of host plants and weeds can reduce the disease incidence. Previously scientists of CCRI Multan and different research organization have tried to incorporate resistant gene from G. arborium and G. herbacium by inter-specific crossing with Gossypium hirsutum l. hexaploid population of above mentioned inter-specific cross was developed together with back crossing with upland cotton but success in this aspect is not significant. Secondly, amphidiploids of resistant diploid species followed by crossing as well as back crossing with upland cotton were studied but resistance obtained was not strong enough to combat this disease. We consider in future, that synthetic tetraploids should be developed by using resistant diploid species having “a” and D genome such as: 1. Gossypium arboreum × Gossypium gossypioides;2. Gossypium hebraceum × Gossypium gossypioides;3. Gossypium arboreum × Gossypium laxum;4. Gossypium herbaceum × Gossypium laxum