Burewala Strain of Cotton Leaf Curl Virus: A Threat to CLCuV Cotton Resistant Varieties

摘要

Cotton Leaf Curl Virus (CLCuV) is one of the disease of cotton, which is transmitted by whitefly ( Bemisia tabaci Gem). In a survey conducted during the year 2001-2002, it was observed that a new variant of Multan CLCuV was appeared on all resistant cotton varieties in culture at various locations in Vehari district especially in Burewala territory. The appearance of symptoms was experimentally confirmed through graft and whitefly transmission techniques under controlled environments at Central Cotton Research Institute, (CCRI) Multan, Pakistan. Results showed that all commercial varieties in culture, which were resistant to Multan CLCuV disease, fell prey to new variant to Burewala-CLCuV. Not with standing that even parental genetic stock from which these varieties were bred had shown their susceptibility to this new variant of Multan CLCuV (commonly known as Burewala-CLCuV).