Polymerase Chain Reaction-based Detection of Cotton Leaf Curl and Other Whitefly-transmitted Geminiviruses from Sindh

Samples of cotton plants showing symptoms of cotton leaf curl disease were collected from cotton fields in Sindh. Samples of some other plants including tomato, chillies, okra and Hibiscus suspected for whitefly-transmitted geminiviruses were also collected from these areas and total DNA was extracted. Degenerate primers designed to amplify DNA-A of whitefly-transmitted geminiviruses were used in PCR for the amplification of viral DNA. A product of expected (1.4 kb) was obtained from all these samples which confirmed the infection of whitefly-transmitted geminiviruses. PCR primers specific for the two whitefly-transmitted geminiviruses species namely CLCuV-Pk1 and CLCuV-Pk2 found associated with cotton leaf curl disease in Punjab were also used to confirm the identity of cotton leaf curl virus in Sindh. A product specific for CLCuV-Pk1 was obtained from all four symptomatic cotton samples. The results showed that cotton samples were infected with CLCuV-Pk1 while CLCuV-Pk2 was not detected in these samples. This is the first report of detection of whitefly-transmitted geminiviruses on these crops from Sindh. Our data not only confirm the presence of a whitefly-transmitted geminivirus on cotton but also showed that the disease is caused by one of the virus species found in Punjab.