Abstract
Whitefly samples were collected from several greenhouses and identified as Bemisia tabaci by polymerase chain reaction (PCR), followed by sequencing of mtCOI gene that revealed their identity as biotype B MEAM1. Transmission of Cucurbit chlorotic yellows virus (CCYV) by the identified whitefly biotype was estimated by conducting several experiments. The results showed that a single whitefly was sufficient to transmit the virus to healthy seedlings. It was also found that the vector required a 90-min acquisition and inoculation access period to successfully transfer the virus. Moreover, vector was found to be able to retain the virus for 6 days' post acquisition. Efficiency of cucumber and D. stramonium, plants was compared as a source of CCYV inoculum for virus acquisition by B. tabaci and obtained results revealed that cucumber was a more efficient source of virus infection than D. stramonium. Using cucumber as source of infection, 90% of the inoculated plants (from each species i.e. cucumber and D. stramonium), were infected while using D. stramonium, as a source, the percentage of infection in cucumber plants dropped to 60% (cucumber) and to 50% in D. stramonium. These results showed that D. stramonium, is a relatively less efficient source of virus for whitefly acquisition as compared to cucumber. Host range experiments for CCYV showed that all the cucurbit plants were infected and had different levels of symptoms. Cucumis sativus, C. melo, C. amaranticolor and D. stramonium showed interveinal chlorosis, whereas general yellowing and reduced growth were observed in all positively tested hosts. (C) 2018 Friends Science Publishers