Molecular studies on the transmission of Sri Lankan cassava mosaic virus (SLCMV) in cassava by Bemisia tabaci collected from cassava and cassava based crops

摘要: Cassava mosaic disease, caused by cassava mosaic geminiviruses are transmitted by Bemisia tabaci. Field surveys were conducted in cassava growing areas of Tamil Nadu during 2008-2009. Results showed that a there was high infection (89.09%) due to use of infected planting material (stem cuttings), while the whitefly borne infection was found to be very low (10.01%). Disease symptoms were generally mild. There was no change in disease incidence over the survey period. The B. tabaci were collected from cassava, tomato and bhendi separately and colonies reared on the same host. The meristem derived virus free cassava plant produced from apical meristem culture was studied to determine their ability to transmit Sri Lankan cassava mosaic virus (SLCMV) from cassava to cassava. Virus free plants were confirmed by polymerase chain reaction (PCR) using geminivirus degenerate primers. For the transmission studies virus acquisition access period (AAP) of 24 h on virus infected cassava leaves and 48 h virus inoculation access periods (IAP) on virus free healthy leaves were given to the all whiteflies that were reared on different host. SLCMV was absolutely transmitted by whiteflies reared on cassava but tomato and bhendi whiteflies did not transmitted SLCMV. The results were confirmed by using multiplex PCR. The transmission ability of this Hemipteran insect with SLCMV revealed that they were able to transmit the viruses from cassava to cassava effectively. Aim of this study was to observe that the tomato and bhendi whiteflies are able to transfer cassava mosaic virus (CMV) in comparison with the whiteflies of cassava.