TOMATO YELLOW LEAF CURL VIRUS: EFFICIENCY OF ACQUISITION, RETENTION AND TRANSMISSION BY BEMISIA TABACI (GENNADIUS), IN LIBYA

The sweet potato whitefly ,Bemisia tabaci (Gennadius)is considered as vector for numerous plant viruses ,including tomato yellow leaf curl virus(TYLCV). Experiments confirmed the ability of Bemisia tabaci adult to acquire and transmit the virus to the tomato plantations in Libya .The acquisition threshold feeding period ranged 30-40 min from infected tomato plant to healthy celery and from infected celery plant to healthy one 25 – 40 min . Moreover, retransmission from infected celery plants to healthy tomato plants 30 - 45 min. On the other hand inoculation threshold feeding period ranged from5-10min.The incubation period in white fly Bemisia tabaci was21-24 hours but in tomato plants ranged from 10-12 days and in celery plants 7-9 days. The Retention period of Tomato Yellow Leaf Curl Virus (T Y LC V) in whitefly Bemisia tabaci was 8- 11 days. Results of this study will help to understand the epidemiology of(TYLCV) in tomato plantations .Also the tomato plants and virus vector relationships of Libyan isolate are reported for the first time. Conclusively, from these results, it could be concluded that transmission experiments proved that tomato yellow leaf curl geminivirus is transmitted by Bemisia tabaci in a persistent manner.