Effect Of Vector Density, Plant Age And Temperature On The Transmission Of Tomato Leaf Curl Taiwan Virus By The Whitefly Bemisia Tabaci

In recent years, Tomato leaf curl Taiwan virus (ToLCTWV) has caused disease epidemics and heavy losses to crop production in several tomato-growing regions in China. To provide basic information for the control of tomato leaf curl virus disease, we investigated the capacity of the Bemisia tabaci Middle East-Asia Minor 1 cryptic to acquire and retain ToLCTWV, as well as the effects of vector density, plant age, and temperature on the transmission of ToLCTWV by the whitefly. ToLCTWV DNA was detected in 3.3% of the whiteflies when they had fed for 0.5 h on ToLCTWV-infected tomato plants and was detected in 100% of the whiteflies when the acquisition access period increased to 48 h. Viruliferous whitefly adults retained ToLCTWV DNA for their entire life. Our data showed that the Bemisia tabaci Middle East-Asia Minor 1 cryptic was an efficient vector for ToLCTWV. Transmission was achieved to 50%-60% of the plants by one adult per plant, and the frequency of transmission approached or reached 100% when the vector density increased to five per plant. Vector density and plant age are two main factors affecting disease severity of tomato seedlings, which increased with a vector density but decreased with plant age, respectively. Temperature had a significant effect on the incidence of disease, but no significant effect on disease severity. In addition, the interactions between temperature and plant age, between vector density and plant age as well as the interactions between the three factors all had significant effects on the disease index. These results suggested that cultivating virus-free and healthy seedlings is of vital importance in the control of ToLCTWV diseases in the field.