Abstract:

Tomato leaf curl a geminivirus is a contagious pathogen of tomato, many other crops and weeds as well. It has wide host range, the responsible agent for this is whitefly (Bemisia tabaci), a polyphagous vector, which also spread it on large scale. This pathogen is responsible for major reduction in yield of tomato growing countries. To evaluate the effect of virus titer on crop yield, ten commercial cultivar of the tomato plant were selected. The yield potential along with other traits of these cultivars was assessed on the basis of symptom development and virus DNA accumulation. We establish the relationship between the virus titer, symptom severity and agro-economic traits. Our results explain that the high level of virus accumulation in the plant tissue results in the development of severe symptoms and leads to major reduction in yield in case of susceptible cultivars, but this is not true for the cultivars showing intermediate resistance. The virus DNA remains low and approximately constant in resistant cultivars and has minimal effect on the yield and plant health.

Key words: Geminiviruses, Tomato leaf curl virus, Vector, Virus titer, Agro-economic.