Comparative Evaluation of Disease Induced by Three Strains of Tobacco etch virus in Capsicum annuum L.

Tobacco etch virus (TEV; genus Potyvirus) strains HAT, Mex21, and N were evaluated comparatively for their pathogenicity and effects on growth of Capsicum annuum L. 'Calwonder'. Each TEV strain induced an initial systemic symptom of vein-clearing but subsequent disease symptoms ranged from mild (HAT) to moderate (Mex21) to severe (N). Effects on plant growth parameters closely reflected disease symptoms induced by each TEV strain. HAT-infected Calwonder plants did not differ from the healthy control for plant height, internode lengths, and aboveground fresh weight of shoots. Root dry weight, however, was less for HAT-infected plants than for the healthy control. Mex21 affected plants more severely, with significantly shorter plant height (at 20, 30, and 40 days postinoculation), reduced root dry weight, and shortened internodes compared with HAT and healthy control treatments. Aboveground fresh weight of Mex21-infected plants was significantly less than for the healthy control. N induced significant negative effects relative to each of the other treatments for plant height, aboveground shoot fresh weight, root dry weight, and internode lengths. The effects on Calwonder fruit production mimicked disease severity and effects on plant growth for the respective TEV strains.