Experimental host range and natural reservoir of sweet potato leaf curl virus in the United States

Sweet potato leaf curl virus (SPLCV), a sweet potato whitefly (Bemisia tabaci) transmitted begomovirus, causes serious yield losses to many sweet potato cultivars. Using experimental whitefly transmissions in a greenhouse (choice tests) and in a growth chamber (no-choice tests), we evaluated 111 plant species in 30 families to determine the host range of SPLCV. The host range was limited to plants in the genus Ipomoea within the family Convolvulaceae. In total, 38 of 45 Ipomoea species tested were susceptible to SPLCV infection. Surveys were conducted during the 2007-2009 sweet potato growing seasons in Mississippi and South Carolina to evaluate morning glory species as potential reservoir hosts for SPLCV. In the sweet potato experimental fields and surrounding areas, a large proportion of volunteer sweet potatoes, as well as a high percentage of annual and perennial morning glories tested positive for SPLCV. Understanding the host range and potential virus reservoir host plants will ultimately help in the development of an effective disease management strategy that is based on the consideration of agroecological factors.