Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2011
Publication Date: 5/28/2011
Citation: Ling, K., Harrison Jr, H.F., Simmons, A.M., Zhang, S., Jackson, D.M. 2011. Experimental Host Range and Natural Reservoir of Sweet Potato Leaf Curl Virus in the United States. Crop Protection. 30:1055-1062. Interpretive Summary: The U.S. produced 966,785 metric tons of sweetpotatoes in 2009 with a farm gate value of over $410 million. In recent years, sweet potato leaf curl virus (SPLCV), a whitefly transmitted virus first reported in the U.S. in 1998, has caused significant yield losses (ranging 10 to 80%). An important step in understanding the factors influencing epidemiology of the disease is to evaluate host range and to identify natural virus reservoir hosts. ARS scientists at Charleston, SC, in cooperation with a scientist at Alcorn State University, evaluated 111 plant species in 30 families using natural whitefly transmission, and determined that the host range for SPLCV was limited to morning glory plants in the genus Ipomoea. In total, 38 of 45 Ipomoea species tested were susceptible to SPLCV infection. Additionally, surveys conducted in South Carolina and Mississippi also identified natural SPLCV infections on volunteer sweetpotatoes and wild morning glories. These results demonstrated that SPLCV-infected volunteer sweetpotatoes and wild morning glories may serve as virus inoculum sources, particularly those perennial morning glories that can survive winter months in southern states where sweetpotatoes are grown. Understanding the host range and potential virus reservoirs will ultimately help in the development of an effective disease management strategy that is based on consideration of agroecological factors.
Technical Abstract: Sweet potato leaf curl virus (SPLCV), a sweetpotato whitefly transmitted begomovirus, could potentially cause serious yield losses to many sweetpotato cultivars. Using experimental whitefly transmission experiments in a greenhouse (choice tests) and in a growth chamber (no-choice tests), we evaluated 111 plant species in 30 families for a host range study to SPLCV. The host range of SPLCV 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 also conducted during the 2007-2009 sweetpotato growing seasons in Mississippi and South Carolina to evaluate wild morning glories as potential reservoirs for SPLCV. Results showed that in the sweetpotato production fields and surrounding areas, a large proportion of volunteer sweetpotatoes, as well as high percentage of annual and perennial morning glories contained SPLCV. Understanding the host range and potential virus plant reservoirs will ultimately help in the development of an effective disease management strategy that is based on the consideration of agroecological factors.