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Sweet potatoes, both orange- and white-fleshed varieties, are widely grown in Florida. Foliar pests, leafminers, whiteflies and armyworms, are generally not difficult to manage; in fact insecticides should be avoided to conserve their natural enemies. More serious are those pests whose immature stages feed on roots: sweetpotato weevil, wireworms, banded cucumber beetles, pale-striped and sweetpotato flea beetles, and in south Florida, Diaprepes weevils and white grubs.

Sweet potatoes, both orange- and white-fleshed varieties, are widely grown in Florida. Foliar pests, leafminers, whiteflies and armyworms, are generally not difficult to manage; in fact insecticides should be avoided to conserve their natural enemies. More serious are those pests whose immature stages feed on roots: sweetpotato weevil, wireworms, banded cucumber beetles, pale-striped and sweetpotato flea beetles, and in south Florida, Diaprepes weevils and white grubs.

Tobacco explants were transformed by Agrobacterium-mediated transformation with sense and antisense constructs of the movement protein genes (BC1 and BV1) of tomato mottle geminivirus (TMoV). Transgenic plants were tested for virus resistance either by exposure to viruliferous whiteflies carrying TMoV or cabbage leaf curl geminivirus (CabLCV) for a 72-h inoculation period or by continuous exposure to TMoV during the life of the plants. The transgenic lines were scored for disease symptoms, and virus replication and distribution were determined by enzyme-linked immunosorbent assay and dot blot hybridizations. Transgenic plants which expressed a mutated form (identified in a previous study) of the BC1 gene showed TMoV and CabLCV resistance. Three resistant phenotypes were observed: a delay in symptom development, a recovery from early symptoms, and an absence of virus symptoms at all stages. Geminivirus was detected in inoculated leaves but was not readily detected in leaves beyond the inoculation sites in the highly resistant plants. The geminivirus resistance conferred by expression of the spontaneously mutated BC1 gene (detected after transformation) in transgenic tobacco may involve transdominant negative interference.

This document is HS924, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date December 1990. Revised September 2013.

This document is HS924, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date December 1990. Revised September 2013.

This document is HS924, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date December 1990. Revised September 2013.