Master of Science (MS)


Plant Pathology and Crop Physiology

Document Type



Plant viruses have shown to be the cause of the yellow vein symptoms on the foliage of several ornamental plants. In this study five ornamental plants: oxalis (Oxalis debilis var. corymbosa) cv. Golden Veined Oxalis, geranium (Pelargonium peltatum) cv. Crocodile, pseuderanthemum (Pseuderanthemum carruthersii) cv. Golden Net Bush (narrow leaf and broad leaf variants), honeysuckle (Lonicera japonica) cv. Yellow Net Honeysuckle and coleus (Solenostemon scutellarioides) cv. Electric Lime, showing foliar yellow vein were used. Graft transmissions indicated that, except for coleus, the foliar yellow vein of all other plants was caused by infectious agents, likely plant viruses. With the exception of Golden Veined Oxalis, attempts to identify a virus as the causal agent of the foliar yellow vein in geranium, pseuderanthemum, and honeysuckle failed. Successful whitefly (Bemisia tabaci biotype B) transmission of the foliar yellow vein of Golden Veined Oxalis suggested that a begomovirus was the causal agent. Therefore, PCR amplifications were conducted using degenerate primers for the genus Begomovirus. A 1.2 kb PCR product was obtained using the primer set PAL1v1978/ PAR1c496 and a 0.7 kb product with the primer set AV494/AC1048. These sets of primers have been used widely to detect and identify begomoviruses. Sequencing of the fragments confirmed the begomovirus nature of the amplified DNA from Golden Veined Oxalis. Sequence information and phylogenetic analyses revealed that the Golden Veined Oxalis begomovirus was closely related to Tomato yellow spot virus and Sida mottle virus, two begomoviruses reported to infect solanaceous and legume crops. The host range of the virus isolated from Golden Veined Oxalis begomovirus, designated Oxalis yellow vein virus, is not known. This finding illustrates the potential spread of plant viruses to different geographical areas through the commercialization of virus- infected ornamental plants.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Valverde, Rodrigo