Date of Award


Document Type


Degree Name

Master of Science (MS)


Plant and Environmental Science

Committee Chair/Advisor

Elizabeth Cieniewicz

Committee Member

Guido Schnabel

Committee Member

David Coyle

Committee Member

Juan Carlos Melgar


Prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), and peach latent mosaic viroid (PLMVd) are important pollen-borne pathogens that affect peach orchards in the southeastern United States. My aim with this research is to identify potential sources of virus/viroid inoculum sources in the wild and determine pathogen movement and interactions between wild Prunus spp. and cultivars of peach (P. persica). In Chapter I, I review the literature on pollen borne viruses and viroids in peach. In Chapter II, I surveyed for these pathogens near peach production areas in South Carolina and Georgia, sampling from three endemic wild Prunus species: black cherry (P. serotina), Chickasaw plum (P. angustifolia), and Carolina cherry laurel (P. caroliniana). The presence of PNRSV was confirmed in wild P. serotina and P. caroliniana but neither PDV nor PLMVd were found in the collection. There was no relationship between virus infection status and tree age. A phylogenetic analysis of the isolates obtained was performed with other isolates from around the world and PNRSV type groups and our samples showed clustering with a reference group isolate that was obtained from peach in the U.S. In Chapter III, we sequenced PNRSV isolates from P. persica from the Musser Fruit Research Center at Clemson University, South Carolina, and recorded bloom dates from wild P. serotina; bloom data for peach was provided by Dr. Juan Carlos Melgar. Samples from peach mostly clustered with wild Prunus in the reference group that pertained to the peach isolate from the U.S., but some isolates grouped with another reference isolate from cherry obtained from Germany, Europe. Bloom data presented a gap of approximately one week between species with peaches blooming first and being followed by wild P. serotina. The results of these studies altogether suggest that wild Prunus spp. have the capacity of serving as virus reservoir, but the initial source of pollen-borne spread of the virus could be P. persica.

Author ORCID Identifier




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