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Submitted to: Canadian Journal of Plant Pathology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/2/2007 Publication Date: 9/2/2007 Citation: Huang, Q. 2007. Natural occurances of Xyella fastidiosa in a commercial nursery in Maryland. Canadian Journal of Plant Pathology. 29:299-303. Interpretive Summary: X. fastidiosa is a slow growing, xylem inhabiting, nutritionally fastidious and insect-transmitted bacterium. It is associated with bacterial leaf scorch and decline in many economically important landscape trees and shrubs including elm, oak and maple. It is also an important plant pathogen in the landscape nursery trade. Since the natural occurrence of X. fastidiosa in commercial nurseries is unknown and such information is greatly needed to ensure the production of healthy plant materials, we conducted a survey in 2003 and 2004 in a wholesale and production nursery in Maryland using antibody- and DNA-based methods to determine the natural occurrence of X. fastidiosa in nursery plants and wild and cultivated plants surrounding the nursery. Our results indicate a possible association of X. fastidiosa with the nursery plants crape myrtle, Japanese stewartia, Schipka laurel and Japanese flowering cherry, as well as with the nursery surrounding plants mimosa and sassafras, previously unknown hosts of the bacterium. X. fastidiosa was also detected in the nursery plants dogwood and willow oak, as well as in the nursery surrounding plants red oak, box elder and wild grape, previously reported hosts of the bacterium. The red oak and box elder plants on the edge of the nursery showed leaf scorch symptoms and harbored high populations of the bacterium. However, the Xylella-positive nursery and other plants from the local environment were symptomless and the bacterial populations in those plants were low. It is possible that the red oak and box elder are a source of the X. fastidiosa in the nursery plants. Our work will be of value primarily to arborists and other members of the nursery and landscape industry, and to plant pathologists interested in diseases caused by X. fastidiosa. Technical Abstract: Since Xylella fastidiosa is an important plant pathogen in the landscape nursery trade, a survey was conducted in 2003 and 2004 in a commercial wholesale and production nursery in Maryland to determine the natural occurrence of X. fastidiosa in nursery plants and surrounding vegetation using enzyme-linked immunosorbent and nested polymerase chain reaction assays specific for the bacterium. Our results indicate a possible association of X. fastidiosa with the nursery plants crape myrtle (Lagerstroemia indica), Japanese stewartia (Stewartia pseudocamellia), Schipka laurel (Prunus laurocerasus ‘Schipkaensis’) and Japanese flowering cherry (P. serrulata ‘Kwanzan’), as well as with the nursery surrounding plants mimosa (Albizia julibrissin) and sassafras (Sassafrass albidum), previously unknown hosts of the bacterium. X. fastidiosa was also detected in the nursery plants dogwood (Cornus florida) and willow oak (Quercus phellos), as well as in the nursery surrounding plants red oak (Q. spp.), box elder (Acer negundo) and wild grape (Vitis spp.), previously reported hosts of the bacterium. The red oak and box elder plants on the edge of the nursery showed leaf scorch symptoms and harbored high populations of the bacterium. However, the Xylella-positive nursery and other plants from the local environment were symptomless and the bacterial populations in those plants were low. It is possible that the red oak and box elder are a source of the X. fastidiosa in the nursery plants. |
