Submitted to: Canadian Journal of Plant Pathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/18/2003
Publication Date: 12/15/2003
Citation: Huang, Q., Li, W.N., Hartung, J.S. 2003. First report of xylella fertidiosa in japanese beech bonsai. Canadian Journal of Plant Pathology. 25:401-405. Interpretive Summary: We recently observed a disorder in Japanese beech bonsai with symptoms similar to those seen in Xylella fastidiosa-infected leaves of elm. X. fastidiosa is associated with bacterial leaf scorch and decline in many economically important landscape trees and shrubs including elm, oak, sycamore, maple and oleander. X. fastidiosa is a slow growing, xylem inhabiting, nutritionally fastidious and insect-transmitted bacterium. It has a very wide host range, affecting over 30 plant families including both mono- and dicotyledonous plants. The bacterium causes significant economic losses in many agriculturally important plants including grape (Pierce¿s disease) and citrus (citrus variegated Chlorosis) in the United States and Brazil, respectively. In order to determine whether X. fastidiosa was present in the affected bonsai, we utilized independent antibody- and DNA-based methods. Results of both tests were positive, indicating the presence of the bacterium in the affected bonsai specimen. This is the first time that X. fastidiosa has been found associated with a beech tree, and the affected bonsai specimen is of exceptionally high cultural value. Our work will be of value primarily to plant pathologists and entomologists interested in diseases caused by X. fastidiosa and to members of the bonsai community interested in preserving unique horticultural masterpieces of the art of living sculpture.
Technical Abstract: A disorder was recently observed in a 79-year-old Japanese beech (Fagus crenata) bonsai with symptoms including marginal necrosis of leaves bordered by a chlorotic halo, premature leaf browning and defoliation. Leaf midrib extracts from the affected bonsai reacted with an antiserum specific for Xylella fastidiosa in an enzyme-linked immunosorbent assay. When the total DNA from the leaf midribs of the affected bonsai was extracted and subjected to polymerase chain reaction with primers specific for Xylella fastidiosa, a 472-bp PCR product was detected. The PCR product was confirmed to be the predicted Xylella fastidiosa product by sequencing and sequence comparison with the reported genomic sequence of Xylella fastidiosa. ELISA and PCR assays of leaf midrib extracts of a symptomless Japanese beech plant were negative. This is the first report of Xylella fastidiosa associated with leaf scorch in high-valued bonsai and in beech.