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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #400417
Research Project: Development of New Stone Fruit Cultivars and Rootstocks for the Southeastern United States

Location: Fruit and Tree Nut Research

Title: No evidence for vertical transmission of xylella fastidiosa subsp. multiplex in peach seed

Author
item JOHNSON, KENDALL - University Of Georgia
item Chen, Chunxian
item Bock, Clive
item BRANNEN, PHILLIP - University Of Georgia

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2023
Publication Date: 11/1/2023
Citation: Johnson, K.A., Chen, C., Bock, C.H., Brannen, P.M. 2023. No evidence for vertical transmission of Xylella fastidiosa subsp. multiplex in peach seed. Plant Health Progress. 24(4):516-518. https://doi.org/10.1094/PHP-11-22-0121-BR.
DOI: https://doi.org/10.1094/PHP-11-22-0121-BR

Interpretive Summary: Phony peach disease (PPD), caused by Xylella fastidiosa (Xf), has been one of the most important diseases in the southeastern United States and recently its prevalence in commercial orchards has increased. Whether transmission via rootstock seeds occurs and contributes to the increase remains unknown. In addition to propagation concerns, seed transmissibility has implications for global movement of peach seeds and international phytosanitary efforts. According to two experiments on seeds collected from PPD-symptomatic peach trees, we can conclude that no additional evidence is gained to support transmission of Xf from Xf-infected peach mother trees to seeds. Additional long-term studies to observe and test seedlings derived from such seeds should be conducted in the future – to reinforce the conclusions from this study.

Technical Abstract: Phony peach disease (PPD), caused by Xylella fastidiosa (Xf) subspecies multiplex (Xfm), is an important disease of peach in the southeastern United States. Seed transmission of Xf has not been reported for PPD, and research published in 1933 indicated seedlings grown from seed of PPD trees did not develop the disease. Two molecular detection techniques, qPCR and isothermal amplification, were utilized to determine whether the Xf bacterium could be detected in peach seed collected from PPD-infected trees; in addition, embryos were tested for Xf using qPCR. Xf was not detected in the 325 seed individually tested, 25 by qPCR and 300 by isothermal amplification. Furthermore, Xf was not detected in the 25 individually tested embryos using qPCR. Our studies provide no new evidence to support vertical transmission of Xf from Xf-infected peach trees to peach seeds. However, prior to concluding that vertical transmission does not occur, additional studies to observe and test seedlings produced from seed collected from PPD trees should be conducted.