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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #418293
Research Project: Identifying Vulnerabilities in Vector-host-pathogen Interactions of Grapevine and Citrus Pathosystems to Advance Sustainable Management Strategies

Location: Crop Diseases, Pests and Genetics Research

Title: First report of Xylella fastidiosa subsp. multiplex infecting southern shagbark hickory (Carya carolinae-septentrionalis)in Georgia, USA

Author
item Chen, Jianchi
item HOTCHKISS, MICHAEL - Retired ARS Employee
item Hilton, Angelyn
item Chen, Chunxian
item Bock, Clive

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2024
Publication Date: 1/2/2025
Citation: Chen, J., Hotchkiss, M.H., Hilton, A.E., Chen, C., Bock, C.H. 2025. First report of Xylella fastidiosa subsp. multiplex infecting southern shagbark hickory (Carya carolinae-septentrionalis)in Georgia, USA. Plant Disease. https://doi.org/10.1094/PDIS-09-24-1990-PDN.
DOI: https://doi.org/10.1094/PDIS-09-24-1990-PDN

Interpretive Summary: Southern shagbark hickory is a deciduous tree in the walnut family that includes several commercially important nut-producing trees such as walnut and pecan. Related tree species could be hosts to the same pathogens. This study reports the first detection and characterization of the bacterial pathogen, Xylella fastidiosa, infecting a shagbark hickory tree in Byron, GA. New information generated by this research could be used to adapt the management of pecan bacterial leaf scorch and other economically important diseases of crops casued by Xylella in the Southeast U.S.A.

Technical Abstract: Southern shagbark hickory (SSH, Carya carolinae-septentrionalis) is one of several deciduous trees in the family Juglandaceae that includes pecan (C. illinoinensis), an important tree nut crop in U. S. A. In September, 2023, symptoms of leaf scorch were noticed on SSH trees planted in a hickory collection at the USDA-ARS, Byron, GA. Leaf samples were collected and infection of Xylella fastidiosa (Xf) was confirmed using conventional PCR with four Xf-specific primer sets. A DNA sample was further selected for next generation sequencing (NGS) using Illumina NovaSeq 6000 (PE150) platform. A total of 58,601,960 paired reads were generated and mapped to the genomes of Xf subsp. multiplex M12 (NC_010513.1) and Xf subsp. fastidiosa M23 (NC_010577.1) using Bowtie2, resulting in overall alignment rates of 0.97% and 0.95%, respectively, which confirmed the Xfm infection status (~71X genome coverage). Knowledge of the causal agents of the disease in Carya species is important for disease management in both agricultural plantings and natural stands of trees. Furthermore, Xylella pathogens have national and international phytosanitary significance.