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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Molecular Plant Pathology Laboratory » Research » Publications at this Location » Publication #426466
Research Project: Omics-Based Approach to Detection, Identification, and Systematics of Plant Pathogenic Phytoplasmas and Spiroplasmas

Location: Molecular Plant Pathology Laboratory

Title: First report of Fagopyrum esculentum Moench infected by a ‘Candidatus Phytoplasma aurantifolia/citri’-related strain in Taiwan

Author
item FENG, YA-CHIH - Ministry Of Agriculture
item HUNG, TING-HSUAN - National Taiwan University
item Wei, Wei
item CHANG, TING-LIN - Ministry Of Agriculture
item CHIU, YEN-HSIN - Ministry Of Agriculture

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2025
Publication Date: 8/25/2025
Citation: Feng, Y., Hung, T., Wei, W., Chang, T., Chiu, Y. 2025. First report of Fagopyrum esculentum Moench infected by a ‘Candidatus Phytoplasma aurantifolia/citri’-related strain in Taiwan. Plant Disease. https://doi.org/10.1094/PDIS-06-25-1280-PDN.
DOI: https://doi.org/10.1094/PDIS-06-25-1280-PDN

Interpretive Summary: Buckwheat is primarily cultivated in Russia, China, and Ukraine for its dietary value and role as a cover crop. In 2024, buckwheat plants in Taichung, Taiwan, exhibited unusual symptoms such as phyllody (flowers resembling leaves) and virescence (green flowers instead of their typical colors). These symptoms indicated they were infected with phytoplasmas, a type of minute bacteria. In collaboration with Taiwanese scientists, an ARS scientist based in Beltsville, Maryland, confirmed the presence of phytoplasmas in diseased buckwheat plants by conducting molecular diagnostics using two unique genetic markers. The phytoplasma strains that induce buckwheat phyllody (BWP) disease belong to the 16SrII-A subgroup. This is the first report of BWP disease in buckwheat in Taiwan. These findings will assist researchers and students in detecting, identifying, and understanding phytoplasmas, as well as their host range and geographical distribution. Furthermore, the results carry significant implications for extension workers and farmers seeking to develop effective disease monitoring and management strategies aimed at preventing the spread of these pathogens through cover crops and potential reservoirs.

Technical Abstract: In 2024, Fagopyrum esculentum Moench (buckwheat) plants in Taichung, Taiwan, exhibited floral abnormalities, including phyllody and virescence. These symptoms suggest a phytoplasma infection associated with buckwheat phyllody disease. To confirm the phytoplasma infection, symptomatic buckwheat samples underwent nested PCR analysis of the 16S rRNA gene, which yielded positive results in all specimens. iPhyClassifier analysis identified the phytoplasma strains linked to Buckwheat Phyllody (BWP) disease as 'Candidatus Phytoplasma aurantifolia/citri '- related strains within the 16SrII-A subgroup. The representative strain was designated as BWP TSIPS 3-1. Further characterization of BWP TSIPS 3-1 involved amplifying and sequencing the secY gene, revealing 100% identity with the black gram witches’-broom phytoplasma found in Maymar. While the 16SrII-A subgroup strains have been documented in various Taiwanese plants, this study represents the first identification of BWP disease in buckwheat in Taiwan, thereby expanding the known host range of 'Ca. Phytoplasma aurantifolia/citri'-related strains. These findings raise concerns that buckwheat may act as a reservoir for phytoplasmas and their insect vectors, highlighting the necessity for monitoring and management strategies to combat phytoplasma diseases in buckwheat cultivation, reduce economic losses, and safeguard crop health.