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Poster: Diseases of Plants: Disease Detection & Diagnosis


Evidence for seed transmission of Xylella fastisiosa in pecan (Carya illinoinensis).
K. CERVANTES (1), D. Ray (1), R. Stamler (2), J. French (1), J. Soneji (3), R. Heerema (4), L. Grauke (5), J. Randall (4) (1) New Mexico State University, U.S.A.; (2) New Mexico State University, U.S.A.; (3) NMSU, U.S.A.; (4) New Mexico State Universitye,

Xylella fastidiosa is a gram-negative bacterial phytopathogen found exclusively in the xylem tissue of host plants. In pecan (Carya illinoinensis), X. fastidiosa was previously shown to be the causal agent of pecan bacterial leaf scorch (PBLS) in the United States and was shown to result in yield losses and a reduction in overall plant health. We observed that X. fastidiosa in pecan is difficult to detect through PCR due to non-specific amplification and inhibition from phenolic compounds, additional efforts are being made to improve PCR diagnosis of this pathogen in pecan tissue and to determine the location of bacterial populations in infected trees. In previous studies on pecan, X. fastidiosa was presumed to be solely transmitted via xylem-feeding insect vectors such as sharpshooters and spittlebugs. However, in this study, PCR and sequence analysis identified the presence of X. fastidiosa in pecan seed from multiple cultivars. Currently, greenhouse studies are in progress to determine if X. fastidiosa in pecan seeds is viable and able to colonize seedling tissues. In addition, a microbiome enrichment kit will be used to identify microbial populations present in the samples using next generation sequencing (NGS).