Infection of blueberry cultivar Emerald with a California Pierce’s disease strain of Xylella fastidiosa and acquisition by glassy-winged sharpshooter

Authors: Burbank, Lindsey; Sisterson, Mark; O'Leary, Michael

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/26/2019
Publication Date: 7/31/2019
Citation: Burbank, L.P., Sisterson, M.S., O'Leary, M.L. 2019. Infection of blueberry cultivar Emerald with a California Pierce’s disease strain of Xylella fastidiosa and acquisition by glassy-winged sharpshooter. Plant Disease. 104(1):154-160. https://doi.org/10.1094/PDIS-05-19-1126-RE.
DOI: https://doi.org/10.1094/PDIS-05-19-1126-RE

Interpretive Summary: Bacterial leaf scorch disease caused by Xylella fastidiosa occurs in southern highbush blueberry varieties in the southeastern United States. However, some blueberry varieties are more susceptible to infection and severity of disease is often dependent on specific strain of the pathogen. It is not known whether X. fastidiosa strains causing disease in grape in the San Joaquin Valley of California can also spread to blueberry, a crop which is expanding in the state. Glassy-winged sharpshooter, one of the insects that carries X. fastidiosa in California often feeds on blueberry, leading us to investigate it’s potential to spread this pathogen to blueberry in the San Joaquin Valley. Using experimental infections, an X. fastidiosa strain collected from grapevine in the San Joaquin Valley can cause disease in some blueberry varieties, and can be carried by glassy-winged sharpshooters that have fed on infected blueberry plants. Understanding whether the X. fastidiosa strains that infect grapevine in California can spread to blueberry in the area is an important consideration for pest and disease management in the San Joaquin Valley where multiple crops are planted in close proximity.

Technical Abstract: Bacterial leaf scorch disease, caused by Xylella fastidiosa, occurs in southern highbush blueberry varieties in the southeastern United States. Susceptibility to X. fastidiosa varies by blueberry cultivar, and these interactions are often strain-specific. Xylella fastidiosa subsp. fastidiosa is the causal agent of Pierce’s disease in grapevines and has been problematic in the San Joaquin Valley of California since introduction of the glassy-winged sharpshooter (Homalodiscus vitripennis). Glassy-winged sharpshooter is known to feed on blueberry, a crop which is expanding in the San Joaquin Valley. Currently, little is known concerning potential for spread of X. fastidiosa between grape and blueberry in this region. The ability of a Pierce’s disease strain of X. fastidiosa from the San Joaquin Valley to cause disease in southern highbush blueberry and the potential for glassy-winged sharpshooter to transmit X. fastidiosa between blueberry and grapevine was investigated. Experimental inoculations showed that the X. fastidiosa subsp. fastidiosa strain Bakersfield-1 can cause disease in blueberry cultivar Emerald, and that glassy-winged sharpshooter can acquire X. fastidiosa from artificially inoculated blueberry plants under laboratory conditions. Understanding the possibility for X. fastidiosa strains from the San Joaquin Valley to infect multiple crops grown in proximity is an important consideration for area-wide pest and disease management.