Asexual Propagation of Grapevine Transmits Pierce’s Disease Pathogen (Xylella fastidiosa) to Rooted Cuttings

An objective of this study was to investigate rooting success of grape cuttings propagated from vines symptomatic of Pierce’s disease. Additional objectives were to assess if rooted cuttings could survive and produce viable plants, and determine if Xylella fastidiosa (causal agent of Pierce’s disease) could be found in rooted cuttings. In Jan. 2008, cuttings were taken from symptomatic and asymptomatic ‘Merlot’ and ‘Cabernet Sauvignon’ grapevines growing in the Hill Country and Gulf Coast regions of Texas. Six weeks after cuttings were propagated, each cutting was uprooted and evaluated for rooting and infection parameters. Cuttings were then planted in containers and held in the greenhouse to evaluate survivability. To confirm the presence of X. fastidiosa, propagated cuttings were tested by real-time polymerase chain reaction. Data indicate several rooted cuttings tested positive for X. fastidiosa and appeared viable and healthy. Therefore, vines infected with X. fastidiosa have the ability to produce asexually propagated cuttings, and potentially contaminate non-infected vineyards.