Pierce's Disease
Research Updates

piercesdisease.cdfa.ca.gov

What is Pierce's Disease?

Pierce's Disease is a bacterial infection, which is spread by bugs that feed on grapevines, particularly the "glassy winged sharpshooter." Grapevines that become infected with PD can quickly become sick and die.

glassy-winged sharpshooter

Distinguishing Carmenere from similar cultivars by DNA typing


  • Author(s): Boursiquot, J.; Bowers, John; Hinrichsen, P.; Meredith, C; Munoz, C.; Narvaez, C.; Valenzuela, J.;
  • Abstract: A total of 93 vines from five vineyards in Chile that were originally planted as Merlot, four vines from a cultivar collection in Chile, and two vines in California were analyzed with SSR DNA markers to confirm their identity. DNA profiles were compared to those of previously confirmed reference vines. Vines in the Chilean vineyards matched the DNA profiles of either Merlot or Carmenere, consistent with prior visual identification of these vines. The four vines from the cultivar collection matched Carmenere, although they were originally planted as Merlot. Both California vines were confirmed as Carmenere, although one was originally imported as Cabernet franc. Two markers, VVMD28 and VVMD31, are particularly useful for distinguishing Carmenere from Merlot. VVMD31 will also distinguish Cabernet franc from the other two cultivars, as will VVMD27. Although these three cultivars can be distinguished visually, DNA typing is a valuable adjunct for verifying identity, particularly for vines in nurseries and foundation plantings.
  • Publication Date: Jan 2001
  • Journal: American Journal Of Enology And Viticulture