news and research about Pierce's Disease

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.

Breeding PD resistant winegrapes. [Previous title: Increased breeding efforts for the development PD resistant table and raisin grapes with implications for winegrape breeding.]

PIs: Andrew Walker, Alan Tenscher

Reports:

Research Papers

  • Variation in recombination rates across Vitis species
    Recombination rate data are presented for three populations of grape based on framework genetic linkage maps developed with simple-sequence repeat markers. These linkage maps were constructed from different Vitis species and represent three genetic backgrounds. The first population is pure Vitis vinifera, derived from a cross of the European cultivars Riesling and Cabernet Sauvignon. The second is an interspecific cross between two commercially used rootstock cultivars of different North American Vitis species parentage, Ramsey (Vitis champinii) and Riparia Gloire (Vitis riparia). The third population, D8909-15 (Vitis rupestris x (Vitis arizonica/Vitis girdiana form)) x F8909-17 (V. rupestris x (V. arizonica/Vitis candicans form)), is an F1 from two half-sibs. Genome-wide and chromosome-wide recombination rates varied across the three populations and among the six Vitis parents. Global recombination rates in the parents of the third F1 population, with a complex Vitis background, were significantly reduced. In the first and third populations, the recombination rate was significantly greater in the male parent. Specific genome locations with frequent heterogeneity in recombination were identified, suggesting that recombination rates are not equal across the Vitis genome. The identification of regions with suppressed or high recombination will aid grape breeders and geneticists who rely on recombination events to introgress disease resistance genes from the genomes of wild Vitis species, develop fine-scale genetic maps, and clone disease resistance genes.
    2009-01-01
  • Use of molecular markers to correct grape breeding errors and determine the identity of novel sources of resistance to Xiphinema index and Pierce's disease
    Over the past 15 years, the grape breeding program at the University of California, Davis, has been evaluating Vitis rupestris x Muscadinia rotundifolia selections for resistance to the dagger nematode, Xiphinema index, and to Pierce's disease (PD). Selections from these crosses exhibit very strong resistance to X index and PD. In addition to breeding efforts, populations from these crosses have been used to develop genetic maps and locate resistance loci. Genetic mapping efforts recently began incorporating SSR markers to refine and expand existing maps. The use of SSR markers revealed that the mapping population parents were not crosses of V rupestris x M. rotundifolia. This discovery led to testing of the entire group of 161 V rupestris x M. rotundifolia progeny. All possible male parents surrounding the V rupestris female parents in the vineyard where the crosses were made were genetically fingerprinted with up to 15 SSR markers to determine the true male parents. Results indicated that most of the male parents were from collections of forms of V. arizonica gathered in Mexico in 1961. These now correctly identified selections represent novel sources of very strong resistance to X. index and PD
    2007-01-01
  • Identification and molecular mapping of PdR1, a primary resistance gene to Pierce's disease in Vitis
    A major quantitative trait locus (QTL) controlling resistance to Pierce's disease (PD) of grape, caused by the bacterium Xylella fastidiosa (Xf), was identified on a Vitis linkage map and denoted as 'Pierce's disease resistance 1' (PdR1). Placement of the locus was accomplished by evaluating a family of full-sib progeny from a cross of two PD-resistant interspecific hybrids with resistance inherited from Vitis arizonica. Resistance was measured under greenhouse conditions by direct quantification of Xf numbers in stem tissues as well as by evaluation of disease symptoms based on leaf scorch and a cane maturation index (CMI). A large QTL (LOD 17.2) accounting for 72% of the phenotypic variance in bacterial numbers was localized to linkage group 14 of the male parent F8909-17. The approximate 95% confidence interval around the QTL peak extended 5.7 cM when using composite interval mapping. The other disease evaluation methods (leaf scorch and CMI, respectively) placed the resistance QTL to the same region on linkage group 14, although at wider 95% confidence intervals (6.0 and 7.5 cM), lower peak LOD scores (11.9 and 7.7) and accounting for less phenotypic variance (59 and 42%). This is the first report of an Xf resistance QTL mapped in any crop species. The relevance of the markers located in the region spanning the QTL will be discussed, addressing their usefulness for the development of PD-resistant grape cultivars.
    2006-04-01
  • Resistance to Pierce's disease in Muscadinia rotundifolia and other native grape species
    Pierce's disease (PD), caused by the bacterium Xylella fastidiosa, is a major disease of grapevines. Grape species native to southern areas of North America where the disease is severe have evolved resistance to PD. Using controlled greenhouse trials, a quantitative assessment of the level of resistance in cultivated and wild selections of five native grape species was made. Conclusions were based on estimates of bacterial concentrations in stem tissue via ELISA and subjective evaluations of disease symptoms. Vitis labrusca, native to the northeast United States where PD is absent, appears to be as susceptible as Vitis vinifera. California natives Vitis californica and Vitis girdiana appear to be moderately susceptible, although there was significant variation among the V girdiana selections. In contrast, Muscadinia rotundifolia and Vitis arizonica, both native to areas of severe disease pressure, appear to be very resistant. A pattern of resistance correlating with geographic variation in disease pressure was also evident within species. Wild accessions of M. rotundifolia from cooler areas such as Tennessee, where PD is uncommon, supported up to 20x higher concentrations of bacteria than the accessions from Florida where PD is severe. Trials with wild accessions of V girdiana showed a similar pattern, with susceptible selections supporting up to 100x higher bacterial concentrations. Results demonstrated a gradient of resistance both among and within species, consistent with the hypothesis that PD resistance has evolved in response to disease pressure. This study identifies candidate plant material for breeding projects and provides insight into the genetic and physiological basis of PD resistance in native grapes.
    2006-01-01
  • Refined mapping of the Pierce's disease resistance locus, PdR1, and Sex on an extended genetic map of Vitis rupestris x V-arizonica
    A framework genetic map based on genomic DNA-derived SSR, EST-derived SSR, EST-STS and EST-RFLP markers was developed using 181 genotypes generated from D8909-15 (female) x F8909-17 (male), the '9621' population. Both parents are half siblings with a common female parent, Vitis rupestris 'A. de Serres', and different male parents (forms of V. arizonica). A total of 542 markers were tested, and 237 of them were polymorphic for the female and male parents. The female map was developed with 159 mapped markers covering 865.0 cM with an average marker distance of 5.4 cM in 18 linkage groups. The male map was constructed with 158 mapped molecular markers covering 1055.0 cM with an average distance of 6.7 cM in 19 linkage groups. The consensus '9621' map covered 1154.0 cM with 210 mapped molecular markers in 19 linkage groups, with average distance of 5.5 cM. Ninety-four of the 210 markers on the consensus map were new. The 'Sex' expression locus segregated as single major gene was mapped to linkage group 2 on the consensus and the male map. PdR1, a major gene for resistance to Pierce's disease, caused by the bacterium Xylella fastidiosa, was mapped to the linkage group 14 between markers VMCNg3h8 and VVIN64, located 4.3 and 2.7 cM away from PdR1, respectively. Differences in segregation distortion of markers were also compared between parents, and three clusters of skewed markers were observed on linkage groups 6, 7 and 14.
    2006-11-01

Funding sources:

  • Funded by: CDFA PD/GWSS Board
  • Budget: $382,500.00
  • Start date: 2003-07-01
  • Stop date: 2009-06-30
  • Status: APPROVED
  • Funded by: CDFA PD/GWSS Board
  • Budget: $532,200.00
  • Start date: 2004-01-01
  • Stop date: 2007-01-01
  • Status: APPROVED