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

SEQUENCE DIVERGENCE IN TWO MITOCHONDRIAL GENES (COI AND COII) AND IN THE ITS2 RDNA FRAGMENT IN GEOGRAPHIC POPULATIONS OF GONATOCERUS MORRILLI, A PRIMARY EGG PARASITIOD OF THE GLASSY-WINGED SHARPSHOOTER


  • Author(s): de Le?n, Jesse; III, Russell; Jones, Walker; Morgan, David;
  • Abstract: The aim of the present study was to resolve the genetic relationships of geographic populations of Gonatocerus morrilli, a primary egg parasitoid of the Glassy-winged Sharpshooter. A phylogenetic approach was implemented by sequencing two mitochondrial genes (COI and COII) and the Internal Transcribed Spacer-2 (ITS2) region of several individuals per population. Two populations from Weslaco, TX (WTX) (collected at different times), one from Quincy, FL (QFL), two from California (CA) (Orange and San Diego counties), and an outgroup (G. ashmeadi) were analyzed. For all three sequence fragments, percentage sequence divergence (%D) (as measured by genetic distance), the results demonstrated that both the WTX and QFL populations were closely related; in constrast, the %D between WTX and CA fell within the range of the outgroup, G. ashmeadi. For all three sequence fragments, Nieghbor-Joining distance trees separated the CA and WTX and QFL populations into two distinctive clades (A and B). The topology of the clades in each case was supported by very strong bootstrap values, 100% in the three sequence fragments (COI, COII, and ITS2). The present molecular phylogenetics results provide strong evidence that G. morrilli from California may be a different species. The findings of the present study are important to the Glassy-winged Sharpshooter/Pierces disease biological control program in California.
  • Publication Date: Dec 2004
  • Journal: 2004 Pierce's Disease Research Symposium