DEVELOPMENT AND UTILITY OF A ONE-STEP SPECIES-SPECIFIC MOLECULAR DIAGNOSTIC MARKER FOR GONATOCERUS MORRILLI DESIGNED TOWARD THE INTERNAL TRANSCRIBED SPACER REGION 2 (ITS2) TO MONITOR ESTABLISHMENT IN CALIFORNIA

• Author(s): de Le?n, Jesse; Morgan, David; Logarzo, Guillermo; Triapitsyn, Serguei;
• Abstract: In addition to the one-step species-specific molecular diagnostic ISSR-PCR DNA fingerprinting method, we developed an additional one-step molecular diagnostic marker gmtx toward Gonatocerus morrilli (Howard) designed toward the ribosomal internal transcribed spacer region 2 (ITS2) to aid in monitoring establishment in California. Gonatocerus morrilli, the imported natural enemy from Texas, is very closely related to G. walkerjonesi, the native California species. Specificity assays with this newly developed marker and a total of 16 Gonatocerus Nees species demonstrated that it was highly specific toward the species that it was designed for (G. morrilli), as cross-reactivity was not seen with any of the tested species, including all species belonging to the morrilli subgroup of the ater species group of Gonatocerus. Anaysis of the release TX/MX colony used before the summer of 2005 with this species-specific diagnostic marker confirmed previous results that the release TX/MX colony was not the imported G. morrilli, but the native species G. walkerjonesi, confirming a colony contamination. Analysis of post-released G. morrilli collections with this diagnostic marker detected G. morrilli in a site where it was previously released, in accordance with our recent finding using two other diagnostic markers used in combination, ITS2 fragment size and ISSR-PCR DNA fingerprinting. The current results confirm the utility of the newly developed species-specific ITS2 molecular diagnostic marker as an excellent tool to aid in monitoring the establishment of the imported natural enemy of the glassy-winged sharpshooter, G. morrilli. These results and molecular tools are critical to the biological control program in California. We now have in our hands the molecular technology to evaluate the G. morrilli biological control program in California from start to finish, that is, monitor establishment, dispersal, and efficacy of natural enemies and improve mass rearing.
• Publication Date: Nov 2006
• Journal: 2006 Pierce's Disease Research Symposium