Author
Backus, Elaine | |
JOOST, P - UNIV OF CALIF-RIVERSIDE | |
HABIBI, JAVAD - UNIV OF MISSOURI | |
Shugart, Holly |
Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings Publication Acceptance Date: 10/13/2004 Publication Date: 12/7/2004 Citation: Backus, E.A., Joost, P.H., Habibi, J., Shugart, H. 2004. Sharpshooter feeding behavior in relation to transmission of the Pierce's Disease bacterium. Proceedings of CDFA Pierce's Disease Control Program Research Symposium. p. 84-87. Interpretive Summary: The introduction of the glassy-winged sharpshooter into California has caused a great increase in PD disease incidence in many grape-growing regions. Although host plant resistance to the Xf bacterium and/or vector is being sought, research is hampered by lack of detailed knowledge of the transmission process. The purpose of this research is to identify the precise sharpshooter feeding behaviors on grape that control inoculation of PD bacterium to grape. The ultimate goal of our research is develop a Stylet Penetration Index that could provide a rapid means of screening grape varieties for host plant resistance. Technical Abstract: The recent introduction of the glassy-winged sharpshooter in southern California has caused a great increase in PD disease incidence in many grape-growing regions. Although host plant resistance to the Xf bacterium and/or vector is being sought, research is hampered by lack of detailed knowledge of the transmission process. The purpose of this research is to characterize the feeding behavior of sharpshooters on grape, and to identify the precise stylet activities that permit inoculation of PD bacterium during feeding. To do this, we are using electropenetration graph (EPG) monitoring of feeding, videomicrography of stylet movements, and histology of salivary sheaths. This year's correlation experiments further characterized EPG waveforms and showed that the specific stages of stylet penetration they represent can be linked to formation of specific branches of a correlated salivary sheath. Also, inoculation of the Xf bacterium is associated with shorter durations of waveform B1 (in pathway), longer C (vascular ingestion) and shorter N (vascular salivation). The ultimate goal of our research is to identify the role(s) of specific sharpshooter probing behaviors in Xf transmission and to develop a Stylet Penetration Index that could provide a rapid means of screening grape varieties for host plant resistance. |