1a. Objectives (from AD-416)
1. To collect the ex situ and/or in situ volatile emission of select native and non-native oak trees (Quercus spp.). 2. To analyze collected volatile organic compounds (VOCs) via GC-MS and identify possible chemotaxonomy trends and/or chemotype identifiers of selected trees to various insect pests. 3. To identify VOCs with kairomonal behavior to select insect pests.
1b. Approach (from AD-416)
To accomplish the stated objectives the following approach will be utilized by the graduate student under the mentorship of Professor Richard Karban and secondary supervision of John J. Beck: 1. Perform ex situ VOC analysis on a large portion of selected oak tree (Quercus spp.) leaves to determine general VOC emission trends. 2. Utilize the in situ small-scale collection method (collection bag, SPME) of the USDA-ARS PMR unit to acquire VOCs from select trees identified from ex situ analysis. 3. Separate and identify collected VOCs via GC-MS analyses. 4. Develop a chemotaxonomic tree based upon trends of identified VOCs and herbivore damage. 5. Utilize electrophysiological and/or behavioral bioassays to determine kairomonal activity. Documents NFCA with UC Davis.
3. Progress Report
The research under the NFCA seeks to collect the in situ volatile emission of select native and non-native oak trees with the intent to develop/discover possible chemotaxonomy trends and/or chemotype identifiers. The project is in the final three months of the first and only year of investigation. The cooperator has been updated on progress of the study via weekly and/or biweekly phone calls, email exchange, site visits, and copies of internal data spreadsheets. Research results obtained since the start of the project include: 1) a volatile collection method was developed and optimized (in situ) for this particular analyte and system; 2) fifty-five oak species were analyzed in duplicate for their non-damaged and damaged volatile output; 3) collected volatiles were separated and identified by GC-MS (polar and non-polar columns); and, 4) data is currently being analyzed and statistics being applied. The goals of this project, collecting and identifying volatiles as potential kairmones for oak insect pests, are related to Objective 3 of the in-house project and are a direct application of methods developed in this laboratory.