Plants are attacked by a variety of herbivore feeding guilds and respond with specific responses to specific attacks, which may be localized or systemic. How a plant defends against one feeding guild may alter the plants response against a different feeding guild. A better understanding of these interactions will allow for the development of refined pest management programs. One situation in which this may occur is in interactions between chewing and piercing/sucking herbivores, such as aphids. Aphids are important crop pests primarily due to their ability to transmit viruses, the efficacy of which can be affected by plant defenses. To determine if systemic induction has an effect on aphid feeding behaviors, three soybean varieties, (Progeny 4906RR, Davis, and Lyon) were induced with either soybean looper (SBL), Chrysodeixis includes (Walker), larvae, foliar jasmonic acid, or foliar salicylic acid. Three days post induction, green peach aphid (GPA), Myzus persicae (Sulzer), apterae feeding behavior was recorded on induced and control plants using the Electrical Penetration Graph (EPG) technique. SBL feeding bioassays were used to assess the effect of previous SBL herbivory, JA or SA on SBL larval weight, and to confirm systemic induction. Both previous herbivory and JA reduced SBL larval weights when fed Progeny 4906RR tissue, while herbivory had no effect on SBL larval weights when fed Davis tissue, suggesting SBL does not induce a defensive response in Davis. SA did not induce a response in either variety. Neither herbivory nor JA had an effect on SBL larval weight in Lyon, suggesting it does not induce a defensive response. However, SA increased SBL larval weights. SBL herbivory decreased several behaviors associated with nonpersistant virus transmission in both Progeny and Davis, but had no effect on aphid feeding behavior in Lyon. Jasmonic acid induction increased several behaviors associated with nonpersistant virus transmission in both Progeny and Davis. Exogenous SA application also increased behaviors associated with nonpersistant virus transmission in all three varieties. These results suggest that inducing host plant resistance using exogenous JA application may have positive effects by reducing herbivore performance. However, both JA and SA may potentially have negative impacts by increasing nonpersistant virus transmission.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-07122015-144221 |
| Date | 16 July 2015 |
| Creators | Dryburgh, John L |
| Contributors | Davis, Jeffrey, Stout, Michael, Huang, Fangneng |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-07122015-144221/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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