Document: CLA-3-42-9

Talking ramets: Induction of defense against herbivory in ramets by attack on connected ramets in the clonal plant Fragaria chiloensis .

GOLDSTEIN, B.*, P.ALPERT, C.HOLZAPFEL, A.L.MAFFUCCIO and H.A.PARAG

University of Massachusetts, Amherst, MA 01003-5810 USA ¹

Abstract:
In many plants, herbivory induces responses, including chemical defenses, that deter further herbivory. We hypothesized that clonal plants can transmit signals for the induction of chemical defenses against herbivores through connections between ramets and defend unattacked ramets against likely future herbivory. No test for such signal transmission between ramets of clonal plants appears to have been published before. Infection of ramets of Fragaria chiloensis (beach strawberry) with Tetranychus urticae (two-spotted spider mite) increased phenol concentration in connected, unattacked ramets. When these ramets were subsequently infested with mites, mite population growth was slower than on ramets connected to another unattacked ramet. These results strongly support the hypothesis that herbivory on one ramet of a clonal plant can induce chemical defense against herbivory in connected ramets. We conclude that ramets can "talk". Induced response in unattacked ramets appeared to be advantageous to the plant since it decreased herbivore performance. However, we could not show that clonal integration of induced defense also increased plant growth. Experiments in which total herbivore burden per clone is held constant are now testing this further.

Keywords: herbivory, induced-defense, clonal-plant

This abstract is being presented at: 4:30 PM in session:
Oral Session #48: Anti-Predator Responses: Fish to Sagebrush.