Towards the development of ash varieties resistant to emerald ash borer
Abstract
The emerald ash borer (EAB; Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a destructive invasive beetle from Asia which has killed millions of ash trees (Fraxinus spp.) throughout North America. This phloem-feeding borer is capable of killing otherwise healthy trees and colonizes trees as small as saplings - most affected trees die within four years of colonization. Asian ash species (i.e., Manchurian and Chinese) appear to be more resistant to EAB than those native to North America (e.g., green, white, and black ash). In this project we use reciprocal and conspecific grafts of these five ash species to determine the extent to which resistance to EAB can be conferred to a scion when grafted onto resistant rootstock. Specifically, I addressed this question through the analysis of leaf associated volatile organic compounds (VOCs) of each grafted tree to determine the extent to which: 1) rootstocks influence the composition of VOCs of a grafted scion; and 2) herbivory by adult female beetles induces changes in the VOCs released by the reciprocal grafts. Volatile profiles of the ash species differed quantitatively and adult EAB feeding induced systemic changes in VOC profiles of grafted ash. This work may pave the way toward developing systems for propagating Fraxinus scions that are resistant to EAB and exploit potential phytochemical connectivity between roots and shoots.
Degree
M.S.
Advisors
Ginzel, Purdue University.
Subject Area
Entomology|Plant sciences
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