Comparative phloem chemistry of Manchurian (Fraxinus mandshurica) and two North American ash species (Fraxinus americana and Fraxinus pennsylvanica).
Recent studies have investigated interspecific variation in resistance of ash (Fraxinus spp.) to the exotic wood-boring beetle, emerald ash borer (EAB, Agrilus planipennis). Manchurian ash (Fraxinus mandshurica) is an Asian species that has coevolved with EAB. It experiences little EAB-induced mortality compared to North American ashes. Host phloem chemistry, both constitutive and induced, might partly explain this interspecific variation in resistance. We analyzed the constitutive phloem chemistry of three ash species: Manchurian ash and North American white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash. Analysis of the crude phloem extracts revealed the presence of an array of phenolic compounds including hydroxycoumarins, a monolignol, lignans, phenylethanoids, and secoiridoids. Both qualitative and quantitative differences were observed among the three ash species. Hydroxycoumarins and the phenylethanoids, calceloariosides A and B, were present only in the phloem of Manchurian ash and might represent a mechanism of resistance against EAB.
Eyles
Alieta
A
Department of Plant Pathology, The Ohio State University, 201 Kottman Hall, 2021 Coffey Road, Columbus, OH 43210, USA. eyles.1@osu.edu
Jones
William
W
Riedl
Ken
K
Cipollini
Don
D
Schwartz
Steven
S
Chan
Kenneth
K
Herms
Daniel A
DA
Bonello
Pierluigi
P
D002851:Chromatography, High Pressure Liquid; D031661:Fraxinus / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D052585:Phloem / Q000737:chemistry*; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet