Journal of Chemical Ecology (2003) 29, 1417-1433

Niels Agerbirk, Carl E. Olsen, Bo M. Bibby, Hanne O. Frandsen, Lea D. Brown, Jens K. Nielsen and J. Alan A. Renwick (2003)
A saponin correlated with variable resistance of Barbarea vulgaris to the diamondback moth Plutella xylostella
Journal of Chemical Ecology 29 (6), 1417-1433
Abstract: Two types of Barbarea vulgaris var. arcuata, the G-type and the P-type, differed in resistance to larvae of the diamondback moth (DBM) Plutella xylostella. Rosette plants of the G-type were fully resistant to the DBM when grown in a greenhouse or collected in the summer season, but leaves collected during the late fall were less resistant, as previously found for flea beetle resistance. The P-type was always susceptible. Extracts of resistant leaflets inhibited larval growth in a bioassay, and a growth-inhibiting fraction was isolated by activity-guided fractionation. A triterpenoid saponin (1) was isolated from this fraction and identified as 3-O-ß-cellobiosyloleanolic acid from spectroscopic data and analysis of hydrolysis products. The decrease in resistance of the G-type in the fall was correlated with a decrease in the level of 1, from 0.6-0.9 to <0.2 µmol/g dry wt. Compound 1 was not detected in the susceptible P-type. We conclude that 1 is correlated with the variable resistance of B. vulgaris foliage to the DBM.
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Link to article at publishers website
Database assignments for author(s): Niels Agerbirk, Jens Kvist Nielsen

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plutella xylostella	Wintercress (Barbarea)