Annals of Applied Biology (2006) 148, 17-26

A. Vikram, L.H. Lui, A. Hossain and A.C. Kushalappa (2006)
Metabolic fingerprinting to discriminate diseases of stored carrots
Annals of Applied Biology 148 (1), 17-26
Abstract: Volatile metabolites from headspace gas of carrot cv. Vita-treat inoculated with water or four different pathogens Botrytis cinerea, Erwinia carotovora subsp. carotovora, Aspergillus niger and Fusarium avenaceum were profiled using gas chromatography and mass spectrometry to develop a technology to discriminate diseases. The inoculation of carrot roots with water or different pathogens released a total of 137 different volatile metabolites. Among them, 39 compounds were relatively consistent and 11 were specific to one or more diseases/inoculations. E. carotovora subsp. carotovora produced seven disease-specific metabolites: 1-butanol, 3-methyl; 1-pentanol; 1-propanol, 2-methyl; 2,3-butanedione; boronic acid, ethyl; butane, 1-methoxy-3-methyl; and ethane, ethoxy. Some metabolites were disease/inoculation discriminatory and were not detected in all treatments: 1,2-dimethoxy-ethene was common in carrots inoculated with E. carotovora subsp. carotovora and B. cinerea, while 2-butanone, 3-chloro-4-hydroxy-1,4-diphenyl was common in carrots inoculated with E. carotovora subsp. carotovora, F. avenaceum and water-inoculated control. The significant mass ions, based on univariate analysis, from a total of 150 (46-195 m/z) and compounds from a total of 32 were further subjected to stepwise discriminant analysis and discriminant analysis. The models for 3 days after inoculation (DAI) were better than those for 6 DAI and 3 + 6 DAI, where up to 90% of the observations were correctly classified into respective inoculations. The disease-discriminatory compounds from different diseases/inoculations and discriminant analysis models developed here have the potential for the early detection and discrimination of postharvest diseases of carrot cv. Vita-treat, after validation under commercial conditions.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ajjamada C. Kushalappa

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
surveys/sampling/distribution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis cinerea	Stored fruits/vegetables
	Aspergillus niger	Stored fruits/vegetables
	Fusarium avenaceum	Stored fruits/vegetables
	Pectobacterium carotovorum	Stored fruits/vegetables