Comparison between volatile emissions from transgenic apples and from two representative classically bred apple cultivars
While most risk assessments contrast a transgenic resistant to its isogenic line, an additional comparison between the transgenic line and a classically bred cultivar with the same resistance gene would be highly desirable. Our approach was to compare headspace volatiles of transgenic scab resistant apple plants with two representative cultivars (the isogenic ‘Gala’ and the scab resistance gene-containing ‘Florina’). As modifications in volatile profiles have been shown to alter plant relationships with non-target insects, we analysed headspace volatiles from apple plants subjected to different infection types by gas chromatography-mass spectrometry. Marked differences were found between healthy and leafminer (Phyllonorycter blancardella) infested genotypes, where emissions between the transgenic scab resistant line and the two cultivars differed quantitatively in four terpenes and an aromatic compound. However, these modified odour emissions were in the range of variability of the emissions recorded for the two standard cultivars that proved to be crucial references.
KeywordsMalus × domestica Plant pathogen Herbivory Trophic interaction Volatiles Terpenes
This project was supported by a grant of the Swiss Federal Office of the Environment (BAFU) to S. Dorn, A.S. Rott and C. Gessler. We thank H.-R. Roth for statistical, C. Fornallaz and E. Connor for technical advice, and A. Najar-Rodriguez and D. Mazzi and two anonymous reviewers for useful comments on the manuscript.
- Cuéllar J (1991) Statistical process control for nonnormally distributed variables through the use of transformations. ASMC 91 Proceedings, pp 143–148Google Scholar
- Reissig WH, Weires RW, Forshey CG (1982) Effects of Gracillariid leafminers on apple tree growth and production. Environ Entomol 11:958–963Google Scholar