Abstract

The differences in composition and concentrations of volatile allelochemicals between transgenic Bacillus thuringiensis (Bt) cotton and non Bt cotton leaves were compared and analyzed by using gas chromatography-mass spectrometry (GC-MS). The dominant compounds present in both non Bt and Bt cotton leaves were α-caryophyllene (4.62, 1.42), β-myrcene (3.67, 3.68), β-carene (0.31, 0.80), benzene acetaldehyde (0.88, 0.48), heptanoic acid (2.0, 0.67), 1-methoxy, 2-methyl benzene (0.67, 0.30) and acetic acid, phenyl methyl ester (4.32, 2.48). The differences in main components and ratios of volatile allelochemics between Bt cotton and non Bt cotton suggested that, the expression of Bt toxin protein in cotton was found to have an impact on their volatile profiles.

Key words: Bt cotton (RCH₂ Bt), non-Bt cotton, gas chromatography-mass spectrometry (GC-MS).