Acetonitrile (methyl cyanide) emitted by the African spider plant (Gynandropsis gynandra L. (Briq)): Bioactivity against spider mite (Tetranychus urticae Koch) on roses

作者：Nyalala S O; Petersen M A; Grout B W W^*

来源：Scientia Horticulturae, 2011, 128(3): 352-356.

DOI：10.1016/j.scienta.2011.01.036

• Gynandropsis gynandra
• Acetonitrile
• Spider mite
• Volatile emissions
• Repellent activity
• Rose

The African spider plant (Gynandropsis gynandra L. (Briq)) has repellent properties against spider mite on roses (Rosa hybrida L) when grown as a companion plant. Gas chromatography-mass spectrometry (GC-MS) has been used to identify potential volatile compounds in the foliar emissions of this plant that may contribute to the anti-mite properties. Acetonitrile (methyl cyanide) was the most abundant compound emitted by entire plants and detached leaves of five lines of both glasshouse- and field-grown G. gynandra, with only trace levels emitted by roses grown under similar conditions. A toxicity bioassay was conducted to evaluate the bioactivity of acetonitrile against spider mite, and >= 2.5 mu L/L of air rendered 100% of the mites inactive. Removal of the compound after an initial exposure of up to 5.0 mu L/L of acetonitrile allowed some 10% of the mites to recover mobility, but above this level no mobility was observed. This study provides a very strong indication that foliar emissions of acetonitrile by G gynandra are responsible, to a significant degree, for the spider mite repellent activity of the plant when used as an intercrop with roses.

• 出版日期2011-4-11