TY - JOUR
T1 - Acetonitrile (methyl cyanide) emitted by the African spider plant (Gynandropsis gynandra L. (Briq))
T2 - bioactivity against spider mite (Tetranychus urticae Koch) on roses
AU - Nyalala, Samuel Odeyo
AU - Petersen, Mikael Agerlin
AU - Grout, Brian William Wilson
PY - 2011/4/11
Y1 - 2011/4/11
N2 - 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 μL/L of air rendered 100% of the mites inactive. Removal of the compound after an initial exposure of up to 5.0 μL/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.
AB - 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 μL/L of air rendered 100% of the mites inactive. Removal of the compound after an initial exposure of up to 5.0 μL/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.
U2 - 10.1016/j.scienta.2011.01.036
DO - 10.1016/j.scienta.2011.01.036
M3 - Journal article
SN - 0304-4238
VL - 128
SP - 352
EP - 356
JO - Scientia Horticulturae
JF - Scientia Horticulturae
IS - 3
ER -