Table 1. Volatile emissiona by Brassica nigra HR+ (+) or HR− (−) plants in response to eggs of Pieris brassicae (PB) and Mamestra brassicae (MB) sampled at 24 or 72 h after oviposition.
| Treatment → | Uninfested | 24PB− | 24PB+ | 72PB− | 72PB+ | 24MB− | |
| ID | Compound ↓ | (N = 25) | (N = 5) | (N = 5) | (N = 5) | (N = 5) | (N = 5) |
| Aliphatic | |||||||
| 1 | 2-Methylpropanal | 11.56±2.2 | 7.97±1.5 | 17.93±4.8 | 3.57±0.8* | 6.63±1.0 | 4.47±1.3 |
| 2 | 2-Methyl-2-propenal | 23.78±4.6 | 12.19±0.5* | 34.63±9.7 | 5.36±1.3 | 8.06±1.2 | 9.26±1.5 |
| 3 | Ethyl acetate | 134.44±25.9 | 2.92±0.9 | 21.81±8.0 | 3.69±1.2 | 4.29±1.5 | 12.75±10.4 |
| 4 | 2-Methyl-1-propanol | 4.41±0.8 | 3.82±1.2 | 6.49±2.8 | 1.42±0.4 | 4.18±1.5 | 1.48±0.4 |
| 6 | 2-Butenal | 10.70±2.1 | 7.28±1.1 | 17.93±5.9 | 3.25±0.6* | 4.23±0.6 | 3.85±0.4 |
| 7 | 3-Methylbutanal | 12.33±2.4 | 8.16±1.8 | 17.44±3.1 | 5.63±1.8 | 6.64±1.4 | 4.45±0.6 |
| 8 | 2-Methylbutanal | 8.37±1.6 | 5.46±2.1 | 11.08±2.9 | 4.85±2.4 | 4.50±1.1 | 2.89±0.3 |
| 9 | 1-Methoxy-2-propanol | 134.94±26.0 | 192.25±81.7 | 244.20±78.9 | 41.31±10.6 | 87.75±53.5 | 63.17±14.1 |
| 10 | 1-Penten-3-ol | 189.90±36.5 | 64.13±9.9 | 396.15±115.0 | 34.91±15.8* | 253.93±134.9 | 187.68±61.9 |
| 11 | 2-Pentanone | 43.81±8.4 | 47.31±19.5 | 39.54±11.6 | 8.06±2.0* | 15.20±2.9 | 18.20±5.5 |
| 12 | 3-Pentanone | 53.60±10.3 | 36.34±22.2 | 68.65±29.7 | 8.25±2.0* | 78.72±43.8 | 37.48±12.4 |
| 15 | 4-Methyl-2-pentanone | 7.08±1.4 | 3.92±1.3 | 6.57±1.9 | 1.34±0.3 | 2.23±0.3 | 2.41±1.1 |
| 17 | (E)-2-Pentenal | 2.53±0.5 | 1.10±0.3 | 3.15±1.4 | 0.31±0.2* | 1.28±0.5 | 1.67±0.7 |
| 18 | 2,4-Pentanedione | 55.07±10.6 | 112.50±89.9 | 45.09±14.0 | 2.45±1.2 | 16.10±7.7 | 11.76±3.6 |
| 19 | 4-Methyl-3-penten-2-one | 68.92±13.3 | 64.25±35.2 | 37.59±7.7 | 8.67±2.5* | 23.77±11.2 | 15.84±5.8 |
| 20 | (Z)-3-Hexen-1-ol | 215.11±41.4 | 44.56±12.6 | 179.94±74.5 | 18.05±6.4* | 43.50±18.3 | 174.64±109.8 |
| 23 | 6-Methyl-2-heptanone | 29.31±5.6 | 17.21±2.5 | 34.10±4.7 | 6.63±0.7* | 15.83±2.8 | 16.36±2.8 |
| 24 | (Z)-3-Hexen-1-yl acetate | 573.69±110.4 | 105.04±18.8 | 422.09±111.9 | 45.69±12.3* | 171.72±65.4 | 478.74±173.1 |
| 28 | Methyl 2-ethylhexanoate | 2.81±0.5 | 1.47±0.7 | 3.69±1.1 | 1.29±0.5* | 1.98±0.7 | 0.87±0.5 |
| 38 | Undecan-2-one | 13.61±2.6 | 11.20±1.0 | 20.18±4.3 | 3.94±0.6* | 8.54±1.6 | 7.93±0.8 |
| Aromatic | |||||||
| 30 | o-Cresol | 36.76±7.1 | 33.26±15.6 | 49.88±7.9 | 7.51±1.2* | 17.50±2.7 | 18.05±3.4 |
| 33 | 2-Phenylacetonitrile (benzyl cyanide) | 8.91±1.7 | 4.82±0.6 | 10.27±4.4 | 1.91±0.3* | 4.39±0.8 | 3.31±0.9 |
| 47 | Lilial | 18.95±3.6 | 5.10±0.6 | 20.95±3.6 | 2.71±0.5* | 20.12±9.6 | 14.48±8.4 |
| 49 | 2-Ethylhexyl salicylate | 5.76±1.1 | 4.92±3.4 | 15.31±6.3 | 1.73±1.4 | 5.74±3.0 | 10.85±4.8 |
| Terpenoids | |||||||
| 22 | α-Pinene | 55.24±10.6 | 22.78±7.1 | 109.40±44.9 | 11.74±3.3 | 12.47±4.4 | 24.32±12.7 |
| 25 | 3-Carene | 48.16±9.3 | 17.96±8.9 | 75.99±22.3 | 5.72±1.5* | 13.73±4.7 | 25.93±13.3 |
| 26 | (S)-Limonene | 68.75±13.2 | 29.85±11.9 | 76.41±25.6 | 14.19±5.4 | 10.70±3.8 | 39.98±32.5 |
| 27 | α -Phellandrene | 10.15±2.0 | 10.19±4.8 | 11.52±3.0 | 1.83±0.8* | 11.75±7.0 | 10.99±2.6 |
| 29 | (E)-β-Ocimene | 5.97±1.1 | 22.69±6.6* | 82.28±42.2* | 4.55±2.1 | 5.42±2.0 | 3.68±2.0 |
| 32 | p-Mentha-1,5,8-triene | 8.91±1.7 | 3.60±0.9 | 14.75±3.2 | 1.63±0.7* | 3.01±0.7 | 4.36±1.3 |
| 34 | Isopulegon | 2.75±0.5 | 1.20±0.3 | 4.04±1.0 | 0.55±0.1* | 1.20±0.2 | 1.42±0.4 |
| 35 | p-Menthan-3-one | 4.62±0.9 | 1.67±0.7 | 4.02±1.9 | 27.09±25.8 | 23.60±21.9 | 2.53±1.6 |
| 36 | Isomenthone | 2.50±0.5 | 2.36±0.3 | 3.30±0.2 | 10.65±10.0 | 10.79±8.8* | 1.44±0.7 |
| Treatment → | Uninfested | 24PB− | 24PB+ | 72PB− | 72PB+ | 24MB− | |
| ID | Compound ↓ | (N = 25) | (N = 5) | (N = 5) | (N = 5) | (N = 5) | (N = 5) |
| 37 | Menthol | 25.64±4.9 | 14.95±4.4 | 31.32±7.1 | 47.74±42.9 | 53.01±40.8 | 14.64±2.8 |
| 39 | 7-α-H-Silphiperfol-5-ene | 88.22±17.0 | 151.09±61.2 | 363.17±116.3 | – | 13.70±13.5 | 15.88±15.9 |
| 40 | Presilphiperfol-7-ene | 13.36±2.6 | 15.13±7.6 | 83.12±34.4 | 0.06±0.1 | 6.81±6.8 | 0.61±0.6 |
| 41 | 7-β-H-Silphiperfol-5-ene | 32.16±6.2 | 46.07±17.4 | 143.24±55.6 | – | 4.82±4.8 | 5.11±5.1 |
| 43 | Silphiperfol-6-ene | 10.09±1.9 | 17.14±9.2 | 40.07±15.8 | – | 2.42±2.4 | 1.81±1.8 |
| 44 | α-Funebrene | 10.80±2.1 | 29.44±23.7 | 8.42±8.4 | 4.81±2.1 | 11.26±4.5* | 18.37±10.6 |
| 45 | Longifolen | 13.10±2.5 | 6.66±2.1 | 17.41±3.1 | 4.02±1.3 | 20.06±13.4 | 6.71±2.2 |
| 48 | Guaiazulene | 10.04±1.9 | 5.57±1.7 | 11.40±3.2 | 2.29±0.7* | 3.17±1.4 | 5.00±1.1 |
| 50 | Cembrene | 16.90±3.3 | 14.07±8.7 | 54.27±16.6 | 1.28±0.8 | 15.73±3.5 | 9.78±1.5 |
| N and/or S containing | |||||||
| 16 | 1,2-Dimethyldisulfide | 66.36±12.8 | 39.86±8.1 | 420.67±341.7 | 33.40±20.2 | 19.96±2.1 | 22.90±5,2* |
| 21 | Allyl isothiocyanate | 393.18±75.7 | 63.65±38.0 | 782.07±391.7 | 53.90±20.8* | 147.79±50.1 | 641.32±565.5 |
| 46 | 2-Phenylethyl isothiocyanate | 13.86±2.7 | 3.06±1.0 | 20.23±7.8 | 1.06±0.4* | 10.81±2.9 | 3.92±0.9* |
| Cyclic/Heterocyclic | |||||||
| 5 | Tetrahydrofuran | 2.49±0.5 | 1.96±0.2 | 4.66±1.3 | 1.37±0.4 | 1.07±0.2 | 1.65±0.8 |
| 13 | Methylcyclohexane | 11.56±2.2 | 5.20±0.8 | 19.64±8.4 | 3.79±1.7 | 4.08±1.2 | 6.73±2.3 |
| 14 | Pyrazine | 9.15±1.8 | 7.32±2.4 | 12.03±2.5 | 3.58±1.4 | 3.28±1.0 | 3.38±0.5* |
| 31 | 2,2,6-Trimethyl-4-methylene-2H-pyran | 21.35±4.1 | 55.11±47.3 | 12.36±2.9 | 3.43±1.9 | 6.20±2.3 | 9.69±5.5 |
| 42 | 4-(3-Cyclohexen-1-yl)-3-buten-2-one | 4.65±0.9 | 5.58±1.8 | 9.73±4.0 | 1.51±0.8 | 1.19±0.7 | 4.60±1.2 |
a
Volatile emissions are given in mean peak area ± SEM/g fresh weight of foliage divided by 105 with the number of replicates between brackets.
*
values with asterisk indicate significant differences in emission quantities between oviposition-induced B. nigra and uninfested control for each treatment (Mann-Whitney U-test).