灰茶尺蠖为害诱导茶树释放的互利素的鉴定

Identification of Synomones Emitted from Tea Plants Damaged by Ectropis grisescens

为鉴定灰茶尺蠖为害诱导茶树释放的互利素,遂以SDE法提取灰茶尺蠖为害茶梢和正常茶梢挥发物,经GC-MS检测,分别鉴定出31和25种组分,二者总含量相对于等剂量内标的含量分别是1863.8%和1124.6%。与正常茶梢相比,灰茶尺蠖为害茶梢挥发物中苯甲醛、反-2-癸烯醛、吲哚、水杨酸、反-2-己烯醛和己醛含量显著增加。将灰茶尺蠖为害茶梢挥发物的18种主要组分分别溶于液体石蜡制成10^-4 g/m L味源,以Y形嗅觉仪检测茶尺蠖绒茧峰对味源的趋性;与液体石蜡相比,苯甲醛、水杨酸、反-2-己烯醛和己醛诱效显著,反-2癸烯醛、4-庚烯醛和吲哚的诱效明显,其他11组分无明显诱效。再将前7种组分配成10^-2g/mL引诱剂,分别载于橡皮头制成诱芯,附于芽绿粘板上,在茶园茶尺蠖绒茧蜂盛发期实施诱捕,携带前4种诱芯的芽绿粘板诱捕的蜂数明显多于后3种、且显著多于无诱芯的芽绿粘板,而且携带10^-2 g/mL苯甲醛、水杨酸和反-2-己烯醛等量混合物诱芯的诱效最强。认为苯甲醛、水杨酸、反-2-己烯醛和己醛是灰茶尺蠖取食诱导的茶树互利素。

In order to identify the synomones released from tea plants damaged by Ectropis grisescens, the volatile compounds from E. grisescens-damaged tea shoots(EGDTS) and the intact tea shoots(ITS) were collected by the simultaneous distillation extraction method(SDE), and then detected by gas chromatography coupled of mass spectrometer. Thirty-one and twenty-five components were respectively identified, and the total contents of these volatile components from the two samples relative to internal standards of the same quality were respectively 1863.8% and 1124.6%. Compared with the volatiles from ITS, ample benzaldehyde, E-2-decenal and indole were detected in volatiles from EGDTS and contents of salicylic acid, E-2-hexenal and hexanal were significantly higher. The eighteen principal components identified from EGDTS were respectively dissolved in liquid paraffin to make a series of odor sources at 10^-4 g/mL, and responses of the parasitic wasp Apanteles sp. to these odors were observed using Y-tube olfactometer. The results showed that benzaldehyde, compared with liquid paraffin, benzaldehyde, salicylic acid, E-2-hexenal and hexanal significantly attracted the wasps, E-2-decenal, 4-heptenal and indole showed obvious attraction, while the other eleven components showed no attraction. The seven components showing attractive activities were further prepared as attractants at 10^-2 g/mL and then loaded onto rubber septa. A rubber spetum was singly attached on a bud green sticky board and used to trap the parasitic wasp at its peak occurrence. The wasp catches of the former 4 components were obviously more than those of the latter 3 components, and significantly more than those of the blank control. Especially, the blend of equal amount of benzaldehyde, salicylic acid and E-2-hexenal at 10^-2 g/mL showed the strongest attraction. Therefore, benzaldehyde, salicylic acid, E-2-hexenal and hexanal are the synomones of tea plant induced by E. grisescens.