马尾松诱导挥发性有机化合物的快速变化

Rapid Changes of Induced Volatile Organic Compounds in Pinus massoniana

对马尾松进行未受害、接虫咬食为害、人工剪叶3种处理后,按不同的时间序列取样,用TCT-GC-MS分析叶片挥发物的成分及相对含量。结果表明:1)不同受害方式对马尾松挥发物的释放有不同影响。人工剪叶检测出的挥发物种类略少于虫害;释放高峰早于虫害。2)同一受害方式的不同受害程度对挥发物的快速诱导变化不同。与对照相比,轻度虫害后莰烯、β-蒎烯、水芹烯、石竹烯、(E)-法尼烯在1h升高,但挥发物相对含量出现高峰的时间没有明显的规律性,而重度虫害后三环萜、月桂烯、莰烯、β-蒎烯、水芹烯、石竹烯24h达到高峰;人工剪叶使马尾松轻度受害后,有些挥发物1h达到高峰,有些24h后才升至最高,相对含量出现高峰的时间没有明显的规律性;而人工剪叶重度损伤后,挥发物出现释放高峰的时间多在1h或2h。3)在整个快速诱导过程中,挥发物β-蒎烯的相对含量明显升高,72h仍高于对照,说明该化合物在马尾松的诱导抗性中具有重要作用。

Using TCT-GC-MS technique, the composition and relative contents of volatile compounds were analyzed in undamaged （control）, insect-damaged （ID） and artificially-damaged （AD） leaves of Pinus massoniana in field at different times and levels of damage. The results showed that, although volatile substances were highly released earlier in AD leaves plants, they were significantly less abundant in AD than in ID leaves treatments. Also, the damage level considerably influenced the changes of induced volatile products from leaves. Compared with the control, the emission rate of camphene, β-pinene, phellandrene, caryophyllene and （E）-farnesene was high after 1 h in 25% - 40% ID-affected leaves, whereas that of tricyclene, myrcene, camphene, β-pinene, phellandrene and caryophyllene reached its maximum after 24 h in 60 % - 75 % ID- affected leaves. In the same manner, some volatile compounds in AD leaves treatment displayed their peak just after 1 h, but others after 24 h. AD and ID leaves at 25% - 40% damage level did not exhibit an obvious regularity with time, however, in 60 % - 75 % AD leaves, peaks of volatile substances were attained after 1 or 2 h. The results also showed that the relative contents of β-pinene increased and was higher in damaged than control plants. β-pinene plays an important role in inducing insect resistance of P. massoniana trees.