Abstract:
【Objective】The variation of rice volatiles induced by rice planthopper was determined to provide theoretical basis for for the development of new chemical insecticides and the mechanism of rice resistance to rice planthopper.【Method】YD1665, a rice material with a high resistance to planthopper and TN1, a susceptible material to rice planthopper, were infested by rice planthopper for 0 h or 12 h.They were expressed as Y0, Y12, T0 and T12.The volatile compounds of Y0, Y12, T0 and T12 were extracted before and after rice planthopper feeding by solid-phase microextraction(SPME), and determined by the method of gas chromatography-mass spectroscopy(GC-MS).【Result】The analysis of constitutive volatiles of rice showed that contents of 2-hexenal, leaf alcohol and β-ionone were high in both T0 and Y0.But some components of volatile chemicals were obviously different between them.It was only detected in Y0 for 2-pentanone and 2, 2, 4, 6, 6-pentamethyl-heptane, whilst it was only detected in T0 for 2-ethyl furan and hexadecanal.The analysis of induced volatiles of rice showed that ketones represented by 2-pentanone was the main constituent volatiles of Y12, while aldehydes represented by 2-hexenal was the main constituent volatiles of T12.It was only detected in Y12 for major substances such as 2-pentanone and 2, 2, 4, 6, 6-pentamethyl-heptane, while it was only detected in T12 for major substances such as 2-ethylfuran, pentadecanal, (E, E)-2, 4-hexadienal and(E, E)-2, 4-heptadienal.2-hexenal and β-ionone were the main volatile components in both Y12 and T12.The comparison in volatiles of rice before and after planthopper induction showed that the number of volatile kinds increased in both Y12 and T12 after induction.There were the most obvious changes in content of alkanes, ketones and alcohols in Y12 induced by planthopper.However, there were a little change in T12.There were large variation range in several volatile matters such as 2-pentanone, methyl salicylate, hexanal, heptadecane, leaf alcohol, (E)-2-hexen-1-alcohol and 2, 6-dimethyl-cyclohexanol.There were large variation range in several volatile matters of in Y12, such as pentadecanal, beta-cyclocitral, hexadecanal, (E)-2-hexene-1-alcohol, leaf alcohol, βionone and isopropyl myristate.【Conclusion】There are large variation range in some volatile matters including salicylate methyl ester, isopropyl myricolate, 2-pentanone, β-ionone, pentadecanal, hexadecanal, (E)-2-hexene-1-alcohol, leaf alcohol, hexanal and 2, 6-dimethyl-cyclohexanol after planthopper induction.There might be a close relationship between these substances and rice resistance against planthopper.