Study on Secondary Plant Compounds of Insect Resistant and Susceptible Rice Varieties

Abstract

Plant volatiles were extracted form leaved and leaf sheath of Supan buri 90, a variety of rice resistant to brown planthopper, Supan buri 60 and Tai chung Native 1, varieties of rice susceptible to brown planthopper, using steam distillation and solvent extraction method. The crude extracts obtained were subjected to analysis by capillary gas chromatography/mass spectrometry (GC/MS) operated in electron impact mode. Various types of volatile compound were identified and some volatiles were assumed to be involved in resistance of rice to brown planthopper due to their absence in susceptible rice varieties or their present in resistant rice variety. Among them was 3,7-dimethyl-2, 6-octadienal, a terpene aldehyde reported as main constituent of lemon-grass oil.