Articles
PHENOLICS IN RICE PHLOEM SAP AS SUCKING DETERRENTS TO THE BROWN PLANTHOPPER, NILAPARVATA LUGENS
Article number
381_100
Pages
691 – 694
Language
Abstract
The biochemical basis of resistance of rice plants to the brown planthopper, Nilaparvata lugens, was investigated.
Phloem sap samples of resistant and susceptible rice plants were screened for UV light-absorbing compounds by means of high performance liquid chromatography (HPLC). The presence of three flavonoid C-glycosides (schaftoside and two of its isomers) in rice phloem was established, and rice stem extract fractions containing these three flavonoids were used for feeding experiments with the planthopper.
Electronic monitoring of the feeding behaviour of the insect showed that the flavonoid mixture in concentrations similar to those in the stems of the resistant variety exhibited an ingestion inhibiting activity to N. lugens, but that there was hardly any inhibition when the flavonoid concentration was ten times lower.
Because a higher level of these phenolics was found in the resistant rice variety than in the susceptible ones studied, they may be involved in the resistance of rice against the brown planthopper.
Phloem sap samples of resistant and susceptible rice plants were screened for UV light-absorbing compounds by means of high performance liquid chromatography (HPLC). The presence of three flavonoid C-glycosides (schaftoside and two of its isomers) in rice phloem was established, and rice stem extract fractions containing these three flavonoids were used for feeding experiments with the planthopper.
Electronic monitoring of the feeding behaviour of the insect showed that the flavonoid mixture in concentrations similar to those in the stems of the resistant variety exhibited an ingestion inhibiting activity to N. lugens, but that there was hardly any inhibition when the flavonoid concentration was ten times lower.
Because a higher level of these phenolics was found in the resistant rice variety than in the susceptible ones studied, they may be involved in the resistance of rice against the brown planthopper.
Authors
R.J. Grayer, J.B. Harborne, F.M. Kimmins, P.C. Stevenson, H.N.P. Wijayagunasekera
Keywords
Oryza sativa, Gramineae, flavonoid C-glycosides, rice resistance
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