Dynamics Of Eu₂O₃ Content In Both Rice Plants And Insect Body Under Nilaparvata Lugens (St(?)l) (Homoptera: Delphacidae) Infestation

Changes of Eu2O3 content in roots, stems and leaves at the tillering stage of two representative rice varieties under N. lugens nymph infestation were studied using rare-earth element as a fluorescent tracer. Results were as followings:1,Under soil culture condition, rice plants at the tillering stage of two representative rice varieties, Shenyou 1 and Xieyou 963, were subjected to N. lugens nymph infestation at three densities(30,60 and 120 nymphs per hill) for 3 and 6 days. Eu2O3 content of Shenyou 1 was more sensitive to N. lugens infestation than xieyou 963, with significant reduction of Eu2O3 contents in roots, stems and leaves at 3 and 6 days after 30,60 and 120 nymphs infestations compared to Xieyou 963. The influence of N. lugens on Eu2O3 contents in roots, stems and leaves were complex, depending significantly on both infestation duration and density. In CK experiments, Eu2O3 content of Xieyou 963 was lower than Shenyou 1.2,Under the soil culture condition, Eu2O3 content of N. lugens nymph which feed on Shenyou 1 was higher than that on Xieyou 963. Eu2O3 content in insect body was also related to N. lugens density. Eu2O3 content in N. lugens body for 30 nymphs per hill was lower than that for 60 nymphs per hill, but higher than that for 120 nymphs per hill. Eu2O3 content in N. lugens nymph which feed on Xieyou 963 decreased with increase of density. Eu2O3 content of insect body at 6 days after N. lugens infestation increased compared to at 3 days significantly, with significant high Eu2O3 content on Shenyou 1 compared to on Xieyou 963.3,Under the water culture condition, Eu2O3 content in Shenyou 1 was more sensitive to N. lugens infestation than Xieyou 963, with significant reduction of Eu2O3 contents in roots, stems and leaves at 3 days after 30 and 60 nymphs infestations compared to Xieyou 963. Influence of N. lugens infestation on Eu2O3 contents in roots, stems and leaves was complex, depending significantly on both infestation duration and density. In CK experiments, Eu2O3 content in Xieyou 963 was lower than Shenyou 1.4,Under the water culture condition, Eu2O3 content in N. lugens nymph which feed on Shenyou 1 was significantly higher than that on Xieyou 963. For Shenyou 1, Eu2O3 content in insect body at 60 nymphs per hill was higher than that at 30 nymphs per hill. In contrast, Eu2O3 content in N. lugens which fed on Xieyou 963 decrease with increase of density.5,Under the water culture condition, honeydew amount produced by N. lugens which fed on Shenyou 1 marked with Eu2O3 showed a significant difference compared to control (non-marked). In contrast, there was no significant difference on honeydew amount of N. lugens between on marked Xieyou 963 and on non-marked. But honeydew amount produced by N. lugens showed a significant difference between two rice varieties. Eu2O3 content in N. lugens which fed on marked rice plants had a significant difference between two varieties, however, Eu2O3 content in N. lugens which fed on non-marked rice plants between two varieties. For the same rice varieties, Eu2O3 content in N. lugens body showed a significant difference between marked and non-marked rice plants.