Abstract:Change of gibberellin (GA) in roots and leaves at tiller stage of two representative rice varieties, super-high-yield rice Peiai 64S/E32 and TN1, was studied with enzyme-linked immunosorbent assay (ELISA) to explore the relationship between rice tolerance and endogenous plant hormones under Nilaparvata lugens infestation. The results indicated that at the tiller stage, GA contents in roots of super-high-yield rice Peiai 64S/E32 at 3 days increased significantly after 60 or 90 nymphs/plant infestation, GA contents in roots and leaves of TN1 at 3 days also increased significantly after 30, 60 or 90 nymphs/plant infestation. However, GA contents in leaves of super-high-yield rice Peiai 64S/E32 at 6 days after 60 or 90 nymphs/plant infestation decreased significantly, so did GA contents in roots of TN1 at 6 days after 30 nymphs/plant infestation. These results showed that the two rice varieties had the same variation trend, GA contents in leaves and roots increased at 3 days, while decreased at 6 days after N.lugens infestation, but the change range of GA contents of tolerant variety was wider, the effective duration was shorter, and the ratio of GA contents in roots to that in leaves (R∶L ratio) did not show significant changes when compared with that of susceptible rice variety.