Abstract: The small brown planthopper(SBPH),Laodelphax striatellus Fallén(Homoptera: Delphacide), is a serious pest in rice(Oryza sativaL．). Diaminobenzidine(DAB) hydrogen peroxide(H₂O₂) staining of rice leaf infested by SBPH indicated pest response was earlier in resistant rice than that in the susceptible． Accumulation of H₂O₂was detected in the resistant variety infested by SBPH for 3 days but not in the susceptible rice． The H₂O₂content declined gradually to the initial level in resistant rice cells but tended to increase in the susceptible rice with the damage extended． Observation with scanning electron microscope(SEM) on epidermis of affected rice leaves indicated that wound healing likely caused by some substance secreted by rice was found in the resistant variety and then protected the infected seedling but not existed in the susceptible． Observation with(TEM) on ultrastructure of rice leaf cells showed the chloroplast structure was integrate，Whose grana thylakoid and lamellar structure were intact in resistant rice but disordered arrangement of the internal chloroplast structure appeared in the susceptible variety infested by SBPH for 3 days． Chloroplast membrane structure dissolved in both tested rice and was loose and disordered in susceptible rice but lamellar structure still existed and arranged orderly when the tested rice seedling was infested for 6 days．

Key words: Rice, Small brown planthopper, Reactive oxygen species, Ultrastructure

CLC Number: 

• S435