中文摘要：

为探明苗龄、光照强度和施氮量对水稻主要防御酶活性的影响及其与抗褐飞虱的关系,分别就苗龄、光照强度和施氮量等因子对不同抗褐飞虱水稻品种苯丙氨酸解氨酶（PAL）、多酚氧化酶（PPO）和过氧化物酶（POD）活性的影响进行研究。结果表明：IR56、Ptb33和570011对褐飞虱生物型II的抗性与PAL和PPO活性密切相关,RHT对II型的抗性与PAL、PPO和POD活性密切相关,RP1976-18-6-4-2对II型的抗性与PAL活性密切相关,570011对II型的抗性与PAL和PPO活性密切相关;IR56对褐飞虱孟加拉型的抗性与PAL、PPO和POD活性密切相关,Rathu Heenati（RHT）和RP1976-18-6-4-2对孟加拉型的抗性与与PPO密切相关,570011对孟加拉型的抗性与POD活性密切相关。苗龄、光照强度和施氮量的单独作用或交互作用对不同水稻中防御酶活性有明显影响,但品种不同,其影响程度也不同。苗龄、光照强度和施氮量单独或是交互作用显著影响IR56中PAL和PPO、RHT和RP1976-18-6-4-2中PPO、Ptb33中POD及570011中PAL和POD的活性,苗龄显著影响IR56和RP1976-18-6-4-2中POD的活性,光照强度和施氮量单独或交互作用显著影响RHT和RP1976-18-6-4-2中PAL的活性,施氮量显著影响RHT中POD的活性,光照强度显著影响Ptb33中PAL的活性;苗龄和光照强度单独或交互作用显著影响570011中PPO的活性。

英文摘要：

In order to clarify the effect of seedling stage, light intensity and N application rate on the activities of defensive enzymes of rice and relationship with the resistance to brown planthopper （ Nilaparvata lugens）, the activities of phenylalnine ammonialyase （PAL）, polyphenol oxidase （PPO） and peroxidase＆amp;nbsp;（ POD） in different rice varieties were studied after treated with different seedling stage, light intensity and nitrogen （N） application levels. The results showed that the resistance of IR56, Ptb33 and 570011 to BPH biotype II was closely related with the activities of PAL and PPO, RHT to BPH biotype II was related with the activities of PAL, PPO and POD, RP1976-18-6-4-2 to BPH biotype II was related with the activities of PAL, and 570011 to BPH biotype II was related with the activities of PAL and PPO. The resistance of IR56 to BPH biotype Bangladesh was closely related with the activities of PAL, PPO and POD, resistance of RHT and RP1976-18-6-4-2 to BPH biotype Bangladesh was closely related with the activity of PPO and resistance of 570011 to BPH biotype Bangladesh was closely related with the activities of POD. The separate action or interaction effect of seedling stage, light intensity and N application rate on activities of defensive enzymes in rice was obviously, and effect degree different in different varieties. The separate action or interaction influence of seedling stage, light intensity and N application rate on PAL and PPO activity of IR56, PPO activity of RHT and RP1976-18-6-4-2 , POD activity of Ptb33 and PAL and POD activity of 570011 was significantly. POD activity of IR56 and RP1976-18-6-4-2 only significantly affected by seedling stage. The separate action or interaction effect of light intensity and N application rate on PAL activity of RHT and RP1976-18-6-4-2 was obviously. POD activity of RHT affected by N application rate and PAL activity of Ptb33 affected by light intensity was significantly. PPO activity of 570011 affected by seedling stage and light in