Effects Of Nitrogen Fertilizer On The Resistance Of Transgenic CrylAb Rice Against Cnaphalocrocis Medinalis(Guenee) And Rice Planthoppers

Nitrogen is a crucial factor for plant growth and applying nitrogen fertilizer is an important tactics to enhance crop development and yield.Increasing nitrogen can promote crop growth,however,at the same timeincrease the risk of pest occurrence.Pest management is more complex when nitrogen fertilizer is applied in Bt paddy fields.In this paper,we studied the effects of nitrogen fertilizer on physiological and biochemical traits of transgenic crylAb rice and its resistance to pests.It was determined that transgenic rice harboured greater resistance against Cnaphalocrocis medinalis Guenee(Lepidoptera:Crambidae)compared with non-transgenic rice.Only one larvae ofC.medinalis was found on non-nitrogen and normal nitrogen treatment of transgenic crylAb rice respectively.There were many more C.medinalis larvae in the non-transgenic rice and most of them appeared in the early stage.There were no significant difference in the amount of C.medinalis among nitrogen treatments.Rice planthoppers caused damage during the whole growth period of transgenic crylAb rice and non-transgenic rice,and most of them were nymphae.The whitebacked planthoppers appeared in the early stage and the brown planthoppers existed in the later stage.No significant differences were observed in the mean mass of the rice planthopper nymphae,whitebacked planthopper adults and brown planthopper adults among nitrogen groups.Nitrogen and transgenesis had no adverse effects on the ratio of female and wing type differentiation for the whitebacked planthoppers and brown planthoppers.Nitrogen fertilizer contributed to the expression of the CrylAb protein.The amount of CrylAb protein differed significantly according to stages and tissues.In booting stage,contents of nitrogen and amino acids in stem of rice increasedwith the increase of nitrogen fertilizer.Nitrogen could enhance the activity of SOD,CAT and POD.The result of oviposition preference of C.medinalis showed that C.medinalis preferred to lay eggs on non-transgenic rice with normal nitrogen treatment.The least amounts of eggs were laid intransgenic crylAb rice with low nitrogen treatment.Nitrogen and transgenic crylAb rice had no adverse effects on the oviposition preference of C.medinalis.