Response Difference of the Defence Enzymes of Flue-cured Cultivars to Phytophora parasitica var.nicotiana

Four different resistance cultivars,Yun85(high resistance,HR),K326(middle resistance,MR),Jingyehuang(middle susceptibility,MS) and Hongda(high susceptibility,HS) were used to study SOD,POD,PPO and PAL active dynamic and relation with resistance after inoculation with Phytophora parasitica var.nicotiana.The result showed that compared with control,SOD,POD,PPO and PAL activity of difference resistance cultivars all appeared obvious increase after inoculation.And disease-resistant cultivar raise was rising faster than susceptible cultivars and keep higher activity.POD activity of resistance cultivars was earlier than susceptible cultivar.Rising range and holding time of PPO and PAL activity of disease-resistant cultivars were greater and longer than susceptible one.Correlation analysis showed that there was a positive correlation between SOD,POD,PPO and PAL and resistance.All above results demonstrated that there was obvious response difference of SOD,POD,PPO and PAL activity to P.parasitica var.nicotiana and was direct correlation with cultivar resistance.