Study On Some Physiological And Biochemical Characters Of Resistance To Late Blight In Potato

The paper got further research on the difference and change in cell defence enzyme,cytohydrolists and cell active oxygen in six resistant(tolerance) and susceptible potato variety during the inoculation and non-inoculation period by using a method of comparative physiology. Clarified the physiological characteristics of potato to P . infestans. The major results studied in the paper are abstracted as follows:1. The cell defence enzyme(POD,PPO,PAL),cytohydrolists(β-1,3-glucanase) and cell active oxygen(CAT,SOD,APX,O2-.,ASA)owe the low component expression level in the healthy plant.The activieties of cell defence enzyme,cell wall hydrolytic enzyme and the metabolism rate of cell active oxygen growed rapidly in the inoculation period.The region of the resistant variety was larger than the susceptible ones.2. During the phase of the pathogen infecting, the incresing amount of the activities of PPO,POD and PAL in the resistant varieties were higher than it in the susceptible ones,and the time of it lasted longer . Clarified the phenolic compound metabolism was the most important component in the mechanism of potato diseace resistance.3. The activities of theβ-1,3-glucanase enzyme growed gradually during thegrowth procedures, the pathogen infecting induced the activity ofβ-1,3-glucanase enzyme increase.The enzyme in the susceptible ones growed slowly.In addition,the enzyme in the resistant ones growed rapidly.4.The metabolism rate of cell active oxygen increaseed in the potato inoculation period, the resistant varieties had higher CAT,APX activities,the produce rate of O2-.and the content of AsA than the susceptible ones;the increasing of the produce rate of O2-. Leaded to the growth of the activities of SOD,CAT,APX.However, Anti-Oxidant nonenzyme system-AsA content improved. They all took part in the clear up the active oxygen in potato, so as to keep the banlance of oxygen metabolism .5.In the healthy potato plants,the activities of PPO,PAL,POD,APX and the content of AsA could be regarded as the inheret resistance indexs;In the phase of the pathogen infecting,PPO,POD,SOD,APX,β-1,3-glucanase activities and AsA,O2-. content could be used as the inducing physiological indexes.