The Preliminary Study Of Biological Characteristic Of Powdery Midew And Its Host Resistance Responses

Recently , powdery mildew of Pugionium Gaertn. is major disease during aartificial domestication and cultivation. It resulted in leaf malformation and lower production. So it seriously affected the development and utilization of plant resources on Pugionium Gaertn. .In this paper, the disease symptoms and characteristics is observed records in detail. The biological characteristics of Pathogenicbacteria and physiological and biochemical changes of disease plant are researched deeply. The results is as follow:1. The powdery mildew of Pugionium cornutum (L.) Gaertn. belong to (Erysiple Cruciferarum(opiz) Junell)of Ascomycotina Erysiple .2. During the peak incidence of powdery mildew, the P.cornutum (L.) Gaertn disease index is 21.05, up to the anti-(MR) level. And ax P. d olabratum (L.) Gaertn. wing disease index is 75.93,up to the high (HS) level.3. The conidiophore of powdery mildew germinated rate decreased obviously when the temperature was under 5℃or above 30℃. It also can germinate in the situation whose relative humidity ranges 20% ~ 100%. Its germinated rates were respectively 62.25% and 79.11% in dark and scattered light. But its germination rates was only 33.34% in direct sunlight. It indicated that a strong light can inhibit their germination, and their germination rate is 0 in UV 30min irradiation.4. The natural condition, SOD,PPO,PAL,POD activity were all increase rapidly in disease-resistant and disease plants.the PAL,POD,PPO activity in disease-resistant plant were significantly higher than ones in disease plant. But SOD activity in disease-resistance plant was lower than the one in disease plant. So SOD,POD,PPO and PAL activity are interrelated to Pugionium Erysiphaceae resistance to powdery mildew .5. The natural condition, soluble protein content and chlorophyll a content in disease-resistant and disease plants were quickly decline but soluble sugar and MDA content were increased. So the content change of soluble protein, chlorophyll A, soluble sugar and MDA are interrelated to Pugionium Erysiphaceae resistance to powdery mildew .