| Camellia oleifera is one of the four oil-bearing woody plants in the world. In China, its planting area is over 4,000,000 hectare. Exobasidium gracile(shirai) Syd becomes the restrictive factor of its quality and quantity because it is often exposed to the effects around Pure Brightness Day. But little the research was conducted on biological characteristics of the pathogen, and the pathology of Camellia oleifera blister blight. This study was carried out on the Camellia oleifera leaves affected. According to the research of the biological characteristics of Exobasidium gracile(shirai) Syd, the physiological and biochemical indicators or index, endogeneous hormones and components of soluble proteins in the leaves affected, we tried to find the law of the physiological and biochemical response of Camellia oleifera leaf affected. And this can help the future study of the interaction mechanism between Camellia oleifera and Camellia oleifera blister blight. The results are as follows:The study on biological characteristics of Exobasidium gracile(shirai) Syd indicated: it grew best in PDA culture medium; it could grow between 15～31℃, pH3～7, and ceased at＜10℃and＞35℃,＜pH2 and＞pH8; the optimal temperature and pH value were 25℃and pH5.5, respectively.Physiological and biochemical indicators were changed greatly after the effect. Chlorophyll and carotinoid contents kept descending, always obviously lower than the control, with 7.36% and 2.27% of the control at the worst stage. The activities of superoxide dismutase (SOD) and peroxidase (POD) had a falling tendency and always lower than the control. They went down by 87.6% and 67.4% respectively. Compared with the activities of SOD and POD, the contents of soluble sugar, free praline, melondialdehyde (MDA), and the activity of phenylalanine ammonialyase (PAL) showed great difference. They increased till the peak in the pink leaves, with 50.23mg·g-1FW,75.54ug·g-1FW,63.28umol·g-1FW and 20.8U·min-1·g-1Fw respectively. But in turn they descended.The content of endogenous hormones also showed a remarkable change. At first, the content of indolle-3-acetric acid (IAA) increased steadily and reached the first peak value of 19.98ug·g-1FW in the pink leaves, with 11.68 times of the control. Then it went down gradually. But again it ascended sharply, 22.2 times of the control. The content of absdisic acid (ABA) also changed obviously. It was 19.76% of the control in the dark red leaves, and then it kept increasing till 12.09% higher in the yellow leaves. But there was no ABA in the white leaves. The content of GA3 first increased by 61.47% in the pink leaves and in turn decreased. This study also discovered that there was a few IAA and ABA in the fermented liquid, but GA3 did not appear.According to the result of SDS-PAGE, the molecular weights of the leaves affected were from 14.4 to 66.2KD, with the concentration of 14.4-43.0KD. Compared with the control, about 15KD protein appeared, but about 20.8KD, 40.1KD and 67.2KD lost. Besides, there was a 24.1KD protein whose richness was always higher than that of the control. Also, a 24.1KD protein was higher only in the pink leaves. |
