Research Of Diapause Characteristic Of Carposina Sasakii And Physiological Adaptation Of Fruit Damaged By C. Sasakii

Carposina sasakii causes the most serious and common damage to the fruit trees in the northern China, it overwinters by diapause of mature larvae. It borer holes to fruits and cause them losing value, it also causes great harm to the quality of fruit in C hina. In this study we measured the changes of several key enzymes related to diapause of C. sasakii, and compared the changes of the resistance and physiological and biochemical indexes of three apple varieties—Gala, Jonaglod, Golden Delicious after artificial inoculation of C. sasakii, thus provide theories to wintering adaptation mechanisms and sustainable management of C. sasakii?s and plant of fruit trees. The results are as follows: 1.Changes of five metabolic enzymes activities of Carposina sasakii diapause during wintering.The activities of four metabolic enzymes(trehalase, hexokinase, pyruvate kinase, alkaline phosphatase) were significant differences at different time of diapause, but sorbitol dehydrogenase activity had no significant difference. The highest activity of trehalase appeared in the early diapause, then gradually decreased with the prolongation of diapauses duration. Hexokinase activity was low at early diapause, then with the prolongation of diapauses duration increased rapidly and decreased rapidly. Pyruvate kinase activity reached the highest level in the mid-diapause, but the highest alkaline phosphatase activity appeared in the early diapause. This indicated that C. sasakii improve their cold tolerance by regulating metabolic enzymes during the winter, and ensure to get through winter. 2. The influence of Carposina sasakii on physiological metabolism of different apple varieties.The results showed that Gala had more wormholes than Jonagold and Golden Delicious with the damage of C. sasakii(P<0.05), and no significant difference were discovered between Jonagold and Golden Delicious. The soluble protein content was increased in all 3 varieties induced by C. sasakii damage, and had no significant differences with those without damage, but significantly lower than artificial needling. Compared with those without damage, the SOP activity in Gala and Golden Delicious damaged by C. sasakii increased, in Jonagold reduced significantly, but all significantly higher than artificial needling. The POD activity was increased significantly in all 3 varieties induced by C. sasakii damage, and in Jonagold and Golden Delicious were significantly higher than in Gala, but had no significant difference with artificial needling. There was not significant difference among the CAT activities in all three cultivars between induced by C. sasakii damage and those without damage, but higher than needling ones. The damage of C. sasakii could induce a series reactions in host-plants. Gala had more wormholes than Jonagold and Golden Delicious, but the activity of POD in Jonagold and Golden Delicious were significantly higher than in Gala. 3. The space transmission of induced resistance of Fuji apple trees.The protein concent of Fuji apple with the damage of C. sasakii was higher than control and those without damage, and had significant difference with control; The activity of SOD was higher than control and those without damage, the activity of control was the lowest of all treaments; the activity of POD was higher than control and those without da mage, and had significant difference with control, and no significant difference was discovered between control and those without damage; the activity of CAT was lower than control and those without damage, and the activity of control was the highest of all treaments. Study shows that, Fuji apples damaged by C. sasakii can transmit the harmful signals to the nearby fruits and cause the changes of defensive enzymes activities of these fruits, but the harmful signals can not transmit to the fruits far from the damaged fruit.