Delayed Changes in Chemical Substances Induced by Masson Pine Damage

Changes in chemical substances induced by damage from masson pine trees Wang Yan, Li Zhenyu, Ge Fengmin (Beijing Forestry University, Beijing 100083, China; 2. Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China) Effects of chemical substances in pine needles. The results showed that the secondary metabolites (tannins, phenols) induced by pests feeding on pine needles increased slightly compared with the manual cutting and the nutrient-soluble sugars did not change much. Three kinds of treatments were used to deal with the damage of Pinus massoniana to the pests, the damage to the leaves, and the undamaged leaves. Changes in the content of chemical substances in pine needles were followed for 3 consecutive years. As a result, it was found that whether pests were feeding or damaged, or the victims were cutting leaves, the contents of secondary metabolites in the needles were reduced, and the soluble sugar content was reduced until they were restored to their original levels after one year; the trend of protein changes was always The content of the victim treatment was higher than the content of the untreated treatment, indicating that the change in chemical substances induced after Pinus massoniana had a hysteresis characteristic.

245: A plant's induced resistance to insects refers to the tissue and chemical reactions made by plants after they are harmed by insects, including the necrotic reactions of plant tissues, changes in the quality and quantity of nutrients in the plants themselves, the secretion of toxic compounds, Produce chemical substances that attract natural enemies of pests. Depending on the length of the action generation, induced resistance can be divided into Rapidly induced-resistance and Delayed induced-resistance. The former refers to the influence of contemporary herbivorous insects, which generally reduces the fertility of insects by 5% to 10%; the latter is the effect of one to several successive generations of herbivorous insects, which can reduce the cumulative fertility of insects by more than 70%. As for how long and how long the induced resistance persists, it has not been reported at home and abroad. For 3 consecutive years, we tracked changes in chemical substances induced by Pinus massoniana post-damage. We investigated the effects of different victimization methods on these changes, aiming to analyze some mechanisms of the periodic occurrence of Dendrolimus punctatus from the perspective of nutritional ecology. Effectively carry out the ecological regulation of forest pests to provide a theoretical basis.

Fund Projects Chinese Academy of Sciences “Ninth Five-Year Plan” Key Support Projects Correspondence Author 1 Materials and methods 1.1 In each time series, the content of protein in pine needles treated by pests and leaf cuttings was lower than that of non-victim treatment. Analysis of variance showed that, except for August of 1996, there were significant differences in protein content in the leaves of Pinus massoniana treated at other times (P 3 summary and discussion experiments showed that the damage was caused by feeding on Pinus massoniana, cutting the leaves, or not After the three kinds of treatments, the content of secondary metabolites (tannins, phenols) in the needles changed gradually. After being dealt with by the victims, the contents of the secondary metabolites decreased, and they rose again in the second year, showing some regularity. The change of protein content in the needle was always victimized (insect and cut leaves) treated group was lower than the control group, indicating that there was a hysteresis effect in the change of chemical substances induced after the damage of Pinus massoniana, which may have a certain regulatory effect on the population of Dendrolimus punctatus. In addition, the volatile secondary metabolite (pinene) content released by Pinus massoniana is also closely related to its resistance to oviposition and resistance to feeding, and some volatile secondary metabolites may be found in the damaged needles of Pinus massoniana. The reduction, together with the reduction in the amount of leaf after the victim, will reduce the total volatile matter content, and it will not attract more female massonsidetail moths to lay eggs, and it will also affect the massontail caterpillars. The population of the next generation, which further provides some possible explanations for the mechanism of periodic outbreak of Dendrolimus punctatus from the perspective of nutrition ecology.

From the changes in chemical substances caused by P. massoniana subjected to insect pests and damaged leaves, the tannin content of secondary metabolites induced after the damage of pine caterpillars was higher than that of the manual cutting treatments, and the content of phenolic compounds and soluble sugars were different. Not obvious. Ge Feng et al. found that artificial leaf cutting simulation was similar to pest damage and also had a regulatory effect on the Dendrolimus punctatus population. Therefore, artificial leaf cutting simulation damage method can be used to properly cut pine needles to achieve the regulation of Dendrolimus punctatus population, ease caterpillar damage, and delay its outbreak.