关键词: 新疆野苹果, 苹果小吉丁虫, 抗虫性, 次生代谢物质, 营养物质

Abstract: In order to study the impact of nutrients, secondary metabolites of Xinjiang Wild Apple (Malus sieversii (Lebed.)Roem) on the threat of Agrilus mali Mats., this study took individual wild apple trees with various degrees of pest resistance as experiment material to find the relationship between nutrients, secondary metabolites of the trees and resistance to Agrilus mali Matsumura by correlation regression analysis method. The results indicated that there was significant difference in nutrients within individual apple tree with various degrees of Agrilus mali Matsumura resistance. In all cases, total soluble protein and soluble sugar in phloem, falling into a range of 4.02~21.72 mg/g, were significantly higher than that of xylem. Among all nutrients, the level of soluble protein of K2 was the lowest at 26.10 mg/g, while G1 was the highest at 45.74 mg/g. Generally, infected plants were higher in soluble protein than pest-resistant ones. Significant difference was observed in tannin, flavones, and total phenols contents within individual plant, featuring a lower content of flavones in phloem ranged from 0.31 to 0.89 mg/g , and a higher one between 1.93 and 4.05 mg/g in xylem. The average tannin content was 1.24 mg/g in pest-infected plants and 0.69 mg/g in pest-resistant plants. This significant difference means that the degree of pest resistance increases as the tannin content increases. In infected plants, G6 total phenols was the lowest at 1.43 mg/g, while in resistant ones K2 total phenols was the highest at 3.96 mg/g. The tannin content and total phenols content in xylem were significantly and positively correlated to resistance to Agrilus mali Matsumura. Namely, higher tannin and total phenols content led to better Agrilus mali Matsumura resistance and less damage from the pest. Nutrients content in Xinjiang wild apple was significantly and negatively correlated to Agrilus mali Matsumura resistance, while secondary metabolites content was significantly and positively correlated to Agrilus mali Matsumura resistance. Wild apple trees suffered less harm from Agrilus mali Matsumura as secondary metabolites level increases, which had some reduction and inhibition effects on the pest.