【目的】研究不同处理对元宝枫嫩枝扦插生根的影响,筛选出适合元宝枫嫩枝扦插的最佳处理,分析营养物质含量、酶活性变化与插穗生根的关系,初步探究元宝枫的生根机理。【方法】以幼化和3年生的元宝枫母树为材料,分析生长调节剂(IBA、NAA、生根液)浓度、采穗部位(上部、下部)、幼化处理和扦插时间(6月和9月)等因素对元宝枫扦插生根的影响,调查生根率、愈伤率、根数、根长等生根指标,测定生根过程中营养物质(可溶性糖和可溶性蛋白)含量、氧化酶[过氧化物酶(POD)、多酚氧化酶(PPO)、吲哚乙酸氧化酶(IAAO)]活性的变化。【结果】IBA和NAA处理的最适质量浓度分别为500和800 mg/L,生根率分别为59.3%和52.7%;生根液处理的最适浓度为体积分数1.43%(稀释70倍),生根率为43.9%,三者之间差异显著,经生长调节剂处理后插穗各生根指标均优于对照。此外,6月扦插的生根效果优于9月,幼化处理插穗生根效果优于3年生母树,上部插穗扦插生根效果优于下部插穗,且上述处理均达到显著差异水平。插穗生根过程中,处理组可溶性糖含量的变化呈现先下降后上升的变化趋势,可溶性蛋白含量、POD及PPO活性整体呈先上升后下降的变化趋势;而IAAO活性呈下降—上升—下降的变化趋势。对照变化趋势与处理组大致相同,但处理组峰值出现时间均比对照提前了5~10 d。【结论】元宝枫不定根发生属于混合生根类型。幼化母树的上部插穗使用IBA 500 mg/L处理各生根指标均达到最优,生根率为81.3%。生长调节剂处理可以提高营养物质代谢速度和相关酶合成进程,对插穗生根有促进作用。

【Objective】 In order to investigate the effects of different treatments on the rooting of softwood cuttings of Acer truncatum and find the best treatment method. We analyzed the relationship between changes in nutrient content, oxidase activity, and rooting of cuttings, and preliminarily explored the rooting mechanism of A. truncatum. 【Method】 Using rejuvenated A. truncatum trees and three-year-old A. truncatum mother trees as study materials, we conducted an analysis of the effects of growth regulators [indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) and a rooting solution], cutting positions (upper and lower parts), rejuvenation, and cutting time (June and September) on the rooting of A. truncatum. Furthermore, we examined the rate of root growth, callus formation, number of roots, root length, and other indicators of root development. Additionally, changes in nutrient contents (soluble sugar and soluble protein) and changes in oxidase activity [peroxidase (POD), polyphenol oxidase (PPO), and indole-3-acetic acid oxidase (IAAO)] were measured during the rooting process. 【Result】 The optimum IBA and NAA concentrations were 500 and 800 mg/L respectively, and the rooting rates were 59.3% and 52.7%, respectively. The optimal concentration for the rooting solution was a 1.43% volume fraction (70-fold) dilution, which achieved a rooting rate of 43.9%. Significant differences were observed among the three treatments, with all rooting indexes of cuttings treated with growth regulators performed better than those of the control. Additionally, the rooting effect of cuttings in June was better than that in September; the rooting effect of rejuvenated mother trees was better than that of 3-year-old trees; and the rooting effect of upper cuttings was better than that of lower cuttings. There were substantial differences observed following these treatments. During the rooting of the cuttings, the changes in the soluble sugar content following the treatment displayed a decreasing trend followed by an increasing trend. The soluble protein content, POD activity, and PPO activity initially increased and then decreased. However, the IAAO activity displayed a trend of decrease-increase-decrease. The control group exhibited a similar changing trend to that of the treatment group, but the peak time for the treatment group was 5-10 days earlier than that of the control. 【Conclusion】 The adventitious root formation of A. truncatum was categorized as a mixed rooting type. When the upper cuttings of rejuvenated mother trees were treated with IBA 500 mg/L, all rooting indexes were optimized, and the rooting rate peaked at 81.3%. Growth regulator treatment can improve the metabolism rate of nutrients and the synthesis process of related oxidase, and has a facilitative effect on the rooting of cuttings.