北美红枫‘十月光辉’扦插技术及生化分析

Cutting methodology and biochemical analysis of Acer rubrum‘October Glory Maple’

以当年生北美红枫‘十月光辉’枝条为试验材料,通过研究基质类型、生长调节物质和扦插时间等因素对插穗生根的影响,确定‘十月光辉’扦插快繁技术,通过分析插穗生根能力与扦插过程中生理特性间的关系,旨在为‘十月光辉’的种苗无性快繁提供理论依据。结果表明:以腐殖质土∶蛭石∶石英砂=3∶1∶1的质量比为扦插基质,用15 mg·L^(-1)萘乙酸(NAA)处理插穗基部30 min,在春季进行扦插时‘十月光辉’的生根效果最好,生根率达68%。生根过程中,插穗内可溶性糖和可溶性蛋白含量随扦插时间延长而下降,但经NAA处理的插穗内可溶性糖和可溶性蛋白的含量显著高于对照,表明插穗内可溶性糖和可溶性蛋白的积累与维持可能是决定‘十月光辉’扦插能否生根的主要因子。NAA处理的插穗基部皮4种酶活性变化规律不同,过氧化物酶(POD)和吲哚乙酸氧化酶(IAAO)活性显著低于对照,而过氧化氢酶(CAT)和多酚氧化酶(PPO)活性显著高于对照,表明插穗内IAAO、POD、CAT和PPO活性可通过调控插穗的生长素水平、活性氧含量及插穗褐化程度等间接影响生根能力。丙二醛(MDA)含量与插穗生根呈负相关,经NAA处理的插穗内MDA含量显著低于对照,表明NAA处理可降低插穗膜脂过氧化程度,有利于插穗生根。

Taking the annual branches of Acer rubrum‘October Glory Maple’as experimental objects,we studied the influence of substrate type,growth regulators,and cutting time on the rooting ability of cuttings.To develop fast propagation technology for‘October Glory Maple’cuttings,we analyzed the relationship between the rooting ability of the cuttings and their physiological characteristics during cutting.This study revealed dynamic physiological changes in‘October Glory Maple’that may provide a theoretical basis for the rapid propagation of‘October Glory Maple’by promoting fast,robust rooting of cuttings.Using humus soil∶vermiculite∶quartz sand=3∶1∶1 as the cutting substrate and 15 mg·L^(-1)(naphthalene acetic acid)NAA to treat the base of the cuttings for 30 minutes,the best‘October Glory Maple’rooting effect was observed with cuttings obtained in spring.Under these conditions,the rooting rate reached 68%.Throughout the course of treatment,the nutrient content in the cuttings decreased with cutting time.However,soluble sugar and soluble protein contents in cuttings treated with NAA were substantially higher than those of control cuttings(CK).The accumulation and maintenance of soluble sugar and protein levels in cuttings might be the main factors determining whether‘October Glory Maple’cuttings could take root.Changes in four enzyme activities in NAA-treated cuttings were different.POD and IAAO activities were significantly lower than those of CK,whereas CAT and PPO activities were significantly higher than those of CK.IAAO,POD,CAT,and PPO activities in cuttings can indirectly affect rooting ability by regulating their auxin levels,reactive oxygen species content,and degree of browning.MDA content displayed a negative correlation with rooting of cuttings.The MDA content in NAA-treated cuttings was significantly lower than that of CK,showing that NAA treatment could reduce the degree of lipid peroxidation in panicle membranes,which is beneficial in root cuttings.