外源激素在金雀花扦插生根进程中的调节机制

摘要

In the present study,we treated the stem cuttings of Cytisus scoparius with one exogenous hormones,indole acetic acid (IAA)(900 mg/L) and control group to discuss the process of rooting relationship between the endogenous substance and pace of change to investigate the mechanisms underlying root formation in stem cuttings and to optimize stem cutting propagation techniques.The results showed that the exogenous hormone treatment had a significant effect on the rooting time and rooting traits of the cuttings,which reduced the time to adventitious root formation by 5 days.The rooting characters (rooting percentage 79.97％,main root number 13,main root length 71.68 mm) were 1.5-3.2 times of CK.In addition,the levels of soluble sugar,starch,soluble proteins and antioxidases dynamically changed,with the time to peak value or time to valley value of each parameter synchronized well with the initiation of adventitious roots.The contents of soluble sugar,starch and soluble protein in treatment and control group were in the trend of"V","V"and "A" in the process of rooting.However,exogenous hormone treatment accelerated the consumption of soluble sugars and starch and enhanced the accumulation of soluble protein (reduced the time to the valley or peak value by 10 days as compared to that of the control group and the valley or peak value of treatment were significantly higher than control group,which increased by 6.2％,86.1％ and 11.2％).The activities of POD in treatment and control group were in the trend of"V",and the activities of PPO and SOD all showed a "A" shape.However,exogenous hormone treatment significantly increased the activity of the three enzymes (reduced the time to the valley or peak value by 5 days as compared to that of the control group and the valley or peak value of treatment were significantly higher than control group,which increased by 8.7％,4.4％ and 7.8％).In conclusion,exogenous hormone treatment significantly accelerated the rate of nutrient metabolism and the synthesis of antioxidant enzymes (POD,SOD and PPO) and shortened the rooting cycle of cuttings,thus promoting the regeneration of adventitious roots.%以2年生金雀花实生苗为试验材料,采用IAA(900 mg/L)与清水(CK)处理插穗,分析了插穗生根过程中营养物质含量及抗氧化酶活性的动态变化,探讨了生根进程与内源物质之间节奏变化的关联性,旨在为揭示金雀花扦插生根机理、建立扦插繁殖技术体系提供理论依据.结果表明:外源激素处理对金雀花扦插生根时间及生根性状具有极显著影响,处理将不定根发生时间缩短了5d,各生根性状(生根率79.97％,平均根数13,平均根长71.68 mm)提高为CK的1.5～3.2倍.可溶性蛋白、碳水化合物及各抗氧化酶活性的动态变化表明,各指标的峰值或谷值的出现时间与生根进程高度契合,这反映了生根形态与其生理代谢之间具有高度的协同性.在生根进程中,处理和CK的可溶性糖、淀粉及可溶性蛋白质的含量均分别呈“V”、“V”和“A”的变化趋势,但处理加速了可溶性糖与淀粉的消耗速度及可溶性蛋白质的积累速度(三指标含量的谷值或峰值到达时间均比CK提前了10d,谷值或峰值大小分别比CK提高了6.2％、86.1％和11.2％);处理与CK的POD、PPO和SOD的活性均分别呈现“V”、“A”和“A”形变化趋势,然而处理显著提高了三种酶的活性(三指标活性的峰值或谷值到达时间均比CK提前了5d,谷值或峰值大小分别比CK提高了8.7％、4.4％和7.8％).综上所述,外源激素处理显著加快了营养物质代谢速度和抗氧化酶(POD、SOD和PPO)的合成进程,缩短了插穗生根周期,从而促进了不定根再生.