IBA对芍药扦插生根的影响及生根过程中相关酶活性的变化

Effects of IBA on Stem Cutting and Activity of Related Enzymes During Rooting of Paeonia lactiflora Pall.

以芍药‘大富贵’品种为材料,用1000、2000和3000mg·L-13个浓度的IBA处理进行扦插对比试验,研究其生根过程中过氧化物酶(POD)、多酚氧化酶(PPO)、吲哚乙酸氧化酶(IAAO)活性的动态变化。结果表明:IBA处理极显著地提高了插穗的生根率、根数和总根长,其中以2000mg·L-1为IBA最佳生根浓度,将生根周期缩短18d,并明显提高了生根质量。在生根过程中,插穗中POD、PPO活性分别呈现"缓慢上升→下降→急剧上升→下降"和"降→升→降"的变化趋势,但与对照组相比,处理组的变化更为剧烈,峰值出现提前了18d。IAAO活性在对照和处理中呈现不同的变化趋势:前者为"升→降→升",而后者为"降→降→升"。此外,高活性的POD、PPO有利于不定根的形成,低活性的IAAO则促进生根。

Effects of IBA at various concentrations on the rooting formation of stem cuttings of Paeonia lactiflora ＇ Dafugni＇ was investigated. Changes in activities of peroxidase （POD） , polyphenol oxidase （PPO） and indoleacetic acid oxidase （IAAO） during rooting were also investigated. The rooting percent, the number and total length of roots significantly increased as the cuttings were pretreated with IBA at various concentrations. The pretreatment with 2 000 mg·L^-1 IBA exhibited the best rooting responses, i. e. 18 days of rooting in advance and significantly improved quality of the adventitious roots. POD and PPO activities showed the trend as slow increase and then decrease, followed by rapid increase and then decline, and decrease, then and final decrease, respectively. A similar trend existed between IBA-treated and non-IBA-treated cuttings. However, the activities of the two enzymes in IBA-treated cuttings changed more sharply and the peak in their activities appeared 18 d earlier than those of non-IBA-treated cutting. IAAO activity of non-IBA-treated cutting maintained a high level increased, then declined, and finally increased, while in IBA-treated cuttings it declinedand then increased, during rooting. The high activities of POD and PPO and low activity of IAAO appeared to be suitable indexes for rooting.