外源IBA对裸花紫珠扦插生根和内源激素含量变化的影响

Effects of IBA Treatments on Adventitious Rooting and Endogenous Hormones Contents of Shoot Cuttings of Callicarpa nudiflora

以药用植物裸花紫珠(Callicarpa nudiflora)1年生半木质化枝条为材料,采用吲哚丁酸(IBA)5个浓度(0、1 000、1 500、2 000、2 500 mg/L)处理。每隔6 d从1 500 mg/L IBA浓度与对照处理插穗的基部取样1次,测定在生根过程中内源吲哚乙酸(IAA)、脱落酸(ABA)、赤霉素(GA3)、玉米素核苷(ZR)含量的变化。扦插80 d后,采用隶属函数法综合评价生根效果。结果表明:不同IBA浓度处理对插穗生根影响差异显著。与对照相比,IBA处理不同程度地提高了插穗的生根率、平均生根数、最长根长和平均根长,降低了偏根率。其中,以1 500 mg/L IBA处理生根效果最好,其生根率、根体积最大,综合评价指数最高。在裸花紫珠插穗根原基诱导和愈伤组织形成阶段,1 500 mg/L IBA处理可提高插穗基部IAA和GA3含量,降低ABA和ZR含量,IAA/ABA和IAA/ZR比值迅速升高。在不定根形成、发生及生长发育阶段,IAA含量下降,IAA/ABA和IAA/ZR比值逐渐降低。较低的内源ABA、ZR含量和较高的IAA、GA3含量及IAA/ABA、IAA/ZR比值,有利于裸花紫珠插穗半木质化插穗不定根的形成和发育。

The semi-wooden shoot cuttings of a medicinal plant Callicarpa nudiflora were collected and treated with indole-3-butyric acid （IBA） （concentrations 0, 1 000, 1 500, 2 000 and 2 500 mg/L） The endogenous hormones （IAA, ABA, GA3, ZR） contents of cuttings of 1 500 mg/L IBA treatment were detected every 6 days interval. Rooting responses were measured and assessed by using a comprehensive assessment index after 80 days in the greenhouse. The significant difference was found among the five treatments. IBA treatments （1 000, 1 500, 2 000 and 2 500 mg/L） increased rooting rate, average root number, the largest and average root length, root volume and decreased hyponastie root rate significantly. The maximum rooting rate, root volume, and the highest comprehensive evaluation index of rooting capacity were obtained in the treatment of 1 500 mg/L IBA treatment. In the phase of root primordium inducement and formation of callus, 1 500 mg/L IBA treatment increased the content of endogenous IAA and GA3 content of cuttings, inhabited the ABA and ZR activity, correspondingly increasing of the value of IAA/ABA and IAA/ZR. The content of endogenous IAA, and the value of IAA/ABA and IAA/ZR were gradually decreased when the adventitious root went to the period of formation and development phase treated by 1 500 mg/L IBA. The results demonstrated that the lower content of endogenous ABA and ZR, the higher content of IAA, GA3 and the rate of IAA/ABA and IAA/ZR, were beneficial to the formation and development of adventitious roots of semi-wooden shoot cuttings of C. nudiflora.