外源激素处理对三峡消落带落羽杉扦插生根的影响

为优选落羽杉大龄母树插穗的扦插繁殖技术，以期培育大量的落羽杉良种壮苗满足三峡消落带植被修复的需要，采用正交试验设计，探究不同外源激素、浓度以及处理时间对三峡消落带落羽杉大龄母树插穗扦插生根的影响，运用隶属函数法对各处理生根情况进行综合评价。结果表明：（1）落羽杉插穗皮部和愈伤组织处均有不定根伸出，两处不定根数量分别占不定根总数的63.9%和36.1%；（2）4种外源激素中，吲哚丁酸（IBA）+萘乙酸（NAA）（等质量比）和IBA处理的插穗生根效果最好，NAA处理次之，生根粉（ABT）处理效果最差；（3）5种浓度（50 mg/L、100 mg/L、150 mg/L、200 mg/L和250 mg/L）之间的处理效果无显著差异；（4）4种处理时间（2 h、4 h、6 h和8 h）中，4 h处理的插穗生根效果最佳；（5）26个处理组合中，（IBA+NAA）×150 mg/L×4 h处理组合和NAA×250 mg/L×4 h处理组合的平均隶属函数值最高，分别为0.83和0.82，清水对照的平均隶属函数值最低，为0.05。研究初步验证了皮部生根是落羽杉大龄母树插穗的主要生根方式，筛选出三峡消落带原位适生落羽杉大龄母树插穗扦插的两种较佳处理组合为（IBA+NAA）×150 mg/L×4 h和NAA×250 mg/L×4 h。

Effects of exogenous hormone on rooting of Taxodium distichum cuttings from the hydro-fluctuation belt of the Three Gorges Reservoir

To optimize the cutting propagation technology of the Taxodium distichum for cultivating a large number of T. distichum seedlings to meet the needs of vegetation restoration in the fluctuating zone of the Three Gorges Reservoir, an orthogonal experiment design was used to explore the effects of different exogenous hormones, concentrations and treatment time on rooting of cuttings of elder T. distichum in the hydro-fluctuation belt of the Three Gorges Reservoir. Besides, the subordination function was used to comprehensively evaluate the rooting condition of the cuttings. Results showed that:(1) The number of adventitious roots protruding from the bark and the callus accounted for 63.9% and 36.1% of the total number of adventitious roots, respectively; (2) Among these 4 exogenous hormones, IBA+NAA (mass ratio 1:1) and IBA (Indolebutyric acid) had the best effectiveness, followed by NAA (Naphthalene acetic acid), and ABT rooting powder was the poorest; (3) There was no significant difference in facilitating rooting of the cuttings among the five concentrations (50 mg/L, 100 mg/L, 150 mg/L, 200 mg/L and 250 mg/L); (4) Among these 4 treatment times (2 h, 4 h, 6 h and 8 h), the treatment time of 4 h had the best effectiveness; (5) Among these 26 treatment combinations, (IBA+NAA)×150 mg/L×4 h and NAA×250 mg/L×4 h had the highest average subordinate function value of 0.83 and 0.82, respectively; and the control group had the lowest average subordinate function value of 0.05. In this study, it was preliminarily verified that bark rooting was the main way of rooting of the cuttings from elder T. distichum, and (IBA+NAA)×150 mg/L×4 h and NAA×250 mg/L×4 h were suitable treatments for cutting propagation of elder T. distichum in the hydro-fluctuation belt of the Three Gorges Reservoir.