摘 要

纳塔栎（Quercus nuttallii）是壳斗科（Fagaceae）栎属（Quercus)的落叶乔木，树体高大挺拔，秋季叶色变红，极具观赏价值，且具有较强的耐涝能力，具有在我国长江中下游平原地区推广的潜力。目前，纳塔栎的繁殖方式主要是种子繁殖，鲜有关于其无性繁殖的报道。本文通过研究不同基质以及不同激素处理对纳塔栎插穗生根过程中相关酶活性和内源激素含量的影响，揭示纳塔栎插穗生根机理，为纳塔栎无性系快繁提供科学依据。试验结果如下：

（1）以200 mg/kg ABT处理的插穗为材料，以珍珠岩为基质，研究纳塔栎扦插生根过程中营养物质含量的变化。结果发现，可溶性糖含量先下降后上升再下降；而淀粉含量出现两个峰值，激素处理显著提高了淀粉含量；可溶性蛋白大致呈现先上升后下降的变化趋势。

（2）扦插过程中，POD和PPO活性均出现两个峰值，且变化趋势相同。高活性的POD有利于增强插穗的抗逆性；而PPO对愈伤组织和不定根的形成有着促进作用，处理组PPO活性显著高于对照组。SOD活性在扦插初期上升，达到峰值后降低；MDA含量在初期短暂上升后持续下降，且含量低于对照组。

（3）本试验中，GA₃、ZR、ABA呈现先上升后下降的变化趋势，IAA则在下降后再次上升。高含量的GA₃有利于愈伤组织的形成；愈伤组织的出现伴随着ZR含量的降低，而随着不定根生成，由于自身合成了ZR，含量小幅上升；ABA对插穗生根有抑制作用，处理组插穗基部ABA含量始终低于对照组；较高浓度的内源IAA有利于愈伤组织的产生以及根原基的分化和生根；IAA/ABA值较小，这可能是纳塔栎扦插生根率较低的原因之一，激素处理的插穗基部IAA/ABA值高于对照组。

关键词：纳塔栎；嫩枝扦插；基质；外源激素；生根机理

A study on rooting mechanism of Quercus nuttallii softwood cuttings

Abstract

Quercus nuttallii is a deciduous tree species which belongs to the genus Quercus of Fagaceae family. It is tall and majestic with reddish leaf color in autumn. This species has great ornamental value and strong waterlogging tolerance. Quercus nuttallii has the potential of being promoted in the middle and lower reaches of the Yangtze River in China. At present, the main way of propagation of Quercus nuttallii is seed propagation, with few reports about its clonal propagation. The effects of different substrates and different hormones on related enzyme activities and endogenous hormone contents of Quercus nuttallii cuttings are studied in this thesis, revealing the rooting mechanism of Quercus nuttallii cuttings and providing a scientific basis for rapid clonal propagation of Quercus nuttallii.

Cuttings treated with 200mg/kg ABT were used to study the changes of nutrient content during the rooting process of Quercus nuttallii cuttings. The result showed that soluble sugar content goes down firstly, then goes up and then goes down again, while starch content has two peaks. Hormone treatment significantly increases the starch content. The variation trend of soluble protein roughly ascends firstly and then descends.

Two peaks both appear in POD and PPO activity with the same trend during the cutting process. POD with high activity is conducive to enhancing cuttings resistance; PPO has a role in promoting the formation of callus and adventitious roots. The activity of treatment group is significantly higher than the control group. The activity of SOD increases in incipient cuttings, which decreases when it reaches to the peak; after the initial short rise, the content of MDA continues to decline, with a lower content than the control group.

In this experiment, the content of GA₃, ZR and ABA shows the trend of increasing firstly and then decreasing, however the content of IAA rises again after falling. GA₃ of high content is beneficial to the formation of callus; the appearance of callus is accompanied with a decrease of ZR content, but with the formation of adventitious roots, the content of ZR increases slightly due to its synthesis; ABA has inhibition of root of cuttings, and the content in the base of cuttings of ABA in the treatment group is always lower than that in the control group; the higher concentration of endogenous IAA is conducive to the formation of callus and the differentiation and rooting of root primordium; the ratio of IAA / ABA is small, which is one of the reasons for lower rooting rate of Quercus nuttallii cuttings. The ratio of IAA / ABA at the base of cuttings treated by hormone is higher than that of the control group.

Keywords: Quercus nuttallii; softwood cutting; substrates; exogenous hormone; rooting mechanism

目录

前 言 1

1 文献综述 2

1.1 纳塔栎研究进展 2

1.1.1 分布状况 2

1.1.2 生长特性 2

1.1.3引种栽培 2

1.1.4应用价值 3

1.2扦插生根机理研究 3

1.2.1 营养物质与生根的关系 3

1.2.2 激素与扦插生根的关系 4

1.2.3 酶活性与生根的关系 4

1.2.4 抑制物质与生根的关系 5

1.3 纳塔栎扦插繁殖研究现状 5

2 材料与方法 6

2.1 试验地概况 6

2.2 纳塔栎生根机理研究 6

2.2.1 试验设计 6

2.2.2 测定指标与方法 6

2.3 数据统计与分析 9

3 结果与分析 10

3.1 扦插过程中可溶性糖含量的变化 10

3.2 扦插过程中淀粉含量的变化 11

3.3 扦插过程中可溶性蛋白含量的变化 11

3.4 扦插过程中POD活性变化 12

3.5 扦插过程中PPO活性变化 13

3.6 扦插过程中SOD活性变化 13

3.7 扦插过程中MDA含量的变化 14

3.8 扦插过程中各类激素含量的变化 15

4 讨论 17

4.1 营养物质含量与扦插生根的关系 17

4.2 POD活性与扦插生根的关系 18

4.3 PPO活性与扦插生根的关系 18

4.4 SOD活性与扦插生根的关系 19

4.5 MDA含量与扦插生根的关系 19