Eucommia ulmoides (E. ulmoides) is a significant national strategic resource in China. It is a natural high quality rubber resource, with great development potential. We found large differences in rooting ability during adventitious root (AR) formation in two E. ulmoides improved varieties. Therefore, we used two improved varieties of E. ulmoides, ‘Huazhong 6’ (H6, with rooting rate 85.3%) and ‘Huazhong 8’ (H8, with rooting rate 22.5%) to explore the cutting rooting mechanism. In this study, we mainly determined the morphological development process of E. ulmoides cutting rooting, and compared the rooting-related indexes of the two improved varieties, and the changes in physiological indexes closely related to rooting, which include endogenous hormones, oxidases and nutrients in the phloem of the basal stem. The results showed that indole–3–acetic acid (IAA), zeatin riboside (ZR), IAA/ZR and indoleacetic acid oxidase (IAAO) were the key factors that caused big differences in rooting ability between the two E. ulmoides improved varieties. The increase in endogenous hormone IAA content and IAA/ZR value were necessary for the formation of AR. The increase in IAA content was beneficial to AR formation. The activity of IAAO was significantly negatively correlated with the rooting ability of the E. ulmoides cuttings. The high IAAO activity of the H8 cuttings led to the consumption of IAA. Although the content of IAA increased, the rooting conditions were not reached. The accumulation of nutrients before rooting also has an important effect on rooting; it is easy for cuttings to root when the carbon–nitrogen ratio (C/N) value is high. This research provides an improved understanding of the cellular and physiological underpinnings of the AR process in woody plants. In addition, it provides a theoretical basis and foundation for subsequent research on E. ulmoides cuttage technology.

中文翻译：

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两个杜仲良种生根能力及生理变化比较

杜仲（E. ulmoides）是我国重要的国家战略资源。是一种天然优质橡胶资源，具有很大的开发潜力。我们发现两个E. ulmoides改良品种在不定根 (AR) 形成过程中的生根能力存在很大差异。因此，我们利用杜鹃花2个改良品种'华中6号'（H6，生根率85.3%）和'华中8号'（H8，生根率22.5%）来探索扦插生根机制。在本研究中，我们主要确定了E. ulmoides的形态发育过程切根，比较了两个改良品种的生根相关指标，以及与生根密切相关的生理指标的变化，包括基部茎韧皮部的内源激素、氧化酶和养分。结果表明，吲哚-3-乙酸（IAA），玉米素核苷（ZR），IAA / ZR和吲哚乙酸氧化酶（IAAO）是导致在生根两者能力很大的差异的主要因素杜仲改良品种。内源性激素IAA含量和IAA/ZR值的增加是AR形成所必需的。IAA含量的增加有利于AR的形成。IAAO的活性显著负的生根能力相关杜仲插条。H8 插条的高 IAAO 活性导致了 IAA 的消耗。虽然IAA含量增加，但未达到生根条件。生根前养分的积累对生根也有重要影响；碳氮比（C/N）值高时，插条容易生根。这项研究提供了对木本植物 AR 过程的细胞和生理基础的更好理解。此外，也为后续黄花菜扦插技术的研究提供了理论依据和基础。