Rooting, Enzyme Activities, and Endogenous Hormones of Zhongcha 108 Cuttings Affected by Plant Regulator Application

Objective Rooting, enzyme activities, and endogenous hormones of Zhongcha 108 stem cuttings were studied to determine the applicability of root growth promotors for plant propagating.

Methods Different types of growth regulators in varied concentrations were applied on Zhongcha 108 stem cuttings to determine the effects on rooting and plant physiology. Activities of indole acetic acid oxidase (IAAO), peroxidase (POD), and polyphenol oxidase (PPO) of the plantlets were detected by spectrophotometry, and contents of endogenous indole acetic acid (IAA), abscisic acid (ABA), and zeatin riboside (ZR) by ELISA.

Results Application of exogenous hormones, 1-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA), promoted rooting of the cuttings. Although increasing NAA concentration brought about greater root growth, the application at 150 mg·L⁻¹ rendered the highest growth rate of 89.82% and fresh root weight of 0.18 g, as well as 8.26 and averaging 3.78 longest roots per cutting. The applied regulators raised the content of IAA and ABA with a declined activity of IAAO in the tissue which stimulated root growth.

Conclusion By applying 150 mg·L⁻¹ NAA on Zhongcha 108 stem cuttings, rooting of the plantlets was significantly enhanced to facilitate the propagation program.