Effects of growth regulators and medium on cuttage adventitious root occurrence of Alniphyllum fortunei

This study aims to investigate the effects of growth regulators and medium on cuttage adventitious root occurrence of Alniphyllum fortunei, and to provide theoretical for A. fortunei propagation by cutting.

Using lignified branches of 2-year-old A. fortunei as the cuttings, an orthogonal experimental design with four factors and three levels was employed to investigate the effects of growth regulator type, concentration, treatment duration, and medium composition on adventitious root formation. Combined with anatomical observations, a total of twelve cuttings growth indices were measured and statistically analyzed to clarify the regulatory effects of each factor on cutting rooting and seedling growth.

The soluble sugar content, PPO, and IAAO in the A. fortunei growth regulator treatment group were higher than those in the control group during both the adventitious root formation stage and the adventitious root growth stage. The average root length, average root diameter, root volume, fine root specific root length and fine root specific root area of NAA treatment group were significantly higher than those of other treatments; regulator type × concentration, regulator type × treatment time mean analysis showed that the rooting effect of high concentration (1 500 mg·L^-1) and low treatment time (10 min) of NAA treatment was better. Four principal components were extracted by principal component analysis, which were the comprehensive growth status of aboveground and underground parts, root coarseness index, root length index, and comprehensive growth status of root system. The highest comprehensive score was T13, that is, 75% vermiculite+25% perlite was selected as the matrix, and 1 500 mg·L^-1 IAA was used for 10 min. the rooting rate was 71.87%, and the rooting index was 147.19.

The root system growth of A. fortunei cuttings belongs to the callus rooting type, with adventitious roots emerging around 56 days. Through growth regulator treatment, the dynamic changes in soluble sugar content and oxidase activity (PPO、POD、IAAO) in A. fortunei cuttings can be accelerated, thereby promoting rooting. Cuttings of Alniphyllum fortunei exhibited optimal growth under the T13 treatment, offering a reference for large-scale clonal propagation.