Effect of Propagation Media and Plant Growth Regulators on Adventitious Rooting of Softwood Cuttings of Apocynum lancifolium Russanov

Abstract

Background and objective: <i>Apocynum lancifolium</i> Russanov is a perennial herb native to Korea and belonging to the family Apocynaceae. Herein, cutting mediums and plant growth regulators (PGRs) were examined to investigate the requirements for the cutting propagation of <i>A. lancifolium</i>.Methods: The study was conducted over a period of 6 weeks from May to June 2023. As types of cutting medium for propagation by cutting, Kanuma soil, commercial potting mixes, perlite, and peat moss were used, and the PGRs of indole-3-butyric acid (IBA) at varying concentrations (100, 500, and 1,000 mg⋅L<sup>-1</sup>) and a 1:1 (v/v) solution of Rootone (0.4% 1-naphthylacetamide) diluted in water were applied for this study. After six weeks, growth characteristics, including cutting survival rate, rooting rate, shoot height, the number of leaves, root length, the number of roots, dry weight of shoots, and dry weight of roots, were examined.Results: Among the different growing substrates used for experimentation, the cutting survival rate on Kanuma soil (81.7 ± 5.0%) was the highest, followed by commercial potting mixes (40.0 ± 7.2%) and perlite (66.7 ± 2.7%), while the lowest cutting survival rate was on peat moss (35.0 ± 6.3%). On treatment with Kanuma soil (81.7 ± 5.0%), the rooting rate was also significantly greater than that when treated with other substrates. In the PGR experiment, the cutting survival rate and rooting rate treated with Rootone (0.4% 1-naphthylacetamide) were significantly higher than those when treated with other substrates. Further, the number of roots increased with an increase in the IBA concentration. Based on the results, we recommend treating <i>A. lancifolium</i> cuttings with Rootone and Kanuma soil to ensure successful cutting propagation of <i>A. lancifolium</i>.Conclusion: This mass production system for <i>A. lancifolium</i> via cutting propagation shows promise in terms of scalability and could help with germplasm conservation efforts for <i>A. lancifolium</i>.