Zhang Mengzi, Montanez Cynthia, Pearson Brian J, Li Yuncong, Chen Jianjun
Mid-Florida Research and Education Center, Environmental Horticulture Department, University of Florida, Apopka, FL, United States.
Mid-Columbia Agricultural Research and Extension Center, College of Agricultural Sciences, Oregon State University, Hood River, OR, United States.
Front Plant Sci. 2025 Aug 29;16:1650327. doi: 10.3389/fpls.2025.1650327. eCollection 2025.
Kratom () has gained increasing attention for its potential to manage pain and alleviate opioid withdrawal symptoms. Despite growing interest, production practices, including vegetative propagation, remain underexplored. This study compared indoor aeroponics with greenhouse mist systems for rooting kratom cuttings and evaluated the effects of photoperiod, rooting hormone, and cultivar on the rooting success.
In Study I, stem cuttings collected from 'MR-Malaysian' over two seasons, 180 each, were rooted in aeroponic units, 15 cuttings per unit. Twelve aeroponic units were randomly assigned to 10-, 14-, or 24-hour photoperiods in environmentally controlled growth rooms, with four units per room. In parallel, cuttings from the same cultivar were evaluated in a greenhouse mist system across three seasons. In each season, 60 cuttings were rooted in four trays, 15 each. In Study II, cuttings derived from three cultivars (MR-Malaysian, DR-Bumblebee, and Hawaii) were tested simultaneously using the indoor aeroponic and greenhouse mist systems, with or without rooting hormone treatments (5 mg/L IBA and 2.5 mg/L NAA). A series of rooting parameters was collected during the two studies.
A 14-hour photoperiod significantly enhanced root initiation and root growth compared to a 10-hour photoperiod, as indicated by increased root length, area, branching, and biomass. The aeroponic system consistently promoted high rooting percentages (85%-92%) and root growth, whereas the greenhouse mist system exhibited high seasonal variability (7%-98%) and inconsistent rooting success. In Study II, 'MR-Malaysian' overall outperformed the others, exhibiting high rooting rates and root growth with a relatively short production cycle, as well as being less susceptible to . Hormone application increased the number of roots, but it had minimal effects on other parameters.
Our results showed that the aeroponic system consistently yielded a significantly higher rooting percentage and better rooting quality compared to the greenhouse mist system across the three cultivars. Such qualities included greater final root number, root dry mass, root length, root area, root volume, and higher numbers of root tips, forks, and crossings. However, the aeroponic system may pose a possibility of spreading pathogens. This study, for the first time, demonstrates that photoperiod, rooting system, and cultivar are crucial factors in rooting kratom cuttings. The aeroponic system represents a new and effective way of propagating kratom cuttings year-round.
kratom（）因其在管理疼痛和缓解阿片类药物戒断症状方面的潜力而受到越来越多的关注。尽管兴趣日益浓厚，但包括营养繁殖在内的生产实践仍未得到充分探索。本研究比较了室内气培法和温室喷雾系统对kratom插条生根的影响，并评估了光周期、生根激素和品种对生根成功率的影响。
在研究I中，从“MR - 马来西亚”品种在两个季节收集的茎插条，每个季节180个，在气培装置中生根，每个装置15个插条。十二个气培装置被随机分配到环境控制的生长室中的10小时、14小时或24小时光周期，每个房间四个装置。同时，来自同一品种的插条在温室喷雾系统中进行了三个季节的评估。在每个季节，60个插条在四个托盘中生根，每个托盘15个。在研究II中，使用室内气培法和温室喷雾系统同时测试了来自三个品种（MR - 马来西亚、DR - 大黄蜂和夏威夷）的插条，有无生根激素处理（5 mg/L吲哚丁酸和2.5 mg/L萘乙酸）。在两项研究中收集了一系列生根参数。
与10小时光周期相比，14小时光周期显著增强了根的起始和根的生长，表现为根长度、面积、分支和生物量增加。气培系统始终促进高生根率（85% - 92%）和根的生长，而温室喷雾系统表现出高季节变异性（7% - 98%）且生根成功率不一致。在研究II中，“MR - 马来西亚”总体表现优于其他品种，生根率高，根生长良好，生产周期相对较短，且对......不太敏感。激素处理增加了根的数量，但对其他参数影响最小。
我们的结果表明，与温室喷雾系统相比，气培系统在三个品种中始终产生显著更高的生根率和更好的生根质量。这些质量包括最终根数量更多、根干质量、根长度、根面积、根体积以及更高数量的根尖、根叉和交叉点。然而，气培系统可能存在传播病原体的可能性。本研究首次证明光周期、生根系统和品种是kratom插条生根的关键因素。气培系统代表了一种全年繁殖kratom插条的新的有效方法。
