Department of Chemistry and Biology, Ryerson University, Toronto, Canada.
PLoS One. 2019 Mar 18;14(3):e0213434. doi: 10.1371/journal.pone.0213434. eCollection 2019.
The burgeoning cannabis market requires evidence-based science such that farmers can quickly and efficiently generate new plants. In part, horticultural operations are limited by the success of cloning procedures. Here, we measured the role of environmental conditions and cultivar identity on the success of generating long branch material with many meristems in planting stock (mothers) and in rooting success of stem-derived clones. To evaluate the influence of lighting treatments on the optimal production of branching mothers, four lighting conditions (Fluorescent High Output T5s [T5], Metal halide lamps [MH], Plasma lamps [PL], or Metal halide lamps augmented with far red LED lights [MH+FR]) were applied to two cultivars of container grown plants (Cannabis sativa L. 'Bubba Kush', 'Ghost Train Haze') grown in peat-based organic substrates in mylar grow tents. To evaluate the influence of lighting, cutting tool (secateurs or scalpels), and stem wounding (present/absent) on optimal rooting of stems, three lighting conditions (Fluorescent T8s, T5, PL) were applied to three cultivars of peat pellet grown plants (C. sativa L. 'Bubba Kush', 'Ghost Train Haze', 'Headband'). Mothers grown under T5 and MH (vs MH+FR) produced ~30% more meristems. However, growing mothers under MH+FR were 19% taller than mothers under T5, with ~25% longer internodes on dominant stems than plants under any other lighting condition. Canopies were denser under T5 because petiole length was ~30% shorter under T5 and fan leaves were longer and narrower under MH+FR and MH+FR and PL, respectively, than under other lighting conditions. Cultivar Ghost Train Haze stems rooted most frequently and most quickly. Wounded stems were 162% more likely to root than unwounded stems and rooted 1.5 days earlier. Our results will guide producers attempting to maximize the rate of clone production in licensed facilities; although results may differ among cultivars, where cultivars differed in their average phenotype as mother plants, and their propensity to root from cuttings, and the speed with which they produced those roots.
蓬勃发展的大麻市场需要基于证据的科学，以便农民能够快速有效地培育新植株。在某种程度上，园艺操作受到克隆程序成功与否的限制。在这里，我们测量了环境条件和品种身份对种植母株（母体）中产生具有许多分生组织的长枝材料的成功率以及茎衍生克隆生根成功率的影响。为了评估光照处理对产生分枝母体的最佳效果，将四种光照条件（荧光高输出 T5 灯[T5]、金属卤化物灯[MH]、等离子灯[PL]或金属卤化物灯与远红 LED 灯[MH+FR]组合）应用于在岩棉生长帐篷中用泥炭基有机基质种植的两种容器植物（大麻 sativa L. 'Bubba Kush'，'Ghost Train Haze'）。为了评估光照、切割工具（修枝剪或解剖刀）和茎伤（有/无）对茎最佳生根的影响，将三种光照条件（荧光 T8 灯、T5、PL）应用于三种泥炭丸粒种植植物（大麻 sativa L. 'Bubba Kush'，'Ghost Train Haze'，'Headband'）。在 T5 和 MH（与 MH+FR 相比）下生长的母体产生了约 30%更多的分生组织。然而，在 MH+FR 下生长的母体比在 T5 下生长的母体高 19%，主茎的节间长度约长 25%，比任何其他光照条件下的植物都长。在 T5 下，冠层更密集，因为叶柄长度在 T5 下约短 30%，而在 MH+FR 和 MH+FR 下的扇叶更长更窄，而在其他光照条件下则更窄。品种“Ghost Train Haze”的茎生根率最高，生根速度最快。受伤的茎比未受伤的茎生根的可能性高 162%，生根时间早 1.5 天。我们的结果将指导生产者在许可设施中尝试最大限度地提高克隆繁殖率；尽管结果可能因品种而异，但在母体植物的平均表型、生根倾向以及产生这些根的速度方面存在差异。
