Insight of the seed germination of Lily species under different chemical treatments and light conditions

Lily seeds are commonly used for commercial production and genetic breeding, and their germination rates under different light conditions can be improved by chemical treatments. However, there is a lack of research to systematically screen the pre-treatment methods that are most suitable for various lily species. The study selected six lily species (Lilium pumilum DC., Lilium davidii var. unicolor, Lilium auratum var. platyphyllum, Lilium lancifolium Thunb., Lilium distichum Nakai, and Lilium pensylvanicum Ker Gawl.) and employed a randomized complete block three-factor factorial design, with three factors being species, chemical treatments (0.1% KNO₃, 0.1% K₃PO₄, and different concentrations of GA₃), and light duration (0 h/d, 12 h/d, and 24 h/d). Each treatment included three replicates. Before sowing, the seeds were disinfected with 2% sodium hypochlorite solution for 15 min and rinsed with distilled water, then soaked in the corresponding solution for 1 h. Treated seeds were placed in petri dishes and incubated in an artificial climate chamber at 25 °C, with moist filter paper maintained and light conditions set accordingly. Germination was monitored continuously for 40 days, and the germination start time, completion time, and germination rate were recorded. Germination was defined as radicle emergence through the seed coat by 1-2 mm. The results showed that different lily species responded significantly differently to chemical treatment and light conditions. GA₃ treatment generally improved germination performance, and some species also showed a promoting effect under KNO₃ or K₃PO₄ treatment. Comprehensive analysis revealed that L. lancifolium performed consistently well under multiple treatment conditions and can be selected as the preferred species for stimulation treatment.