This study aimed to elucidate the seed desiccation sensitivity and dormancy characteristics of two evergreen broadleaf tree species, Camphora officinarum Nees and Neolitsea sericea (Blume) Koidz., to provide baseline data for ex situ conservation strategies. Based on the probabilistic model of Daws et al. (2006), both species exhibited desiccation-sensitivity probabilities greater than 0.5 (C. officinarum = 0.706; N. sericea = 0.774), indicating a high likelihood of recalcitrant seed behavior. Imbibition tests revealed rapid water absorption within 24–72 hours in both species, confirming the absence of physical dormancy (PY). Furthermore, microscopic observations showed fully developed, non-endospermic embryos at dispersal, thereby ruling out morphological dormancy (MD). Following a 12-week cold stratification at 4℃, germination experiments were conducted under alternating temperature regimes (25/15℃ and 30/20℃) combined with GA3 treatments (0, 100, 500, 1000 ppm). Two-way ANOVA detected a significant Temperature × GA3 interaction for both species (p < 0.05). In C. officinarum, the highest final germination (46.3%) occurred at 25/15℃ with 500 ppm GA3, accompanied by reductions in mean germination time (MGT) and T50; these results suggest the alleviation of non-deep physiological dormancy (PD). Conversely, N. sericea showed overall low germination with a weak response to GA3, and partial germination occurred primarily at the higher temperature, implying a more complex, temperature-dependent PD. These findings provide a practical basis for optimizing ex situ conservation protocols for recalcitrant Lauraceae species.

This study was conducted to develop a method of treatment with plant growth regulators to enhance the value of a foliage plant, Spathiphyllum wallisii Hort. The plant growth regulators BA and GA3 were applied alone or in combination at different concentration levels. BA treatment was effective in increasing the plant height of S. wallisii Hort. compared with the control. GA3 treatment significantly increased plant height and leaf length compared with those in the control, while the number of leaves decreased. The number of flowers per plant was approximately 1 in the control treatment, while GA3 treatment increased the number of flowers to 5.3–9.3 per plant. The highest number of flowers per plant was 9.3 upon treatment with 300 mg·L-1 BA + 1,000 mg·L-1 GA3. However, GA3 treatment caused physiological disorder. Part of the leaves exhibited white discoloration. This symptom was considered to involve transformation of leaves into flowers on S. wallisii Hort., caused by gibberellin treatment. These results showed that gibberellin treatment was effective in inducing flowering of S. wallisii Hort. The presence of flowers is important for the ornamental value of pot plants. Therefore, gibberellin treatment could improve the ornamental value of S. wallisii Hort. by increasing the number of flowers.

This study evaluated the germination characteristics and predicted longevity of Weigela subsessilis, an endemic plant in Korea, under long-term seed bank storage. Seeds from 16 accessions were stored at –18 °C for 0, 5, 10, and 20 years, and their germination performance was assessed. The initial germination percentage (78.75%) remained stable after five years (79.67%) but declined significantly after ten years (62.90%). Two accessions tested after 20 years showed a steep reduction to 14.86%. MGT and T50 were stable, GI increased slightly, but PV and GV declined, suggesting dormancy release alongside reduced vigor. Seed longevity was predicted using Probit analysis The estimated initial viability (Ki) was 1.15, with a slope of –0.092, yielding a predicted P50 of 12.5 years (95% CI: 11.2–13.8 years). The confidence interval broadened with longer extrapolations, underscoring the uncertainty of projections beyond 15–20 years where empirical data remain limited. These results provide the first empirical evidence of viability decline in W. subsessilis seeds over two decades of storage. They highlight the need for systematic monitoring in seed banks, with testing recommended at five-year intervals beyond ten years of storage. Regeneration or recollection strategies should also be implemented as viability approaches critical thresholds. This study offers essential baseline data for developing conservation strategies for Korean endemic species and contributes to the sustainable management of native plant genetic resources.