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.

Introduction
Materials and Methods
    Seed collection and preparation
    Seed morphology and water absorption
    Moisture content determination
    Prediction of desiccation sensitivity
    Imbibition test
    Germination test
    Statistical analysis
Results and discussion
    Seed morphology
    Desiccation sensitivity
    Germination behavior and dormancy characteristics
Acknowledgement
References

• Da-Bin Yeom(Division of Forest Biodiversity, Korea National Arboretum, Po-Cheon, 11186, Korea)
• Yeon-Ji Lee(Division of Forest Biodiversity, Korea National Arboretum, Po-Cheon, 11186, Korea)
• Seong-Hyeon Yong(Division of Forest Biodiversity, Korea National Arboretum, Po-Cheon, 11186, Korea)
• Ye-Rim Choi(Division of Forest Biodiversity, Korea National Arboretum, Po-Cheon, 11186, Korea)
• Mi-Jin Jeong(Division of Forest Biodiversity, Korea National Arboretum, Po-Cheon, 11186, Korea) Corresponding author