Spore Germination and Prothallium Development Conditions of Pyrrosia petiolosa (H. Christ) Ching
Background : This study was conducted to determine the optimal conditions of growth medium, temperature, and light quality for efficient propagation of Pyrrosia petiolosa spores. Methods and Results : P. petiolosa spores were collected from Andong-si area in February 2015, and the spores were subjected to a careful selection process. The selected spores were stored at the Korea National Wild Plant Seed Bank (4℃, RH 40%) and used as our experimental materials (GR0000182302). The spore germination rate and prothalium development were high in Knop media (24.5%), which had low mineral content. The germination rate increased with the increase in temperature and reached its maximum, 24.5%, at 25°C. The germination rate was also measured under different light conditions, and the highest rate of 28.7% was observed under LED blue light compared to fluorescent lights (24.5%). The germinated spores developed into heart-shaped prothallia under LED blue light; however, 3 weeks after sowing, prothallium development decreased compared to fluorescent lights. Conclusion : In conclusion, the optimal P. petiolosa In vitro propagation method include spore germination on Knop medium at 25°C under LED blue light, and the change in light source to fluorescent light 3 weeks after sowing for prothallium formation and proliferation.