Spore germination and prothallus growth of Dryopteris erythrosora, Dryopteris crassirhizoma, and Onoclea orientalis under different temperature conditions

Establishing a cultivation technique using spores for fern propagation is necessary. Dryopteris erythrosora, Dryopteris crassirhizoma, and Onoclea orientalis were used as test plants. Spore germination experiments were performed at 10 ℃, 15 ℃, 20 ℃, 25 ℃, and 30 ℃. The area of the prothallus collected after 90 days was measured using ImageJ software. The final germination rate was about 50% for D. erythrosora, 100% for D. crassirhizoma, and 20–95% for O. orientalis. The final germination rate was similar at 10 to 30 ℃ for D. erythrosora and D. crassirhizoma, and was highest at 10 ℃ for O. orientalis. For prothallus growth, 20 ℃ or 25 ℃ for D. erythrosora and 20 ℃ for D. crassirhizoma and O. orientalis were suitable