Effects of Basic Medium Types and Plant Growth Regulators on Seed Germination and Protocorm Differentiation of Pleione maculata (Lindl.) Lindl. (Orchidaceae)

Pleione maculata (Lindl.) Lindl. is an epiphytic herb of the genus Pleione D. Don, Orchidaceae, which has important ornamental, medicinal, economic, and ecological values, and its market demand is increasing. However, the lack of a system for seed breeding technology severely limits the production of large-scale cultivation of this species. The purpose of this study was to optimize the medium and to study the effects of basic medium types, plant growth regulators, natural additives, and sucrose concentration on seed germination and protocorm-like body (PLB) proliferation and differentiation. In this study, the highest percentage of seed germination was observed on B5 + 1.0 mg/L NAA + 20 g/L glucose + 1 g/L protein + 20 g/L potato homogenate (PH) + 1 g/L activated carbon (AC) + 6 g/L agar (pH 5.7–5.8), which reached 86.26%. The best medium type for protocorm proliferation was 1/2 MS + 1 mg/L NAA + 1.0 mg/L 6-BA + 20 g/L sucrose + 100 g/L PH + 1 g/L protein + 1 g/L activated charcoal + 5.8 g/L agar (pH 5.7–5.8), which multiplication factor was 3.20. The best media for protocorm differentiation was 1/2 MS + 0.5 mg/L NAA + 1.0 mg/L 6-BA + 100 mL/L CW + 20 g/L sucrose + 1 g/L protein + 1 g/L activated charcoal + 5.8 g/L agar (pH 5.7–5.8), which multiplication factor was 5.77. Therefore, by adjusting the type of medium, plant growth regulators, and sucrose concentration, the aseptic germination and protocorm differentiation of P. maculata seeds can be achieved.