Asymbiotic Seed Germination and in vitro Seedling Development of Paphiopedilum liemianum Fowlie, an Endangered Terrestrial Orchid in Northern Sumatra, Indonesia

Abstract

Paphiopedilum liemianum Fowlie, is a terrestrial orchid species and endemic in Northern Sumatra, Indonesia. However, due to a deep dormancy that the seed display at dispersion and the difficulty to obtain uniform plant in a short time period, micropropagation may be a feasible alternative. l'vficropropagation by in vitro seed germination techniques have been applied to the conservation of endangered orchid. Four months old seeds of P. liemianum germinated on five different basal media. All media were supplemented with 2.5 µM a-apthalleneacetic acid (NAA) and cultures were incubated in the dark for 4 weeks followed by protocorm development at condition a 16/8 h LID photoperiod. Germination percentage was 78.8% in Vacin and Went (VW) medium were significantly higher than other basal media. To evaluated the effect of organic nutrient additives on seed germination and protocorm development, the seed were cultured on VW medium amended with different of organic nutrient. Additives, especially 10% Coconut Water (CW) to VW medium improved the protocorm development well, with 33.3% the protocorm development to stage 5 (seedling). The seedlings were cultured on VW medium supplemented with different concentrations (0.0, 1.0, 2.0, 3.0 and 4.0 µM) of thidiazuron (TDZ). Healthy plantlets with developed leaves and roots were planted in pots with sphagnum moss and grown under ex vitro condition and the result was 76% survival rate after 4 weeks.