In vitro seed germination of Paphiopedilum lowii, an endangered slipper orchid in North Borneo

Abstract

Abstract. Ragu VS, Ombokou R, Repin R, Molidin D, Miadin R, Aziz ZA. 2022. In vitro seed germination of Paphiopedilum lowii, an endangered slipper orchid in North Borneo. Biodiversitas 23: 5687-5694. Paphiopedilum lowii (Lindl.) Stein is alarmingly decreasing in numbers due to habitat destruction and over-collection. Propagation through seed is one effort to conserve the species. In vitro method offers better results for seed germination in orchids, but the success of germination is species-specific. Hence, this research aimed to evaluate different types of media [(½ strength Murashige & Skoog and Orchimax Medium (Duchefa Biochemie)], and to determine the effects of sucrose [0% 1%, 2% and 3% (w/v)], peptone [0%, 0.1% and 0.2% (w/v)], coconut water [0%, 10%, 20% and 30% (v/v)] and fertilizer [Orchid Focus - 0%, 0.1% and 0.2% (v/v)] on seed germination. The protocorm size was also determined after 12 weeks of observation. Half-strength MS media consistently gave higher seed germination, ½ MS supplemented with 1% (w/v) sucrose, 0.1% (w/v) peptone, 0% (v/v) coconut water and 0.1 % (v/v) fertilizer resulted in the highest seed germination at 5.32% ± 5.9, 19.27% ± 9.34, 11.33% ± 3.80 and 19.31% ± 9.03 respectively. Despite being 12 weeks in culture, the sizes of the protocorms are small (0.222±0.089 mm diameter, 0.703±0.280 mm circumference, and 0.045±0.043 mm² area); this requires future investigation. These findings can serve as base information for further enhancement of seed germination and development of propagation methods of P. lowii for use in a conservation program.