Effects of light, agar, activated charcoal, and culture medium on the germination and early development of Dendrobium seedlings

Abstract

The objectives of this study were to determine the optimal light conditions, agar concentration, and quantity of activated charcoal in asymbiotic media to improve the in vitro seed germination rate and early seedling development of the epiphytic orchids Dendrobium nobile Lindl. and Dendrobium phalaenopsis Fitzg. Two independent experiments with complete randomized designs were conducted. (1) Treatments were arranged in a split-plot scheme. Seeds in each sub-plot were exposed to one of four light conditions (dark, white fluorescent, red fluorescent + white fluorescent, or red fluorescent) and grown in one of four types of culture media (MS: Murashige and Skoog, ½ MS: half strength MS, K: Knudson C, and VW: Vacin and Went media). (2) Treatments were arranged in a 4 × 5 × 5 factorial scheme (four types of culture media: MS, ½ MS, K, and VW; five concentrations of agar: 0.0, 2.0, 4.0, 6.0, or 8 g L−1; and five concentrations of activated charcoal: 0.0, 1.5, 3.0, 4.5, or 6.0 g L−1). The highest germination rates and early seedling development were observed 45 days after seeding in the presence of white light for D. nobile and red + white light for D. phalaenopsis in MS and ½ MS culture media. Based on the findings of the present study, the use of MS and ½ MS culture media solidified with 4.0–8.0 g L−1 of agar and without activated charcoal is recommended for the optimal propagation of seeds and seedlings of these Dendrobium species.

Optimization Parameter for Production of Protocorm-Like Body and Growth of Grammatophyllum Speciosum

“…Therefore, 4.5 g/L of agar is seen to be optimum for the growth of plantlets. Other than that, Sorgato et al (2020) reported that no presence of charcoal and concentration of agar more than 4.0 g/L resulted in better growth of protocorm-like bodies similar to the indings in Figure 3 . Therefore, not only 4.5 g/L of agar is suitable for plantlets growth but also is optimal for PLBs.…”

Ex-situ conservation of the native orchid Coelogyne rochusseni de Vriese from the Bukit Rimbang and Bukit Baling Wildlife Reserve Areas

“…Furthermore, the 3 g/L -1 activated charcoal concentration produced the highest germination percentage due to the limited light provided to the medium. According to Sorgato et al (2020), germination was accelerated under light limitation on the medium. The development stages of C. rochussenii de Vriese with four basal media are visualized in Fig.…”

“…The germination of seeds via in-vitro propagation is still low with a range of 30-45%, meanwhile, the germination percentage is influenced by the presence of light in the medium (Sorgato et al, 2020). Besides, the various types of orchids respond differently to the percentage of light in the media, hence, it is necessary to add a light-reducing ingredient in the form of activated charcoal.…”

In vitro growth of Cattleya nobilior Rchb. f.: culture media, sealing systems and irradiance

“…Several factors may influence the germination, growth and development of plants grown in vitro. These factors include the culture medium, sealing system and light condition used for cultivation (Silva et al 2015, Silva et al 2016, Sorgato et al 2020. Some adjustments are still necessary in the culture medium formulation for each orchid species, especially native ones.…”