Utilization of coir fibers as an eco-friendly substitute for costly gelling agents for in vitro orchid seed germination

The efficacy of coir as a supportive base and as an alternative to standard, costly agar-gelled media, was explored as a means for propagating Cymbidium pendulum (Roxb.) Sw. in vitro through seedling culture. Germination time and morphological differences were compared for embryos cultured on coir fibers soaked in distilled water, in a standard Mitra orchid growing medium with and without agar. Although seeds failed to germinate on coir fibers soaked in distilled water, germination was seen only in the seeds that were grown on the coir fibers soaked in the Mitra nutrient solution, and on agar gelled solution. Time taken for the seeds to germinate and for further growth and development was virtually the same in both the media. Seedlings bearing leaves and roots were obtained in 15 weeks on the coir-based medium. These seedlings were subsequently transferred to the greenhouse in clay pots containing a mixture of coir, charcoal and brick pieces where 90% seedlings survived. The use of coir fiber instead of agar during the initial phase of seed germination and seedling development offers a less costly alternative for cultivating C. pendulum and could be used for other orchid species.