An effective in vitro propagation of Coelogyne mossiae Rolfe: An endangered endemic orchid of Western Ghats, India

Abstract

Coelogyne mossiae Rolfe, an unexplored taxon given its red-listed status by IUCN was selected for in vitro propagation studies due to its conservational significance. The mature pods harboring viable seeds were subjected to inoculation on eight different nutrient media, revealing full-strength Murashige and Skoog (MS) media as highly efficient for seed germination (96.65 %) and subsequent stages of seedling development. Protocorm explants are used for micropropagation on MS media supplemented with various plant growth regulators (PGRs). α- Naphthaleneacetic acid (NAA) in the concentration of 0.5 mg/L facilitated optimal shoot induction resulting in an average of 2.39 multiple buds and 2.46 cm shoot length while 1.0 mg/L 6-Benzyl amino purine (BAP) augmented cultures provided 2.32 multiple shoot buds with an average 1.92 cm height. Half macro-MS augmented with 0.5 mg/L BAP promoted pseudobulb elongation (0.73 cm) while 0.5 mg/L NAA supported root formation (8.33 roots with an average length of 1.12 cm). The resultant plants were acclimatized in pots containing coco peat and brick pieces, exhibiting a survival rate of 63.23 %. The anatomical characteristics of the hardened plants provided insight into factors conducive to their adaptability. Also, the 3-month-old hardened plants demonstrated significantly greater total photosynthetic pigment (0.4915±0.00 mg g-1), total carbohydrate content (72.33±1.69 mg SSE/g), and total protein content (40.26±0.53 mg BSAE/g) when compared to in vitro plants. These findings underscore the potential of in vitro propagation techniques in the conservation and sustainable utilization of Coelogyne mossiae.