Organic growth supplement stimulants for in vitro multiplication of Cymbidium pendulum (Roxb.) Sw

The aim of this study was to establish protocol for in vitro regeneration and multiplication of Cymbidium pendulum through protocorms, as explants using organic growth supplements such as banana homogenate, coconut water, and peptone. The effect of growth supplements was tested on multiplication (neo-formation of secondary protocorms from primary protocorms) of protocorms, development of maximum number of shoots and early plantlets in M medium (Mitra medium). Though the explants regenerated in the absence or presence of growth adjuncts in the medium; the regeneration frequency was found significantly higher in organic growth supplement-enriched medium than control. The protocorm segments (primary) regenerated into protocorm-like bodies (secondary protocorms) which eventually differentiated into shoots; no intervening callus stage was observed. Among the treatments, the highest regeneration frequency, robust shoots and root formation was recorded in banana homogenate (50 g/l); the roots were lengthy, thick, and covered all over the surface by root hairs. Higher concentration of banana homogenate (75 g/l) proved detrimental for the survival of cultures; the protocorm-like bodies showed necrosis and they perished soon after. Coconut water (10%) and peptone (2 g/l) supplemented medium proved optimum for profuse multiplication of protocorm-like bodies (PLBs) their early growth into plantlets. The treatments with organic growth supplements gave better and early plantlets as compared to control. Among these tested organic growth supplements, peptone (2 g/l) and coconut water (10%) proved beneficial for multiplication of regenerants, maximum number of shoots formation and early plantlet development; whereas banana homogenate (50 g/l) favoured the highest regeneration frequency and healthy growth of plantlets.