In vitro propagation of white-flower mutant of Rhynchostylis gigantea (Lindl.) Ridl. through immature seed-derived protocorm-like bodies

Abstract

Rapid in vitro propagation of white-flower mutant of Rhynchostylis gigantea (Lindl.) Ridl. was established for the first time through 4 month old immature seed-derived protocorm-like bodies (PLBs). 75% of PLBs developed from immature seeds cultured on half-strength MS medium with 0.05 mg·l-1 6-BA and 0.2 mg·l-1 NAA within 70 days upon transfer to MS medium with 2.0 mg/l-1 BA and 1.0 mg·l-1 NAA were induced to produce callus. Maintenance of the callus was achieved by subculturing the callus at an interval of 2 months on medium having the same level of growth regulators. The callus turned up to protocorm-like bodies upon transfer to hormone-free MS medium after 30 days of culture and later developed to shoots with 2-4 leaves. Transfer of the emerged shoots to half strength MS medium containing 100 g·l-1 banana homogenate facilitated root development and shoot growth. Plantlets established ex vitro exhibited 95% survival. Key words: Plant regeneration, protocorm, Rhynchostylis gigantea (Lindl.) Ridl., somatic embryogenesis.