Flower stalk segments of Dendrobium hybrids Sonia 17 and 28 collected from plants grown in the net-house of the Department were washed under running tap water and followed by a neutral liquid detergent, Extran (5% v/v; Merck India Ltd., Mumbai), for 5 min. After thorough wash in double distilled water, the flower stalk segments were sterilized using 0.1% (w/v) mercuric chloride solution for 9-12 min. They were then washed thoroughly with sterile double distilled water. Sterilized flower stalk segments cut into a size of 10-15 mm with one bud were cultured on half strength Murashige and Skoog15 medium.