Standardisation of in vitro techniques for rapid multiplication of Trichopus zeylanicus Gaertn

Abstract

Studies were conducted on standardisation of in vitro techniques for rapid multiplication of Trichopus zeylanicus Gaertn at the Plant Tissue Culture Laboratory of the Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara during 1995-1997. Surface sterilization was standardised for different explants. Treatment with 0.1 per cent mercuric choloride for 5 min was found to be the best for all the explants. Explants collected during January to April showed lower contamination and maximum survival. Soaking seeds in water for one hour was found to reduce the number of days for germination but lower germination percentage. Young, purple shoots were observed to show maximum establishment and growth. Establishment percentage and maximum number of buds was observed to be highest in SH media supplemented with BA compared to 2iP and KIN. Also exposure to light was favourable for better establishment of buds. Proliferation rate was higher at higher concentration of BA but shoot development was better at lower concentration of BA. Addition of adenine sulfate increased the proliferation rate of buds and development of shoots but supplements like yeast extract and casein hydrolysate were not effective in promoting shoot growth. Tender leaf and petiole explants were found to respond better than mature explants and percentage of callus initiation and callus index was higher in combinations of NAA and 2,4-D with BA. Direct organogenesis was observed in 1/2 MS supplemented with BA and NAA. Regeneration of healthy and longer shoots were obtained in MS medium supplemented with KIN. Somatic embryogenesis was observed in media containing BA and BA + coconut water, and embryoid germination was obtained in MS medium. Maximum rooting was obtained by culturing shoots in media containing brassinolide for one week and thereafter transfer to IBA. Earlier rooting was obtained in liquid medium. Keeping in 1/2 MS with reduced sucrose and increased light intensity in the culture room for two weeks before transfer to hardening unit resulted in better survival of plantlets.