Division of Biotechnology, Indian Institute of Horticultural Research, Bangalore, 560 089.
*Corresponding author's: E-mail: vageesh@iihr.ernet.in
1Department of Biotechnology, Kuvempu University, Shankaraghatta, Shimoga, 577 451.
Effect of growth regulators on shoot morphogenesis in hypocotyl and cotyledonary leaf explants, shoot elongation and root induction has been studied. Hypocotyl explants showed callus initiation and direct regeneration response after 3–5 and 13–15 days of culture initiation, respectively. Cotyledonary leaf explants showed callus initiation and callus-mediated shoot regeneration response after 7–8 days and 3 weeks of culture initiation. Growth regulators did not affect callus initiation response but they markedly influenced regeneration response. Culture medium (full-strength MS salts, vitamins, 3% sucrose and 0.8% agar) containing 2 μM and 0.05 μM NAA induced highest shoot regeneration in hypocotyl explants (65.71%), whereas culture medium containing 10 μM BAP and 0.5 μM NAA induced highest 18.33% shoot regeneration in cotyledonary leaf explants. Either increase or decrease in BAP concentration than this resulted in reduction in shoot regeneration response. Addition of BAP to shoot elongation medium was found beneficial for shoot elongation and shoot regeneration medium was efficient in shoot elongation also. Addition of auxins in root induction medium has reduced number of days taken for root induction and increased in number of roots and root length. In hardening, 90–95% of rooted shoots survived and all the plantlets were morphologically normal.
Direct regeneration, hypocotyl, cotyledonary leaves, auxins, BAP
