caa a22 4500 463236041 CHVBK 20180405153257.0 cr unu---uuuuu 170326e20070701xx s 000 0 eng 10.1007/s11240-007-9244-1 doi (NATIONALLICENCE)springer-10.1007/s11240-007-9244-1 Direct and callus-mediated protocorm-like body induction from shoot-tips of Dendrobium chrysotoxum Lindl. (Orchidaceae) [Elektronische Daten] [Jonojit Roy, Soumi Naha, Madhumita Majumdar, Nirmalya Banerjee] An efficient method of mass propagation of Dendrobium chrysotoxum Lindl. was developed using a shoot-tip culture system. Both direct and callus-mediated formation of protocorm-like bodies (PLBs) occurred from the basal cut surface of explants. Frequency of callusing was best in the presence of 2μM thidiazuron (TDZ) or N6-benzylaminopurine (BAP). The callus exhibited complete hormone autonomy for growth and differentiation of PLBs and was maintained for 18months without any exogenous growth regulators, an aspect important for minimising somaclonal variation. However, the rate of callus growth and PLB formation varied with application of cytokinin and auxin. In addition, the callus exhibited a differential sensitivity to the exogenous cytokinins. While BAP promoted callus growth and PLB differentiation, TDZ was inhibitory to callus mediated PLB formation and caused extensive necrosis of callus. Although α-naphthaleneacetic acid (NAA) had no significant effect on the induction of callus, subsequent growth was best in its presence. Using a 3-month subculture period, a 69-fold increase in callus weight was achieved with 0.5μM NAA, while as many as 133 PLBs could be obtained per 100mg callus in the presence of 1μM NAA. For direct PLB formation, the optimum cytokinin dosage was dependent upon the type of cytokinin used. While TDZ was most effective at a concentration of 1μM (15 PLBs per explant), for similar PLB yield the application of 8μM BAP was essential. Springer Science+Business Media B.V., 2007 Hormone-autonomous culture nationallicence Micropropagation nationallicence Orchid nationallicence Shoot-tip culture nationallicence BAP : N6-benzylaminopurine nationallicence NAA : α-Naphthaleneacetic acid nationallicence PGR : Plant growth regulator nationallicence PLB : Protocorm-like body nationallicence TDZ : Thidiazuron nationallicence Roy Jonojit Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut Naha Soumi Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut Majumdar Madhumita Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut Banerjee Nirmalya Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut Plant Cell, Tissue and Organ Culture Kluwer Academic Publishers 90/1(2007-07-01), 31-39 0167-6857 90:1<31 2007 90 11240 https://doi.org/10.1007/s11240-007-9244-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11240-007-9244-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Roy Jonojit Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut NATIONALLICENCE 700 1- Naha Soumi Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut NATIONALLICENCE 700 1- Majumdar Madhumita Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut NATIONALLICENCE 700 1- Banerjee Nirmalya Department of Botany, Visva-Bharati, 731235, Santiniketan, West Bengal, India aut NATIONALLICENCE 773 0- Plant Cell, Tissue and Organ Culture Kluwer Academic Publishers 90/1(2007-07-01), 31-39 0167-6857 90:1<31 2007 90 11240 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer