caa a22 4500 445841478 CHVBK 20180317145345.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s10725-010-9504-7 doi (NATIONALLICENCE)springer-10.1007/s10725-010-9504-7 The role of meta -topolins in alleviating micropropagation problems [Elektronische Daten] [Stephen Amoo, Jeffrey Finnie, Johannes Van Staden] Low shoot multiplication, morphological abnormalities, poor rooting frequency and high cost of production are among the factors challenging the micropropagation of ornamental perennials and garden plants. Most of these problems can be alleviated by using the appropriate type and concentration of plant growth regulator(s) (especially cytokinins) in developing efficient micropropagation protocols. In this study, we investigated the effects of five different aromatic cytokinins (BA, Kin, mT, mTR and MemTR) on adventitious shoot production from shoot-tip explants of B. greenii, a critically endangered plant with horticultural potential. Of all the cytokinin concentrations evaluated, the highest adventitious shoot production (5.88±0.73 shoots/explant) was observed in cultures containing 7μM MemTR. Low adventitious shoot production, which was not significantly different from that of the control, was observed at all the concentrations of kinetin (Kin), suggesting that it is a weak cytokinin for shoot production in this species. All the treatments with BA alone showed higher adventitious shoot production when compared to the BA treatments supplemented with NAA concentrations. At equimolar concentrations, however, all the BA concentrations had a higher abnormality index than the other cytokinins. It is noteworthy that the abnormality index in all the topolin treatments was much lower than that recorded at the lowest BA concentration. Almost all the abnormality indices recorded with mTR and MemTR concentrations were lower than that of the control. Given that the explants used were from BA-containing cultures, it is likely that the abnormalities recorded using mTR and MemTR were carry-over effects of BA. Culturing under 16h light/8h dark conditions resulted in a higher production of adventitious shoots with lengths greater than 10mm compared to culturing under continuous light. This measure could help reduce the cost of production. Regenerated shoots were successfully rooted and acclimatized with a 65% survival frequency and no observable morphological variation. The developed micropropagation protocol has the potential for producing more than 60,000 transplantable shoots per year from a single shoot-tip explant of this critically endangered species. Springer Science+Business Media B.V., 2010 Conservation nationallicence Plant growth regulator nationallicence Threatened species nationallicence Tissue culture nationallicence Topolins nationallicence [9G]BA : 6-Benzylamino-9-β-d-glucopyranosylpurine nationallicence BA : 6-Benzyladenine nationallicence DMRT : Duncan's multiple range test nationallicence IBA : Indole-3-butyric acid nationallicence Kin : Kinetin nationallicence Me m TR : meta-Methoxy topolin riboside nationallicence MS : Murashige and Skoog (1962) medium nationallicence m T : meta-Topolin nationallicence m TR : meta-Topolin riboside nationallicence NAA : α-Naphthalene acetic acid nationallicence PGR : Plant growth regulator nationallicence PPF : Photosynthetic photon flux nationallicence Amoo Stephen Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa aut Finnie Jeffrey Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa aut Van Staden Johannes Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa aut Plant Growth Regulation Springer Netherlands 63/2(2011-03-01), 197-206 0167-6903 63:2<197 2011 63 10725 https://doi.org/10.1007/s10725-010-9504-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10725-010-9504-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Amoo Stephen Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa aut NATIONALLICENCE 700 1- Finnie Jeffrey Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa aut NATIONALLICENCE 700 1- Van Staden Johannes Research Centre for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, Private Bag X01, 3209, Scottsville, South Africa aut NATIONALLICENCE 773 0- Plant Growth Regulation Springer Netherlands 63/2(2011-03-01), 197-206 0167-6903 63:2<197 2011 63 10725 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer