caa a22 4500 445842008 CHVBK 20180317145347.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10725-011-9597-7 doi (NATIONALLICENCE)springer-10.1007/s10725-011-9597-7 Auxin stability and accumulation during in vitro shoot morphogenesis influences subsequent root induction and development in Eucalyptus grandis [Elektronische Daten] [Muhammad Nakhooda, M. Watt, David Mycock] Recent results showed that after 16months in the field, micropropagated eucalyptus plants have an inferior root system to cuttings. Such differences may be due to the plant growth regulators supplied during the culture stages of standard protocols, which are targeted at optimising plantlet yields and not root quality. This study investigated such a proposal, focusing on auxins in an easy-to-root clone. Initial results showed that the auxin provided in the standard protocol (NAA for multiplication and IBA for elongation) enabled 100% rooting in auxin-free medium, where rooting was faster than on IBA-rooting media. When auxin supply was omitted from multiplication and restricted to NAA or IAA during elongation, rooting in an auxin-free medium was reduced to 68 and 31%, respectively, reflecting the stabilities of these auxins in plant tissues. Additionally, 15% of shoots from the NAA-medium and 65% from the IAA-medium produced roots with altered graviperception. GC-MS analysis of these shoots revealed a relationship between free IAA-availability and altered graviperception. This was further tested by adding the IAA-specific transport inhibitor 2,3,5-triiodobenzoic acid to rooting media with IBA, IAA or NAA, which resulted in 100, 70.9 and 20.6% rooting, respectively. At least 40% of the sampled root tips had atypical starch grain deposition and abnormal graviperception. It is proposed that, at least in this clone, while IBA and NAA can be used for in vitro root induction, IAA is necessary for development of graviresponse. Springer Science+Business Media B.V., 2011 Eucalyptus nationallicence Graviperception nationallicence Plant growth regulators nationallicence Root quality nationallicence AG : Altered graviperception nationallicence GC-MS : Gas chromatography-mass spectrometry nationallicence IAA : Indole-3-acetic acid nationallicence IBA : Indole-3-butyric acid nationallicence NAA : α-Naphthalene acetic acid nationallicence TIBA : 2,3,5-triiodobenzoic acid nationallicence PGR : Plant growth regulator nationallicence Nakhooda Muhammad School of Biological and Conservation Sciences, University of KwaZulu-Natal, Durban, South Africa aut Watt M. School of Biological and Conservation Sciences, University of KwaZulu-Natal, Durban, South Africa aut Mycock David School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa aut Plant Growth Regulation Springer Netherlands 65/2(2011-11-01), 263-271 0167-6903 65:2<263 2011 65 10725 https://doi.org/10.1007/s10725-011-9597-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10725-011-9597-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nakhooda Muhammad School of Biological and Conservation Sciences, University of KwaZulu-Natal, Durban, South Africa aut NATIONALLICENCE 700 1- Watt M. School of Biological and Conservation Sciences, University of KwaZulu-Natal, Durban, South Africa aut NATIONALLICENCE 700 1- Mycock David School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa aut NATIONALLICENCE 773 0- Plant Growth Regulation Springer Netherlands 65/2(2011-11-01), 263-271 0167-6903 65:2<263 2011 65 10725 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer