ABSTRACT Besides being employed as an efficient plant growth retardant for field, garden and potted plants, paclobutrazol (PBZ) is also used in laboratory experiments, mainly in aseptic cultures, both in autoclaved and non-autoclaved form. Therefore it is not known if autoclaving can partial or completely inactivates the product, thus decreasing its efficacy. Thus a simple experiment was carried out to assess to what extent the autoclaving process can affect some growth components and dry mass accumulation and partition in sunflower seedlings, by employing the techniques of plant Growth Analysis. Autoclaving did not modify either qualitative or quantitatively any of the plant responses to PBZ as well their reversions by gibberellic acid.
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nullRibeiro, D. , Müller, C. , Bedin, J. , Rocha, G. and Barros, R. (2011) Effects of autoclaving on the physiological action of paclobutrazol. Agricultural Sciences, 2, 191-197. doi: 10.4236/as.2011.23026.
 PGRSA (2007) Plant growth regulation handbook of the Plant Growth Regulation Society of America, 4th edn. Athens, (GA).
 ICI – Imperial Chemical Industries PLC, Plant Protection Division (1986) Clipper. Surrey, UK.
 Rademarcher, W. (2000) Growth retardants: Effects on gibberellins biosynthesis and other metabolic pathways. Annual Review of Plant Physiology and Plant Molecular Biology 51, 501-531.
 Kulkarni, V.J. (1988) Chemical control of tree vigour and promotion of flowering and fruiting in mango (Mangifera indica L.) using paclobutrazol. The Journal of Horticultural Science 63, 557-566.
 Wilkinson, R.I. and Richards, D. (1991) Influence of paclobutrazol on growth and flowering of Rhododrendon ‘Sir Robert Peal’. HortScience 26, 282-284.
 Tukey, L.D. (1983) Vegetative control and fruiting on mature apple trees treated with PP333. Acta Horticulture 137, 103-109.
 Gosh, A., Chikara, J., Chandhari, D.R., Prakashi, A.R., Boricha, G. and Zala, A. (2010) Paclobutrazol arrests vegetative growth and unveils unexpressed yield potential of Jathropa curcas. Journal of Plant Growth Regulation 29: 307-315.
 Early, J.D. and Martin, G.C. (1988) Translocation and breakdown of 14C-labeled paclobutrazol in ‘Nemaguaro’ peach seedlings. HortScience 23: 196-200.
 Muller, C. (2007) Efeito do paclobutrazol na germina??o e no metabolismo do etileno em sementes de Stylosantes humilis HBK. MSc dissertation, Universidade Federal de Vi?osa, Vi?osa.
 Snir, I. (1988) Influence of paclobutrazol on in vitro growth of sweet cherry shoots. HortScience 23, 304-305.
 Panaia, M., Senaratna, T., Bunn, E., Dixon, K.W. and Sivasithamparam, K. (2000) Micropropagation of the critically endangered Western Australian species, Symonanthus bancroftii (F. Muell.) L. Haegi (Solanaceae). Plant Cell Tissue and Organ Culture 63, 23-29.
 Albany, N.R., Vilchez, J.A., Garcia, L. and Jiménez, E. (2005) Comparative study of morphological parameters of Grand Nain banana (Musa AAA) after in vitro multiplication with growth retardants. Plant Cell Tissue and Organ Culture 83, 357-361.
 Haughan, P.A., Burden, R.S., Lenton, J. and Goad, J. (1989) Inhibition of celery cell growth and sterol biosynthesis by the enantiomers of paclobutrazol. Phytochemistry 3, 781-787.
 Chen, J.-T. and Chang W.-C. (2003) Effects of GA3, ancymidol, cycocel and paclobutrazol on direct somatic embryogenesis of Oncidium in vitro. Plant Cell Tissue and Organ Culture 72: 105-108.
 Kucharska, D. and Olikowska, T. (2008) The influence of paclobutrazol in the rooting medium on the quality of chrysanthemum vitroplants. The Journal of Fruit and Ornamental Plant Research 16, 417-424.
 Kyte, L. and Kleyn, J. (1996) Plant from test tubes – An introduction to micropropagation, 3rd edn, Timber Press, Portland.
 Richards, F.J. (1969) The quantitative analysis of growth. In: Steward, F.C. Ed., Plant physiology – A treatise. Academic Press, New York, 3-76.
 Hunt, R., Causton, D.R., Shipley, B. and Askey, A.P. (2002) A modern tool for classical plant growth analysis. Annals of Botany 90, 485-488.
 LeCain, D.R., Schekel, K.A. and Wample, R.L. (1986) Growth retarding effects of paclobutrazol on weeping fig. HortScience 21, 1150-1152.
 Bultynck, L. and Lambers, H. (2004) Effects of applied gibberellic acid and paclobutrazol on leaf expansion and biomass allocation in two Aegilops species with constrasting leaf elongation rates. Physiologia Plantarum 122: 143-151.
 Nagel, O.W. and Lambers, H. (2002) Changes in the acquisition and partitioning of carbon and nitrogen in the gibberellin-deficient mutants A70 and W335 of tomato (Solanum lycopersicum L.). Plant, Cell and Environment 25, 883-891.
 Auras, N.E. (1997) Efeitos do paclobutrazol sobre a morfologia e anatomia foliar, crescimento e parte aérea, distribui??o de biomassa e trocas gasosas em girassol. DSc dissertation, Universidade Federal de Vi?osa, Vi?osa.
 Hunt, R. (1990) Basic growth analysis. Unwin Hyman, London.
 Cox, A.C. and Keever, G.J. (1988) Paclobutrazol inhibits growth of Zinnia and Geranium. HortScience 23: 1029-1030.
 Bidadi, H., Yamaguchi, S., Asahina, M. and Satoh, S. (2010) Effects of shoot-applied gibberellin/gibberellin-biosynthesis inhibitors on root growth and expression of gibberellins biosynthesis genes in Arabidopsis thaliana. Plant Root 4, 4-11.
 Gou, J., Strauss, S.H., Tsai, C.J., Fang, K., Chen, Y., Jiang, X. and Busov, V.B. (2010) Gibberellins regulate lateral root formation in Populus through interactions with auxin and other hormones. The Plant Cell 22: 623-635.