Effects of temperature on adventitious root development in microcuttings of Eucalyptus saligna Smith and Eucalyptus globulus Labill

The effects of different tempteratures on in vitro-grown microcuttings and as a pre-treatment in cutting-donor seedlings of Eucalyptus saligna Smith and Eucalyptus globulus Labill were investigated in relation to adventitious rooting both with and without the exogenous root-inducing phytohormone auxin. E. globulus was more sensitive to continuous higher temperatures applied to donor plants and cuttings; the latter yielded overall best rooting response in day/night cycles of 30degreesC/20degreesC. In general, E. saligna was more resistant to higher temperatures and root growth was strongly inhibited by 15degreesC. The presence of exogenous auxin promoted rooting, particularly at lower and higher temperatures. (C) 2004 Elsevier Ltd. All rights reserved.