Abstract:

Eucalyptus urophylla MLA clone(MLA) was difficult-to-root clone. E.urophylla U₆ clone(U₆) and E. ABL No.12 W₅ clone(W₅) were relatively easy-to-root clones. After the cuttings of MLA, U₆ and W₅ were treated with indoleacetic acid(IAA), indolebutyric acid(IBA), and nathphylacetic acid(NAA), the activities of peroxidase (POD), polyphenol oxidase(PPO) and indoleacetic acid oxidase(IAAO) increased regularly. The differences of enzyme activities in different stages of rooting were very significant. It was indicated that the origin and development of adventitious roots in Eucalyptus were relative to POD,PPO, and IAAO. The differences of the promoting efficiency of IAA, IBA, and NAA to different clones and different oxidase activities were significant or very significant. The mechanism of promoting oxidase activities and promoting rooting of Eucalyptus cuttings by auxins was discussed.

Key words: Eucalyptus, Rooting of cuttings, Auxins, Oxidases