Micropropagation and rejuvenation of Sequoia sempervirens (Lamb) Endl: a review

Abstract

This article describes the botanical, biological and forest-tree characteristics of Se- quoia sempervirens, the reasons for interest in its in vitro vegetative multiplication, the difficulty in achieving this from old and remarkable trees, and reviews means of overcoming this limitation. Among such means are the repeated culture of stem fragments on media containing appropriate hormonal combinations, the micrografting of buds originating from old trees onto juvenile rootstocks, and regeneration of buds from previously rejuvenated material. The value and limitations of these protocols and of morphological, physiological and biochemical markers of rejuvenation are dis- cussed. The experimental conditions required for the formation of somatic embryos are described. Increased knowledge of in vitro micropropagation will be essential to enhance the use of clonal se- lection and offer practical outlets to studies concerning somatic hybridization and somatic embryo- genesis.