Prospects for the Mass Production of Improved Stock of Forest Trees by Cell and Tissue Culture

An annotated chronological bibliography of cell and tissue culture studies with forest tree species is presented. The current status of cell and tissue culture as a tool for tree improvement is considered against the background of work with other plant species. Techniques and strategies which have been used to induce differentiation in plant cultures are outlined. The main methods seem to be sequential treatments of growth regulators or nutrients, simplification of media, and growth regulator balances. Additional unexploited treatments such as spatial and temporal gradients, and environmental variables are suggested. There is a new prospect of adding traits and producing genetic combinations which could not be obtained by sexual crossing. This would involve mutation, transcession, transduction, transformation, and somatic cell hybridization. Invitro methods can also be used in forestry for preservation of gene resources, production of homozygous specimens, prediction of phenotypic expression, production of disease-free specimens, study of host-parasite relations, and study of mycorrhizae. We conclude that cell and tissue culture has a great potential value to forestry.