Epilogue

Abstract

Techniques for tree tissue culture have improved rapidly over the last few years. Advances in embryogenesis, in protoplast research and in genetic engineering have been considerable. However, in general, all these advances have not yet resulted in extensive commercial application of tree tissue culture. Commercial micropropagation is presently limited to a few hardwood and palm tree species. Propagation rates are often still too low and costs too high to be effective. Furthermore, propagation is often not yet sufficiently true-to-type and the methods employed are not always reliable enough to allow commercialization. Automation of the procedures is obviously required. With regard to genetic engineering, progress in this field has been very rapid. Nevertheless, we still have to learn how to handle multiple gene combinations and in particular genes isolated from the crop species rather than from microorganisms. The genetics of crops has to be better understood before genetic engineering will become truly effective. Much research clearly remains to be done.