Progress in the biotechnology of trees

Abstract

An increasing world population and rise in demand for tree products, especially wood, has increased the need to produce more timber through planting more forest with improved quality stock. Superior trees are likely to arise from several sources. Firstly, forest trees can be selected from wild populations and cloned using macropropagation techniques already being investigated for fruit tree rootstocks. Alternatively, propagation might be brought aboutin vitro through micropropagation or sustained somatic embryogenesis, with encapsulation of the somatic embryos to form artificial seeds. Tree quality could be improved through increased plant breeding and it is likely that experienced gained, to date, in the breeding of fruit species will be useful in devising strategies for forest trees. Since the development of techniques to regenerate woody plants from explant tissues, cells and protoplasts, it is now feasible to test the use of tissue culture methods to bring about improvements in tree quality. Success has already been achieved for tree species in the generation of somaclonal and protoclonal variation, the formation of haploids, triploids and polyploids, somatic hybrids and cybrids and the introduction of foreign DNA through transformation. This review summarizes the advances made so far in tree biotechnology, and suggests some of the directions that it might take in the future.

Stomatal length and frequency as a measure of ploidy level in black wattle, Acacia mearnsii (de Wild)

“…In order to meet the needs of the forestry industry, breeding and production programmes are constantly being adapted to provide suitable genotypes for particular purposes. Besides the more conventional breeding strategies, various biotechnological techniques are also employed (Durzan, 1988) and include mutation breeding, transformation (Hammat, 1992), tissue culture, hybridization, chromosome doubling (polyploidization) and clonal propagation.…”