Hardwood tree biotechnology

Abstract

Due to the commercial importance of some conifer species, advances in conifer biotechnology often appear to overshadow equally significant advances in the biotechnology of angiosperm forest trees. However, progress with some hardwood forest trees has been just as promising as that made with conifers, and in some areas, has surpassed conifer biotechnology, particularly in the past few years. Until relatively recently, progress with in vitro propagation and gene transfer in hardwood forest trees was confined primarily to the genus Populus. Similarly, compared to other hardwood species, the greatest progress has been made both in the areas of genomics and modification of wood quality traits in this genus. However, the advances in in vitro propagation, in general, and somatic embryogenesis, in particular, have brought mass clonal propagation of other top commercial hardwood trees, in particular Eucalyptus, closer to reality and gene transfer systems have been reported for a number of them. While by far the most extensive application of genomic tools, including genomic sequencing, expressed sequence tags, transcript profiling and molecular markers, has also been made with Populus, these tools are now being applied to wider range of hardwood species. Just as with conifers, potential biotechnology applications for hardwood forest species include development of trees with faster growth, altered wood quality, and insect and disease resistance. In addition, some hardwood species are being manipulated for such non-traditional uses as phytoremediation. Given these advances and the worldwide importance of the products derived from them, it is likely that in vitro propagated and transgenic hardwood forest trees will have just as great an impact on commercial forestry and our environment as the top coniferous species.