DNA Use in Tree Breeding

Jun 12, 01:17 PM

Current Headlines: By Paddy Rooney

Although plant breeding programmes have been around for centuries, trees present a particular problem.

For most agricultural and horticultural plants, you can see within a year or so whether the desired characteristics have been produced, so that interesting products can be marketed within a commercially-viable time scale.

But even for relatively fast-growing conifer species it may be 25 years or more before a useful new variety can be made available to foresters, while for slow-growing hardwoods you must think in terms of human lifetimes.

For anybody interested in improving the quality of our woodlands - and their appearance - this is a formidable challenge.

Some of our forebears may have been able to consider planting a wood or an avenue of trees for the benefit of future generations.

Nowadays, though, with a constantly-changing economic environment, such farsightedness is impractical.

But help could be at hand, thanks to DNA analysis. The practical problem in plant breeding has been the uncertainty about whether young plants have inherited desired - or indeed undesired - traits from their parents.

Young plants therefore have had to be grown on a trial-and-error basis until the qualities became evident, which is both time- consuming and wasteful.

If, however, DNA markers can be identified which are consistently associated with specific traits, it will be possible to tell much sooner whether these are present in a young plant, saving the time and space (and money!) required for the growing-on process.

Traits of particular interest for commercial timber producers include growth rate, stem straightness and wood density; if these in particular can be identified early, the potential benefits would be very considerable. And if markers for these can be found, the exciting possibility arises of identifying markers for others, aesthetic as well as commercial.

The research division of the Forestry Commission has started a programme with Sitka spruce on three sites with widely-different environmental characteristics, including one in Wales, to investigate the possibilities.

It is sensible to start with a single commercial species, but hopefully before too long it will be possible to incorporate a wider range.

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