Fast-growing oak holds fertiliser key

A Dundee University botanist is going to Australia to study the roots of an unusual tree, after beating competition from 12 Commonwealth countries for a scholarship from the Association of Rhodes Scholars in Australia.

Keith Skene of Dundee's department of biological sciences will study the Silky Oak, a fast-growing tree which is able to survive in very poor soil and is grown commercially for timber.

The tree, more correctly known as Grevillea robusta, has special roots, "cluster roots" which release acid into the soil, freeing phosphates which can then be absorbed by the plant. "If we knew how these cluster roots operated in the long term, it could lead to a reduction in our dependency on fertilisers," Mr Skene said.

"One of the tasks we as scientists face next is to look at the possibility of engineering other plants to produce such cluster roots."

The roots are extremely unusual in that they are not permanent, said Mr Skene. They are produced as needed, grow for a fixed term, and are discarded within a month or two.

"If we could find out the stopping and starting mechanisms, the answers could have implications for all kinds of problems, including cancer research."