Video report by ITV News Anglia's Malcolm Robertson
Scientists say a tree in Norfolk could hold the key to fighting ash dieback.
The tree named Betty in a wood near Norwich has been identified as having a very high tolerance to the disease.
Chalara ash dieback, which could kill millions of ash trees, was first identified in the UK in 2012 and experts fear it could have the same devastating impact on the country's woodlands and landscape as Dutch elm disease in the 1970s.
But a team of researchers from the UK, Denmark and Norway have identified genetic markers in ash trees which are tolerant to the disease, raising hopes of selective breeding to produce trees which are less susceptible to the ash dieback fungus.
A tree, nicknamed "Betty", in a Norfolk Wildlife Trust woodland near Norwich was predicted by the markers to show a very high tolerance to the disease.
Betty is a mature tree which is currently healthy, despite being next to trees which are infected.
Researchers think British ash trees may be more resistant than those on the continent.