Good News for Ash?


Newly discovered markers allow selection of dieback-tolerant ash trees 15 January 2016, by Gavin McEwan, HorticultureWeek A team led by researchers at the University of York have identified genetic markers that can be used to predict whether individual trees will succumb to ash dieback. Professor Ian Bancroft – Image: BBSRC The researchers sequenced the RNA of a population of trees of varying susceptibility to identify genes which correlated with disease symptoms, allowing them to identify gene markers that correlated with low susceptibility. They then used these markers to successfully predict which trees from a second population were likely to have low susceptibility to the fungal pathogen Hymenoscyphus fraxineus. The technique now allows pre-screening of individual tree seedlings to identify disease-tolerant individuals before they are planted out. John Innes Centre emeritus fellow Professor Allan Downie said: “This offers a way around anticipated loss of more than 90 per cent of UK ash trees, by identifying and selecting those ash seedlings most likely to survive the epidemic of ash dieback currently sweeping across the country.” University of York chair of plant genomics Professor Ian Bancroft added: “The approach we have used has never previously been used to screen for disease-resistant plants and in principle could be applied to identify disease tolerance in other species of trees that are currently being threatened by a range of tree pests and pathogens.”...