Puntos de Interés
Vegetation
Graphiosis - Resistant Elms
Graphiosis is a highly virulent disease that spreads rapidly and is very difficult to control by chemical, biological or forestry methods.
Since the beginning of the 20th century, elm populations throughout Europe have suffered high mortality rates from this disease. For experts, the selection and improvement of resistant genotypes is the best alternative for the recovery of the elm, which is one of the most important landscape features in temperate zones and is currently endangered.
The species is of great importance because of the role that elm groves played in the past. Such ecosystems stabilised river banks, reducing the effects of flooding. They are also an important refuge for wildlife and provide a cool, shady environment, ideal for combating the summer heat.
Since 1990, the Ministry for Ecological Transition and the Demographic Challenge has been at the forefront of the Spanish Programme for the Conservation of Elms, at the Polytechnic University of Madrid, and has succeeded in developing seven varieties tolerant to this disease.
Since its inception, the activities of this programme have been oriented towards contact with the disease. Studies have also been carried out on the particular conditions of this disease in Spain, taking into account the three agents involved: host, pathogen and vector. In this way, a sampling of the elm trees that have been affected by this disease has been carried out. In addition, the fungus causing graphiosis was studied using 32 strains from the provinces with the most problems with this disease. Ninety isolations were subsequently made to find out the biological cycle and different tests were carried out with two key objectives: to conserve the genetic resources of the elm and to obtain new genetic variables resistant to the disease.