title: Phylogeography: English elm is a 2,000-year-old Roman clone.
abstract: The outbreak of Dutch elm disease in the 1970s ravaged European elm populations, killing more than 25 million trees in Britain alone; the greatest impact was on Ulmus procera, otherwise known as the English elm. Here we use molecular and historical information to show that this elm derives from a single clone that the Romans transported from Italy to the Iberian peninsula, and from there to Britain, for the purpose of supporting and training vines. Its highly efficient vegetative reproduction and its inability to set seeds have preserved this clone unaltered for 2,000 years as the core of the English elm population--and the preponderance of this susceptible variety may have favoured a rapid spread of the disease.
authors.affiliation: Departamento de Silvopascicultura, Ciudad Universitaria s/n, 28040 Madrid, Spain. lgil@montes.upm.es
authors.forename: Luis
authors.initials: L
authors.lastname: Gil
authors.forename: Pablo
authors.initials: P
authors.lastname: Fuentes-Utrilla
authors.forename: Alvaro
authors.initials: A
authors.lastname: Soto
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Cervera
authors.forename: Carmen
authors.initials: C
authors.lastname: Collada
mesh_terms: D018742:DNA, Chloroplast / Q000235:genetics; D005060:Europe; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000706:statistics & numerical data; D012150:Polymorphism, Restriction Fragment Length; D018644:Roman World; D013997:Time Factors; D034403:Ulmus / Q000235:genetics*; D006113:United Kingdom
chemical_list: D018742:DNA, Chloroplast