title: Physiological and biochemical responses to severe drought stress of nine Eucalyptus globulus clones: a multivariate approach.
abstract: Seasonal drought, typical of temperate and Mediterranean environments, creates problems in establishing plantations and affects development and yield, and it has been widely studied in numerous species. Forestry fast-growing species such as Eucalyptus spp. are an important resource in such environments, selected clones being generally used for production purposes in plantations in these areas. However, use of mono-specific plantations increases risk of plant loss due to abiotic stresses, making it essential to understand differences in an individual clone's physiological responses to drought stress. In order to study clonal differences in drought responses, nine Eucalyptus globulus (Labill.) clones (C14, C46, C97, C120, C222, C371, C405, C491 and C601) were gradually subjected to severe drought stress (<14% of field capacity). A total of 31 parameters, physiological (e.g., photosynthesis, gas exchange), biochemical (e.g., chlorophyll content) and hormonal (abscisic acid [ABA] content), were analysed by classic and multivariate techniques. Relationships between parameters were established, allowing related measurements to be grouped into functional units (pigment, growth, water and ABA). Differences in these units showed that there were two distinct groups of E. globulus clones on the basis of their different strategies when faced with drought stress. The C14 group (C14, C120, C405, C491 and C601) clones behave as water savers, maintaining high water content and showing high stomatal adjustment, and reducing their aerial growth to a great extent. The C46 group (C46, C97, C222 and C371) clones behave as water spenders, reducing their water content drastically and presenting osmotic adjustment. The latter maintains the highest growth rate under the conditions tested. The method presented here can be used to identify appropriate E. globulus clones for drought environments, facilitating the selection of material for production and repopulation environments.
authors.affiliation: Área de Fisiología Vegetal, Departamento de Biología de Organismos y Sistemas, Instituto Universitario de Biotecnología de Asturias, Universidad de Oviedo, c/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Spain victorgrandagarcia@gmail.com.
authors.forename: Víctor
authors.initials: V
authors.lastname: Granda
authors.affiliation: Estación Experimental de La Mata del Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), 33820 Asturias, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Delatorre
authors.affiliation: Área de Fisiología Vegetal, Departamento de Biología de Organismos y Sistemas, Instituto Universitario de Biotecnología de Asturias, Universidad de Oviedo, c/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Spain.
authors.forename: Candela
authors.initials: C
authors.lastname: Cuesta
authors.affiliation: Área de Fisiología Vegetal, Departamento de Ingeniería y Ciencias Agrarias, Universidad de León, 24071 León, Spain.
authors.forename: María L
authors.initials: ML
authors.lastname: Centeno
authors.affiliation: Área de Fisiología Vegetal, Departamento de Biología de Organismos y Sistemas, Instituto Universitario de Biotecnología de Asturias, Universidad de Oviedo, c/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Fernández
authors.affiliation: Área de Fisiología Vegetal, Departamento de Biología de Organismos y Sistemas, Instituto Universitario de Biotecnología de Asturias, Universidad de Oviedo, c/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Rodríguez
authors.affiliation: Estación Experimental de La Mata del Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), 33820 Asturias, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Feito
mesh_terms: D055864:Droughts; D005052:Eucalyptus / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D016468:Forestry; D015999:Multivariate Analysis; D013312:Stress, Physiological
keywords: Eucalyptus; abiotic stress; clonal variability; clones; cluster analysis; principal component analysis