Granda Víctor, Delatorre Carolina, Cuesta Candela, Centeno María L, Fernández Belén, Rodríguez Ana, Feito Isabel
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
Estación Experimental de La Mata del Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), 33820 Asturias, Spain.
Tree Physiol. 2014 Jul;34(7):778-86. doi: 10.1093/treephys/tpu052. Epub 2014 Jul 8.
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.
季节性干旱是温带和地中海环境的典型特征，它给人工林的建立带来问题，并影响树木的生长发育和产量，许多物种都对此进行了广泛研究。在这类环境中，像桉属树种这样的林业速生树种是重要资源，在这些地区的人工林中，通常选用选定的无性系进行生产。然而，单一种植园的使用增加了因非生物胁迫导致植物损失的风险，因此了解单个无性系对干旱胁迫的生理反应差异至关重要。为了研究干旱响应中的无性系差异，对九个蓝桉（Labill.）无性系（C14、C46、C97、C120、C222、C371、C405、C491和C601）逐渐施加严重干旱胁迫（田间持水量的<14%）。通过经典和多变量技术分析了总共31个参数，包括生理参数（如光合作用、气体交换）、生化参数（如叶绿素含量）和激素参数（脱落酸[ABA]含量）。建立了参数之间的关系，使相关测量能够分组为功能单元（色素、生长、水分和ABA）。这些单元的差异表明，基于面对干旱胁迫时的不同策略，蓝桉无性系可分为两个不同的组。C14组（C14、C120、C405、C491和C601）无性系表现为节水型，保持高含水量，气孔调节能力强，并在很大程度上减少地上部分生长。C46组（C46、C97、C222和C371）无性系表现为耗水型，含水量急剧降低，并呈现渗透调节。在测试条件下，后者保持最高生长速率。这里介绍的方法可用于识别适合干旱环境的蓝桉无性系，便于为生产和重新造林环境选择材料。
