title: Physiological integration of connected balsam poplar ramets.
abstract: Clonal integration between ramets can be an ecological advantage of clonal plant species in environments where resources are patchily distributed. We investigated physiological integration among Populus balsamifera L. ramets under drought stress in order to demonstrate water sharing between connected ramets. Pairs of connected ramets were grown in separate pots in the greenhouse where half of ramets had the parental root connection severed and half were left intact. Drought stress was applied to one ramet, and growth, specific leaf area (SLA), net photosynthesis, stomatal conductance, leaf water potential and carbon isotopic composition (δ(13)C) were measured after an 8-week growing period. Droughted ramets connected to watered ramets were able to maintain high gas exchange activity and water potential, similar to watered ramets. Leaf water potential and SLA results showed that the root connection was more beneficial for proximal compared with distal ramets. The parental root connection also allowed droughted ramets to discriminate more against (13)C compared with severed ramets. In conclusion, this study shows compelling evidence of physiological integration of connected P. balsamifera ramets through water sharing.
authors: Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, 341 rue Principale Nord, Amos, QC J9T 2L8, Canada k-emmanuel.adonsou@uqat.ca.
authors: Kokouvi Emmanuel
authors: KE
authors: Adonsou
authors: Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, 341 rue Principale Nord, Amos, QC J9T 2L8, Canada.
authors: Annie
authors: A
authors: DesRochers
authors: Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, 445 boul. Université, Rouyn-Noranda, QC J9X 5E4, Canada.
authors: Francine
authors: F
authors: Tremblay
mesh_terms: D000222:Adaptation, Physiological; D018533:Biomass; D002247:Carbon Isotopes / Q000378:metabolism; D055864:Droughts; D004463:Ecology; D004777:Environment; D010788:Photosynthesis; D018515:Plant Leaves / Q000502:physiology; D018517:Plant Roots / Q000254:growth & development / Q000502:physiology*; D032107:Populus / Q000254:growth & development / Q000502:physiology*; D012100:Reproduction, Asexual; D012987:Soil; D013312:Stress, Physiological; D014197:Trees; D014867:Water / Q000502:physiology*
chemical_list: D002247:Carbon Isotopes; D012987:Soil; D014867:Water
keywords: clonal integration; drought stress; leaf water potential; net photosynthesis; stomatal conductance; water translocation; δ13C