tailieunhanh - Báo cáo khoa học: "esponse of Pinus pinaster Ait. provenances at early age to water supply. I. Water relation parameters"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Response of Pinus pinaster Ait. provenances at early age to water supply. I. Water relation parameters. | 179 Ann. For. Sci. 56 1999 179-187 Inra Elsevier Paris Original article Response of Pinus pinaster Ait. provenances at early age to water supply. I. Water relation parameters Manuel Fernandez Luis Gil José A. Pardos Unidad de Anatomia Fisiologia y Genética ETS de Ingenieros de Montes Ciudad Universitaria s n Universidad Politécnica de Madrid 28040 Madrid Spain Received 8 December 1997 revised 11 March 1998 accepted 17 August 1998 Abstract - The seasonal evolution of tissue water relations was assessed in 1-year-old seedlings of four Pinus pinaster Ait. provenances growing in a nursery and subjected to two water supply regimes. Seedlings were also submitted to water stress cycles in a controlled environment chamber. Water relation parameters were deduced from pressure-volume curves. Significant differences were found between water supply regimes and measurement dates and sometimes among provenances. For the lowest water availability treatment osmotic potential at full turgor decreased by MPa in some provenances whereas well-watered seedlings showed almost no osmotic adjustment. Provenances originating from hotter sites demonstrated a larger and more rapid acclimation to water stress conditions than provenances from colder sites. Osmotic adjustment as an initial or short-term reaction together with longer-term changes in cellular elasticity are both observed in p. pinaster in response to water shortage. These physiological adaptations complement known morphological adaptations to drought stress in this species. With caution assessment of these parameters in young seedlings can be used as a tool for early selection and prediction of future performance under conditions of water limitations. Inra Elsevier Paris. maritime pine early selection water relation parameter Résumé - Réponse au stress hydrique des provenances de Pinas pinaster Ait. à un âge précoce. I. Paramètres hydriques. L evolution saisonnière des relations hydriques a été déterminée chez quatre .