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Báo cáo lâm nghiệp: "Starch and soluble carbohydrates in leaves of water-stressed oak saplings"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: "Starch and soluble carbohydrates in leaves of water-stressed oak saplings. | Ann Sci For 1996 53 263-268 Elsevier INRA 263 Short note Starch and soluble carbohydrates in leaves of water-stressed oak saplings D Épron E Dreyer Écophysiologie forestiere Centre de Nancy Inra 54280 Champenoux France Received 6 September 1994 accepted 19 July 1995 Summary Four-year-old potted saplings of Quercus petraea Matt Liebl were exposed to water shortage by withholding irrigation. After 10 days predawn leaf water potential was decreased to -2.0 MPa and leaf photosynthesis was reduced by 55 . At this stage starch and sucrose concentrations were decreased by 47 and 48 respectively. A five-fold increase was observed in glucose and fructose concentrations of water-stressed saplings compared with well-watered plants. These results suggested that drought-induced changes in sugar composition contribute to osmotic adjustment in this species. oak Quercus I soluble carbohydrate starch sucrose water stress Resume Amidon et glucides solubles dans les feuilles de jeunes plants de chêne soumis à un deficit hydrique. Des jeunes plants en pot de Quercus petraea Matt Liebl ãgés de 4 ans ont été soumis à un deficit hydrique en supprimant I irrigation. Après 10 jours le potential hydrique en fin de nuit était de -2 0 MPa et la photosynthèse foliaire réduite de 55 . À ce Stade les concentrations en amidon et en saccharose étaient diminuées de 47 et 48 respectivement. Les concentrations foliaires en glucose et en fructose des plants soumis à la sécheresse étalent augmentées d un facteur 5 par rapport aux plants bien irrigués. Ces résultats suggèrent que les changements de la composition glu-cidique des feuilles tors d un deficit hydrique contribuent à un ajustement osmotique Chez cette espèce. chêne Quercus deficit hydrique amidon saccharose glucide soluble Present address Institut des sciences et des techniques de I environnement pole universitaire du Pays de Montbéliard BP 427 25211 Montbéliard cedex France. 264 D Epron E Dreyer INTRODUCTION Sessile oak Quercus petraea is .