Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Endurcissement à la sécheresse et accumulation de glucides solubles et d’acides aminés libres dans les phyllodes d’Acacia cyanophylla Lindl. | Ann Sci For 1997 54 155-168 Elsevier INRA 155 Article original Endurcissement à la sécheresse et accumulation de glucides solubles et d acides amines libres dans les phyllodes A Acacia cyanophylla Lindl A Albouchi1 R Ghrir2 MH El Aouni3 1 Institut national de recherches en ỊỊénie rural eaux et forets BP 2 Ariana 2080 2 Institut national de recherches scientifique et technique BP 95 Hammam Lif2050 3 Faculte des sciences de Bizerte Jarzouna 7021 Tunisie Reọu le 25 septembre 1995 accepté le 3 avril 1996 Summary - Drought hardening soluble carbohydrates and free amino acid accumulation in Acacia cyanophylla Lindl phyllodes. Two plots of 8-month-old plants of Acacia cyanophylla Lindl grown in the greenhouse have been subjected to two contrasting water feedings. The first was nearly maximum evapotranspiration D and the second was D 6. Three plants of each water feeding were subjected to a drying cycle by water withholding after 1 3 5 and 13 months in order to allow the emergence of adaptive mechanisms in hard drought. At the beginning of each drying cycle water potential component had been measured at 1 Pm in order to evaluate the effect of drought preconditioning duration on the D 6 plants. At the end of each cycle marked by zero turgor the same measures had been made and the remaining phyllodes were used to determine the concentration of free amino acids soluble sugars and starch. We noted at the beginning of the cycles that D plants had a slight decrease in osmotic potential and a slight increase in the turgor these variations seemed to be related to age. The response of D 6 plants varied with the duration of preconditioning. After I month at the beginning of the cycle their turgor was less than that of D plants. At the end of the cycle they had a less negative osmotic potential and lower contents of free amino acids as compared to D plants. This suggests that a 1 month preconditioning to D 6 treatment was insufficient to induce hardening mechanisms. After 3 months .
