Processes at the plasma membrane and plasmalemma ATPase during dormancy

International audienc

Intensive production of juvenile cuttings by mother microplant culture in Hydrangea macrophylla "Leuchtfeuer"

International audienc

Involvement of cold temperature in the nutrient flux orientation into the peach-tree single node cuttings

International audienc

Température et énergétique de croissance des bourgeons de noyer au moment du débourrement

National audienc

Using intracellular pH to evaluate growth inhibition of stawberry plants

International audienc

Influence of temperature on the dynamics of ATP, ADP and non-adenylic triphosphate nucleotides in vegetative and floral peach buds during dormancy

absen

État hydrique et mouvements d'eau dans les tubercules d'Helianthus tuberosus L lors de la dormance et de sa levée

L'étude du métabolisme hydrique des tubercules de tompinambour (Helianthus tuberosus L) dormants, placés soit à 24 °C (condition de boulage), soit à 4 °C (condition de levée de dormance) a permis de mettre en évidence le rôle de l'eau dans la dormance et sa levée. Chez les tubercules maintenus à 24 °C, les modifications de la teneur en eau dans les tronçons 2 et 3, au 15e j, pourraient être liées à l'initiation du processus de boulage (30e j). L'augmentation du potentiel osmotique et de la teneur en eau, dans la base des tubercules, permet d'envisager que cette base rend possible l'alimentation en sucres et probablement en eau lors de la croissance tubérisée. Chez les tubercules maintenus à 4 °C, après 9-10 semaines de séjour au froid, d'importantes modifications ont lieu : il y a un afflux d'eau et de matières de réserve vers le bourgeon.Water status and water movements in tubers of Helianthus tuberosus L during dormancy and breaking of dormancy. The study of water parameters in dormant Jerusalem artichokes tubers (Helianthus tuberosus L) kept at 24 °C ("boulage" process) and at 4 °C (to break the dormancy), in darkness showed the role of water during dormancy and the breaking period. During the first 15 d at 24 °C, the water content in the region adjacent to the bud increased (fig 4a), and that in the middle region decreased (fig 3a); this could indicate water movement. The fact that osmotic potential in the basal region increased (fig 2b) and that its water potential was higher than in the middle region (fig 2c) could indicate that the basal region supplied the middle region with sugars and probably with water. The water content increase in the basal region (fig 2a) could explain the increase of osmotic potential in this same region. In tubers kept at breaking conditions of dormancy at 4 °C, during the first weeks the same variations in basal and middle regions were observed. The differences between both treatments (24 °C and 4 °C) were found to be the variation range and the speed at which the variations took place. After these first wk at 4 °C, the decrease in the osmotic potential of the bud (fig 7b) led to an increase in bud water potential (fig 7c); this could indicate water supply by the bud to the adjacent region and explain the increase in turgor pressure of the bud and the water content (fig 7a). It was therefore concluded that after 9-10 wk at 4 °C, significant changes occurred in water status of Helianthus tuberosus L tubers

Development of photosynthetic ability of hybrid walnut plantlets during acclimatization

International audienc

Dormancy in vegetative buds of peach: relation between carbohydrate absorption potentials and carbohydrate concentration in the bud during dormancy and its release

International audienc