However, size is only one criterion that may be used to measure growth. During this process, cells increase in volume manyfold and become highly vac-uolate. Glosbe utilise des cookies pour vous offrir la meilleure expérience. The largest component of plant growth is cell expansion driven by turgor pressure. Cherchez des exemples de traductions leaf primordium dans des phrases, écoutez à la prononciation et apprenez la grammaire. The shoot apex fluctuates in shape and size during a plastochron- the time interval between the formation of one leaf primordium and the initiation of next leaf primordium. They have definite sites of origin on the shoot apex according to the phyllotaxis of plant. These results suggest that any attempt to simulate leaf area development and growth of wheat plants for P-limited conditions should include the effects of the deficiency on leaf emergence. Growth in plants is defined as an irreversible increase in volume. Leaf primordia are formed on the flanks of shoot apical meristem. Cell division gradually stops, and with it the associated syntheses thus there is no increase in the DNA of the nuclei of the meristem after the last division. In this work a phosphorus deficiency that reduced shoot growth by 25% at 44 days after emergence significantly modified the structure of the plants by increasing the value of the phyllochron and delaying tillering. The early growth of the axillary bud proceeds quite vigorously until a certain number of leaf primordia has been formed then apical activity slows. P deficiency delayed or even suppressed the emergence of certain tillers. The effects of P on the value of the phyllochron were attributed to both a reduced rate of leaf primordia initiation, and to a reduced leaf elongation rate. free area must be available on the surface of the apical cone far enough below the summit or growing-point before a leaf primordium can be determined. The final number of leaves was not affected by P. Phosphorus deficiency increased the time from emergence to double ridge and anthesis. P deficiency delayed the emergence of leaves on the main stem and on the tiller 1. The plastochron was calculated from the inverse of the rate of leaf primordia initiation in the apex. The phyllochron was calculated as the inverse of the rate of leaf emergence calculated from the regression of number of leaf tips (PHY-Ltip), Haun index (PHY-Haun), and as the cumulated thermal time between the emergence of two consecutive leaves (PHYtt). In Experiment 2 there were two levels of P supply, P1 and P4, and we examined the effects of P on leaf primordia differentiation and leaf emergence. In Experiment 1 we studied leaf emergence, leaf elongation, tiller emergence, shoot growth, and P uptake under four levels of P supply (mM) 0.025 (P1), 0.05 (P2), 0.1 (P3), and 0.5 (P4), and. With the onset of the reproductive state within a runner, a precocious bud primordium (the axillary tissue of a double ridge), which later develops into an inflorescence, is initiated in the axil of the youngest leaf pri-mordium. In two simultaneous experiments we examined the effects of phosphorus (P) supply on leaf area development in wheat (Triticum aestivum L.) grown in sand with nutrient solutions. primordia are present in the axils of the youngest two or three leaf primordia on each runner.
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