Modelling of the Uptake, Flow and Utilization of C, N and H2O within Whole Plants of Ricinus communis L. Based On Empirical Data

摘要: Summary An empirically based modelling technique was used to quantitatively depict uptake, flow and utilization of C, N H2O for a 9 day period in mid vegetative growth NO3-fed castor bean (Ricinus communis L.) exposed mean salinity stress 128 mol m-3 NaCl. The models incorporated data on C : weight ratios solutes phloem sap pressure-induced xylem exudates leaves, stem internodes petioles, net increments or losses plant parts, transpirational shoot organs respiratory from parts root. A computational developed assess the extent transfer within internally sited (stem segments petioles) addition traffic through these terminal (root, apex leaves). Molar inputs H2O: were 4803: 22: 1. Half daytime photosynthetic gain by translocated initially root, 33 % lost root respiration, 17% night 8% cycled system 40% finally into dry matter, 10% matter. corresponding budget showed 93% initial leaf laminae, 32% backflow 15 water involved 98% loss transpiration, 2% incorporation tissues commitment transport. Xylem exchanges mostly phloem. predicted steep upward gradient decreasing use efficiency with age, due principally poor CO2 fixation relation youngest leaves. Comparison fluxes between internode those passing out leaves indicated progressive lateral abstraction traces serving lower subsequent passage this cauline upper regions shoot. Data compared earlier obtained information partitioning nodulated white lupin (Lupinus albus L.).