2010 Volume 48 Issue 3 Pages 117-125
The growth parameters of Lockhart's equation were determined in expanding leaves of tomato plants (Solanum lycopersicum L.) subjected to different relative humidity in the dark. In tomato leaves, sizes of the growth-induced water potential exhibited linear relations with the relative growth rates (RGR) under various vapor pressure difference (VPD) conditions between leaves and the ambient air. When transpiration rates of tomato plants became significantly larger, lines formed between the growth-induced water potential and RGR had a translational relation as VPD increased. Then, the transpiration-induced water potential became proportionally larger as VPD increased. These results indicated that transpiration flux and growth flux have additive relations, suggesting that water fluxes for growth and transpiration are linearly superimposed.
