in this study the response of 9 rapeseed genotypes were evaluated at the seedling stage using different irrigation levels (50, 70 and 100% fc). a factorial experiment based on rcbd was conducted in the research greenhouses of urmia university with four replications during summer of 2013. some physiological traits such as relative water content, stomatal conductance, transpiration, photosynthesi...

paclobutrazol was utilized to analyze its role in water stress amelioration and post drought recovery of container-grown pear ( pyrus communis cv. biroti ) saplings. following planting, paclobutrazol was applied as soil drench at concentration of 0, 0.15 and 0.3 mg per pot. three months following planting, saplings were subjected to three water stress treatments of: 0, -0.4 and -0.8 mpa. contro...

Different spatial distributions of soil moisture were imposed on field-grown grapevines by applying the same irrigation volumes to the entire (DI; deficit irrigation) or part of the (PRD; partial root zone drying) root zone. Five treatments were applied: controls irrigated at 60% ETc (crop evapotranspiration) for the whole season (308 mm year(-1)); DI-1 and PRD-1 that received the same irrigati...

The hypothesis of optimal stomatal conductance predicts conductance should vary with changes of the vapor pressure difference between leaf and air (VPD) to keep the partial derivative of transpiration rate (E) with respect to assimilation rate (A) constant ( partial differentialE/ partial differentialA = lambda). Stomatal conductance of Amaranthus powellii Wats. decreased strongly with increasi...

Transpiration is controlled by evaporative demand and stomatal conductance (gs ), and there can be substantial genetic variation in gs . A key parameter in empirical models of transpiration is minimum stomatal conductance (g0 ), a trait that can be measured and has a large effect on gs and transpiration. In Arabidopsis thaliana, g0 exhibits both environmental and genetic variation, and quantita...

Experimental evidence is presented to show that the O enrichment in the leaf biomass and the mean (timeaveraged) transpiration rate are positively correlated in groundnut and rice genotypes. The relationship between oxygen isotope enrichment and stomatal conductance (gs) was determined by altering gs through ABA and subsequently using contrasting genotypes of cowpea and groundnut. The Peclet mo...

The water permeability of the leaves of three deciduous plants (Acer campestre, Fagus sylvatica, Quercus petraea) and two evergreen plants (Hedera helix, Ilex aquifolium) was analysed in order to assess its role as a mechanism of drought resistance. Cuticular permeances were determined by measurement of the water loss through adaxial, astomatous leaf surfaces. Minimum conductances after complet...

We studied the effect of scion donor-tree age on the physiology and growth of 6- to 7-year-old grafted Scots pine (Pinus sylvestris L.) trees (4 and 5 years after grafting). Physiological measurements included photosynthethetic rate, stomatal conductance, transpiration, whole plant hydraulic conductance, needle nitrogen concentration and carbon isotope composition. Growth measurements included ...