This study is to test the effects of Bt gene introduction on the foliar water/nitrogen use efficiency in cotton. We measured leaf stomatal conductance, photosynthetic rate, and transpiration rate under light saturation condition at different stages of a conventional cultivar (zhongmian no. 16) and its counterpart Bt cultivar (zhongmian no. 30) that were cultured on three levels of fertilization...

The response of whole-plant water-use efficiency, termed transpiration efficiency (TE), to variation in soil fertility was assessed in a tropical pioneer tree, Ficus insipida Willd. Measurements of stable isotope ratios (delta(13)C, delta(18)O, delta(15)N), elemental concentrations (C, N, P), plant growth, instantaneous leaf gas exchange, and whole-plant water use were used to analyse the mecha...

During plant-transpiration, water molecules having the lighter stable isotopes of oxygen and hydrogen evaporate and diffuse at a faster rate through the stomata than molecules having the heavier isotopes, which cause isotopic enrichment of leaf water. Although previous models have assumed that leaf water is well-mixed and isotopically uniform, non-uniform stomatal closure, promoting different e...

Just as a soggy paper straw is prone to yielding under the applied suction of a thirsty drinker, the xylem tracheids in leaves seem prone to collapse as water potential declines, impeding their function. Here we describe the collapse, under tension, of lignified cells peripheral to the leaf vein of a broad-leaved rainforest conifer, Podocarpus grayi de Laub. Leaves of Podocarpus are characteriz...

Expansive growth of organs has a very large genotype × environment (G×E) interaction. Maximum leaf expansion rate observed in the absence of stress and of evaporative demand has a genetic variability which is usually smaller than environmental effects. The mechanisms driving the reduction in leaf growth rate under stress, namely changes in cell division rate, in cell-wall mechanical properties ...

The leaf is a hydraulic bottleneck, accounting for a large part of plant resistance. Thus, the leaf hydraulic conductance (K(leaf) ) is of key importance in determining stomatal conductance (g(s) ) and rates of gas exchange. Previous studies showed that K(leaf) is dynamic with leaf water status and irradiance. For four species, we tested the combined impacts of these factors on K(leaf) and on g...

this research was carried out to evaluate the effects of some morphophysiological traits on white sugar yield of 10 commercial sugar beet (beta vulgaris l.) varieties. all experiments were conducted in four important sugar beet growing areas in iran, i.e. moghan, khoy, karaj and zarghan in 2006 and 2007. the experiment was arranged as a randomized complete block design with three replications i...