1. The wetland sedge Scirpus olneyi Gray displays fast rates of CO 2 assimilation and responds positively to increased atmospheric CO 2 concentration. The present study was aimed at identifying the ecophysiological traits specific to S. olneyi that drive these CO 2 -assimilation patterns under ambient and elevated CO 2 conditions. 2. The net ecosystem exchange (NEE) of CO 2 between S. olneyi co...

Jojoba (Simmondsia chinensis [Link] Schneider) is an important crop in desert climates. A relatively high frequency of periods of chilling and high photon flux density (PFD) in this environment makes photoinhibition likely, resulting in a reduction of assimilation capacity in overwintering leaves. This could explain the low net photosynthesis found in shoots from the field (4-6 micromoles per s...

We formulate and analyze two dynamic energy budget models, a net assimilation model with constant allocation strategy and a net production model with a 2-stage allocation strategy, with the objective of determining strategies that maximize the expected lifetime reproductive energy. The per capita death rate depends on the organism's size, as for example when the main cause of death is predation...

Individual groups of peach (Prunus persica [L.] Batsch) seedlings stressed to -17, -26 and -36 bars recovered to control levels within 1, 3, and 4 days, respectively. Stomatal resistance was significantly correlated with both leaf water potential and net photosynthesis. In seedlings stressed to -52 bars, leaf water potential and stomatal resistance recovered sooner than net photosynthesis, desp...

We formulate and analyze two dynamic energy budget models, a net assimilation model with constant allocation strategy and a net production model with a 2-stage allocation strategy, with the objective of determining strategies that maximize the expected lifetime reproductive energy. The per capita death rate depends on the organism’s size, as for example when the main cause of death is predation...

the phenotypic diversity of potato, solanum tuberosum was assessed using morphological traits. to verify, how this diversity is distributed among the main potato varieties in the growing areas in iran. a total of eleven potato varieties, ramose, sante, shepody, marfona, maradona, milova, santana, boren, cosima, granola and agria, were evaluated under vivo and situ experimental conditions in isf...

nineteen bread wheat genotypes were selected to examine the effect of glycine betaine (gb, 100 mm) on various photosynthetic gas exchange parameters under drought stress and to study the relationship of these parameters with non-enzymatic antioxidants. drought stress caused a significant decline in net co2 assimilation rate (pn), stomatal conductance (gs), intercellular co2 concentration (ci) a...

predation rate is basic to any investigation of prey-predator interaction and a major component in the selection of predators for biological control. the predation rate of variegated lady beetle, hippodamia variegata (goze), fed on different densities (20, 40, 60, 80 and 100) of third instar nymphs of cotton aphid, aphis gossypii glover, was studied under laboratory conditions (25 ± 1 °c, 65 ± ...

Tobacco (Nicotiana rustica L. cv. Basmas) plants were exposed to a daily dose of 10 kJ m-1d-1 of UV radiation and treated with 0.5 mM exogenous polyamines (PAs) applied to the nutrient solution for two weeks. Dry weight of leaves increased under UVAB treatment in the absence of PAs and presence of spermidine but not putrescine. In the presence of putrescine, UVA treatment caused a significant i...