intercellular space, and reduce leaf thickness and surface area ( Ojeda-Barrios et al., 2012 ). Hu and Sparks (1991) noted that stomatal conductance ( g S ) and net photosynthesis (P n ) were reduced concomitantly by low Zn levels. Heerema et al. (2017
Cyrus A. Smith, James L. Walworth, Mary J. Comeau, Richard J. Heerema, and Joshua D. Sherman
Francesco Montesano and Marc W. van Iersel
were measured 26 d after the start of the treatments. Leaves were exposed to a photosynthetic photon flux ( PPF ) of 1000 μmol·m −2 ·s −1 and a CO 2 concentration of 400 μmol·mol −1 for at least 20 min, using a portable photosynthesis system (CIRAS-1
M. Carmen González-Mas, M. José Llosa, Antonio Quijano, and M. Angeles Forner-Giner
Carrizo citrange, which could not surpass 73% ( Fig. 1B ). This could be the result of the incomplete reoxidation of Q A, leading to the downregulation of photosynthesis in comparison with the other rootstocks under assay. In conclusion, based on
J. Ryan Stewart, Reid D. Landes, Andrew K. Koeser, and Andrea L. Pettay
evaluate the relative vigor, as indicated by net photosynthesis and plant growth, of three taxa that grow wild in relatively small areas in the United States and may merit use in managed landscapes: Calycanthus occidentalis Hook. & Arn. (western
John W. Moon Jr.
179 ORAL SESSION (Abstr. 715-722) CROSS-COMMODITY PHOTOSYNTHESIS
Francesco Loreto, Domenico Tricoli, Mauro Centritto, Arturo Alvino, and Sebastiano Delfine
Short-term fumigation with 1% methanol in air was carried out to investigate effects on the photosynthetic apparatus of horticultural species characterized by leaves with different stomatal distribution. Methanol decreased the photosynthetic capacity of all species. The hypostomatous cherry (Prunus avium L.) was the most sensitive species. Between the two amphistomatous species, the effect was smaller in pepper (Capsicum annuum L. var. annuum) than in melon (Cucumis melo L.). A 4-minute fumigation caused a stronger inhibition of photosynthesis than a 90-second fumigation. The time course of the inhibition of the photosynthetic electron transport following a methanol fumigation of cherry leaves suggests that methanol starts inhibiting photosynthesis and photorespiration after ≈60 seconds and that the effect is complete after 180 seconds. This inhibition is not permanent, however, since gas-exchange properties recovered within 24 hours. Methanol vapor effects were greatest when leaves were fumigated on the surfaces with stomata. However, fumigation with methanol does not affect stomatal conductance. Therefore, inhibition of photosynthesis following methanol fumigation can be attributed to a temporary inhibition of biochemical reactions.
P. Lootens and J. Heursel
The short-term effects of photosynthetic photon flux (PPF), day/night temperatures and CO2 concentration on CO2 exchange were determined for two Phalaenopsis hybrids. At 20 °C, the saturating PPF for photosynthesis was 180 μmol·m-2s-1. At this PPF and ambient CO2 level (380 μL·L-1), a day/night temperature of 20/15 °C resulted in the largest daily CO2 uptake. Higher night temperatures probably increased the respiration rate and lowered daily CO2 uptake in comparison with 20/15 °C. An increase in the CO2 concentration from 380 to 950 μL·L-1 increased daily CO2 uptake by 82%.
John Erwin, Tanveer Hussein, and David J. Baumler
temperatures for pepper photosynthesis range from 25 to 35 °C, and temperatures outside this range can limit the yield; for example, C . chinense flower abortion increased 2-fold and fruit set decreased 3-fold when greenhouse temperatures were increased from