Gas exchange and growth of bald cypress seedlings from selected U.S. Gulf Coast populations: responses to elevated salinities

1995 ◽  
Vol 25 (9) ◽  
pp. 1409-1415 ◽  
Author(s):  
S.R. Pezeshki ◽  
R.D. Delaune ◽  
H.S. Choi
Keyword(s):  
Gas Exchange ◽  
Biomass Production ◽  
Growth Traits ◽  
Gulf Coast ◽  
Net Photosynthesis ◽  
Salinity Treatment ◽  
Root Porosity ◽  
Bald Cypress ◽  
Freshwater Source ◽  
Freshwater Population

Bald cypress (Taxodiumdistichum (L.) Rich.) seedlings from two sources in Louisiana were tested for a possible difference in salt tolerance. The study was conducted in rhizotrons under controlled environmental-conditions. Seedlings were subjected to a control (no flood or salt) and three combinations of flooding salinity: flooding only, flooding plus 68 mol•m−3 salt (4 ppt), and flooding plus 136 mol•m−3 salt (8 ppt). Both populations survived the flooding and salinity treatments for the duration of the study. However, gas exchange and net biomass production were reduced in both populations as salinity of floodwater increased from 0 to 136 mol•m−3. The gas exchange and biomass data indicated that plants from the freshwater source had higher growth rates than the brackish plants. This superiority was also maintained under all the treatments except the highest salinity treatment. Significantly greater net photosynthetic capacity per unit area of leaf was found for the freshwater population than for the brackish population in 68 mol•m−3 salt. In addition, greater root porosity, height growth, and biomass production (shoot, root) were found for the freshwater population than for the brackish population under different treatments. The data indicate that there is a potential for population differentiation in bald cypress, as shown primarily by differences in growth traits. However, the data do not support the hypothesis that bald cypress plants from the brackish source have a capacity to survive and grow better in saltwater than plants from the freshwater source. In fact, combined flooding and salinity treatments resulted in significant reductions in net photosynthesis as compared with the control in both sources.

scholarly journals Growth and Photosynthetic Responses of Three Lycoris Species to Levels of Irradiance

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 134-137 ◽  
Author(s):  
Panpan Meng ◽  
Ying Ge ◽  
Qianjin Cao ◽  
Jie Chang ◽  
Peng Pan ◽  
...  
Keyword(s):  
Biomass Production ◽  
Biomass Allocation ◽  
Growth Traits ◽  
Net Photosynthesis ◽  
Experimental Period ◽  
High Irradiance ◽  
Cut Flowers ◽  
Full Sunlight ◽  
Green Leaves ◽  
Photosynthetic Responses

Lycoris species have appealing characteristics for potting plants, cut flowers, and landscaping decorations, including attractive foliage, which is very similar to that of cymbidium. Lycoris species have been extensively propagated and marketed in Asia. Understanding the response of Lycoris spp. to irradiance intensity will help the horticultural industry improve the production of potting plants of those species. We studied the responses of photosynthesis, growth, and biomass allocation of potted Lycoris spp. (L. chinensis, L. longituba, and L. sprengeri) bulbs grown under three levels of irradiance, i.e., 100%, 70%, and 30% full sunlight. We found that in terms of biomass production L. chinensis can be cultivated under all levels of irradiance studied from full to 30% sunlight. For L. longituba, high irradiance levels increased the rate of net photosynthesis. For both L. chinensis and L. longituba, the full sunlight treatment produced the most attractive plants characterized by shorter, wider, and darker green leaves, features that appeal to consumers. However, none of the growth traits of L. sprengeri were affected by the irradiance treatment over the entire experimental period. It can be concluded that potting plants of L. chinensis and L. longituba are best produced under full sunlight, whereas L. sprengeri can be produced under irradiance levels from 30% to full sunlight.

Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

1994 ◽  
Vol 24 (5) ◽  
pp. 954-959 ◽  
Author(s):  
L.J. Samuelson ◽  
J.R. Seiler
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Soil Fertility ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Red Spruce ◽  
Fertility Treatment ◽  
Sink Strength ◽  
Growth Enhancement ◽  
Growing Seasons

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

Photosynthesis and Transpiration in Damaged and Undamaged Spruce Trees

1996 ◽  
Vol 51 (3-4) ◽  
pp. 200-210 ◽  
Author(s):  
Aloysius Wild ◽  
Peter Sabel ◽  
Lucia Wild-Peters ◽  
Ursula Schmieden
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Natural Habitat ◽  
Late Summer ◽  
Net Photosynthesis ◽  
Diurnal Course ◽  
Physiological Homeostasis ◽  
Use Efficiency ◽  
Needle Loss ◽  
Light Saturation Curves

Abstract The investigations presented here focus on the CO2/H2O gas exchange in damaged and undamaged spruce trees while using open-air measurements as well as measurements under defined conditions in the laboratory. The studies were performed at two different sites in the Hunsrück and the Westerwald mountains. In the laboratory the CO2/H2O gas exchange was measured on detached branches under controlled conditions in the course of two years. CO2 saturation curves were also generated. In addition CO2 compensation points were deter­ mined employing a closed system. In the natural habitat diurnal course measurements of photosynthesis and transpiration as well as light-saturation curves for photosynthesis were performed. In parallel with the photosynthesis and transpiration measurements, measurements of the water potential were taken at both locations. The photosynthetic capacity and transpiration rate show a typical annual course with pronounced maxima in spring and late summer and minima in summer and winter. The needles of the damaged trees exhibit higher transpiration rates and a distinct reduction in photosyn­ thesis than the needles of the undamaged trees during two seasons. The diurnal course measurements of net photosynthesis and transpiration show a maximum in photosynthesis and transpiration in the afternoon in May and September, but a characteristic midday depression in July. Photosynthesis was markedly lower and transpiration higher in the needles of the damaged trees. The damaged trees show a lower increase in the light and CO2 saturation curves and higher CO2 compensation points as compared to the undamaged trees. The water potential reaches much lower values during the course of the day in needles of the dam­ aged trees. The reduction of the photosynthetic rate on one hand and the increase in transpiration on the other hand result in an extreme lowering of the water use efficiency in photosynthesis. The damage to the thylakoid membranes and to the guard cells obviously results in a pro­ found disturbance of the physiological homeostasis of the needles and could thus lead to premature needle loss.

scholarly journals Physiological responses of beet plants irrigated with saline water and silicon application

2020 ◽  
Vol 11 ◽  
pp. E3113
Author(s):  
José Sebastião de Melo Filho ◽  
Toshik Iarley da Silva ◽  
Anderson Carlos de Melo Gonçalves ◽  
Leonardo Vieira de Sousa ◽  
Mario Leno Martins Véras ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Concentration ◽  
Saline Water ◽  
Block Design ◽  
Essential Element ◽  
Net Photosynthesis ◽  
Crop Productivity ◽  
Experimental Unit ◽  
Randomized Block Design

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.

Nitrogen form affects physiological responses and root expansigenous honeycomb aerenchyma in the emergent macrophyte Acorus americanus

Botany ◽  
2014 ◽  
Vol 92 (8) ◽  
pp. 541-550 ◽  
Author(s):  
María Alejandra Equiza ◽  
Janusz J. Zwiazek
Keyword(s):  
Constructed Wetlands ◽  
Oil Sands ◽  
Negative Impact ◽  
Chlorophyll Concentration ◽  
Net Photosynthesis ◽  
Solution Culture ◽  
Fresh Mass ◽  
Root Porosity ◽  
N Form ◽  
Acorus Americanus

High nitrogen (N) concentrations and high NH4+:NO3− ratios that are characteristic of heavily eutrophic and constructed wetlands may be detrimental to the growth and establishment of macrophytes in wetlands formed in the oil sands reclamation areas. This study investigates the effects of N form on the physiology, growth, and root expansigenous honeycomb aerenchyma structure of Acorus americanus (Raf.) Raf., an important macrophyte targeted for wetland reclamation in Canada. Three populations of A. americanus were grown in aerated solution culture and provided for up to 3 months with two different concentrations of N (2 mmol·L−1, 8 mmol·L−1) as NH4+, NO3−, or NH4+ + NO3−. Fresh mass and physiological parameters including gas exchange, chlorophyll fluorescence, stomatal traits, nitrogen and chlorophyll concentration, root morphology, and aerenchyma structure were examined. The effects of N form were concentration-dependent. At 2 mmol·L−1 N, NH4+ + NO3− plants had higher fresh mass, photosynthetic rates, number of first-order roots, root diameter, and maximum root length than those provided solely with NH4+ or NO3−. At 8 mmol·L−1 N, both NH4+ and NH4+ + NO3− treatments had a negative impact on growth, net photosynthesis, and chlorophyll concentrations, and they also led to thinner and shorter roots with necrotic tips, a significant reduction in fractional root porosity, and a denser aerenchyma with smaller lacunae. The results indicate that high levels of NH4+-N may negatively affect the establishment of A. americanus plants in constructed wetlands through its impact on growth, net photosynthesis, and root morpho-anatomy.

Design and testing of twig chambers for ozone fumigation and gas exchange measurements in mature trees

1994 ◽  
Vol 102 ◽  
pp. 541-546 ◽  
Author(s):  
Wilhelm M. Havranek ◽  
Gerhard Wieser
Keyword(s):  
Gas Exchange ◽  
Net Photosynthesis ◽  
Ambient Air ◽  
Field Conditions ◽  
Chamber System ◽  
Mature Trees ◽  
Diurnal Courses ◽  
Controlled Conditions ◽  
Design And Testing

SynopsisA twig chamber system was developed for the exposure of mature trees to ozone (O3) under field conditions. The fumigation system allowed the exact control of O3 concentrations in the chambers, the measurement of O3 uptake as well as gas exchange measurements under ambient and controlled conditions during and after O3 fumigation. Because of differences in individual twigs the system should provide the exposure of replicates to different O3 treatments. Tests showed that temperature, humidity and O3 concentrations inside the chambers were comparable with diurnal courses observed in the field. Comparative gas exchange measurements indicated that there were no differences in net photosynthesis and conductance of twigs outside the chambers and twigs which remained within the chambers for 23 weeks receiving ambient air.

scholarly journals Biomass production and leaf gas exchange of perennial legumes associated with bananas

2016 ◽  
Vol 11 (6) ◽  
pp. 487-493
Author(s):  
Edineide Lima Barbosa Francisca ◽  
Feitosa De Lacerda Claudivan ◽  
De Oliveira Feitosa Hernandes ◽  
Jardelson Ferreira Francisco ◽  
Vieira Amorim Aiala ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Biomass Production ◽  
Leaf Gas Exchange ◽  
Perennial Legumes

Response of Gas Exchange in Jointed Goatgrass (Aegilops cylindrica) to Environmental Conditions

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 562-569 ◽  
Author(s):  
David R. Gealy
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Environmental Conditions ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Soil Matric Potential ◽  
Dark Respiration Rate ◽  
Matric Potential ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass

Gas exchange of jointed goatgrass leaves was affected by temperature, irradiance level, and soil matric potential. Net photosynthesis of leaves under saturating irradiance (PPFD3= 1850 (μE·m–2·s−1) was optimum at about 20 C. At 25 C, net photosynthesis was nearly 90% of maximum at a PPFD of 800 μE·m–2·−1. Transpiration, and presumably water use, increased steadily with temperature from 10 to 40 C. Dark respiration rate and compensation points for light and for CO2increased exponentially, or nearly so, from 10 to 40 C. Soil moisture deficits of −130 kPa reduced net photosynthesis and transpiration by about 30 and 55%, respectively, compared to well-watered plants.

Sign in / Sign up

Export Citation Format

Share Document