Inheritance of temperature adaptation in intra- and inter-specific Populus crosses

1992 ◽  
Vol 22 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Allan P. Drew ◽  
James A. Chapman
Keyword(s):  
Interspecific Hybrid ◽  
Response Curve ◽  
Stomatal Density ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Leaf Conductance ◽  
Temperature Adaptation ◽  
Optimum Rate ◽  
Intraspecific Hybrid

Populustrichocarpa Torr. & Gray from Alaska was crossed with the same species from a Montana population, and the resulting intraspecific hybrid was crossed with Populusdeltoides Bartr. ex Marsh, from Minnesota. Ramets from the five parents and hybrids were tested for the response of leaf conductance to temperature of the prior night. Leaf stomatal density and size were determined and net photosynthesis was measured between 15 and 40 °C for all clones. Alaska and Montana sources of P. trichocarpa and their hybrid showed mildly sensitive leaf conductance responses to 10 °C nights and comparable responses to 4 °C nights. The Alaska parent had an optimum rate of net photosynthesis at 20 °C, 10 °C lower than that of its hybrid, but the Montana parent's temperature response curve was less clearly defined. Although the P. trichocarpa hybrid was intermediate or similar to both parents in temperature adaptation, in stomatal density, size, and Q-ratio it was more similar to the Alaska parent. The P. deltoides parent and its interspecific hybrid exhibited a sensitive pattern of leaf conductance response to cool nights. The hybrid had a net photosynthetic temperature response curve that closely paralleled that of the P. deltoides parent, yet rates were lower, between 20 and 35 °C, in both compared with the P. trichocarpa parent. The interspecific hybrid more closely resembled the P. deltoides than the P. trichocarpa parent in overall temperature adaptation and had morning leaf conductance higher than that of both. Stomatal density and size were more unlike the P. deltoides than the P. trichocarpa parent, and the Q-ratio of the hybrid was intermediate to that of the parents.

Seasonal ecophysiology and leaf morphology of four successional Pennsylvania barrens species in open versus understory environments

1993 ◽  
Vol 23 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Brian D. Kloeppel ◽  
Marc D. Abrams ◽  
Mark E. Kubiske
Keyword(s):  
Gas Exchange ◽  
Stomatal Density ◽  
Net Photosynthesis ◽  
Leaf Conductance ◽  
Response Curves ◽  
Tissue Water ◽  
Specific Leaf Mass ◽  
Leaf Mass ◽  
Quercus Spp ◽  
Open Versus

Seasonal net photosynthesis, water relations, and leaf structure were measured in co-occurring saplings of Quercusvelutina Lam., Quercusprinus L., Sassafrasalbidum (Nutt.) Nees, and Acerrubrwn L. from adjacent open and understory sites in the central Pennsylvania barrens, United States. Saplings of all species exhibited significant physiological and morphological plasticity, which included greater area-based photosynthesis, leaf conductance, water-use efficiency, stomatal density, specific leaf mass, and leaf thickness on the open site. However, only Q. velutina had greater net photosynthesis in the open versus understory when photosynthesis was expressed on a mass basis. The earlier successional Quercus spp. and S. albidum exhibited higher diurnal and seasonal gas exchange in the open than the later successional A. rubrum, although all species exhibited significant diurnal declines in photosynthesis. Quercus spp. exhibited a 56–62% greater decrease in diurnal water potential compared with S. albidum and A. rubrum in both the open and understory. Sassafras maintained high gas-exchange rates in the open without experiencing large diurnal tissue water deficits. Seasonal variations in net photosynthesis and leaf conductance were significantly correlated with each other and with specific leaf mass. Light-response curves predicted greater saturating light levels and greater rates of maximum photosynthesis in the early successional species versus A. rubrum, but similar light compensation values in all species. The results of this study suggest that each species displayed many similar and unique adaptations and responses to varying light and water availability in the barrens environment.

Classification of materials using temperature response curve fitting and fuzzy neural network

2001 ◽  
Vol 94 (1-2) ◽  
pp. 11-18 ◽  
Author(s):  
Young-Jae Ryoo ◽  
Young-Cheol Lim ◽  
Kwang-Heon Kim
Keyword(s):  
Neural Network ◽  
Curve Fitting ◽  
Response Curve ◽  
Fuzzy Neural Network ◽  
Temperature Response ◽  
Fuzzy Neural ◽  
Classification Of Materials

Photosynthetic response of geranium to elevated CO2 as affected by leaf age and time of CO2 exposure

1991 ◽  
Vol 69 (11) ◽  
pp. 2482-2488 ◽  
Author(s):  
D. W. Kelly ◽  
P. R. Hicklenton ◽  
E. G. Reekie
Keyword(s):  
Stomatal Density ◽  
Leaf Age ◽  
Net Photosynthesis ◽  
Leaf Thickness ◽  
Middle Aged ◽  
Future Studies ◽  
Structural Modifications ◽  
Young Leaves ◽  
Developmental Characteristics ◽  
Density Results

Geranium plants were grown from seed in chambers maintained at 350 or 1000 μL∙L−1 CO2. Phtopsynthesis as affected by leaf age and by leaf position was determined. Elevated CO2 enhanced photosynthesis to the greatest extent in middle-aged leaves; very young leaves exhibited little enhancement, and net photosynthesis in the oldest leaves was depressed by elevated CO2. Temporary increases in net photosynthesis (relative to leaves developed at high CO2) resulted when young leaves grown at 350 μL∙L−1 CO2 were switched to 1000 μL∙L−1 CO2. Leaves switched later in development exhibited permanent enhancement. Middle-aged leaves exhibited a temporary depression followed by permanent enhancement. Leaves developed at high CO2 and switched to low CO2 did not exhibit any photosynthetic depression relative to plants grown continuously at low CO2. Similarly, leaves developed at low CO2, switched to high CO2 for various lengths of time, and returned to low CO2 showed no photosynthetic depression. Leaves developed at low CO2 and switched to high CO2 exhibited increases in specific leaf weight and leaf thickness. The increase in leaf thickness was proportional to length of time spent at high CO2. High CO2 depressed the rate at which stomata developed but did not affect final stomatal density. Results suggest that photosynthesis at low CO2 was limited by CO2 regardless of developmental environment, whereas photosynthesis at high CO2 was limited by the developmental characteristics of the leaf. Further, both biochemical and structural modifications appear to be involved in this response. Because of the very different responses of young versus old leaves, future studies should be careful to consider leaf age in assessing response to elevated CO2. Key words: carbon dioxide, elevated CO2, photosynthesis, geranium.

Internal and external control of net photosynthesis and stomatal conductance of mature eastern white pine (Pinusstrobus)

1992 ◽  
Vol 22 (9) ◽  
pp. 1387-1394 ◽  
Author(s):  
C.A. Maier ◽  
R.O. Teskey
Keyword(s):  
Internal Control ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Leaf Conductance ◽  
External Control ◽  
White Pine ◽  
Eastern White Pine ◽  
Pressure Potential ◽  
Growing Seasons ◽  
Xylem Pressure Potential

Leaf gas exchange and water relations were monitored in the upper canopy of two 25 m tall eastern white pine (Pinusstrobus L.) trees over two consecutive growing seasons (1986 and 1987). Examination of the seasonal and diurnal patterns of net photosynthesis and leaf conductance showed that both internal and external (environmental) factors were controlling net photosynthesis and leaf conductance. Internal control was indicated by a rapid increase and then decrease in the photosynthetic capacity of 1-year-old foliage during the development and maturation of current-year foliage, which was independent of environmental conditions. Large differences in net photosynthesis were observed between growing seasons due to seasonal differences in soil water availability, as indexed by predawn xylem pressure potential. Water stress reduced the maximum rate of net photosynthesis and altered the response of net photosynthesis and leaf conductance to absolute humidity deficit.

scholarly journals Photosynthetic responses of three common mosses from continental Antarctica

2005 ◽  
Vol 17 (3) ◽  
pp. 341-352 ◽  
Author(s):  
STEFAN PANNEWITZ ◽  
T.G. ALLAN GREEN ◽  
KADMIEL MAYSEK ◽  
MARK SCHLENSOG ◽  
ROD SEPPELT ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Dark Respiration ◽  
Temperature Response ◽  
Environmental Parameters ◽  
Net Photosynthesis ◽  
Photon Flux ◽  
Terrestrial Vegetation ◽  
Moss Species ◽  
Victoria Land

Predicting the effects of climate change on Antarctic terrestrial vegetation requires a better knowledge of the ecophysiology of common moss species. In this paper we provide a comprehensive matrix for photosynthesis and major environmental parameters for three dominant Antarctic moss species (Bryum subrotundifolium, B. pseudotriquetrum and Ceratodon purpureus). Using locations in southern Victoria Land, (Granite Harbour, 77°S) and northern Victoria Land (Cape Hallett, 72°S) we determined the responses of net photosynthesis and dark respiration to thallus water content, thallus temperature, photosynthetic photon flux densities and CO2 concentration over several summer seasons. The studies also included microclimate recordings at all sites where the research was carried out in field laboratories. Plant temperature was influenced predominantly by the water regime at the site with dry mosses being warmer. Optimal temperatures for net photosynthesis were 13.7°C, 12.0°C and 6.6°C for B. subrotundifolium, B. pseudotriquetrum and C. purpureus, respectively and fall within the known range for Antarctic mosses. Maximal net photosynthesis at 10°C ranked as B. subrotundifolium > B. pseudotriquetrum > C. purpureus. Net photosynthesis was strongly depressed at subzero temperatures but was substantial at 0°C. Net photosynthesis of the mosses was not saturated by light at optimal water content and thallus temperature. Response of net photosynthesis to increase in water content was as expected for mosses although B. subrotundifolium showed a large depression (60%) at the highest hydrations. Net photosynthesis of both B. subrotundifolium and B. pseudotriquetrum showed a large response to increase in CO2 concentration and this rose with increase in temperature; saturation was not reached for B. pseudotriquetrum at 20°C. There was a high level of variability for species at the same sites in different years and between different locations. This was substantial enough to make prediction of the effects of climate change very difficult at the moment.

scholarly journals Photosynthetic plasticity of a tropical tree species, Tabebuia rosea, in response to elevated temperature and [CO2]

2021 ◽  
Author(s):  
Martijn Slot ◽  
Sami Rifai ◽  
Klaus Winter
Keyword(s):  
Tree Species ◽  
Photosynthetic Capacity ◽  
Stomatal Density ◽  
Net Photosynthesis ◽  
Tropical Tree ◽  
Measured Temperature ◽  
Tropical Tree Species ◽  
Neotropical Tree ◽  
Photosynthetic Plasticity ◽  
Tabebuia Rosea

Atmospheric and climate change will expose tropical forests to conditions they have not experienced in millions of years. To better understand the consequences of this change we studied photosynthetic acclimation of the neotropical tree species Tabebuia rosea to combined 4°C warming and twice-ambient (800 ppm) CO. We measured temperature responses of the maximum rates of ribulose 1,5-bisphosphate carboxylation (V), photosynthetic electron transport (J), net photosynthesis (P), and stomatal conductance (gs), and fitted the data using a probabilistic Bayesian approach. To evaluate short-term acclimation plants were then switched between treatment and control conditions and re-measured after 1–2 weeks. Consistent with acclimation, the optimum temperatures (T) for V, J and P were 1–5°C higher in treatment than in control plants, while photosynthetic capacity (V, J, and P at T) was 8–25% lower. Likewise, moving control plants to treatment conditions moderately increased temperature optima and decreased photosynthetic capacity. Stomatal density and sensitivity to leaf-to-air vapor pressure deficit were not affected by growth conditions, and treatment plants did not exhibit stronger stomatal limitations. Collectively, these results illustrate the strong photosynthetic plasticity of this tropical tree species as even fully-developed leaves of saplings transferred to extreme conditions partially acclimated.

scholarly journals Exploring the Relationship between Abundance and Temperature with a Chemostat Model

2016 ◽  
Author(s):  
Cristian A. Solari ◽  
Vanina J. Galzenati ◽  
Brian J. McGill
Keyword(s):  
Mortality Rate ◽  
High Mortality ◽  
Response Curve ◽  
Temperature Response ◽  
Response Curves ◽  
Chemostat Model ◽  
Half Saturation Constant ◽  
Limiting Nutrient ◽  
Response To Temperature ◽  
The Relationship

AbstractAlthough there is a well developed theory on the relationship between the intrinsic growth rate r and temperature T, it is not yet clear how r relates to abundance, and how abundance relates to T. Many species often have stable enough population dynamics that one can talk about a stochastic equilibrium population size N*. There is sometimes an assumption that N* and r are positively correlated, but there is lack of evidence for this. To try to understand the relationship between r, N*, and T we used a simple chemostat model. The model shows that N* not only depends on r, but also on the mortality rate, the half-saturation constant of the nutrient limiting r, and the conversion coefficient of the limiting nutrient. Our analysis shows that N* positively correlates to r only with high mortality rate and half-saturation constant values. The response curve of N* vs. T can be flat, Gaussian, convex, and even temperature independent depending on the values of the variables in the model and their relationship to T. Moreover, whenever the populations have not reached equilibrium and might be in the process of doing so, it could be wrongly concluded that N* and r are positively correlated. Because of their low half-saturation constants, unless conditions are oligotrophic, microorganisms would tend to have flat abundance response curves to temperature even with high mortality rates. In contrast, unless conditions are eutrophic, it should be easier to get a Gaussian temperature response curve for multicellular organisms because of their high half-saturation constant. This work sheds light to why it is so difficult for any general principles to emerge on the abundance response to temperature. We conclude that directly relating N* to r is an oversimplification that should be avoided.

High levels of anatomical and physiological leaf plasticity of Ocotea odorifera (Lauraceae) in response to different radiation intensities

Botany ◽  
2021 ◽  
Vol 99 (1) ◽  
pp. 23-32
Author(s):  
Gabriele Marques Leme ◽  
Flavio Nunes Ramos ◽  
Fabricio José Pereira ◽  
Marcelo Polo
Keyword(s):  
Gas Exchange ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Forest Edge ◽  
Forest Fragments ◽  
Gas Exchange Parameters ◽  
Fragmented Forest ◽  
Forest Interior ◽  
Leaf Plasticity

We investigated morpho-physiological plasticity in the leaves of Ocotea odorifera trees growing under different environmental conditions in a fragmented forest. Microclimatic data were collected in a pasture matrix, forest edge, and forest interior in three Atlantic Forest fragments. Leaf gas exchange, as well as leaf anatomy in paradermal and transversal sections, were evaluated in individuals in these environments. Radiation intensity and temperature had higher effects in the pasture matrix compared with the forest interior and forest edge. However, internal portions of the canopy did not exhibit significant variation in radiation or temperature. External canopy leaves exhibited higher net photosynthesis in plants from the pasture matrix, but there was higher net photosynthesis for internal leaves from the shaded forest interior. Variation in net photosynthesis and other gas-exchange parameters were related to thinner shade leaves in forest interior individuals, and internal leaves with lower stomatal density. Although the pasture matrix, forest edge, and forest interior experienced differences in light and temperature, leaf position in the canopy produced microclimatic variations, which modified gas exchange and anatomy. Thus, O. odorifera shows the potential for reforestation programs because of its high leaf plasticity, which will enable it to overcome variations in light and temperature.

Effects of shading on seagrass morphology and thermal optimal of productivity

2020 ◽  
Vol 71 (8) ◽  
pp. 913 ◽  
Author(s):  
Eunice Kong ◽  
Yan Xiang Ow ◽  
Samantha Lai ◽  
Siti Maryam Yaakub ◽  
Peter Todd
Keyword(s):  
Synergistic Effects ◽  
Light Availability ◽  
Temperature Response ◽  
Leaf Size ◽  
Net Photosynthesis ◽  
Shoot Density ◽  
Net Productivity ◽  
Halophila Ovalis ◽  
Light Levels ◽  
Reduced Light

Light and temperature are important factors affecting seagrass primary productivity. Acclimatisation to reduced light availability may affect the optimal temperature at which seagrasses photosynthesise, potentially causing synergistic effects between increasing water temperatures and decreasing light levels on coastal productivity. This study investigated the effects of reduced light availability on the morphology (leaf size, shoot density) and thermal optimal of net productivity in Halophila ovalis (R.Br.) Hook. A 12-week in situ shading experiment was conducted at Chek Jawa Wetlands, Singapore, testing high (68% shading), low (49%) and control (0%) shadings. Every 4 weeks, photosynthetic and respiration rates of H. ovalis leaves and the root–rhizome complex were measured in closed incubation chambers at temperatures from 22 to 42°C (at 4°C intervals). A fitted temperature-response model of net photosynthesis was used to estimate the thermal optimal for each shading treatment. High shading reduced shoot density (mean±s.e.) 87.06±7.86% and leaf surface area 31.72±24.74%. Net productivity (6mg O2 g–1 DW h–1) and its thermal optimal (28–30°C) were not significantly different among shading treatments throughout the experiment. Light levels appeared to have minimal influence on the thermal dependency of H. ovalis net productivity.

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