scholarly journals Drought Response of Three Ornamental Herbaceous Perennials

2000 ◽  
Vol 125 (3) ◽  
pp. 310-317 ◽  
Author(s):  
Kelly J. Prevete ◽  
R. Thomas Fernandez ◽  
William B. Miller
Keyword(s):  
Molecular Weight ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Drought Response ◽  
Low Molecular Weight ◽  
Long Term Effects ◽  
Drought Treatment ◽  
Potential Growth ◽  
Herbaceous Perennials ◽  
Substrate Moisture

Boltonia asteroides L. `Snowbank' (Snowbank boltonia), Eupatorium rugosum L. (eastern white snakeroot), and Rudbeckia triloba L. (three-lobed coneflower) were subjected to drought for 2, 4, and 6 days during the fall and spring. Leaf gas exchange, leaf water potential, growth, and carbohydrate partitioning were measured during drought and throughout the following growing season. Leaf gas exchange of B. asteroides was not affected by drought treatment in the fall, not until day 6 of spring drought, and there were no long-term effects on growth. Transpiration and stomatal conductance of R. triloba decreased when substrate moisture decreased to 21% after drought treatment during both seasons. Assimilation of drought-treated R. triloba decreased when substrate moisture content decreased to 12% during spring but was not affected by drought in the fall. There was a decrease in the root-to-shoot ratio of R. triloba that had been treated for 4 days, which was attributed to an increase in the shoot dry weight (DW) of treated plants. Reductions in spring growth of E. rugosum were observed only after fall drought of 6 days, and there were no differences in final DWs of plants subjected to any of the drought durations. Spring drought had no effect on growth index or DW of any of the perennials. Boltonia asteroides and R. triloba had increases in low-molecular-weight sugars on day 4 of drought, but E. rugosum did not have an increase in sugars of low molecular weight until day 6 of drought. Differences in drought response of B. asteroides, E. rugosum, and R. triloba were attributed to differences in water use rates.

scholarly journals Growth, Gas Exchange, and Chlorophyll Fluorescence of Four Ornamental Herbaceous Perennials during Water Deficit Conditions

2006 ◽  
Vol 131 (4) ◽  
pp. 469-475 ◽  
Author(s):  
Terri Starman ◽  
Leonardo Lombardini
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Photochemical Efficiency ◽  
Dry Weight ◽  
Drought Treatment ◽  
Greenhouse Production ◽  
Herbaceous Perennials ◽  
Leaf Level

A study was conducted to characterize the morphological and physiological responses of four herbaceous perennial species subjected to two subsequent drought cycles. Lantana camara L. `New Gold' (lantana), Lobelia cardinalis L. (cardinal flower), Salvia farinacea Benth. `Henry Duelberg' (mealy sage), and Scaevola aemula R. Br. `New Wonder' (fan flower) were subjected to two consecutive 10-day drought cycles. Growth response, leaf gas exchange, and chlorophyll fluorescence were measured during the experiment. The morphology of L. cardinalis and L. camara was not affected by drought, while S. farinacea had reductions in plant height and leaf area and S. aemula had reductions in dry weight. Overall, plant growth and development continued even when substrate water content was reduced to 0.13 mm3·mm-3, which indicated a level of substrate water below container capacity was sufficient for greenhouse production of these species. The drought treatments had little effect on the photochemical efficiency (Fv/Fm) of Photosystem II. An increase in minimal fluorescence (Fo) was observed in S. aemula on the last day of the second cycle. Drought treatment caused increased leaf-level water use efficiency (WUE) at the end of the first cycle in L. cardinalis and S. aemula, but not in L. camara and S. farinacea. Plants of L. camara, S. farinacea, and S. aemula that had received drought during both cycles became more water use efficient by the end of the second cycle, but L. cardinalis did not.

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

scholarly journals Physiological Performance of Pyrus pyraster L. (Burgsd.) and Sorbus torminalis (L.) Crantz Seedlings under Drought Treatment

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1496
Author(s):  
Viera Paganová ◽  
Marek Hus ◽  
Zuzana Jureková
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Water Scarcity ◽  
Prolonged Exposure ◽  
Leaf Gas Exchange ◽  
Total Biomass ◽  
Drought Treatment ◽  
Water Regimes ◽  
Sorbus Torminalis ◽  
Pyrus Pyraster

In this study, seedlings of Pyrus pyraster and Sorbus torminalis were grown for 60 days in the regulated environment of a growth chamber under different water regimes. The measured indicators were the growth and distribution of mass to organs, total biomass, root to shoot mass ratio (R:S), and gas exchange parameters (gs, E, An, and water use efficiency (WUE)). The amount of total biomass was negatively affected by drought. Differences between species were confirmed only for the dry matter of the leaves. P. pyraster maintained the ratio of the mass distribution between belowground and aboveground organs in both variants of the water regime. S. torminalis created more root length for a given dry-mass under drought treatment, but its R:S was lower compared to P. pyraster. The water potential of the leaves (Ψwl) was affected by substrate saturation and interspecific differences. P. pyraster had a demonstrably higher water potential and maintained this difference even after prolonged exposure to drought. After 30 days of different water regimes, Pyrus maintained higher values of gs, An, and E in control and drought treatments, but over a longer period of drought (after 50 days), the differences between species were equalized. The changes of the leaf gas exchange for Pyrus were accompanied by a significant increase in WUE, which was most pronounced on the 40th day of the experiment. A significant and strong relationship between WUE and gs was demonstrated. The results confirmed the different physiological performances of seedlings of tree species and the different mechanisms of their response to water scarcity during drought treatment. P. pyraster presented more acclimation traits, which allowed this taxon to exhibit better performance over a longer period of water scarcity.

scholarly journals Physiological Effects of Mechanical Harvesting in Citrus Trees

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 885C-885
Author(s):  
Kuo-Tan Li* ◽  
James P. Syvertsen
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Leaf Gas Exchange ◽  
Fluorescence Emission ◽  
Stem Water Potential ◽  
Long Term Effects ◽  
Significant Treatment ◽  
Linear Type ◽  
Stem Water ◽  
Citrus Trees

Mechanical harvesting of citrus trees by trunk or canopy shakers can cause leaf and twig removal, bark injury and root exposure. Such problems have restricted the adoption of mechanical harvesting in Florida citrus. We assessed physiological responses of citrus trees that were mechanically harvested with a linear-type trunk shaker, operating at 4 Hz, 70.8 kg mass weight, and 6.5 cm displacement, for 10 or 20 seconds. We measured fruit recovery efficiency, leaf and shoot removal, mid-day stem water potential, leaf gas exchange, and leaf fluorescence emission of mature `Hamlin' and `Valencia' orange trees under restricted or normal irrigation. Shaking treatments effectively removed 90% to 94% of fruit without bark damage. Compared to harvesting by hand, trunk shaking removed 10% more leaf area and twigs, and caused some visible exposure of fibrous roots at the soil surface. There were no significant treatment differences on mid-day stem water potential, leaf gas exchange, and leaf photosystem efficiency. Excessively shaken trees for 20-30 seconds can temporary induce stress symptoms resembling that in trees without irrigation. Trees may have benefited from the low levels of leaf and twig loss after trunk shaking that compensated for any root loss. Long-term effects of trunk shaking will be assessed by tree growth, return bloom, subsequent yield, and carbohydrate reserves.

scholarly journals Isoprene emission and photosynthesis during heatwaves and drought in black locust

2017 ◽  
Vol 14 (15) ◽  
pp. 3649-3667 ◽  
Author(s):  
Ines Bamberger ◽  
Nadine K. Ruehr ◽  
Michael Schmitt ◽  
Andreas Gast ◽  
Georg Wohlfahrt ◽  
...  
Keyword(s):  
Heat Stress ◽  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Black Locust ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Response Curves ◽  
Drought Treatment ◽  
Isoprene Emission

Abstract. Extreme weather conditions like heatwaves and drought can substantially affect tree physiology and the emissions of isoprene. To date, however, there is only limited understanding of isoprene emission patterns during prolonged heat stress and next to no data on emission patterns during coupled heat–drought stress or during post-stress recovery. We studied gas exchange and isoprene emissions of black locust trees under episodic heat stress and in combination with drought. Heatwaves were simulated in a controlled greenhouse facility by exposing trees to outside temperatures +10 °C, and trees in the heat–drought treatment were supplied with half of the irrigation water given to heat and control trees. Leaf gas exchange of isoprene, CO2 and H2O was quantified using self-constructed, automatically operating chambers, which were permanently installed on leaves (n = 3 per treatment). Heat and combined heat–drought stress resulted in a sharp decline of net photosynthesis (Anet) and stomatal conductance. Simultaneously, isoprene emissions increased 6- to 8-fold in the heat and heat–drought treatment, which resulted in a carbon loss that was equivalent to 12 and 20 % of assimilated carbon at the time of measurement. Once temperature stress was released at the end of two 15-day-long heatwaves, stomatal conductance remained reduced, while isoprene emissions and Anet recovered quickly to values of the control trees. Further, we found that isoprene emissions covaried with Anet during nonstress conditions, while during the heatwaves, isoprene emissions were not related to Anet but to light and temperature. Under standard air temperature and light conditions (here 30 °C and photosynthetically active radiation of 500 µmol m−2 s−1), isoprene emissions of the heat trees were by 45 % and the heat–drought trees were by 27 % lower than in control trees. Moreover, temperature response curves showed that not only the isoprene emission factor changed during both heat and heat–drought stress, but also the shape of the response. Because introducing a simple treatment-specific correction factor could not reproduce stress-induced isoprene emissions, different parameterizations of light and temperature functions are needed to describe tree isoprene emissions under heat and combined heat–drought stress. In order to increase the accuracy of predictions of isoprene emissions in response to climate extremes, such individual stress parameterizations should be introduced to current BVOC models.

scholarly journals Isoprene emission and photosynthesis during heat waves and drought in black locust

2017 ◽  
Author(s):  
Ines Bamberger ◽  
Nadine K. Ruehr ◽  
Michael Schmitt ◽  
Andreas Gast ◽  
Georg Wohlfahrt ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Black Locust ◽  
Heat Waves ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Weather Conditions ◽  
Linear Functions ◽  
Drought Treatment

Abstract. Extreme weather conditions, like heat waves and drought, can substantially affect tree physiology and the emissions of biogenic volatile organic compounds (BVOC), including isoprene. To date, however, there is only limited understanding of BVOC emission patterns during prolonged heat and coupled heat–drought stress as well as post-stress recovery. To assess the impacts of heat and heat–drought stress on BVOC emissions, we studied gas exchange and isoprene emissions of black locust trees under controlled environmental conditions. Leaf gas exchange of isoprene, CO2 and H2O was quantified using branch chambers connected to a protontransfer-reaction mass spectrometer and an infrared gas analyzer. Heat and heat–drought stress resulted in a sharp decline of photosynthesis and stomatal conductance. Simultaneously, isoprene emissions increased six- to eight-fold in the heat and heat–drought treatment and resulted in a carbon loss that was equivalent to 12 % and 20 % of assimilated carbon at the time of measurement. Once temperature stress was released at the end of two 15 days long heat waves, stomatal conductance remained reduced, while isoprene emissions and photosynthesis recovered quickly to values of the control trees. Further, we found isoprene emissions to co-vary with net photosynthesis during non-stressful conditions, while during the heat waves, isoprene emissions could be solely described by non-linear functions of light and temperature. However, when isoprene emissions betweentreatments were compared under the same temperature and light conditions (e.g., T = 30° C, PAR = 500 µmol m−2 s−1), heat and heat–drought stressed trees would emit less isoprene than control trees. Ourfindings suggest that different parameterizations of light and temperature functions are needed in order to predict tree isoprene emissions under heat and combined heat–drought stress.

scholarly journals Repeated Mechanical Stress from Leaf Cuvette Influences Leaf Gas Exchange

HortScience ◽  
1992 ◽  
Vol 27 (5) ◽  
pp. 432-434 ◽  
Author(s):  
Thomas E. Marler ◽  
Michael V. Mickelbart
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Mechanical Stress ◽  
Leaf Gas Exchange ◽  
Mangifera Indica ◽  
Mechanical Stimulus ◽  
Persea Americana ◽  
Long Term Effects ◽  
Leaf Chamber ◽  
Fixed Set

Long-term effects on stomatal conductance of mechanical stress from repeated clamping of a porometer leaf cuvette to laminae of avocado (Persea americana Miller), carambola (Averrhoa carambolu L.), hibiscus (Hibiscus rosa-sinensis L.), mango (Mangifera indica L.), and sugar apple (Annona squamosa L.) plants were determined under glasshouse conditions. Following 10 weeks of applying the mechanical stimulus seven times during every 4th day to mature leaves, stomatal conductance was lower than for untreated leaves of all species except mango. Similarly, following 10.5 weeks of applying the stimulus one time every 4th day to expanding leaves of avocado, carambola, hibiscus, and sugar apple, stomatal conductance was lower than for untreated leaves of the same age in all species except hibiscus. Carambola and sugar apple were more sensitive to the mechanical stress than the other species. Thus, the indirect effect of leaf chamber clamping on gas exchange should be known before any conclusions are formulated regarding environmental, cultural, or genetic effects on gas exchange. Random leaf samples from a canopy instead of measurements on a fixed set of leaves may be more appropriate for repeated determinations of leaf gas exchange on a set of plants.

scholarly journals The Toxic Effects of Low Molecular Weight Components of Cow Colostrums: The Short-Term and Long-Term Effects

2018 ◽  
Vol 6 (4) ◽  
pp. 84-91
Author(s):  
A.I. Bozhkov ◽  
◽  
E.G. Ivanov ◽  
N.I. Kurguzova ◽  
Muhammad M.A. Alsardia ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Toxic Effects ◽  
Low Molecular Weight ◽  
Long Term Effects ◽  
Short Term

scholarly journals Impact of Drought and Temperature on Growth and Leaf Gas Exchange of Six Bedding Plant Species Under Greenhouse Conditions

HortScience ◽  
2006 ◽  
Vol 41 (6) ◽  
pp. 1408-1411 ◽  
Author(s):  
Genhua Niu ◽  
Denise S. Rodriguez ◽  
Yin-Tung Wang
Keyword(s):  
Gas Exchange ◽  
Moisture Content ◽  
Net Photosynthetic Rate ◽  
Plant Species ◽  
Photosynthetic Rate ◽  
Leaf Gas Exchange ◽  
Dry Weight ◽  
Volumetric Moisture Content ◽  
Bedding Plant ◽  
Substrate Moisture

The effect of drought on the growth and gas exchange of six bedding plant species—agastache [Agastache urticifolia (Benth.) O. Kuntze `Honeybee Blue'], dusty miller (Cineraria maritima L. `Silverdusty'), petunia (Petunia ×hybrida `Wave Purple'), plumbago (Plumbago auriculata Lam. `Escapade'), ornamental pepper (Capsicum annuum L. `Black Pearl'), and vinca [Catharanthus roseus (L.) G. Don `Titan']—was quantified under greenhouse conditions. Seeds were sown in January and seedlings were grown in the greenhouse until 18 Apr., when two irrigation treatments—drought (D, ≈18% volumetric moisture content at reirrigation) and control (C, ≈25% volumetric moisture content at reirrigation)—were initiated. Leaf net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration (E) were determined in response to a range of substrate moisture content (from ≈5% to 30% by volume) and temperature (from 20 °C to 40 °C). Dry weight of agastache, ornamental pepper, and vinca was unaffected by drought, whereas that of other species was reduced. Leaf area of plumbago and height of plumbago and vinca were reduced by drought. As substrate moisture content decreased from 25% to 10%, Pn, E, and gs decreased linearly in all species except petunia and plumbago. Leaf net photosynthetic rate of all species declined as leaf temperature increased from 20 °C to 40 °C. In contrast, E of all species, except petunia, increased as temperature increased. Transpiration rate of petunia increased as temperature increased from 20 °C to 30 °C, and then decreased between 30 °C and 40 °C. Although petunia had the highest Pn among the tested species, its Pn and gs declined more rapidly compared with the other species as temperature increased from 20 °C to 40 °C or as substrate moisture content decreased, indicating that petunia was most sensitive to high temperature and drought.

Sign in / Sign up

Export Citation Format

Share Document