scholarly journals Calcium-Induced Freezing and Salinity Tolerance in Evergreen Oak and Apple cv. ‘Golden Crown’

2008 ◽  
Vol 34 (3) ◽  
pp. 191-199
Author(s):  
Glynn Percival ◽  
Sally Barnes
Keyword(s):  
Chlorophyll Fluorescence ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Tree Species ◽  
Electrolyte Leakage ◽  
Calcium Nitrate ◽  
Leaf Tissue ◽  
Leaf Chlorophyll ◽  
Evergreen Oak ◽  
Leaf Chlorophyll Fluorescence

Greater variability in weather patterns and later spring frosts equate to poor winter hardiness, premature spring budbreak, and greater susceptibility to low-temperature damage and concomitant deicing salt application. A field trial was undertaken to determine the influence of a range of commercially available calcium fertilizers applied as foliar sprays on the freezing and salinity tolerance of two tree species, evergreen oak (Quercus ilex L.) and apple (Malus cv. ‘Golden Crown’). In all cases, application of calcium sprays increased twig, leaf, and root freezing and salt tolerance of both species as measured by leaf chlorophyll fluorescence and tissue electrolyte leakage bioassays. In the case of apple, a hardiness gain of 4.3°C (7.74°F) was recorded in twig tissue. In the case of evergreen oak, a hardiness gain of 2.1°C (3.78°F) was recorded in leaf tissue. After a –5°C (23°F) (apple) and –6.5°C (20°F) (evergreen oak) freezing stress, root electrolyte leakage values as a measure of cell membrane structural damage were 16% to 27% less in calcium-treated trees compared with noncalcium-treated controls. The salt concentration needed to cause 50% reductions in leaf chlorophyll fluorescence as a measure of photosynthetic efficiency rose by 0.2% to 1.2% in calcium-fertilized trees indicating a positive influence of calcium on enhancing leaf tissue tolerance to salt damage. Differences in the magnitude of freezing and salinity tolerance gained were noticeable between the calcium products used. In general, calcium hydroxide, calcium nitrate borate, and calcium metalosate improved twig, leaf, and root freezing and salt tolerance in both tree species to a greater degree than calcium chloride, calcium sulphate, calcium nitrate, and a calcium–magnesium complex. A significant correlation existed between increased freezing tolerance and internal tissue calcium content. Results of this study indicate that calcium sprays during late summer and fall can increase the freezing and salinity tolerance of evergreen oak and apple during the winter. This should be considered noteworthy for individuals involved in the management of trees in areas subject to subzero temperature fluctuations and/or concomitant applications of deicing salts in the form of sodium chloride.

Leaf chlorophyll fluorescence discriminates herbicide resistance inEchinochloaspecies

Weed Research ◽  
2016 ◽  
Vol 56 (6) ◽  
pp. 424-433 ◽  
Author(s):  
C J Zhang ◽  
S H Lim ◽  
J W Kim ◽  
G Nah ◽  
A Fischer ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Herbicide Resistance ◽  
Leaf Chlorophyll ◽  
Leaf Chlorophyll Fluorescence

scholarly journals Penconazole Induced Heat Tolerance in Scots Pine (Pinus sylvestris) and Evergreen Oak (Quercus ilex)

2010 ◽  
Vol 36 (5) ◽  
pp. 212-220
Author(s):  
Glynn Percival ◽  
Kelly Noviss
Keyword(s):  
Heat Stress ◽  
Chlorophyll Fluorescence ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Electrolyte Leakage ◽  
Quercus Ilex ◽  
Recovery Rates ◽  
Photosynthetic System ◽  
Heat Damage ◽  
Evergreen Oak

The ability of penconazole, a triazole fungicide derivative, to protect against and ameliorate heat stress was studied in evergreen oak (Quercus ilex) and Scots pine (Pinus sylvestris). Under laboratory conditions, heat damage to the leaf photosynthetic system based on the stability of the chlorophyll a/b light-harvesting complex within photosystem II (chlorophyll fluorescence Fo responses) and leaf photochemical efficiency (chlorophyll fluorescence Fv/Fm emissions) of detached leaves was constantly less in penconazole treated trees. In both species, greatest protection of the leaf photosynthetic system to heat induced disorders was achieved by application of penconazole at a concentration of 30 g per liter of water compared to penconazole applied at a concentration of 0.15 or 0.45 g per liter of water. Subjecting containerized trees of both species to 10 minutes at 50°C significantly reduced tree vitality with respect to chlorophyll fluorescence Fo and Fv/ Fm emissions, total foliar chlorophylls, leaf photosynthetic rates (Pn) and significantly increased damage to cellular membrane integrity as manifest by higher leaf electrolyte leakage and visual leaf necrosis between stressed and non-heat stressed well-watered trees. The influence of penconazole applied immediately after heat stress on the pattern of recovery over the following twelve weeks demonstrated penconazole treated trees were the most capable of recovery. With respect to chlorophyll fluorescence Fo and leaf electrolyte leakage values recovery rates of heat damaged trees treated with penconazole ranged from 20%–50% higher than non-triazole treated control trees. In all cases nonpenconazole treated control trees had the least capacity for recovery. Regardless of species, height, leaf area, root, shoot, and total plant dry weight were, in virtually all instances, greater than non-penconazole treated controls. The tactical use of the triazole derivative penconazole as an ameliorant against heat damage and recovery from heat stress in Scots pine and evergreen oak would be of benefit to improve tree recovery rates and growth. From a practical point of view penconazole at 30 g a.i. per liter of water is suggested based on the results of this study.

scholarly journals Sensitivity of Five Container-grown Nursery Species to Chlorine in Overhead Irrigation Water

HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1882-1887 ◽  
Author(s):  
Diane Feliciano Cayanan ◽  
Youbin Zheng ◽  
Ping Zhang ◽  
Tom Graham ◽  
Mike Dixon ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Irrigation Water ◽  
Free Chlorine ◽  
Leaf Chlorophyll ◽  
Content Index ◽  
Overhead Irrigation ◽  
Physocarpus Opulifolius ◽  
Woody Shrubs ◽  
Weigela Florida ◽  
Leaf Chlorophyll Fluorescence

Phytotoxic responses of five container-grown nursery species (Spiraea japonica ‘Goldmound’, Hydrangea paniculata ‘Grandiflora’, Weigela florida ‘Alexandra’, Physocarpus opulifolius ‘Summer Wine’, and Salix integra ‘Hakura Nishiki’) to chlorinated irrigation water and critical free chlorine thresholds were evaluated. Plants were overhead-irrigated with water containing 0, 2.5, 5, 10, and 20 mg·L−1 of free chlorine for 6 weeks. The following measurements were used to assess the treatments: visual injury, growth, leaf chlorophyll content index, leaf chlorophyll fluorescence, leaf net CO2 exchange rate, and stomatal conductance. All species exhibited one or more signs of chlorine injury, including foliar necrotic mottling, foliar necrosis and chlorosis, decreased plant height, and increased premature abscission of foliage with species varying in sensitivity to free chlorine concentrations of irrigation water. The results indicated that the critical free chlorine threshold of S. japonica, H. paniculata, W. florida, and S. integra was 2.5 mg·L−1 and 5 mg·L−1 for P. opulifolius. Our results suggested that irrigation water containing free chlorine less than 2.5 mg·L−1 should not adversely affect the growth or appearance of ornamental woody shrubs.

scholarly journals Effect of Molybdenum on Plant Physiology and Cadmium Uptake and Translocation in Rape (Brassica napus L.) under Different Levels of Cadmium Stress

2020 ◽  
Vol 17 (7) ◽  
pp. 2355
Author(s):  
Zhangxiong Han ◽  
Xuan Wei ◽  
Dejun Wan ◽  
Wenxiang He ◽  
Xijie Wang ◽  
...  
Keyword(s):  
Plant Physiology ◽  
Chlorophyll Fluorescence ◽  
Brassica Napus ◽  
Cd Stress ◽  
Brassica Napus L ◽  
Cd Uptake ◽  
P Values ◽  
Leaf Chlorophyll ◽  
Leaf Chlorophyll Fluorescence ◽  
Cd Translocation

This study investigated the beneficial effect of molybdenum (Mo) application on rape plants (Brassica napus L.) grown in a soil polluted by cadmium (Cd). A pot experiment was conducted to determine how different concentrations of exogenous Mo (0, 50, 100, and 200 mg/kg) affect plant physiology, biomass, photosynthesis, cation uptake, and Cd translocation and enrichment in rape plants under Cd stress (0.5 and 6.0 mg/kg). Under single Cd treatment, plant physiological and biochemical parameters, biomass parameters, leaf chlorophyll fluorescence parameters, and macroelement uptake of rape plants decreased, while their malonaldehyde content, proline content, non-photochemical quenching coefficient, and Cd uptake significantly increased, compared to those of the control group (p-values < 0.05). High-Cd treatment resulted in much larger changes in these parameters than low-Cd treatment. Following Mo application, the accumulation of malondialdehyde and proline decreased in the leaves of Cd-stressed plants; reversely, the contents of soluble protein, soluble sugar, and chlorophyll, and the activities of superoxide dismutase and glutathione peroxidase, all increased compared to those of single Cd treatment (p-values < 0.05). Exogenous Mo application promoted shoot and root growth of Cd-stressed plants in terms of their length, fresh weight, and dry weight. The negative effect of Cd stress on leaf chlorophyll fluorescence was substantially mitigated by applying Mo. Exogenous Mo also improved the uptake of inorganic cations, especially potassium (K+), in Cd-stressed plants. After Mo application, Cd uptake and accumulation were inhibited and Cd tolerance was enhanced, but Cd translocation was less affected in Cd-stressed plants. The mitigation effect of Mo on Cd stress in rape was achieved through the immobilization of soil Cd to reduce plant uptake, and improvement of plant physiological properties to enhance Cd tolerance. In conclusion, exogenous Mo can effectively reduce Cd toxicity to rape and the optimal Mo concentration was 100 mg/kg under the experimental conditions.

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