scholarly journals Effects of Water Stress on Germination and Growth of Wheat, Photosynthetic Efficiency and Accumulation of Metabolites

10.5772/51205 ◽  
2013 ◽  
Author(s):  
Rui Guo ◽  
Wei Ping ◽  
Dao Zhi ◽  
Xiu Li ◽  
Feng Xue
Keyword(s):  
Water Stress ◽  
Photosynthetic Efficiency ◽  
Germination And Growth

Ma2± and water stress effects on germination and growth of Nicotiana tabacum var. BEL W3

1995 ◽  
Vol 129 (4) ◽  
pp. 1144-1145
Author(s):  
G. Santandrea ◽  
R. Calamassi ◽  
A. Bennici ◽  
S. Schiff
Keyword(s):  
Water Stress ◽  
Nicotiana Tabacum ◽  
Stress Effects ◽  
Germination And Growth

scholarly journals Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

2010 ◽  
pp. 139-150 ◽  
Author(s):  
Zorica Popovic ◽  
Slobodan Milanovic ◽  
Zoran Miletic ◽  
Miroslava Smiljanic
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Photosynthetic Efficiency ◽  
Water Regime ◽  
Total Porosity ◽  
Control Group ◽  
Pedunculate Oak ◽  
Short Term ◽  
Soil Water Regime ◽  
Oak Seedlings

Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C) (soil water regime in pots was maintained at the level of field water capacity) and treated (water-stressed, WS) (soil water regime was maintained in the range of wilting point and lentocapillary capacity). The photosynthetic efficiency was 0.642?0.25 and 0.522?0.024 (WS and C, respectively), which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551?0.0100 and 0.427?0.018 in C and WS, respectively). Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T?). Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.

scholarly journals Planting orientation of Portulacaria afra cuttings for thicket restoration: vertical versus horizontal

2019 ◽  
Author(s):  
Mutakusi B Ragimana ◽  
Alastair J Potts
Keyword(s):  
Water Stress ◽  
Photosynthetic Efficiency ◽  
Plant Stress ◽  
Common Garden ◽  
Dry Mass ◽  
Main Stem ◽  
Vertical Orientation ◽  
Total Size ◽  
Horizontal Orientation ◽  
Establishment Phase

Aim. The re-establishment of Portulacaria afra in the landscape-scale Subtropical Thicket Restoration Programme has exclusively used vertically-orientated truncheons (i.e. large cuttings with the main stem planted 10-20 cm into the ground). Despite the planting of millions of truncheons, the rates of survival, growth and restoration are low. This may be driven by browsing pressure and/or drought conditions during the truncheon establishment phase. Here we conduct a common garden experiment to explore the establishment of horizontal versus vertically orientated truncheons. Horizontal truncheons have their main stem buried in the soil and only a few side branches exposed above ground — these truncheons may experience reduced water stress. Here we compared the levels of water stress during the establishment phase of truncheons with different orientation. Location. Eastern Cape, South Africa. Methods. Our experiment involved three planting treatments for truncheons: vertical orientation, horizontal orientation, and horizontal orientation with exposed side branches clipped. Truncheons were grown for two months and plants were well-watered. On two occasions during the experiment, photosynthetic efficiency was measured on all plants to ascertain levels of plant stress. After the experiment, the root, stem and leaf dry mass were recorded for each replicate, as well as leaf moisture. Results. The root mass proportion (of the total plant) was not significantly different among treatments. Despite this, leaf-level photosynthetic efficiency was recorded as significantly lower in vertical truncheons versus horizontal truncheons. Main conclusions. Smaller horizontally-orientated truncheons do not grow roots at a faster rate (relative to their total size) than the larger vertically-orientated truncheons that have more leaf material to support. Nonetheless, under well-watered conditions, the larger truncheons experienced stress evidenced by lowered leaf photosynthetic efficiency values. Thus, we suggest that horizontal buried truncheons may have a higher likelihood of survival under seasonal drought-stress conditions. It remains to be tested whether horizontally-orientated truncheons (with less above-ground biomass) experience lower rates of herbivory than the standard vertical cuttings.

scholarly journals Planting orientation of Portulacaria afra cuttings for thicket restoration: vertical versus horizontal

2019 ◽  
Author(s):  
Mutakusi B Ragimana ◽  
Alastair J Potts
Keyword(s):  
Water Stress ◽  
Photosynthetic Efficiency ◽  
Plant Stress ◽  
Common Garden ◽  
Dry Mass ◽  
Main Stem ◽  
Vertical Orientation ◽  
Total Size ◽  
Horizontal Orientation ◽  
Establishment Phase

Aim. The re-establishment of Portulacaria afra in the landscape-scale Subtropical Thicket Restoration Programme has exclusively used vertically-orientated truncheons (i.e. large cuttings with the main stem planted 10-20 cm into the ground). Despite the planting of millions of truncheons, the rates of survival, growth and restoration are low. This may be driven by browsing pressure and/or drought conditions during the truncheon establishment phase. Here we conduct a common garden experiment to explore the establishment of horizontal versus vertically orientated truncheons. Horizontal truncheons have their main stem buried in the soil and only a few side branches exposed above ground — these truncheons may experience reduced water stress. Here we compared the levels of water stress during the establishment phase of truncheons with different orientation. Location. Eastern Cape, South Africa. Methods. Our experiment involved three planting treatments for truncheons: vertical orientation, horizontal orientation, and horizontal orientation with exposed side branches clipped. Truncheons were grown for two months and plants were well-watered. On two occasions during the experiment, photosynthetic efficiency was measured on all plants to ascertain levels of plant stress. After the experiment, the root, stem and leaf dry mass were recorded for each replicate, as well as leaf moisture. Results. The root mass proportion (of the total plant) was not significantly different among treatments. Despite this, leaf-level photosynthetic efficiency was recorded as significantly lower in vertical truncheons versus horizontal truncheons. Main conclusions. Smaller horizontally-orientated truncheons do not grow roots at a faster rate (relative to their total size) than the larger vertically-orientated truncheons that have more leaf material to support. Nonetheless, under well-watered conditions, the larger truncheons experienced stress evidenced by lowered leaf photosynthetic efficiency values. Thus, we suggest that horizontal buried truncheons may have a higher likelihood of survival under seasonal drought-stress conditions. It remains to be tested whether horizontally-orientated truncheons (with less above-ground biomass) experience lower rates of herbivory than the standard vertical cuttings.

scholarly journals (454) Detecting Plant Stress by Chlorophyll Fluorescence

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1036C-1036
Author(s):  
Hussein Al-Amier ◽  
Robert Lussier ◽  
Ming Coler ◽  
Margaret Stoltzman ◽  
Lyle Craker
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Plant Tissue ◽  
Dark Adaptation ◽  
Photosynthetic Efficiency ◽  
Plant Stress ◽  
Fluorescence Emission ◽  
Sudden Increase ◽  
Stress Symptoms ◽  
Kautsky Effect

The stress level in a plant may be directly associated with the intensity of the Kautsky effect (the sudden increase in fluorescence emission by chlorophyll following a dark adaptation). The decrease in photosynthetic efficiency, linked with the rate of photochemistry of plants under stress, provides a definitive signature (graphical pattern) that can be quantified and monitored, even for plants that have no visible stress symptoms. Using a prototype GrowScanner®, signature differences in plants under nitrogen and water stress, as compared with plants not under stress, could be detected and measured. Returning stressed plants to a nonstressed condition returned the stress signatures to that of control plants not under stress. Development of the technology may provide a relatively quick, presymptomatic methodology for detecting plant stress without sacrificing plant tissue.

scholarly journals Integrated high-resolution phenotyping, chlorophyll fluorescence induction kinetics and photosystem II dynamics under water stress and heat in Wheat (Triticum aestivum)

2019 ◽  
Author(s):  
Arun K. Shanker ◽  
Robert Coe ◽  
Xavier Sirault
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Quantum Yield ◽  
Photosynthetic Efficiency ◽  
Fluorescence Induction ◽  
Chlorophyll Fluorescence Induction ◽  
Maximum Quantum Yield ◽  
Induction Kinetics ◽  
Fluorescence Induction Kinetics ◽  
Chlorophyll Fluorescence Induction Kinetics

AbstractAn experiment was conducted in controlled conditions in three varieties of wheat under water stress, heat and heat +water stress treatments with the objective of studying Chlorophyll a fluorescence, chlorophyll fluorescence induction kinetics and the function of Photosystem II by plant phenotyping as affected by stress. We hypothesised that during stress, specific adaptive strategies are employed by plants, such as structural and functional changes in PS II by which they acquire new homeostasis which may be protective adaptations. Water stress stress treatment was imposed on Water stress and Heat +Water stress treatments at 43 DAS. Heat treatment was imposed on 48 DAS. Maximum quantum yield of primary photochemistry was measured with PAM 2500 and OJIP was measured with FluorPen FP 100 after the onset of stress at four observation times on two days viz., pre-dawn and afternoon during stress. In addition continuous monitoring of photosynthetic efficiency was done with Monitoring PAM. Heat +Water stress stress was more detrimental as compared to Heat or Water stress alone in terms of maximum quantum yield of photochemistry. This could have been due to higher decrease in connectivity between PSII and its antennae resulting in lower photosynthetic efficiency resulting in the impairment and disruption of the electron transport. K step was observed in heat stress and heat +Water stress stress which may be because of damage to Oxygen Evolving Complex indicating that low thermostability of the complex. The stress treatments had a reduction in the plastoquinone pool size as indicated by the reduced area above the OJIP curve. Our study indicated that the instrument PAM 2500 sensed both stresses separately and combined earlier than the other instruments, so in terms of sensitivity PAM 2500 was more effective than FluorPen FP 100 and MultispeQ. Rapid screening of stress was more effectively with FluorPen FP 100 and MultispeQ than by PAM 2500.

Sign in / Sign up

Export Citation Format

Share Document