WATER STRESS AND NITROGEN MANAGEMENT EFFECTS ON GAS EXCHANGE, WATER RELATIONS, AND WATER USE EFFICIENCY IN WHEAT

2011 ◽  
Vol 34 (12) ◽  
pp. 1867-1882 ◽  
Author(s):  
Ejaz Ahmad Waraich ◽  
R. Ahmad ◽  
Saifullah ◽  
A. Ahmad
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Relations ◽  
Nitrogen Management ◽  
Use Efficiency ◽  
Management Effects

scholarly journals Interaction of CO<sub>2</sub> concentrations and water stress in semiarid plants causes diverging response in instantaneous water use efficiency and carbon isotope composition

2017 ◽  
Vol 14 (14) ◽  
pp. 3431-3444 ◽  
Author(s):  
Na Zhao ◽  
Ping Meng ◽  
Yabing He ◽  
Xinxiao Yu
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Environmental Changes ◽  
Isotope Composition ◽  
Water Soluble ◽  
Severe Drought ◽  
Semiarid Areas ◽  
Use Efficiency

Abstract. In the context of global warming attributable to the increasing levels of CO2, severe drought may be more frequent in areas that already experience chronic water shortages (semiarid areas). This necessitates research on the interactions between increased levels of CO2 and drought and their effect on plant photosynthesis. It is commonly reported that 13C fractionation occurs as CO2 gas diffuses from the atmosphere to the substomatal cavity. Few researchers have investigated 13C fractionation at the site of carboxylation to cytoplasm before sugars are exported outward from the leaf. This process typically progresses in response to variations in environmental conditions (i.e., CO2 concentrations and water stress), including in their interaction. Therefore, saplings of two typical plant species (Platycladus orientalis and Quercus variabilis) from semiarid areas of northern China were selected and cultivated in growth chambers with orthogonal treatments (four CO2 concentration ([CO2])  ×  five soil volumetric water content (SWC)). The δ13C of water-soluble compounds extracted from leaves of saplings was determined for an assessment of instantaneous water use efficiency (WUEcp) after cultivation. Instantaneous water use efficiency derived from gas-exchange measurements (WUEge) was integrated to estimate differences in δ13C signal variation before leaf-level translocation of primary assimilates. The WUEge values in P. orientalis and Q.  variabilis both decreased with increased soil moisture at 35–80 % of field capacity (FC) and increased with elevated [CO2] by increasing photosynthetic capacity and reducing transpiration. Instantaneous water use efficiency (iWUE) according to environmental changes differed between the two species. The WUEge in P. orientalis was significantly greater than that in Q. variabilis, while an opposite tendency was observed when comparing WUEcp between the two species. Total 13C fractionation at the site of carboxylation to cytoplasm before sugar export (total 13C fractionation) was species-specific, as demonstrated in the interaction of [CO2] and SWC. Rising [CO2] coupled with moistened soil generated increasing disparities in δ13C between water-soluble compounds (δ13CWSC) and estimates based on gas-exchange observations (δ13Cobs) in P. orientalis, ranging between 0.0328 and 0.0472 ‰. Differences between δ13CWSC and δ13Cobs in Q. variabilis increased as [CO2] and SWC increased (0.0384–0.0466 ‰). The 13C fractionation from mesophyll conductance (gm) and post-carboxylation both contributed to the total 13C fractionation that was determined by δ13C of water-soluble compounds and gas-exchange measurements. Total 13C fractionation was linearly dependent on stomatal conductance, indicating that post-carboxylation fractionation could be attributed to environmental variation. The magnitude and environmental dependence of apparent post-carboxylation fractionation is worth our attention when addressing photosynthetic fractionation.

scholarly journals Yield, Mineral Composition, Water Relations, and Water Use Efficiency of Grafted Mini-watermelon Plants Under Deficit Irrigation

HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 730-736 ◽  
Author(s):  
Youssef Rouphael ◽  
Mariateresa Cardarelli ◽  
Giuseppe Colla ◽  
Elvira Rea
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Water Use Efficiency ◽  
Water Use ◽  
Water Relations ◽  
Fruit Quality ◽  
Stress Conditions ◽  
Irrigated Agriculture ◽  
Marketable Yield ◽  
Use Efficiency

Limited water supply in the Mediterranean region is a major problem in irrigated agriculture. Grafting may enhance drought resistance, plant water use efficiency, and plant growth. An experiment was conducted in two consecutive growing seasons to determine yield, plant growth, fruit quality, leaf gas exchange, water relations, macroelements content in fruits and leaves, and water use efficiency of mini-watermelon plants [Citrullus lanatus (Thunb.) Matsum. and Nakai cv. Ingrid], either ungrafted or grafted onto the commercial rootstock ‘PS 1313’ (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne), under open field conditions. Irrigation treatments were 1.0, 0.75, and 0.5 evapotranspiration rates. In both years (2006 and 2007), marketable yield decreased linearly in response to an increase in water stress. When averaged over year and irrigation rate, the total and marketable yields were higher by 115% and 61% in grafted than in ungrafted plants, respectively. The fruit quality parameters of grafted mini-watermelons such as fruit dry matter and total soluble solids content were similar in comparison with those of ungrafted plants, whereas titratable acidity, K, and Mg concentrations improved significantly. In both grafting combinations, yield water use efficiency (WUEy) increased under water stress conditions with higher WUE values recorded in grafted than ungrafted plants. The concentration of N, K, and Mg in leaves was higher by 7.4%, 25.6%, and 38.8%, respectively, in grafted than in ungrafted plants. The net assimilation of CO2, stomatal conductance, relative water content, leaf, and osmotic potential decreased under water stress conditions. The sensitivity to water stress was similar between grafted and ungrafted plants, and the higher marketable yield from grafted plants was mainly the result of an improvement in nutritional status and higher CO2 assimilation and water uptake from the soil.

Sensitivity of leaf gas exchange to atmospheric drought, soil drought, and water-use efficiency in some Mediterranean Abies species

1991 ◽  
Vol 21 (10) ◽  
pp. 1507-1515 ◽  
Author(s):  
J. M. Guehl ◽  
G. Aussenac ◽  
J. Bouachrine ◽  
R. Zimmermann ◽  
J. M. Pennes ◽  
...  
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Soil Drought ◽  
Drought Adaptation ◽  
Internal Water ◽  
Annual Growth Rings ◽  
Use Efficiency

The responses of CO2 assimilation rate (A), transpiration rate (E), and leaf conductance (g) to increasing leaf to air water vapor concentration difference (ΔW) were investigated (i) using excised shoots from mature trees of Abiesalba, Abiescephalonica, Abiesmarocana, and Abiesnordmanniana and (ii) in situ on a mature tree of Abiesbornmulleriana. Gas-exchange responses to increasing soil drought were also studied in plants of A. bornmulleriana, A. cephalonica, and Cedrusatlantica. Stable carbon isotope composition measurements were carried out on annual growth rings of A. bornmulleriana to estimate the time-integrated values of the ratio of intercellular leaf (Ci) to ambient (Ca) CO2 concentration. Increasing ΔW around the shoots reduced A and g in such a way that either Ci remained constant or its decrease was not pronounced enough for the changes in A to be accounted for by changes in g only. This suggests a direct effect of ΔW on photosynthesis. The different Abies species showed clear differences in water-use efficiency. Abiescephalonica and A. marocana had lower water costs of CO2 assimilation (E/A) than A. nordmanniana and A. alba. It has also been shown that A. cephalonica and A. marocana are characterized by an optimal stomatal control of leaf gas exchange. Stomata closed very rapidly in A. bornmulleriana in response to water supply being withheld, even prior to there being any important decrease in leaf predawn water potential. The stomatal response in C. atlantica was more gradual. In A. bornmulleriana, drought adaptation appears to be linked to the ability to avoid internal water stress, whereas drought adaptation in C. atlantica involves the ability to tolerate internal water stress. The high stomatal sensitivity mA. bornmulleriana is also supported by the isotopic carbon composition data, as shown by the substantial interannual variations in the estimates of Ci/Ca, ranging from 0.48 for the dryest years to 0.61 for the rainy years.

Effect of water stress on leaf level gas exchange capacity and water-use efficiency of wheat cultivars

2016 ◽  
Vol 21 (3) ◽  
pp. 300-305 ◽  
Author(s):  
Sripati Sikder ◽  
Yunzhou Qiao ◽  
Dong Baodi ◽  
Changhai Shi ◽  
Mengyu Liu
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Exchange Capacity ◽  
Wheat Cultivars ◽  
Effect Of Water ◽  
Leaf Level ◽  
Use Efficiency

scholarly journals Water Use Efficiency and Nutritional Status of a New Grapevine Rootstock Selection

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 503
Author(s):  
Davide Bianchi ◽  
Lucio Brancadoro
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Nutritional Status ◽  
Water Use Efficiency ◽  
Stress Tolerance ◽  
Water Use ◽  
Water Availability ◽  
Carbon Assimilation ◽  
Use Efficiency ◽  
Selection Of

The production and quality of grapes are determined by the hydric and nutritional status of the vine. In modern viticulture, the interface between grapevine and soil is represented by the rootstock, which modulates the uptake of water and nutrients. Thus, selection of new rootstocks for abiotic stress tolerance represents an adaptation strategy for viticulture to the new environmental conditions imposed by climate change. The aim of this work is to evaluate the water-use efficiency (WUE) and the nutritional status of a selection of 30 new rootstock genotypes, originating from several breeding programs. WUE and gas exchange were measured for each genotype in two environments characterized by different water availability, and the levels of N, P, K, Mg, Ca, Na, Fe, Mn, and Zn in the leaf blades were determined during the phenological stages of flowering and ripening. Water availability was different in the two environments, affecting gas exchange, with mean values of carbon assimilation of 10.43 ± 0.32 and 3.84 ± 0.34 µmol CO2 m−2 s−1, respectively. Genotypes were classified according to their water stress tolerance, vigor, and affinity for macronutrients and micronutrients. A total of 14 genotypes showed tolerance to water stress, and 10 of them reported high vigor and carbon assimilation. Furthermore, the majority of water-stress-tolerant genotypes had greater affinity for Mg than for K. In further studies, the most promising rootstocks will be evaluated in grafting combination with Vitis vinifera.

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