Excised-leaf water status evaluation and associations in field-grown winter wheat

1993 ◽  
Vol 73 (1) ◽  
pp. 55-63 ◽  
Author(s):  
S. D. Haley ◽  
J. S. Quick ◽  
J. A. Morgan
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Water Loss ◽  
Water Status ◽  
Triticum Aestivum L ◽  
Leaf Water ◽  
Initial Water Content ◽  
Leaf Water Status ◽  
Initial Water ◽  
Selection For

Water status measurements of excised leaves have been proposed as screening criteria for drought resistance in cereal crops. This study was conducted to assess the utility of such measurements in a wheat breeding program, through evaluation of environment and genotype differences in excised-leaf water status and examination of associations with several other traits. Initial water content (IWC) and rate of water loss (RWL) of excised leaves, epicuticular wax content (EW), stomatal frequency (SF), flag leaf area (LA), plant height (HT), heading date (HD), grain yield (GY), and test weight (TW) were measured on 24 winter wheat (Triticum aestivum L.) genotypes grown near Fort Collins, CO, during 1986–1987 and 1987–1988 (F87 and F88, respectively: subirrigated environments) and near Bennett, CO, during 1987–1988 (B88: dryland environment). Differences among genotypes for IWC and RWL were significant for F87 and F88, and nonsignificant for B88. Combined analyses of variance showed significant differences among environments for IWC and RWL. Initial water content was less for B88 than for F87 and F88. Significant genotype × environment (G × E) effects for IWC and RWL suggested that selection for high IWC or low RWL in irrigated environments (F87 and F88) may not provide selections that respond similarly in dryland environments (B88). Correlations for B88 revealed only a small, positive correlation between IWC and GY (r = 0.49*). For F87 and F88, significant correlations were observed between IWC and SF (r = −0.57** and −0.78**), RWL and LA (r = 0.74** and 0.71**), RWL and HT (r = 0.63** and 0.57**), and RWL and HD (r = 0.71** and 0.57**). Neither IWC or RWL were correlated with EW in any environment. Correlations between RWL (subirrigated) and G Y and TW (dryland) suggested that selection for low RWL in irrigated environments could provide some GY or TW advantage in dryland environments, despite observed G × E interaction and lack of RWL differences under the dryland environment. Key words: Cuticular transpiration, Triticum aestivum L., leaf water loss, stomata, drought

scholarly journals Salicylic acid and thiourea ameliorate the negative impact of salt stress in wheat (Triticum aestivum L.) seedlings by up-regulating photosynthetic pigments, leaf water status, and antioxidant defense system

2021 ◽  
pp. 130-145
Author(s):  
Sumaiya Farzana ◽  
Md. Rasel ◽  
Md. Tahjib Ul Arif ◽  
Mohammad Anwar Hossain ◽  
Md. Golam Azam ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Salt Stress ◽  
Photosynthetic Pigments ◽  
Growth And Development ◽  
Water Status ◽  
Triticum Aestivum L ◽  
Growth Characteristics ◽  
Leaf Water ◽  
Negative Effects ◽  
Leaf Water Status

Salinity is one of the most important abiotic stress inhibiting wheat (Triticum aestivum L.) growth and development. Therefore, finding efficient strategies to prevent salt-induced growth retardation and yield loss is critical for modern agriculture to sustain production. The role of exogenous salicylic acid (SA) and thiourea (TU) in regulating salt tolerance was investigated by evaluating morpho-physiological characteristics and antioxidant response in two wheat genotypes at the seedling stage. In both wheat genotypes, salt stress reduced growth characteristics and leaf water status, photosynthetic pigments, while simultaneously increasing the Na+/K+ ratio, hydrogen peroxide (H2O2), and malondialdehyde (MDA). In contrast, exogenous application of SA and/or TU alone in the salt-stressed plants significantly reduced the negative effects of salt stress and improved the growth performance by up-regulating photosynthetic pigments, leaf water status, and proline content in both genotypes. Besides, when compared to seedlings treated only with salt stress, SA and TU played an important role in maintaining lower Na+/K+ levels and reducing oxidative stress by lowering MDA and H2O2 levels in salt-stressed plants through boosting the activities of antioxidant enzymes such as catalase, ascorbate peroxidase, and peroxidase. In addition, hierarchical clustering and principal component analysis revealed a significant interaction among growth characteristics, chlorophyll content, carotenoid content and antioxidant activity with the salt, SA, and/or TU treatments. The findings suggested that exogenous application of SA or TU could be a useful technique for reducing the negative effects of salinity on wheat growth and development.

Relationship of excised-leaf water loss and stomatal frequency in wheat

1993 ◽  
Vol 73 (1) ◽  
pp. 93-99 ◽  
Author(s):  
H. Wang ◽  
J. M. Clarke
Keyword(s):  
Triticum Aestivum ◽  
Water Content ◽  
Water Loss ◽  
Triticum Aestivum L ◽  
Leaf Water ◽  
Genotypic Differences ◽  
Stomatal Frequency ◽  
Stomatal Characteristics ◽  
Growth Room ◽  
Leaf Water Loss

Rate of water loss from excised leaves of wheat (Triticum spp.) is associated with adaptation to dry growing conditions, but the causes of observed genotypic differences are not well understood. This study was conducted to determine the relationship between stomatal characteristics and excised-leaf water status in tetraploid (Triticum turgidum L. var. durum) and hexaploid (Triticum aestivum L.) wheat genotypes. Samples were taken from field and growth-room experiments to measure stomatal frequency (SF) and size, leaf water content at excision (WC0) and 30 min after excision (WC30), rate of water loss (RWL) 30-120 min after excision, epidermal conductance (ge), and relative water content (RWC). SF was not correlated with RWL in the field experiments and was negatively correlated with WC0 and WC30 in tetraploids but not in hexaploids. In the growth-room experiment, SF was positively correlated with ge 50 and 30 min after excision for tetraploid and hexaploid genotypes, respectively. SF was correlated with RWL in tetraploids (r = 0.64*, n = 12) and hexaploids (r = 0.81**, n = 12). However, there were no significant correlations between stomatal characteristics and WC0, WC30 or RWC. These results indicate that SF is perhaps one of several factors influencing genotypic differences in excised-leaf water loss. The inconsistency of this relationship may be due to the influence of other traits affecting RWL. Key words: Leaf water loss, stomata, drought, Triticum aestivum L., T. turgidum L. var. durum

scholarly journals Leaf water relations in epiphytic ferns are driven by drought avoidance rather than tolerance mechanisms

2021 ◽  
Author(s):  
Courtney Campany ◽  
Jarmila Pittermann ◽  
Alex Baer ◽  
Helen Holmlund ◽  
Eric Schuettpelz ◽  
...  
Keyword(s):  
Stomatal Density ◽  
Water Status ◽  
Costa Rican ◽  
Leaf Water ◽  
Leaf Water Status ◽  
Trait Divergence ◽  
Drought Avoidance ◽  
Fern Species ◽  
Selection For

Opportunistic diversification has allowed ferns to radiate into epiphytic niches in angiosperm dominated landscapes. However, our understanding of how ecophysiological function allowed establishment in the canopy and the potential transitionary role of the hemi-epiphytic life form remain unclear. Here, we surveyed 39 fern species in Costa Rican tropical forests to explore epiphytic trait divergence in a phylogenetic context. We examined leaf responses to water deficits in terrestrial, hemi-epiphytic, and epiphytic ferns and related these findings to functional traits that regulate leaf water status. Epiphytic ferns had reduced xylem area (-63%), shorter stipe lengths (-56%), thicker laminae (+41%), and reduced stomatal density (-46%) compared to terrestrial ferns. Epiphytic ferns exhibited similar turgor loss points, higher osmotic potential at saturation, and lower tissue capacitance after turgor loss than terrestrial ferns. Overall, hemi-epiphytic ferns exhibited traits that share characteristics of both terrestrial and epiphytic species. Our findings clearly demonstrate the prevalence of water conservatism in both epiphytic and hemi-epiphytic ferns, via selection for anatomical and structural traits that avoid leaf water stress. Even with likely canalized physiological function, adaptations for drought avoidance have allowed epiphytic ferns to successfully endure the stresses of the canopy habitat.

Assessment of flag leaf water status as drought tolerance discriminating trait in durum wheat (Triticum turgidum var durum L.)

2021 ◽  
Vol 2 (1) ◽  
pp. 016-027
Author(s):  
Hadda Mebarki ◽  
Ouassila Ziane ◽  
Hadjer Merbah ◽  
Hamenna Bouzerzour
Keyword(s):  
Water Content ◽  
Water Loss ◽  
Relative Water Content ◽  
Water Saturation ◽  
Water Status ◽  
Leaf Water ◽  
Leaf Water Status ◽  
Water Saturation Deficit ◽  
Saturation Deficit ◽  
Relative Water

Drought is a prominent limiting factor that impacts negatively durum wheat grain yield. Ten durum wheat breeding lines were evaluated under rainfall conditions at the Field Crop Institute Agricultural Experimental Station of Setif, Algeria, during the 2016/2017 cropping season. The investigation aimed to study the ability of flag leaf water status to discriminate among varieties for drought tolerance trait. Significant variability was observed among the tested varieties for leaf dry, wilted and turgid weights, leaf relative water content, water saturation deficit and excised water loss, after three wilting periods of 30, 60 and 90 minutes dehydration at 40°C. The assessed breeding lines were differentially categorized as drought tolerant and drought sensitive based on either relative water content or water saturation deficit or excised leaf water loss genotypic mean values. Correlation, principal components and cluster analyses indicated an unwanted significant association between excised leaf water loss and relative water content and water saturation deficit and classified the assessed entries into three clusters (CI, C2 and C3). Cluster C1 had high relative water content, low water saturation deficit but high excised water loss, while C3 had low relative water content, low excised leaf water but high-water saturation deficit, C2 being intermediate. Crosses between distant clusters (C1 vs C3) are proposed to generate more variability of the targeted traits in progeny population and to break undesirable linkage between alleles controlling leaf water status, allowing to select efficiently drought tolerant genotypes.

EFFECT OF LEAF ROLLING ON LEAF WATER LOSS IN Triticum spp.

1986 ◽  
Vol 66 (4) ◽  
pp. 885-891 ◽  
Author(s):  
JOHN M. CLARKE
Keyword(s):  
Triticum Aestivum ◽  
Water Loss ◽  
Genotypic Variation ◽  
Triticum Aestivum L ◽  
Leaf Water ◽  
Leaf Rolling ◽  
Triticum Spp ◽  
Leaf Surface Area ◽  
Leaf Water Loss ◽  
Field Plots

The effect of leaf rolling on water loss by wheat (Triticum aestivum L. and T. turgidum L. var. durum) leaves and its relationship to yield and other parameters was studied in field-grown wheat in 1983 and 1984. The influence of rolling on water loss was estimated by measuring water loss from excised leaves held flat during wilting compared to that from control leaves allowed to roll during wilting. Leaf rolling was visually scored for both excised leaves and for intact plants growing in the field. Leaves which were held flat during wilting lost 9–46% more water than the controls, and there was evidence of genotypic variation in the effect of rolling on water loss. Complete rolling reduced leaf surface area by 41–48%. There were inter- and intragenotypic differences in the amount of water lost by excised durum leaves prior to reaching intermediate and high rolling scores. Percentage water loss before reaching an intermediate rolling score ranged from 20 to 84% across genotypes, and from 24 to 84% within the most variable genotype. There were no consistent correlative relationships between leaf rolling score in field plots and yield and other parameters, probably as a result of intragenotypic differences in expression or rolling. Leaf rolling is unlikely to be of adaptive significance to wheat in environments where stress develops rapidly, but could be of potential use where stress develops gradually or is of short duration. This potential could only be exploited if the low water loss prior to onset of rolling observed in some genotypes is heritable.Key words: Triticum aestivum L., T. turgidum L. var. durum, leaf rolling, leaf water loss, drought, wheat

Leaf Gas Exchange and Water Relations of Lupins and Wheat. III. Abscisic Acid and Drought-Induced Stomatal Closure

1989 ◽  
Vol 16 (5) ◽  
pp. 429 ◽  
Author(s):  
IE Henson ◽  
CR Jensen ◽  
NC Turner
Keyword(s):  
Abscisic Acid ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Stomatal Closure ◽  
Triticum Aestivum L ◽  
Leaf Water ◽  
Stomatal Response ◽  
Leaf Water Status

Changes in the content of endogenous abscisic acid (ABA) were followed in glasshouse experiments during stomatal closure induced by drought in leaves of lupin (Lupinus cosentinii Guss. cv. Eregulla) and wheat (Triticum aestivum L. cvv. Gamenya and Warigal), species which differ in stomatal sensitivity to changes in leaf water potential. Increases in bulk leaf ABA concentration were closely correlated with decreases in leaf conductance in both species. In lupin, substantial increases in ABA and decreases in conductance occurred over a very narrow range of leaf water potential. ABA concentrations in wheat leaves were highly negatively correlated with bulk leaf turgor, but there was no significant relationship between ABA and turgor in lupin. However, ABA accumulated progressively in the leaves of both species as soil water content decreased. Stomatal closure in lupin could be induced by supplying exogenous ABA to detached leaves via the transpiration stream at concentrations of 10-4 to 10-2 mol m-3 of (+)-ABA. Abaxial stomata closed more readily than those on the adaxial surface in response to both drought and applied ABA. Stomatal response to ABA was not affected by the presence of the cytokinin zeatin, and zeatin by itself had no effect on conductance. When treatments designed to reduce endogenous cytokinin concentrations were imposed (prolonged leaf detachment or prior drought), stomatal response to low concentrations of ABA was enhanced. However, such treatments did not significantly change the stomatal response to high ABA concentrations, nor affect the stomatal conductance of leaves supplied with water alone. It is concluded that drought-induced stomatal closure could be mediated by ABA in both wheat and lupin, despite the initially small change in leaf water status in the latter species.

scholarly journals Assessment of plant water status in winter wheat (Triticum aestivum L.) based on canopy spectral indices

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0216890 ◽  
Author(s):  
Hui Sun ◽  
Meichen Feng ◽  
Lujie Xiao ◽  
Wude Yang ◽  
Chao Wang ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Water Status ◽  
Triticum Aestivum L ◽  
Plant Water Status ◽  
Plant Water ◽  
Spectral Indices
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