Ecology of Cladonia lichens. III. Comparison of C. caroliniana, endemic to southeastern North America, with three northern Cladonia species

1974 ◽  
Vol 52 (3) ◽  
pp. 565-573 ◽  
Author(s):  
Martin J. Lechowicz ◽  
William P. Jordan ◽  
Michael S. Adams
Keyword(s):  
North America ◽  
Temperature Dependence ◽  
Water Content ◽  
Relative Water Content ◽  
Net Photosynthesis ◽  
Physiological Characteristics ◽  
Pine Barrens ◽  
Microhabitat Selection ◽  
Relative Water ◽  
Northern Species

The net CO2 exchange responses of C. caroliniana in the fall to light, thallus temperature, and thallus relative water content were determined. Cladonia caroliniana responses were compared with three northern Cladonia: C. mitis, C. rangiferina, and C. uncialis. The eco-physiological characteristics of the four species provide some intuitive understanding of their biogeography and their microhabitat selection on the Wisconsin Pine Barrens. The temperature dependence of net photosynthesis of the four species correlates with their distributional relations. Cladonia caroliniana is physiologically adapted to higher temperatures than the three northern species. The limitations of this intuitive comparison are discussed and a quantitative alternative suggested.

scholarly journals Physiological responses of Eucalyptus urophylla young plants treated with biostimulant under water deficit

2019 ◽  
Vol 29 (3) ◽  
pp. 1072
Author(s):  
Rayka Kristian Alves Santos ◽  
Paulo Araquém Ramos Cairo ◽  
Romário Pereira Barbosa ◽  
Janderson De Jesus Lacerda ◽  
Caio Da Silva Mafra Neto ◽  
...  
Keyword(s):  
Plant Growth ◽  
Water Content ◽  
Root Length ◽  
Relative Water Content ◽  
Physiological Responses ◽  
Net Photosynthesis ◽  
Eucalyptus Urophylla ◽  
Main Root ◽  
Hormonal Balance ◽  
Relative Water

Biostimulants consist of a mixture of growth regulators that, when they are sprayed on plants, act on hormonal balance, enhancing its development. Stimulate® is a biostimulant composed by indole butyric acid (0.005%), kinetin (0.009%) and gibberellic acid (0.005%) which promotes root growth, improves water and nutrients uptake, and helps restore plant hormonal balance. This research was based on the hypothesis that Stimulate® spraying can be an alternate way to mitigate negative effects of soil water-limiting on plant growth. The experimental work was performed in greenhouse and aimed to evaluate physiological responses of young plants of Eucalyptus urophylla sprayed with different Stimulate® concentrations and submitted to the following irrigation regimes: full, partial and no irrigation. Leaf water potential, relative water content, net photosynthesis, plant height and main root length were measured. Under water-limited conditions, plants sprayed with Stimulate® showed higher net photosynthesis and relative water content had a less decrease, due to osmotic adjustment. Spraying with Stimulate® also provided greater plant height and longer main root length in plants under water deficit. We conclude that the use of Stimulate® can be a viable option to mitigate negative water stress physiological effects in young plants of Eucalyptus urophylla, helping to partially maintain the plant growth under water-limited conditions.

scholarly journals Effect of soil moisture content and nitrogen fertilizer on survival, growth and some physiological characteristics of Platycladus orientalis seedlings

2020 ◽  
Vol 66 (No. 12) ◽  
pp. 511-523
Author(s):  
Alireza Aliarab ◽  
Elham Okati ◽  
Seyed Ehsan Sadati
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Relative Water Content ◽  
Soil Moisture Content ◽  
Physiological Characteristics ◽  
Total Chlorophyll ◽  
Urea Fertilizer ◽  
Platycladus Orientalis ◽  
Relative Water

Given the important applications of oriental arborvitae (Platycladus orientalis /L./ Franco), we examined the interaction effects of soil moisture content (SMC) and urea fertilizer on survival, growth and some physiological characteristics of seedlings of this species. In this study, 270 uniform oriental arborvitae seedlings were transplanted in 2 kg containers filled with the top soil of the natural stand in Soorkesh forest reserve. After 2 months, 6 levels of SMC (100%, 75%, 50%, 25%, 15% and 10%) and 3 levels of urea [control: 0, low nitrogen (LN): 75 mg·kg<sup>–1</sup>, and high nitrogen (HN): 150 mg·kg<sup>–1</sup>] were used from June till the end of the first growing season in 3 replications and 5 seedlings per replication as subsamples. The results showed that all seedlings survived under SMC above 25% in control and urea fertilizer treatments. However, under 15% and 10% SMC, the seedling survival decreased significantly in control treatment, but adding urea fertilizer significantly increased the survival, especially in HN treatment. Growth and morphological properties of seedlings, including root and shoot length, number of first-order lateral roots and total biomass, showed a significant decrease at 75%. Seedling quality index gradually decreased with SMC reduction, but the addition of urea to the soil significantly increased it under all SMC treatments. The results also indicated that a decrease in SMC significantly decreased relative water content of leaves and total chlorophyll content, and urea fertilizer increased total chlorophyll under all SMC treatments, but it increased relative water content only at 100% to 25%. Moreover, water use efficiency of P. orientalis seedlings significantly increased under low soil moisture treatments, and urea significantly increased it, especially under HN treatment. In conclusion, urea fertilizer, especially in the higher amount (150 mg·kg<sup>–1</sup>), improved growth and quality of seedlings under different soil moisture conditions, and increased their survival under severe drought.

The Method of Plant Water Status Measurement in Sweet Potato (Ipomoea Batatas (L) Lam.)

2010 ◽  
Vol 7 (1) ◽  
Author(s):  
Saraswati Prabawardani
Keyword(s):  
Water Content ◽  
Sweet Potato ◽  
Relative Water Content ◽  
Water Status ◽  
Plant Water Status ◽  
Equilibration Time ◽  
Plant Water ◽  
Font Size ◽  
Potato Leaf ◽  
Relative Water

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning /> <w:ValidateAgainstSchemas /> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables /> <w:SnapToGridInCell /> <w:WrapTextWithPunct /> <w:UseAsianBreakRules /> <w:DontGrowAutofit /> <w:UseFELayout /> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--> <!--[if gte mso 10]> <mce:style><! /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} --> <!--[endif]--> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10pt;">The measurement of plant water status such as leaf water potential (LWP) and leaf relative water content (RWC) is important part of understanding plant physiology and biomass production. Preliminary study was made to determine the optimum amount of leaf abrasion and equilibration time of sweet potato leaf inside the thermocouple psychrometer chambers. Based on the trial, the standard equilibration time curve of a Peltier thermocouple for sweet potato leaf was between 2 and 3 hours. To increase the water vapour conductance across the leaf epidermis the waxy leaf cuticle should be removed or broken by abrasion. The result showed that 4 times leaf rubbings was accepted as the most effective way to increase leaf vapour conductance of sweet potato in the psychrometer chambers. In calculating the leaf relative water content, unstressed water of sweet potato leaves require 4 hours imbibition, whereas water stressed of sweet potato leaves require 5 to 6 hours to reach the saturation time. Either leaf water potential or relative water content can be used as a parameter for plant water status in sweet potato.</span><span style="font-size: 10pt;"> </span></p>

Palmer Amaranth (Amaranthus palmeri) Competition for Water in Cotton

Weed Science ◽  
2015 ◽  
Vol 63 (4) ◽  
pp. 928-935 ◽  
Author(s):  
Sarah T. Berger ◽  
Jason A. Ferrell ◽  
Diane L. Rowland ◽  
Theodore M. Webster
Keyword(s):  
Water Content ◽  
Relative Water Content ◽  
Yield Loss ◽  
Linear Trend ◽  
Palmer Amaranth ◽  
Cotton Production ◽  
Excess Water ◽  
Relative Water ◽  
Competition For Light ◽  
Daily Water

Palmer amaranth is a troublesome weed in cotton production. Yield losses of 65% have been reported from season-long Palmer amaranth competition with cotton. To determine whether water is a factor in this system, experiments were conduced in 2011, 2012, and 2013 in Citra, FL, and in Tifton, GA. In 2011, infrequent rainfall lead to drought stress. The presence of Palmer amaranth resulted in decreased soil relative water content up to 1 m in depth. Cotton stomatal conductance (gs) was reduced up to 1.8 m from a Palmer amaranth plant. In 2012 and 2013 higher than average rainfall resulted in excess water throughout the growing season. In this situation, no differences were found in soil relative water content or cottongsas a function of proximity to Palmer amaranth. A positive linear trend was found in cotton photosynthesis and yield; each parameter increased as distance from Palmer amaranth increased. Even in these well-watered conditions, daily water use of Palmer amaranth was considerably higher than that of cotton, at 1.2 and 0.49 g H20 cm−2d−1, respectively. Although Palmer amaranth removed more water from the soil profile, rainfall was adequate to replenish the profile in 2 of the 3 yr of this study. However, yield loss due to Palmer amaranth was still observed despite no change ings, indicating other factors, such as competition for light or response to neighboring plants during development, are driving yield loss.

Influence of humates to mitigate NaCl-induced adverse effects on Ocimum basilicum L.: relative water content and photosynthetic pigments

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Juan José Reyes-Pérez ◽  
Bernardo Murillo-Amador ◽  
Alejandra Nieto-Garibay ◽  
Luis G. Hernández-Montiel ◽  
Francisco H. Ruiz-Espinoza ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Water Content ◽  
Photosynthetic Pigments ◽  
Relative Water Content ◽  
Ocimum Basilicum ◽  
Relative Water

scholarly journals Assessment of lettuce quality during storage at low relative humidity using Global Stability Index methodology

2012 ◽  
Vol 32 (2) ◽  
pp. 366-373 ◽  
Author(s):  
María Roberta Ansorena ◽  
María Victoria Agüero ◽  
María Grabriela Goñi ◽  
Sara Roura ◽  
Alejandra Ponce ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Relative Humidity ◽  
Global Stability ◽  
Water Content ◽  
Relative Water Content ◽  
Storage Time ◽  
Stability Index ◽  
Total Chlorophyll ◽  
External Zone ◽  
Relative Water

During postharvest, lettuce is usually exposed to adverse conditions (e.g. low relative humidity) that reduce the vegetable quality. In order to evaluate its shelf life, a great number of quality attributes must be analyzed, which requires careful experimental design, and it is time consuming. In this study, the modified Global Stability Index method was applied to estimate the quality of butter lettuce at low relative humidity during storage discriminating three lettuce zones (internal, middle, and external). The results indicated that the most relevant attributes were: the external zone - relative water content, water content , ascorbic acid, and total mesophilic counts; middle zone - relative water content, water content, total chlorophyll, and ascorbic acid; internal zone - relative water content, bound water, water content, and total mesophilic counts. A mathematical model that takes into account the Global Stability Index and overall visual quality for each lettuce zone was proposed. Moreover, the Weibull distribution was applied to estimate the maximum vegetable storage time which was 5, 4, and 3 days for the internal, middle, and external zone, respectively. When analyzing the effect of storage time for each lettuce zone, all the indices evaluated in the external zone of lettuce presented significant differences (p < 0.05). For both, internal and middle zones, the attributes presented significant differences (p < 0.05), except for water content and total chlorophyll.

scholarly journals Growth and physiological response of two biomass sorghum (Sorghum bicolor (L.) Moench) genotypes bred for different environments, to contrasting levels of soil moisture

2015 ◽  
Vol 10 (4) ◽  
pp. 208 ◽  
Author(s):  
Lorenzo Barbanti ◽  
Ahmad Sher ◽  
Giuseppe Di Girolamo ◽  
Elio Cirillo ◽  
Muhammad Ansar
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Water Content ◽  
Aboveground Biomass ◽  
Relative Water Content ◽  
Physiological Response ◽  
Field Capacity ◽  
Biomass Sorghum ◽  
Relative Water

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (<em>Sorghum bicolor</em> (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, <em>i.e</em>., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.

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