Modifications in vapor diffusion resistence of leaves and water relations in barbados cherry plants under water stress

Young sexually and assexually propagated Barbados cherry plants were submitted to water deficit (20 days without irrigation). During this period the accumulation of proline, water potential of branches, osmotic potential, the relative water content of leaves, the leaf diffusive resistance, the transpiration rate and leaf temperature in the cuvette were determined. In addition, photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) were measured in the porometer cuvette. The concentration of proline for both types of plants began to increase on the fifth day without watering, and reached 38.1 times the concentration in the control plants grown from seeds and 26.4 times the concentration in grafted plants on the tenth day without watering. The lowest levels of leaf water potential in the plants suffering from severe water stress varied from -4.5 to -5.7 MPa, the lowest values being observed in the sexually propagated plants. These plants also showed the highest values for transpiration (0.9 mmol.m-2.s-1) and proline concentration (20.42 mg.g-1 DM), the lowest for relative water content of the leaves (38.4%) and diffusive resistance (940 s.m-1) at the end of the experiment. The Barbados cherry plants developed strategies for surviving drought, with differences between various characteristics, resulting from prolonged stress, which significantly influenced the parameters evaluated, with the exception of leaf temperature.

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Comparison of Strawberry F. chilocnsis and F. ×ananassa in Response to Water Stress: I. Leaf Water Potential, Relative Water Content, and Gas Exchange Characteristics

HortScience ◽

10.21273/hortsci.31.4.601c ◽

1996 ◽

Vol 31 (4) ◽

pp. 601c-601

Author(s):

Chuhe Chen ◽

J. Scott Cameron ◽

Stephen F. Klauer

Keyword(s):

Water Stress ◽

Gas Exchange ◽

Water Potential ◽

Water Content ◽

Leaf Water Potential ◽

Relative Water Content ◽

Leaf Water ◽

Severe Water Stress ◽

Relative Water ◽

Gas Exchange Characteristics

Leaf water potential (LWP), relative water content (RWC), gas exchange characteristics, and specific leaf weight (SLW) were measured six hours before, during, and after water stress treatment in F. chiloensis and F. ×ananassa grown in growth chambers. The leaves of both species showed significantly lower LWP and RWC as water stress developed. F. ×ananassa had consistency lower LWP under stressed and nonstressed conditions than F. chiloensis. F. ×ananassa had higher RWC under nonstressed conditions, and its RWC decreased more rapidly under water stress than F. chiloensis. In comparison to F. ×ananassa, F. chiloensis had significantly higher CO2 assimilation rate (A), leaf conductance (LC), and SLW, but not transpiration rate (Tr), under stressed and nonstressed conditions. LC was the most sensitive gas exchange characteristic to water stress and decreased first. Later, A and stomatal conductance were reduced under more severe water stress. A very high level of Tr was detected in F. ×ananassa under the most severe water stress and did not regain after stress recovery, suggesting a permanent damage to leaf. The Tr of F. chiloensis was affected less by water stress. Severe water stress resulted in higher SLW of both species.

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EFEITOS DO DÉFICIT HÍDRICO EM PARÂMETROS FISIOLÓGICOS DE FOLHAS DE SORGO (Sorghum bicolor, L.)

Irriga ◽

10.15809/irriga.1998v3n3p81-88 ◽

1998 ◽

Vol 3 (3) ◽

pp. 81-88

Author(s):

Carlos Augusto Lima Porto ◽

Antonio Evaldo Klar ◽

José Vicente Vasconcelos

Keyword(s):

Water Stress ◽

Sorghum Bicolor ◽

Water Potential ◽

Water Content ◽

Relative Water Content ◽

Water Status ◽

Soil Water Potential ◽

Relative Water ◽

Conductivity Water ◽

Sorghum Bicolor L

EFEITOS DO DÉFICIT HÍDRICO EM PARÂMETROS FISIOLÓGICOS DE FOLHAS DE SORGO (Sorghum bicolor, L.) Carlos Augusto Lima PortoAntonio Evaldo Klar(2)José Vicente VasconcelosDepartamento de Engenharia Rural – Faculdade de Ciências Agronômicas – UNESPFone: (014) 821-3883 Fax: (014) 821-343818603-97’ – Botucatu - SP 1 RESUMO O experimento foi conduzido em casa de vegetação no Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas - UNESP/Botucatu, SP, com delineamento experimental inteiramente casualizado, com 12 repetições. A cultura do sorgo (Sorghum bicolor, L.) foi plantada em vasos que continham 8,0 kg de solo (base em peso de solo seco), pertencente ao grande grupo Terra Roxa Estruturada para os dois tratamentos: a) plantas submetidas a défices hídricos, sendo irrigadas quando o potencial de água no solo chegava a -1,5 MPa, elevando-o às imediações de -0,01 MPa), e b) plantas irrigadas constantemente por capilaridade. Todas as plantas foram irrigadas aos 55 dias após a emergência e os parâmetros avaliados foram: condutância estomática, potencial de água e teor relativo de água nas folhas mais novas totalmente expandidas, com determinações diárias entre as onze e treze horas, até que o potencial de água no solo atingisse valores em torno de -1,5 MPa. Da análise geral dos dados obtidos, pode-se inferir que a variação no status de água na folha observado através do potencial e do teor relativo de água nas folhas pode ser utilizado para indicar o momento de irrigar; ainda estas medições podem ser indicativas das plantas ou cultivares de sorgo que se mostram mais tolerantes à seca e que o mecanismo de adaptação é o “avoidance”. UNITERMOS: Condutividade estomática, potencial de água na folha, teor relativo de água na folha, tolerância à seca. PORTO, C. A . L.., KLAR, A. E. , VASCONCELLOS, V. J. Water deficit on physiological parameters of soybean leaves (Sorghum bicolor L). 2 ABSTRACT A study was carried out at Agricultural Engineering Department, UNESP, Botucatu - SP, with a sorghum crop (Sorghum bicolor, L.) in order to physiologically evaluate the crop response to drought. A completely random design with twelve replications were used. Pots with 8 kg of a medium texture soil (dry weight basis) were used in order to test the influence of the two treatments: a) plants being submitted to a water stress, where irrigation were done when the water potential in the soil (s) were -1,5 MPa, raising it to about -0,01 MPa, and b) plants being always irrigated by capillary. The parameters evaluated were water vapor stomata conductivity, water potential and relative water content in the leaves. All plants were irrigated at 55 days after emergency, with daily determinations from eleven AM to thirteen PM, until soil water potential reaches around -1,5MPa. From the general data analysis, it can be inferred that there was a significant variation in the water status in the leaves by determinations of water potential and relative water content in the leaves, indicating that the method may be used to indicate the moment of irrigation and the plants and cultivars more tolerant to drought. Sorghum plants showed adaptation to water stress under avoidance mechanism. KEYWORDS: Stomata conductivity, water potential in the leaves, relative water content, drought tolerance.

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Effect of drought stress on water relation traits of four soybean genotypes

SAARC Journal of Agriculture ◽

10.3329/sja.v15i2.35146 ◽

2018 ◽

Vol 15 (2) ◽

pp. 163-175 ◽

Cited By ~ 1

Author(s):

JA Chowdhury ◽

MA Karim ◽

QA Khaliq ◽

AU Ahmed ◽

ATM MI Mondol

Keyword(s):

Water Potential ◽

Water Content ◽

Leaf Water Potential ◽

Relative Water Content ◽

Leaf Temperature ◽

Leaf Water ◽

Water Retention Capacity ◽

Retention Capacity ◽

Relative Water ◽

Exudation Rate

An experiment was conducted in a venyl house at the environmental stress site of Bangabandhu Sheikh Mujibur Rahman Agricultural University during September to December 2012 to know the internal water status under drought stress in soybean genotypes, viz. Shohag, BARI Soybean-6, BD2331 (relatively stress tolerant) and BGM2026 (susceptible). Drought (water) stress reduced the leaf water potential in all the genotypes though was more negative in tolerant genotypes than in susceptible ones. The lowest leaf water potential was obtained from BARI Soybean-6 (-1.58 MPa) and the highest in BGM2026 (-1.2 MPa). Relative water content (RWC) decreased remarkably in all the genotypes and reduction was more in susceptible than tolerant genotypes. At 8.00 am, RWC of stressed plants decreased by 9.58, 9.02, 8.90 and 13.90% in the genotype Shohag,, BARI Soybean-6, BD2331 and BGM2026 at vegetative stage, respectively. Drought stress decreased the exudation rate in all the genotypes of soybean and it was 24, 27, 22 and 12 mg h-1 in the genotype Shohag, BARI Soybean-6, BD2331 and BGM2026 at vegetative stage, respectively. Leaf temperatures in drought stressed plant were higher than in well-watered plants. Shohag, BARI Soybean-6, BD2331 and BGM2026 showed 4.7, 4.5 5.2 and 11.07% increase in leaf temperature due to water stress. At drought stressed treatment reduction in leaf water potential, relative water content, exudation rate and water retention capacity were noticed at the three growth stages in all the genotypes with a concurrent increase in leaf temperature. Genotypes BARI Soybean-6, Shohag and BD2331 showed considerably less reduction in relative water content, exudation rate and water retention capacity, high reduction in leaf water potential and less increase in leaf temperature during drought were considered as drought tolerant. However genotype BGM2026 showed considerably high reduction in relative water content, exudation rate and water retention capacity, low reduction in leaf water potential and high increase in leaf temperature was considered as drought susceptible.SAARC J. Agri., 15(2): 163-175 (2017)

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Genetic Analysis of Yield and Physiological Traits in Sunflower (Helianthus annuus L.) under Irrigation and Drought Stress

Notulae Scientia Biologicae ◽

10.15835/nsb629173 ◽

2014 ◽

Vol 6 (2) ◽

pp. 207-213

Author(s):

Azam POURMOHAMMAD ◽

Mahmoud TOORCHI ◽

Seyed S. ALAVIKIA ◽

Mohammad R SHAKIBA

Keyword(s):

Water Stress ◽

Water Potential ◽

Water Content ◽

Leaf Water Potential ◽

Relative Water Content ◽

Proline Content ◽

Leaf Water ◽

Additive Effects ◽

Relative Water ◽

Chlorophyll Index

Implementing appropriate breeding strategies for sunflower, alongside dependable information on heritability and gene effects upon yield and related traits under drought conditions, are all necessary. Thirty sunflower hybrids were produced by line × tester cross of six male-sterile and five restorer lines. Their hybrids were evaluated in three levels of irrigation, as follows: (1) non-stressed plots, irrigated at regular intervals (W1); (2) mild water stress (W2), irrigated from the beginning of the button stage (R4) to seed filling initiation (R6); (3) severe water stress (W3) started from the beginning of button stage (R4) to physiological maturity. Based on observations and specific methods for determination, canopy temperatures, chlorophyll index, relative water content and proline content, were studied by additive effects, under the different irrigation conditions. Canopy temperatures,chlorophyll index, relative water content, leaf water potential, proline content and yield were controlled by additive effects under mild stressed conditions. Under severe stress conditions however, canopy temperatures, leaf water potential and proline content were controlled by additive effects, while chlorophyll index and relative water content were controlled by both additive and dominant effects, as seed yield was mainly influenced by the dominant effects. The narrow sense heritability ranged from 47-97% for all traits, except for chlorophyll fluorescence. Yield correlated positively with chlorophyll index and relative water content, and negatively with canopy temperature and leaf water potential. Therefore, under drought stressed conditions in breeding programs, canopy temperatures, chlorophyll index and relative water content can be reliable criteria for the selection of tolerant genotypes with prospect to higher yields.

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Leaf Water Potential, Relative Water Content, and Diffusive Resistance as Screening Techniques for Drought Resistance in Barley

Agronomy Journal ◽

10.2134/agronj1989.00021962008100010018x ◽

1989 ◽

Vol 81 (1) ◽

pp. 100-105 ◽

Cited By ~ 74

Author(s):

M. A. Matin ◽

Jarvis H. Brown ◽

Hayden Ferguson

Keyword(s):

Water Potential ◽

Water Content ◽

Leaf Water Potential ◽

Drought Resistance ◽

Relative Water Content ◽

Leaf Water ◽

Screening Techniques ◽

Diffusive Resistance ◽

Relative Water

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PARÂMETROS FISIOLÓGICOS DE CULTIVARES DE CEVADA SOB DÉFICITS HÍDRICOS

Irriga ◽

10.15809/irriga.2008v13n4p438-448 ◽

2008 ◽

Vol 13 (4) ◽

pp. 438-448 ◽

Cited By ~ 1

Author(s):

Alexandre Barreto Almeida dos Santos ◽

Antonio Evaldo Klar ◽

Cleber Júnior Jadoski

Keyword(s):

Water Vapor ◽

Water Stress ◽

Water Potential ◽

Water Content ◽

Leaf Water Potential ◽

Relative Water Content ◽

Leaf Water ◽

Barley Cultivars ◽

Leaf Resistance ◽

Relative Water

PARÂMETROS FISIOLÓGICOS DE CULTIVARES DE CEVADA SOB DÉFICITS HÍDRICOS Alexandre Barreto Almeida dos Santos; Antonio Evaldo Klar; Cleber Junior JadoskiDepartamento de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP, [email protected] 1 RESUMO O objetivo deste trabalho foi estudar parâmetros fisiológicos em seis cultivares de cevada (Borema, Lagoa, BRS – 180, BRS – 195, BRS – 225 e EMB – 128), por meio da imposição de ciclos de seca em diferentes estágios fenológicos da cultura. Os tratamentos utilizados foram: T1 - vasos irrigados constantemente até o final do ciclo da cultura; T2 - ciclo de seca iniciado aos 45 dias após a semeadura (DAS) e T3 - ciclo de seca iniciado aos 65 DAS. Avaliaram-se a resistência difusiva ao vapor de água (Rs), teor relativo de água (TRA) e potencial de água na folha (Ψf). Utilizou-se o delineamento em blocos casualizados: quatro blocos, seis cultivares de cevada e três tratamentos, totalizando setenta e duas unidades experimentais. O experimento foi conduzido durante os meses de agosto a novembro de 2005, em estufa plástica localizada na área experimental do Departamento de Engenharia Rural - Faculdade de Ciências Agronômicas de Botucatu – UNESP. Os dados analisados permitiram concluir que todas as cultivares de cevada apresentaram adaptação ao déficit hídrico, porém a cultivar EMB – 128 foi a que apresentou maior tendência à tolerância à seca e a BRS180 amenor. Os resultados mostraram que apenas um ciclo de seca pode aumentar a tolerância à seca. UNITERMOS: resistência difusiva ao vapor de água, teor relativo de água e potencial de água na folha. SANTOS, A. B. A.; KLAR, A. E.; JADOSKI, C. J. PHYSIOLOGICAL PARAMETERS IN BARLEY CULTIVARS UNDER WATER STRESS 2 ABSTRACT The objective of this study was to evaluate some physiological parameters in six barley cultivars (Borema, Lagoa, BRS-180, BRS-195, EMB-128 e BRS-225), under water stress in different crop phenological phases. The treatments were as follows: T1 - pots constantly irrigated until harvest; T2: - water stress starting from 45 days after sowing (DAS) and T3 - water stress starting from 65 DAS. Leaf resistance to water vapor diffusion (Rs), relative water content (RWC), and leaf water potential (Ψl) were used to evaluate drought tolerance. Pots were arranged in a randomized block design with four blocks, six barley cultivars, and three treatments, in a total of seventy two pots. The experiment was conducted from August to November2005 ina polyethylene greenhouse located at the experimental area of Rural Engineering Department – FCA, UNESP – Botucatu - SP. The results showed that all barley cultivars presented some adaptation to water stress, but EMB-128 was the most likely and BRS-180 the least likely to be drought tolerant. The results revealed that only one drought cycle may increase tolerance to drought. KEY WORDS: Leaf resistance to water vapor diffusion, relative water content, and leaf water potential.

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Physiological and morphological traits associated with germinative and reproductive stage of garden orache (A. hortensis L. var. rubra) under water stress

Chemical and Biological Technologies in Agriculture ◽

10.1186/s40538-021-00218-7 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

S. Sai Kachout ◽

S. BenYoussef ◽

A. Ennajah ◽

S. Abidi ◽

A. Zoghlami

Keyword(s):

Water Stress ◽

Water Potential ◽

Water Content ◽

Water Deficit ◽

Relative Water Content ◽

Water Regime ◽

Physiological Parameters ◽

Reproductive Stage ◽

Relative Water ◽

Number Of Branches

Abstract Background Drought is a major problem limiting the growth and development of plants in the world and especially in Tunisia. Halophytes constitute a renewable wealth and they offer great flexibility with regard to abiotic stresses, and they are evaluated for their ecological and potential food use. Results The proposed work identifies the response of Atriplex hortensis var. rubra to the germinal stage and the reproductive stage under a deficient water regime to measure the drought resistance of this plant that has very interesting forage production abilities. The morphological and water parameters are used to characterize the physiological response of this species to the effects of water deficit. For the germination test, four levels of osmotic potential caused by PEG-6000 solutions at different levels of water potential (− 0.1, − 0.5, − 1.0, − 1.5 MPa) were adopted in seed of A. hortensis germination media. The methodology adopted in the second experiment is based on the cultivation of potted plants stored in a semi-controlled greenhouse at flowering stage. The water deficit was imposed on the plants by watering stop for a week, and the control plants are subjected to a water regime maintained irrigated at 100% of the capacity in the field. Drought tolerance was scored 30 days after the drought stress commenced based on the number of branches and leaf, dry biomass, relative water content, leaf water potential, and nitrogen content. No significant difference was observed in germination rates for all PEG concentrations throughout the experiment which are still close to 60%. The results obtained for the second experiment show a high tolerance of A. hortensis under water stress. Drought induced decreases in two physiological parameters, the number of branches and leafs, and the relative water content of annual Atriplex. Heatmap and PCA data revealed that physiological parameters are more sensitive than morphological parameters in distinguishing the control and drought treatments. Conclusions Indeed, the orache is distinguished by a great ability to retain water potential after a month of stress. Thus, height, number of branches, leaf and shoot dry weight, and percentage of nitrogen were significantly similar for controls and stressed for A. hortensis. On the other hand, measured root length and basic and midday water potential show significant variability between controls and stressors. In addition, these results highlight the importance of the resistance of Atriplex halophyte forage to drought.

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

Italian Journal of Agronomy ◽

10.4081/ija.2015.673 ◽

2015 ◽

Vol 10 (4) ◽

pp. 208 ◽

Cited By ~ 2

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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