scholarly journals (452) Growth Responses of Salvia greggii and Dalea frutescens to Drought Stress

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1036A-1036
Author(s):  
Genhua Niu ◽  
Denise S. Rodriguez
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Water Potential ◽  
Water Content ◽  
Water Status ◽  
Irrigation Management ◽  
Growth Responses ◽  
Shoot Number ◽  
Dry Down

Salvia greggii (salvia) and Dalea frutescens (dalea) are two popular shrubs. However, little information is available on their drought tolerance. The objectives of this study were to investigate the effect of various degrees of water stress on growth and to characterize the dynamics of water relations to root substrate water content for developing best irrigation management. Salvia and dalea plants in 12-L plastic containers were grown in a greenhouse and pruned to one node at the base of the soft shoots for salvia or at the same height for dalea prior to the start of the experiment. There were three irrigation regimens: plants were irrigated daily (control), or irrigation was withheld until moderate or severe water stress signs exhibited. After several weeks of intermittent cyclic dry-down irrigation regimens, total shoot number per container was reduced by 40% to 50% for salvia and 35% to 40% for dalea. Average shoot length was reduced by 35% to 45% for salvia and 50% to 65% for dalea in moderate and severe stressed treatments compared to the control. Drought stress resulted in less shoot elongation and fewer new shoots in both species. To examine the relationship between plant water status and substrate water content, a dry down test was performed on five well-watered plants by withholding irrigation until midday water potential dropped to below –4 MPa. As substrate water contents in both species reached 8%, the predawn water potentials did not recover from the midday water potential of the previous day, indicating there was no available water in the substrate for roots to take up. The drought tolerance of these two species needs further study using various growing media.

scholarly journals DEHYDRIN PROFILES OF SOME IRANIAN MELON VARIETIES (Cucumis melo L. Merr) UNDER DROUGHT STRE SS CONDITIONS

2019 ◽  
Vol 18 (6) ◽  
pp. 75-84
Author(s):  
Alireza Motallebi-Azar ◽  
István Papp ◽  
Anita Szegő
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Content ◽  
Water Status ◽  
Field Capacity ◽  
Total Protein Content ◽  
Severe Drought ◽  
Molecular Weights ◽  
Potential Marker ◽  
Relative Water

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.

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

Irriga ◽  
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.

scholarly journals 276 Effects of Water Stress on Super Oxide Dismutase (SOD) and Water Content of Tomato Cultivars at Different Plant Ages

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 490A-490
Author(s):  
S.M. Lutfor Rahman ◽  
Eiji Nawata ◽  
Tetsuo Sakuratani
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Water Potential ◽  
Water Content ◽  
Leaf Water Potential ◽  
Control Level ◽  
Leaf Water ◽  
Stress Treatment ◽  
Relative Water ◽  
Tomato Cultivars

Effects of water stress at different plant ages on SOD activities were studied in two tomato cultivars. Water stress treatment decreased the leaf water potential in all stages, but reduction of leaf water potential was more rapid and pronounced in KF than TM at all DSLs (days of seedlings). After withdrawal of water stress treatment, stressed plants of TM increased leaf water potential to the values of control level in all DSLs, but in KF, leaf water potential of stressed plants were much lower than that of control plants. Effects of water stress on relative water content (RWC) of leaves at 20 DSL showed a similar tendency to that on leaf water potential. The SOD activities in both cultivars showed significant increase by water stress treatment at all DSLs, but the increase of SOD by water stress was larger in TM than in KF. This tendency was observed at all DSLs. The results may indicate that SOD activities play an important role in drought tolerance of tomato at various plant ages and suggest a possible use of SOD activities as a criterion for tomato drought tolerance.

scholarly journals EXTRACTS FROM ASH ROOTS AND VELVETLEAF AFFECT WATER STATUS OF SOUR ORANGE SEEDLINGS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 579b-579
Author(s):  
John E. Fucik ◽  
Dariusz Swietlik
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Water Absorption ◽  
Water Potential ◽  
Plant Material ◽  
Water Status ◽  
Culture Solution ◽  
Sour Orange ◽  
Growth Responses ◽  
Water Culture

Water extracts of cocklebur,CBX (Xanthium spinosa L.) and velvetleaf,VLX (Abutilon theophrasti Medic.) shoots and Mexican ash,AshX (Fraxinus Berlandieriana A.DC.) roots were added to 9 month-old sour orange Citrus aurantium L.) seedlings(SOs) in water culture. Final extract concentrations represented either 50 or 12.5 g. of plant material liter-1 of culture solution, i.e. 1/20 or 1/80 dilutions. Leaf water potential(ψ); stomatal conductance(gs);transpiration(T) and growth responses were measured for 13 days. After 1 day, SOs in AshX and CBX had lower ψ than controls. After 11 days SOs in CBX had higher ψ than the others. ψ responded similarly to both extract concs.. Thru day 5, AshX decreased gs vs. the controls and VLX. By day 11, gs of SOs in AshX was less than for VLX but not the others. On days 1 and 5, gs for VLX at 1/20 was lower than controls but at 1/80, gs's were the highest of all treatments. These results supported by the T rates, growth responses and others findings suggest AshX and VLX induce water stress by reducing water absorption and/or transport in addition to possibly disrupting normal root/shoot communications

Development of a diurnal dehydration index for spring barley phenotyping

2014 ◽  
Vol 41 (12) ◽  
pp. 1249 ◽  
Author(s):  
Pablo Rischbeck ◽  
Peter Baresel ◽  
Salah Elsayed ◽  
Bodo Mistele ◽  
Urs Schmidhalter
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Content ◽  
Water Status ◽  
Spring Barley ◽  
Leaf Water ◽  
Leaf Angle ◽  
Leaf Water Content ◽  
Diurnal Changes ◽  
Angle Distribution

Spectral and thermal assessments may enable the precise, high-throughput and low-cost characterisation of traits linked to drought tolerance. However, spectral and thermal measurements of the canopy water status are influenced by the crops’ soil coverage, the size of the biomass and other properties such as the leaf angle distribution. The aim of this study was to develop a referenced spectral method that would be minimally influenced by potentially perturbing factors for retrieving the water status of differing cultivars. Sixteen spring barley cultivars were grown in field trials under imposed drought stress, natural drought stress and irrigated conditions. The relative leaf water content of barley plants declines diurnally from pre-dawn until the afternoon, and other plant traits such as the biomass change little throughout the day. As an indicator of the current drought stress, pre-dawn and afternoon values of the relative leaf water content were assessed spectrally. Diurnal changes in reflectance are only slightly influenced by other perturbing factors. A new spectral index (diurnal dehydration index) was developed by using the wavelengths 730 and 457 nm collected from an active spectrometer. This index allowed the differentiation of the drought tolerance of barley plants. The diurnal dehydration index was significantly related to final biomass, grain yield and harvest index and significantly different between cultivars. Compared with other indices, the diurnal dehydration index offered a higher stability in retrieving the water status of barley plants. Due to its diurnal assessment, the index was barely influenced by the differences in cultivars biomass at the time of measurement. It may represent a valuable tool for assessing the water status or drought tolerance in breeding nurseries.

scholarly journals Genetic Diversity of Selected Rice Genotypes under Water Stress Conditions

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Mahmoud M. Gaballah ◽  
Azza M. Metwally ◽  
Milan Skalicky ◽  
Mohamed M. Hassan ◽  
Marian Brestic ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Water Stress ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Ssr Markers ◽  
Similarity Index ◽  
Stress Conditions ◽  
Yield Potential ◽  
Drought Tolerant ◽  
Rice Genotypes

Drought is the most challenging abiotic stress for rice production in the world. Thus, developing new rice genotype tolerance to water scarcity is one of the best strategies to achieve and maximize high yield potential with water savings. The study aims to characterize 16 rice genotypes for grain and agronomic parameters under normal and drought stress conditions, and genetic differentiation, by determining specific DNA markers related to drought tolerance using Simple Sequence Repeats (SSR) markers and grouping cultivars, establishing their genetic relationship for different traits. The experiment was conducted under irrigated (normal) and water stress conditions. Mean squares due to genotype × environment interactions were highly significant for major traits. For the number of panicles/plants, the genotypes Giza179, IET1444, Hybrid1, and Hybrid2 showed the maximum mean values. The required sterility percentage values were produced by genotypes IET1444, Giza178, Hybrid2, and Giza179, while, Sakha101, Giza179, Hybrid1, and Hybrid2 achieved the highest values of grain yield/plant. The genotypes Giza178, Giza179, Hybrid1, and Hybrid2, produced maximum values for water use efficiency. The effective number of alleles per locus ranged from 1.20 alleles to 3.0 alleles with an average of 1.28 alleles, and the He values for all SSR markers used varied from 0.94 to 1.00 with an average of 0.98. The polymorphic information content (PIC) values for the SSR were varied from 0.83 to 0.99, with an average of 0.95 along with a highly significant correlation between PIC values and the number of amplified alleles detected per locus. The highest similarity coefficient between Giza181 and Giza182 (Indica type) was observed and are susceptible to drought stress. High similarity percentage between the genotypes (japonica type; Sakha104 with Sakha102 and Sakha106 (0.45), Sakha101 with Sakha102 and Sakha106 (0.40), Sakha105 with Hybrid1 (0.40), Hybrid1 with Giza178 (0.40) and GZ1368-S-5-4 with Giza181 (0.40)) was also observed, which are also susceptible to drought stress. All genotypes are grouped into two major clusters in the dendrogram at 66% similarity based on Jaccard’s similarity index. The first cluster (A) was divided into two minor groups A1 and A2, in which A1 had two groups A1-1 and A1-2, containing drought-tolerant genotypes like IET1444, GZ1386-S-5-4 and Hybrid1. On the other hand, the A1-2 cluster divided into A1-2-1 containing Hybrid2 genotype and A1-2-2 containing Giza179 and Giza178 at coefficient 0.91, showing moderate tolerance to drought stress. The genotypes GZ1368-S-5-4, IET1444, Giza 178, and Giza179, could be included as appropriate materials for developing a drought-tolerant variety breeding program. Genetic diversity to grow new rice cultivars that combine drought tolerance with high grain yields is essential to maintaining food security.

Estimation water status of the vineyard by calculating multispectral index from satellite images

2021 ◽  
Author(s):  
Marta Rodríguez-Fernández ◽  
María Fandiño ◽  
Xesús Pablo González ◽  
Javier J. Cancela
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Spectral Index ◽  
Satellite Images ◽  
Irrigation System ◽  
Water Status ◽  
Stress Index ◽  
Stem Water Potential ◽  
Stem Water ◽  
Water Potential Measurements

<p>The estimation of the water status in the vineyard, is a very important factor, in which every day the winegrowers show more interest since it directly affects the quality and production in the vineyards. The situation generated by COVID-19 in viticulture, adds importance to tools that provide information of the hydric status of vineyard plants in a telematic way.</p><p>In the present study, the stem water potential in the 2018 and 2019 seasons, is analysed in a vineyard belonging to the Rias Baixas wine-growing area (Vilagarcia de Arousa, Spain), with 32 sampling points distributed throughout the plot, which allows the contrast and validation with the remote sensing methodology to estimate the water status of the vineyard using satellite images.</p><p>The satellite images have been downloaded from the Sentinel-2 satellite, on the closets available dates regarding the stem water potential measurements, carried out in the months of June to September, because this dates are considered the months in which vine plants have higher water requirements.</p><p>With satellite images, two spectral index related to the detection of water stress have been calculated: NDWI (Normalized Difference Water Index) and MSI (Moisture Stress Index). Stem water potential measurements, have allowed a linear regression with both index, to validate the use of these multispectral index to determine water stress in the vineyard.</p><p>Determination coefficients of r<sup>2</sup>=0.62 and 0.67, have been obtained in July and August 2018 and 0.54 in June of 2019 for the NDWI index, as well as values of 0.53 and 0.63 in July 2018 and June 2019 respectively, when it has been analysed the MSI index.</p><p>Between both seasons, the difference observed, that implies slightly greater water stress in 2019, is reflected in the climate conditions during the summer months, with an average accumulated rainfall that doesn’t exceed 46 mm of water. Although, the NDWI index has allowed to establish better relationships in the 2018 season respect to the MSI index and the 2019 season, (r<sup>2</sup>=0.60 NDWI in 2018), as well as greater differences in terms of water stress presented in the vineyard.</p><p>With the spectral index calculated, it has been possible to validate the use of these index for the determination of the water stress of the vineyard plants, as an efficient, fast and less expensive method, which allows the application of an efficient irrigation system in the vineyard.</p>

Stomatal conductance and growth of five Alnusglutinosa clones in response to controlled water stress

1988 ◽  
Vol 18 (4) ◽  
pp. 421-426 ◽  
Author(s):  
T. C. Hennessey ◽  
E. M. Lorenzi ◽  
R. W. McNew
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Leaf Area ◽  
Water Status ◽  
Height Growth ◽  
Plant Water ◽  
Black Alder ◽  
Severe Water Stress ◽  
Progressive Water Stress

An experiment to quantify the response of unnodulated, fertilized European black alder (Alnusglutinosa (L.) Gaertn.) seedlings to progressive water stress showed contrasting drought tolerance among five clones, using stomatal conductance, leaf area, and height as indices of drought sensitivity. In particular, one rapidly growing clone (AG 8022-14) showed the ability to moderate changes in water stress more efficiently than the more slowly growing clones. After 30 days of moderate levels of water stress, clones that had higher stomatal conductance also had greater leaf area and height growth. Leaf area and height were both sensitive to plant water status, although no threshold of stress associated with a cessation of leaf area or height expansion was found even though stomatal conductance decreased to 0.05 cm s−1 under severe water stress.

scholarly journals Physiological Responses under Drought Stress of Improved Drought-Tolerant Rice Lines and their Parents

2018 ◽  
Vol 46 (2) ◽  
pp. 679-687 ◽  
Author(s):  
Preeyanuch LARKUNTHOD ◽  
Noppawan NOUNJAN ◽  
Jonaliza L SIANGLIW ◽  
Theerayut TOOJINDA ◽  
Jirawat SANITCHON ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Status ◽  
Physiological Responses ◽  
High Water ◽  
Recurrent Parent ◽  
Potential Candidate ◽  
Substitution Lines ◽  
Chromosome Segment Substitution Lines ◽  
Drought Tolerant

Many of the economically important rice cultivars including ‘Khao Dawk Mali 105’ (KDML105) or jasmine rice, one of the world’s famous rice exported from Thailand suffers from drought due to erratic rainfalls and limited irrigation. To improve drought tolerance and reserve genetic background of KDML105, chromosome segment substitution lines (CSSL) containing drought tolerant quantitative trait loci (DT-QTL) has been previously developed by backcrossing between KDML105 and drought tolerant donor, IR58586-F2-CA-143 (DH212). To understand the physiological responses related to drought tolerance in CSSL lines compared to parents, two CSSLs namely CSSL1-16 and CSSL1-18, respectively were used in this study. Twenty-one-d-old hydroponically grown plants were subjected to 20% PEG for 0, 7, 14 d and then recovered from stress for 3 d. The results indicated that CSSL lines especially, CSSL1-16 showed better performance under drought stress compared to their recurrent parent. Drought tolerance superior CSSL1-16 line was indicated by high water status (high relative water content and leaf water potential), good osmotic adjustment, high proline and greater membrane stability. Moreover, this line was able to resume growth after stress recovery whereas other lines/cultivar could not recover. Similarly, drought tolerant donor showed high water status suggesting that well-maintained plant water status was associated with drought tolerant trait. It could be concluded that the highest drought tolerant line was CSSL1-16 followed by DH212, CSSL1-18 and KDML105. It would be interesting to go further into introgressed section in CSSL1-16 to identify potential candidate genes in DT-QTL for breeding drought tolerant rice in the future.

De-coupling seasonal changes in water content and dry matter to predict live conifer foliar moisture content

2014 ◽  
Vol 23 (4) ◽  
pp. 480 ◽  
Author(s):  
W. Matt Jolly ◽  
Ann M. Hadlow ◽  
Kathleen Huguet
Keyword(s):  
Water Stress ◽  
Moisture Content ◽  
Water Content ◽  
Seasonal Variations ◽  
Seasonal Changes ◽  
Dry Matter ◽  
Water Mass ◽  
Water Status ◽  
Dry Mass ◽  
Dry Matter Partitioning

Live foliar moisture content (LFMC) significantly influences wildland fire behaviour. However, characterising variations in LFMC is difficult because both foliar mass and dry mass can change throughout the season. Here we quantify the seasonal changes in both plant water status and dry matter partitioning. We collected new and old foliar samples from Pinus contorta for two growing seasons and quantified their LFMC, relative water content (RWC) and dry matter chemistry. LFMC quantifies the amount of water per unit fuel dry weight whereas RWC quantifies the amount of water in the fuel relative to how much water the fuel can hold at saturation. RWC is generally a better indicator of water stress than is LFMC. We separated water mass from dry mass for each sample and we attempted to best explain the seasonal variations in each using our measured physiochemical variables. We found that RWC explained 59% of variation in foliar water mass. Additionally, foliar starch, sugar and crude fat content explained 87% of the variation in seasonal dry mass changes. These two models combined explained 85% of the seasonal variations in LFMC. These results demonstrate that changes to dry matter exert a stronger control on seasonal LFMC dynamics than actual changes in water content, and they challenge the assumption that LFMC variations are strongly related to water stress. This methodology could be applied across a range of plant functional types to better understand the factors that drive seasonal changes in LFMC and live fuel flammability.

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