The response of different almond genotypes to moderate and severe water stress in order to screen for drought tolerance

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.

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ROOT CHARACTERISTICS IN COWPEA RELATED TO DROUGHT TOLERANCE AT THE SEEDLING STAGE

Experimental Agriculture ◽

10.1017/s0014479703001108 ◽

2003 ◽

Vol 39 (1) ◽

pp. 29-38 ◽

Cited By ~ 66

Author(s):

T. MATSUI ◽

B. B. SINGH

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Leaf Area ◽

Dry Matter ◽

Stress Conditions ◽

Root Characteristics ◽

Severe Water Stress ◽

Cowpea Varieties ◽

Root Box ◽

Mild Water Stress

Cowpea (Vigna unguiculata) has relatively higher drought tolerance than other legume crops. It is widely grown in semi-arid regions, particularly in West Africa. One objective of the present study was to determine the effects of soil moisture stress on the length, dry matter and distribution of the roots of two cowpea varieties with different drought tolerances. Another objective was to evaluate the pin-board root-box as a method for identifying the role of root characteristics in drought tolerance. Two cowpea varieties, IT96D-604 (drought tolerant) and TVu7778 (drought susceptible), were used in this study. There were three watering treatments, T1 (well-watered), T2 (mild water stress) and T3 (severe water stress). Between varieties, there were no significant differences in shoot and root characteristics except for leaf area in T1. Under T2, the shoot:root ratio (S:R ratio) of IT96D-604 was significantly decreased compared with that under T1 as a result of the increase in root dry matter and decrease in leaf area without significant differences in total dry matter. In addition, the root dry matter per leaf area, which indicates the capacity to absorb water, of IT96D-604 was significantly higher than that of TVu7778. Under T3, the total dry matter of TVu7778 was about one third of those of the other treatments for the same variety, whereas that of IT96D-604 was more than half. Regarding root distribution, the centres of root dry matter and root length density of both varieties moved downwards significantly under water-stress conditions compared with those of the well-watered condition. This tendency was more pronounced in IT96D-604 than in TVu7778. Drought tolerance in IT96D-604 was associated with the increase in root dry matter per leaf area under mild water-stress conditions, and downward movement of roots (increasing access and use of soil moisture in deep soil layers) under mild and severe water stress conditions. In addition, the root-box method was versatile and can be used for studying root responses to edaphic factors relevant to root growth.

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Evaluation of Drought Tolerance of Five Maize Genotypes by Virtue of Physiological and Molecular Responses

Agronomy ◽

10.3390/agronomy12010059 ◽

2021 ◽

Vol 12 (1) ◽

pp. 59

Author(s):

Khalil M. Saad-Allah ◽

Afaf A. Nessem ◽

Mohsen K. H. Ebrahim ◽

Dina Gad

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Expression Patterns ◽

Soluble Sugars ◽

Transcriptional Level ◽

Maize Production ◽

Maize Genotypes ◽

Severe Water Stress ◽

Metabolic Activities ◽

Primary Focus

Drought has been recognized as a potential challenge to maize production around the world, particularly in arid and semi-arid regions. The primary focus of the present study was to investigate the metabolic and physiological adjustment mechanisms as well as drought-responsive gene expression patterns in five maize (Zea mays L.) genotypes (G314, G2, G10, G123, and G326) with varying drought-tolerance capacities at the vegetative stage. Twenty-one days-old maize plants from five maize genotypes were submitted to a well-watered (10 days) watering interval as a control, mild water stress (15 day interval), and severe water stress (20 day interval) treatments in a field experiment for two successive seasons (2019 and 2020). For all maize genotypes, the results showed that water stress significantly reduced plant height, leaf area, biomass, and yield characteristics. However, water stress, which was associated with the length of the watering interval, increased the concentrations of glycine betaine, amino acids, proline, phenols, flavonoids, soluble proteins, and soluble sugars, as well as catalase and peroxidase activities. On the transcriptional level, prolonged water stress increased the expression of drought-responsive genes (LOS5, Rad17, NCED1, CAT1, and ZmP5CS1), with G10 and G123 genotypes being the most drought-resistant. Herein, genotypes G10 and G123 were shown in this study to be relatively water stress tolerant due to improved osmoregulatory, antioxidant, and metabolic activities under water stress conditions, as well as the fact that they were endowed with stress-responsive genes.

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Sensitivity to water stress drives differential decline and mortality dynamics of three co-occurring conifers with different drought tolerance

Forest Ecology and Management ◽

10.1016/j.foreco.2021.118964 ◽

2021 ◽

Vol 486 ◽

pp. 118964

Author(s):

Macarena Férriz ◽

Dario Martin-Benito ◽

Isabel Cañellas ◽

Guillermo Gea-Izquierdo

Keyword(s):

Water Stress ◽

Drought Tolerance

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Physiological and Yield Responses of Green-Shelled Beans (Phaseolus vulgaris L.) Grown under Restricted Irrigation

Agronomy ◽

10.3390/agronomy11030562 ◽

2021 ◽

Vol 11 (3) ◽

pp. 562

Author(s):

Karen Campos ◽

Andrés R. Schwember ◽

Daniel Machado ◽

Mónica Ozores-Hampton ◽

Pilar M. Gil

Keyword(s):

Water Stress ◽

Deficit Irrigation ◽

Pot Experiment ◽

Water Restriction ◽

One Pot ◽

Dry Land ◽

Severe Water Stress ◽

The Face ◽

Use Efficiency ◽

Yield Responses

Common bean is an important crop, consumed as green-shelled bean in several countries. In Chile, green-shelled beans are cultivated often as a dry land crop, vulnerable to drought. The objective of this study was to characterize the hydric and productive responses of four green-shelled bean genotypes subjected to deficit irrigation in order to outline production strategies in the face of increasing water scarcity. Two experiments were evaluated: one pot experiment with three irrigation treatments, supplying 100% of the crop evapotranspiration (ETc) (T100), 50% (T50), and 30% (T30); and an open field experiment with two treatments: 100% (I100) and 40% of ETc (I40). Treatments were applied during reproductive stage in determinate cultivars and vegetative stage in indeterminate plants. Severe water restriction (T30 and I40) in both experiments showed a significant decrease in stomatal conductances, as well as biomass and number of grains per pod; I40 treatment also showed a reduction in chlorophyll fluorescence. Water use efficiency (WUE) was higher under water stress in field (I40), but lower on the T30 treatment from the pot experiment. Determinate cultivars showed 22.7% higher of 100-seed weight compared to indeterminate type, and, thus, higher tolerance to drought. Our results indicate that severe water stress is highly harmful in terms of yield, and a moderate controlled deficit irrigation plus the use of determinate genotypes may be a strategy for producing green-shelled bean successfully under a drought scenario.

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Genetic Diversity of Selected Rice Genotypes under Water Stress Conditions

Plants ◽

10.3390/plants10010027 ◽

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.

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Improving potato drought tolerance through the induction of long-term water stress memory

Plant Science ◽

10.1016/j.plantsci.2015.05.016 ◽

2015 ◽

Vol 238 ◽

pp. 26-32 ◽

Cited By ~ 30

Author(s):

D.A. Ramírez ◽

J.L. Rolando ◽

W. Yactayo ◽

P. Monneveux ◽

V. Mares ◽

...

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Stress Memory

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Change of Ascorbic Acid Level after Grafting of Tomato Seedlings

Zeitschrift für Naturforschung C ◽

10.1515/znc-1999-9-1032 ◽

1999 ◽

Vol 54 (9-10) ◽

pp. 830-833 ◽

Cited By ~ 9

Author(s):

Akira Wadano ◽

Mitsuharu Azeta ◽

Shin-ichi Itotani ◽

Ai Kanda ◽

Toshio Iwaki ◽

...

Keyword(s):

Ascorbic Acid ◽

Water Stress ◽

Ascorbate Peroxidase ◽

Phosphate Buffer ◽

Acid Level ◽

Active Oxygen ◽

Ascorbic Acid Level ◽

Electrochemical Detector ◽

Tomato Seedlings ◽

Severe Water Stress

Grafting is an easy way to produce a new seedling, which can tolerate against various stresses. During the acclimation after grafting, however, the seedlings still suffer a severe water stress. It is well known that water stress produces active oxygen to oxidize ascorbic acid. The concentration of ascorbic acid in the leaves was analyzed by HPLC equipped with an electrochemical detector. The column used was SP-120-5-ODS-BP (DAISO, JAPAN) and elution was performed with 0.1 ᴍ phosphate buffer, pH 3.0. After grafting the seedlings were acclimated under a 6-hr light/dark regimen. The content of ascorbic acid increased gradually during 2 days compared with control. The ascorbate peroxidase showed about constant activity, so the increase of ascorbic acid may be due to its requirement to cure the grafting

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RESPONSE OF PEAS TO ENVIRONMENT: IV. EFFECT OF FIVE SOIL WATER REGIMES ON GROWTH AND DEVELOPMENT OF PEAS

Canadian Journal of Plant Science ◽

10.4141/cjps68-025 ◽

1968 ◽

Vol 48 (2) ◽

pp. 129-137 ◽

Cited By ~ 14

Author(s):

A. R. Maurer ◽

H. F. Fletcher ◽

D. P. Ormrod

Keyword(s):

Water Stress ◽

Soil Water ◽

Growth And Development ◽

Dry Matter ◽

Fresh Weight ◽

Water Regimes ◽

Severe Water Stress ◽

Water Conditions ◽

Before And After ◽

Soil Water Conditions

Pea plants growing in "weighing lysimeters" were subjected to five soil-water regimes to determine their response to varying conditions of soil water imposed at different stages of development. Plants subjected to a minimal water stress developed luxuriantly and continued to grow up to the harvest period. Pea yield and plant height were not reduced, but fresh weight and dry matter were less if irrigation was applied when soil water fell to 60% rather than 88% of that available. A severe water stress after blossom reduced pea yield, irrespective of soil-water conditions prior to blossom. Plants which had been given ample soil water before blossom wilted visibly when a severe stress was imposed in the post-blossom period, yet wilting did not occur in plants subjected to severe water stress both before and after blossom. Severe water stress prior to blossom did not cause a decrease in pea yield if ample soil moisture was made available after blossom.

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Single hyperspectral bands are highly sensitive to water stress in adult mandarin trees

10.5194/egusphere-egu21-12594 ◽

2021 ◽

Author(s):

Pablo Berríos ◽

Abdelmalek Temnani ◽

Susana Zapata ◽

Manuel Forcén ◽

Sandra Martínez-Pedreño ◽

...

Keyword(s):

Water Stress ◽

Water Deficit ◽

Phase Ii ◽

Irrigation Water ◽

Water Status ◽

Irrigation Scheduling ◽

Plant Water Status ◽

Phase Iii ◽

Plant Water ◽

Severe Water Stress

Mandarin is one of the most important Citrus cultivated in Spain and the sustainability of the crop is subject to a constant pressure for water resources among the productive sectors and to a high climatic demand conditions and low rainfall (about 250 mm per year). The availability of irrigation water in the Murcia Region is generally close to 3,500 m3 per ha and year, so it is only possible to satisfy 50 - 60% of the late mandarin ETc, which requires about 5,500 m3 per ha. For this reason, it is necessary to provide tools to farmers in order to control the water applied in each phenological phase without promoting levels of severe water stress to the crop that negatively affect the sustainability of farms located in semi-arid conditions. Stem water potential (SWP) is a plant water status indicator very sensitive to water deficit, although its measurement is manual, discontinuous and on a small-scale. &#160;In this way, indicators measured on a larger scale are necessary to achieve integrating the water status of the crop throughout the farm. Thus, the aim of this study was to determine the sensitivity to water deficit of different hyperspectral single bands (HSB) and their relationship with the midday SWP in mandarin trees submitted to severe water stress in different phenological phases. Four different irrigation treatments were assessed: i) a control (CTL), irrigated at 100% of the ETc throughout the growing season to satisfy plant water requirements and three water stress treatments that were irrigated at 60% of ETc throughout the season &#8211; corresponding to the real irrigation water availability &#8211; except &#160;during: ii) the end of phase I and beginning of phase II (IS IIa), iii) the first half of phase II (IS IIb) and iv) phase III of fruit growth (IS III), which irrigation was withheld until values of -1.8 MPa of SWP or a water stress integral of 60 MPa day-1. When these threshold values were reached, the spectral reflectance values were measured between 350 and 2500 nm using a leaf level spectroradiometer to 20 mature and sunny leaves on 4 trees per treatment. Twenty-four HVI and HSB were calculated and a linear correlation was made between each of them with SWP, where the &#961;940 and &#961;1250 nm single bands reflectance presented r-Pearson values of -0.78** and -0.83***, respectively. Two linear regression curves fitting were made: SWP (MPa) = -11.05 &#8729; &#961;940 + 7.8014 (R2 =0.61) and SWP (MPa) = -13.043 &#8729; &#961;1250 + 8.9757 (R2 =0.69). These relationships were obtained with three different fruit diameters (35, 50 and 65 mm) and in a range between -0.7 and -1.6 MPa of SWP. Results obtained show the possibility of using these single bands in the detection of water stress in adult mandarin trees, and thus propose a sustainable and efficient irrigation scheduling by means of unmanned aerial vehicles equipped with sensors to carry out an automated control of the plant water status and with a suitable temporal and spatial scale to apply precision irrigation.

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