Effect of pattern of water supply on Vicia faba L. 3. Plant water relations, expansive growth and stomatal reactions.

Faba beans cv. Minica, Wierboon, Kristall, Felix, Optica and Alfred grown in the field in the Netherlands were irrigated to near field capacity, or water stressed, between the onset of flowering and the end of the growing season. Leaf water potential ( psi ), osmotic potential ( pi ) and turgor (P) were linearly related to leaf relative water content (RWC) with no significant differences between cultivars. At full turgor, pi hardly differed between water supply treatments, and the slopes of pi vs. RWC were not significantly different between treatments, indicating the absence of osmotic adjustment. Water supply did not affect the slope of P vs. RWC, and it was concluded that the faba bean cultivars lacked mechanisms to keep P high during water stress. Internode growth during flowering was 2-3 times greater in the well watered than in the stressed treatment. In greenhouse studies with cv. Minica, vegetative growth decreased linearly with decreasing P. Maximum stomatal conductance in the field decreased with psi from an estimated maximum level of 1.0 s/cm (at full turgidity and light intensity >800 micro E/msuperscript 2 per s), following a negative exponential curve. It was concluded that vegetative (expansive) growth decreases faster with decreasing P or psi than the stomatal conductance (and most probably faster than the rate of photosynthesis). It is suggested that this result may help to explain the positive effect of mild water stress on reproductive growth in faba beans. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Effects of soil water depletion on the water relations in tropical kudzu

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x1999000700006 ◽

1999 ◽

Vol 34 (7) ◽

pp. 1151-1157

Author(s):

Adaucto Bellarmino de Pereira-Netto ◽

Antonio Celso Novaes de Magalhães ◽

Hilton Silveira Pinto

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Content ◽

Soil Water ◽

Cover Crop ◽

Soil Water Depletion ◽

Pueraria Phaseoloides ◽

Water Depletion ◽

Relative Water ◽

Dry Soil

Tropical kudzu (Pueraria phaseoloides (Roxb.) Benth., Leguminosae: Faboideae) is native to the humid Southeastern Asia. Tropical kudzu has potential as a cover crop in regions subjected to dryness. The objective of this paper was to evaluate the effect of soil water depletion on leaflet relative water content (RWC), stomatal conductance (g) and temperature (T L) in tropical kudzu. RWC of waterstressed plants dropped from 96 to 78%, following a reduction in SWC from 0.25 to 0.17 g (H2O).g (dry soil)-1.Stomatal conductance of stressed plants decreased from 221 to 98 mmol.m-2.s-1, following the reduction in soil water content (SWC). The day after re-irrigation, g of water stressed plants was 15% lower than g of unstressed plants. Differences in T L between waterstressed and unstressed plants (deltaT L) rose linearly from 0.1 to 2.2ºC following progressive water deficit. RWC and T L of waterstressed plants paralled RWC and T L of unstressed plants the day after reirrigation. The strong decrease in SWC found in this study only induced moderate water stress in tropical kudzu. In addition, tropical kudzu recover rapidly from the induced water stress after the re-irrigation.

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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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Differential Activity of Antioxidant Enzymes and Physiological Changes in Wheat (Triticum aestivum L.) Under Drought Stress

Notulae Scientia Biologicae ◽

10.15835/nsb11210390 ◽

2019 ◽

Vol 11 (2) ◽

pp. 266-276

Author(s):

Kamal MIRI-HESAR ◽

Ali DADKHODAIE ◽

Saideh DOROSTKAR ◽

Bahram HEIDARI

Keyword(s):

Water Stress ◽

Drought Stress ◽

Field Capacity ◽

Triticum Aestivum L ◽

Plant Production ◽

Breeding Programs ◽

Drought Tolerant ◽

Severe Water Stress ◽

Significant Difference ◽

Relative Water

Drought stress is one of the most significant environmental factors restricting plant production all over the world. In arid and semi-arid regions where drought often causes serious problems, wheat is usually grown as a major crop and faces water stress. In order to study drought tolerance of wheat, an experiment with 34 genotypes including 11 local and commercial cultivars, 17 landraces, and six genotypes from International Maize and Wheat Improvement Center (CIMMYT) was conducted at the experimental station, School of Agriculture, Shiraz University, Iran in 2010-2011 growing season. Three different irrigation regimes (100%, 75% and 50% Field Capacity) were applied and physiological and biochemical traits were measured for which a significant difference was observed in genotypes. Under severe water stress, proline content and enzymes’ activities increased while the relative water content (RWC) and chlorophyll index decreased significantly in all genotypes. Of these indices, superoxide dismutase (SOD) and RWC were able to distinguish tolerant genotypes from sensitives. Moreover, yield index (YI) was useful in detecting tolerant genotypes. The drought susceptibility index (DSI) varied from 0.40 to 1.71 in genotypes. These results indicated that drought-tolerant genotypes could be selected based on high YI, RWC and SOD and low DSI. On the whole, the genotypes 31 (30ESWYT200), 29 (30ESWYT173) and 25 (Akbari) were identified to be tolerant and could be further used in downstream breeding programs for the improvement of wheat tolerance under water limited conditions.

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683 PB 236 WATER STRESS REDUCES ASPARAGUS GROWTH

HortScience ◽

10.21273/hortsci.29.5.531d ◽

1994 ◽

Vol 29 (5) ◽

pp. 531d-531

Author(s):

Dan Drost

Keyword(s):

Soil Moisture ◽

Water Stress ◽

Root Zone ◽

Near Field ◽

Field Capacity ◽

Fresh Weight ◽

Irrigation Rate ◽

Growing Period ◽

Long Term Study ◽

Irrigation Treatments

In 1992, a long term study was initiated to determine water use of asparagus and to assess water stress effects on asparagus growth. Asparagus (Syn 4-56) crowns were planted and maintained at soil moisture levels near field capacity during the first year. In 1993, irrigation treatments based on 60, 40, and 0 percent of evapotranspiration (ET) were applied to asparagus during the fern growing period (mid-June to October). Soil moisture, shoot and root growth, and fern water potentials were measured throughout the year. Prior to the irrigation treatments, asparagus had 39 buds per plant with a shoot and root fresh weight of 573 and 270 grams, respectively. Soil moisture in the root zone (0 to 60 cm) approached the permanent wilting point in the 40%. and 0% of ET treatments by mid-August. A decrease in irrigation rate from 80 to 0% of ET had no effect on fern fresh weight at the end of the growing season. However, as irrigation rate decreased from 80 to 0% of ET, root fresh weight (586, 533, 415 grams) and bud number (78, 59, 53) decreased linearly. These results suggest yield and growth may be reduced in 1994.

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Water Stress in Dwarfing Cherry Rootstocks: Increased Carbon Partitioning to Roots Facilitates Improved Tolerance of Drought

Horticulturae ◽

10.3390/horticulturae7110424 ◽

2021 ◽

Vol 7 (11) ◽

pp. 424

Author(s):

Will Wheeler ◽

Brent Black ◽

Bruce Bugbee

Keyword(s):

Water Stress ◽

Drought Stress ◽

Root Zone ◽

Water Status ◽

Field Capacity ◽

Carbon Partitioning ◽

Leaf Level ◽

Rate Of Photosynthesis ◽

Cherry Rootstocks ◽

Daily Transpiration

Cherry orchards are transitioning to high-density plantings and dwarfing rootstocks to maximize production, but the response of these rootstocks to drought stress is poorly characterized. We used a 16-container, automated lysimeter system to apply repeated water stress to ungrafted Krymsk® 5 and 6 rootstocks during two growing cycles. Drought stress was imposed by withholding irrigation until the daily transpiration rate of each tree was 25% and 30% of the unstressed rate during the first trial and second trial, respectively. After this point was reached, the root-zone water status was restored to field capacity. Whole-tree transpiration measurements were supplemented with leaf-level gas-exchange measurements. Krymsk® 6 had a higher rate of photosynthesis, more vigorous vegetative growth and less conservative stomatal regulation during incipient drought than Krymsk® 5. At harvest, carbon partitioning to roots was greater in Krymsk® 6 than Krymsk® 5. The conservative rate of water use in Krymsk® 5 could be a function of greater stomatal control or reduced carbon partitioning to roots, which thereby limited transpiration rates. Further studies are needed to confirm that these results are applicable to trees grown using a common grafted scion under field conditions.

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Gas Exchange of Mimosa tenuiflora (Willd.) Poiret Under Water Deficit and Rewatering

Journal of Agricultural Studies ◽

10.5296/jas.v7i4.15338 ◽

2019 ◽

Vol 7 (2) ◽

pp. 297

Author(s):

Francisco Jose Basilio Alves ◽

Antonio Lucineudo Oliveira Freire

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Deficit ◽

Water Availability ◽

Physiological Responses ◽

Soil Mixture ◽

Relative Water ◽

Stomatal Parameters ◽

Variable Water ◽

Mimosa Tenuiflora

This research aimed to evaluate the physiological responses of Mimosa tenuiflora plants submitted to variable water availability conditions during the nursery stage. Twelve-month-old plants kept in plastic pots containing 5 kg of the substrate composed of the subsoil soil mixture and bovine manure (2:1) were submitted to two treatments: irrigated (control) and water stress, which was imposed through the suspension of irrigation, rewatering after seven days of stress. The relative water content (RWC) and stomatal parameters were evaluated. The M. tenuiflora plants responded quickly to the irrigation suspension, promoting the closure of the stomata, occurring reduction in stomatal conductance, transpiration rate and photosynthesis. The instantaneous efficiency in water use of plants under water deficit remained high only until the middle of the period when irrigation was suspended, and then declined until the last day of the water deficit. After rehydration, the plants showed recovery in all evaluated parameters, indicating that the level of stress imposed did not cause irreversible damages in the cells and tissues.

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Effects of compost on water availability and gas exchange in tomato during drought and recovery

Plant Soil and Environment ◽

10.17221/403/2012-pse ◽

2012 ◽

Vol 58 (No. 11) ◽

pp. 495-502 ◽

Cited By ~ 9

Author(s):

T.-T. Nguyen ◽

S. Fuentes ◽

P. Marschner

Keyword(s):

Drought Stress ◽

Stomatal Conductance ◽

Gas Exchange ◽

Water Supply ◽

Water Availability ◽

Field Capacity ◽

Tomato Plants ◽

Permanent Wilting Point ◽

Water Treatments ◽

Wilting Point

Compost can increase soil water availability and nutrient uptake by plants, but it is not clear whether it can also improve the ability of plants to recover after drought stress. Tomato plants (Lycopersicon esculentum L.) were grown in sandy soil without compost or with compost either incorporated or mulched. There were two water treatments: (i) plants grown under sufficient water supply throughout the experiment and (ii) plants grown with sufficient water supply until day 33 after which water was withheld until stomatal conductance was close to zero. Compost addition increased water content at both field capacity and permanent wilting point, but only incorporated compost increased total available water. Compost addition increased shoot and root growth under well-watered and drought stressed conditions with a greater effect by incorporated compost. At sufficient water supply, the rates of photosynthesis and transpiration were similar in all treatments. Drought stressed plants with incorporated compost wilted earlier than control plants, whereas mulched compost increased water availability to plants and hence the number of days until wilting. Photosynthesis and transpiration recovered faster in plants grown with incorporated compost compared to other treatments. The rapid recovery of plants after drought with incorporated compost could be due to their greater root length.

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RESPONSE OF BROCCOLI TO FIVE SOIL WATER REGIMES

Canadian Journal of Plant Science ◽

10.4141/cjps76-154 ◽

1976 ◽

Vol 56 (4) ◽

pp. 953-959 ◽

Cited By ~ 3

Author(s):

A. R. MAURER

Keyword(s):

Water Stress ◽

Water Supply ◽

Brassica Oleracea ◽

Soil Water ◽

Soil Type ◽

Field Capacity ◽

Plant Size ◽

Water Regimes ◽

Soil Water Stress ◽

Head Formation

Plants of broccoli, Brassica oleracea var. italica, were grown in weighing lysimeters and exposed to five soil water regimes. These regimes restored soil water to field capacity at 88% of available water for the wet treatment, 60% for the medium and 32% for the dry. In the wet–dry and dry–wet regimes, water depletion levels were changed at time of head formation. Soil water stress imposed prior to heading reduced plant size, but yield of marketable heads was not significantly reduced from that of plants grown in the wet regime when an adequate water supply was maintained after heading. Yield of marketable heads was least in the dry and wet–dry regimes and intermediate in the medium regime. Plants in the dry–wet regime did not consume as much water as those in the wet regime during the period from heading to harvest. In maritime areas which do not normally experience excessively high temperatures, withholding irrigation until heads begin to form can be recommended, provided the soil type is capable of retaining moisture and is at field capacity at planting.

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Investigation of improving the drought tolerance in persian petunia (Petunia sp.) by exogenous application of salicylic acid and gibberellic acid

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2021.1.4 ◽

2021 ◽

Vol 20 (1) ◽

pp. 37-48

Author(s):

Morteza Goldani ◽

Ali Dolatkhahi ◽

Mahdi Parsa ◽

Navid Vahdati ◽

Zahra Rasouli

Keyword(s):

Salicylic Acid ◽

Water Stress ◽

Stomatal Conductance ◽

Gibberellic Acid ◽

Water Deficit ◽

Abiotic Stress Tolerance ◽

Foliar Spray ◽

Field Capacity ◽

Exogenous Application ◽

Four Levels

Plants respond to water deficit through several mechanisms. Among which, plant hormones play an important role in induction to abiotic stress tolerance. To bring this issue closer, an experiment was conducted to examine whether salicylic acid (SA) and gibberellic acid (GA3) exogenous applications through foliar spray could alleviate detrimental effects of water deficit on Persian petunia. Treatments consisted of water stress in three levels: 100% field capacity (F.C.) as control, 50, and 25% F.C linked with different concentrations of GA3 and SA sprayed at four levels (0, 100, 200 and 300 mg L–1). Results showed that the dry and fresh biomass, leaf area, photosynthetic pigments levels, relative water content (RWC) and the total number of flowers were significantly (P≤0.01) reduced in response to water deficit. However, free proline concentration and root-to-shoot ratio significantly increased in stressed plants. Plants subjected to severe water stress (25% F.C.), exhibit about 66% stomatal conductance rate lower than the plants grown at 100% F.C. The results showed that SA-treated plants exhibited reduced negative effect of water stress on most of the qualitative and quantitative attributes compared to control, while GA3 application had little impact on studied traits. Importantly, stomatal conductance and RWC were improved in water-stressed plants treated with SA. Moreover, SA-treated plants produced more flowers at all water deficit levels compared to GA3 sprayed plants. It can be concluded that Persian petunia plants respond to water deficit through adaptive changes at biochemical and morphological levels and that adverse effects of water deficit could be alleviated by exogenous application of SA.

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Seed Antioxidants Interplay with Drought Stress Tolerance Indices in Chilli (Capsicum annuum L) Seedlings

BioMed Research International ◽

10.1155/2018/1605096 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 7

Author(s):

U. Lakshmi Sahitya ◽

M. S. R. Krishna ◽

R. Sri Deepthi ◽

G. Shiva Prasad ◽

D. Peda Kasim

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Water Content ◽

Stress Tolerance ◽

Chlorophyll Content ◽

Relative Water Content ◽

Field Capacity ◽

Water Regimes ◽

Relative Water ◽

Tolerance Indices

Altering climatic conditions and water stress drastically affects the chilli crop yield. In this scenario we adapted a strategic approach for screening of elite chilli genotypes, by exploring role of seed antioxidants in stress tolerance during vegetative phase. A total of 20 chilli genotypes’ seed antioxidant potential and its effect on water stress tolerance were studied at three water regimes, namely, control (100% Field Capacity), moderate (80% Field Capacity), and severe (60% Field Capacity) stress conditions. Drought tolerance traits relative water content, chlorophyll content, and activities of superoxide dismutase and catalase enzymes were measured. A strong correlation was observed between seed antioxidants and water stress tolerant traits in seedlings. Genotypes KCa-5, KCa-6, and KCa-10 showed low quantity of H2O2 and Malondialdehyde in seeds and maintained high membrane integrity and chlorophyll content in seedlings. High content of proline in KCa-5, KCa-7, and KCa-10 seeds retained high relative water content at seedling stage under severe water stress. Present work reveals genotypic differences of hot pepper to different water regimes. Based on Principal Component Analysis (PCA) of seed antioxidant variables and drought tolerance indices twenty genotypes segregated into three clusters, namely, drought tolerant and susceptible and moderately tolerant.

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