scholarly journals Trocas gasosas foliares e componentes de produção de pimentas malagueta (Capsicum frutescens) submetidas a diferentes tensões de água no solo, na região sul da Bahia / Leaf gas exchange and productions components of chilli peppers (Capsicum frutescens) subjected to different soil water tensions in the south of Bahia

2021 ◽  
Vol 4 (4) ◽  
pp. 5477-5489
Author(s):  
Adriana Ramos ◽  
Roberto Ribeiro Bonina Costa ◽  
Martielly Santana Dos Santos ◽  
Norma Eliane Pereira ◽  
Filipe Oliveira Santos ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Leaf Gas Exchange ◽  
Capsicum Frutescens ◽  
Santa Cruz ◽  
The South

As hortaliças são culturas bastante susceptíveis às deficiências hídricas, principalmente às grandes variações do nível de água no solo, resultando num crescimento reduzido e desuniforme dos frutos. Este trabalho teve como objetivo avaliar as trocas gasosas foliares e os componentes de produção de pimentas malagueta em função de diferentes tensões de água no solo. O experimento foi conduzido no campo de horticultura da Universidade Estadual de Santa Cruz – UESC em delineamento experimental de blocos casualizados com quatro tratamentos em quatro blocos, sendo a unidade experimental composta por cinco plantas por parcela em espaçamento 1,0 x 0,6 m, num total de 80 plantas. Foram aplicados os tratamentos, quando os potenciais matriciais atingiam os valores de 5, 10, 20 e 25 kPa, para os tratamentos T1, T2, T3 e T4, respectivamente, para o tensiômetro instalados a 0,15 m de profundidade. Para a determinação das trocas gasosas foliares foi utilizado o analisador de gases por infravermelho onde foram medidos a taxa fotossintética líquida, a condutância estomática e a transpiração. A colheita foi realizada semanalmente sendo retirados os frutos de coloração avermelhada totalmente maduros e sem danos físicos. Estes foram pesados e a partir dessas informações foram analisados a massa média dos frutos e o número médio de frutos por planta. Os dados foram submetidos à análise de variância e teste de médias. A análise de trocas gasosas foliares obtidas nos tratamentos não apresentaram diferença estatística ao longo do período experimental. Além disso, não houve diferença significativa entre os tratamentos para a massa e quantidade de fruto.

Growth and leaf gas exchange in Populus euphratica across soil water and salinity gradients

2013 ◽  
Vol 51 (3) ◽  
pp. 321-329 ◽  
Author(s):  
J. Y. Li ◽  
C. Y. Zhao ◽  
J. Li ◽  
Y. Y. Yan ◽  
B. Yu ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Leaf Gas Exchange ◽  
Populus Euphratica ◽  
Salinity Gradients

The responses of stomata and leaf gas exchange to vapour pressure deficits and soil water content

Oecologia ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 356-362 ◽  
Author(s):  
T. Gollan ◽  
N. C. Turner ◽  
E. -D. Schulze
Keyword(s):  
Gas Exchange ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Vapour Pressure ◽  
Leaf Gas Exchange

The responses of stomata and leaf gas exchange to vapour pressure deficits and soil water content

Oecologia ◽  
1984 ◽  
Vol 63 (3) ◽  
pp. 338-342 ◽  
Author(s):  
Neil C. Turner ◽  
E.-D. Schulze ◽  
T. Gollan
Keyword(s):  
Gas Exchange ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Vapour Pressure ◽  
Leaf Gas Exchange

Tropical rainforests under severe drought stress: distinct water use strategies among and within species

2021 ◽  
Author(s):  
Angelika Kübert ◽  
Kathrin Kühnhammer ◽  
Ines Bamberger ◽  
Erik Daber ◽  
Jason De Leeuw ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Physiological Responses ◽  
Leaf Water ◽  
Severe Drought ◽  
Subsequent Recovery ◽  
Species Specific

<p>Increasing drought in the tropics is a major threat to rainforests and can strongly harm plant communities. Understanding species-specific water use strategies to drought and the subsequent recovery is therefore important for estimating the risk to tropical rainforest ecosystems of drought. Conducting a large-scale long-term drought experiment in a model rainforest ecosystem (Biosphere 2 WALD project), we evaluated the role of plant physiological responses, above and below ground, in response to drought and subsequent recovery in five species (3 canopy species, 2 understory species). The model rainforest was exposed to a 9.5-week lasting drought. Severe drought was ended with a deep water pulse strongly enriched in <sup>2</sup>H, which allowed us to distinguish between deep and shallow rooting plants, and subsequent rain (natural abundance range of <sup>2</sup>H). We assessed plant physiological responses by leaf water potential, sap flow and high resolution monitoring of leaf gas exchange (concentrations and stable isotopes of H<sub>2</sub>O and CO<sub>2</sub>). Thereby, we could derive plant water uptake and leaf water use efficiency (WUE<sub>leaf</sub>) in high temporal resolution, revealing short-term and long-term responses of plant individuals to drought and rewetting. The observed water use strategies of species and plants differed widely. No uniform response in assimilation (A) and transpiration (T) to drought was found for species, resulting in decreasing, relatively constant, or increasing WUE<sub>leaf</sub> across plant individuals. While WUE<sub>leaf</sub> of some plant individuals strongly decreased due to a breakdown in A, others maintained relatively high T and A and thus constant WUE<sub>leaf, </sub>or increased WUE<sub>leaf</sub> by decreasing T while keeping A relatively high. We expect that the observed plant-specific responses in A, T and WUE<sub>leaf</sub> were strongly related to the plant individuals' access to soil water. We assume that plant individuals with constant WUE<sub>leaf</sub> could maintain their leaf gas exchange due to access to water of deeper soil layers, while plants with increasing/decreasing WUE<sub>leaf</sub> mainly depended on shallow soil water and only had limited or no access to deep soil water. We conclude that the observed physiological responses to drought were not only determined by species-specific water use strategies but also by the diverse strategies within species, mainly depending on the plant individuals' size and place of location. Our results highlight the plasticity of water use strategies beyond species-specific strategies and emphasize its importance for species’ survival in face of climate change and increasing drought.</p>

scholarly journals Water status and gas exchange of umbu plants (Spondias tuberosa Arr. Cam.) propagated by seeds and stem cuttings

2007 ◽  
Vol 29 (2) ◽  
pp. 355-358 ◽  
Author(s):  
José Moacir Pinheiro Lima Filho
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Leaf Gas Exchange ◽  
Leaf Water ◽  
Soil Water Deficit ◽  
Stem Cuttings

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange data collection using psychrometric chambers and a portable infra-red gas analyzer, respectively. Plants propagated by seeds maintained a significantly higher water potential, stomatal conductance, transpiration and photosynthesis under decreasing soil water availability. However, plants propagated by stem cuttings were unable to maintain a favorable internal water balance, reflecting negatively on stomatal conductance and leaf gas exchange. This fact is probably because umbu plants propagated by stem cuttings are not prone to formation of root tubers which are reservoirs for water and solutes. Thus, the establishing of umbu plants propagated by stem cuttings must be avoided in areas subjected to soil water deficit.

scholarly journals Physiological Response of Carambola Trees to Soil Water Depletion in Krome Soils

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 857B-857
Author(s):  
Rashid Al-Yahyai* ◽  
Bruce Schaffer ◽  
Frederick S. Davies
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Gas Exchange ◽  
Stem Water Potential ◽  
Soil Water Depletion ◽  
Water Depletion ◽  
Loam Soil ◽  
Stem Water

The effect of soil water depletion on plant water potential and leaf gas exchange of carambola (Averrhoa carambola L. cv. Arkin) in Krome very gravelly loam soil was studied in an orchard and in containers in the field and in a greenhouse. The rate of soil water depletion was determined by continuously monitoring soil water content with multi-sensor capacitance probes. Stem water potential and leaf gas exchange of carambola in containers were reduced when the soil water depletion level fell below 50% (where field capacity = 100%). Although there was a decrease in the rate of soil water depletion in the orchard as the soil dried, soil water depletion did not go below an average of 70%. This was presumably due to sufficient rainfall and capillary movement of water in the soil. Therefore, soil water content did not decline sufficiently to affect leaf gas exchange and leaf and stem water potential of orchard trees. A decline in soil water depletion below 40% resulted in a concomitant decline in stem water potential of the container trees in the field and greenhouse to below -1.0 MPa. Stomatal conductance, net CO2 assimilation, and transpiration declined significantly when stem water potential was below -1.0 MPa. The reduction of net CO2 assimilation and transpiration was proportional to the decline in stomatal conductance of container trees in the field and greenhouse. Thus, soil water depletion in Krome very gravelly loam soil must be less than 50% before water potential or leaf gas exchange of carambola is affected. Based on these results, irrigation scheduling should be based on physiological variables such as stem water potential and stomatal conductance or the amount rather than the rate of soil water depletion.

scholarly journals Isolates of Arbuscular Mycorrhizal (AM) Fungi Alter Citrus Leaf Gas Exchange during Soil Water Deficit Stress and Recovery

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 541D-541
Author(s):  
Matthew W. Fidelibus ◽  
Chris A. Martin
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Glomus Mosseae ◽  
Leaf Gas Exchange ◽  
Am Fungi ◽  
Water Deficit Stress ◽  
Soil Drying ◽  
Soil Water Deficit ◽  
The Third ◽  
Mycorrhizal Plants

Four AM fungal isolates (Glomus sp.) from disparate edaphic conditions were screened for effects on leaf gas exchange of `Volkamer' lemon (Citrus volkameriana Ten. and Pasq.) plants of similar size under conditions of increased soil water deficit stress and recovery from stress. Mycorrhizal and non-mycorrhizal plants were grown in 8-L containers for 10 weeks under well-watered conditions in a glasshouse and then subjected to three consecutive soil-drying episodes of increased severity (mean soil water tension reached –0.02, –0.06, and –0.08 MPa, respectively). Gas exchange measurements were made on the last day of each soil-drying episode. Plants were irrigated after each soil-drying episode, and measurements were repeated on the following 2 recovery days, when soil remained moist. All measurements were made at mid-day with a LI-COR 6200 portable photosynthesis system. The effect of AM fungi on leaf gas exchange fluxes varied depending on the isolate and the intensity of soil water stress. Leaf gas exchange fluxes always were highest for plants colonized by Glomus mosseae (Nicol. & Gerde.) isolate 114C, except during the third soil-drying episode, when all mycorrhizal plants had similar, and lower, gas exchange fluxes compared with non-mycorrhizal plants. During recovery from the third soil-drying episode, Glomus mosseae isolate 51C had lower leaf gas exchange fluxes compared with all other plants. Our results show that AM fungi can alter leaf gas exchange fluxes of citrus, under conditions of optimal P nutrition, in an isolate-specific manner.

scholarly journals Bell Pepper (Capsicum annum L.) Crop as Affected by Shade Level: Microenvironment, Plant Growth, Leaf Gas Exchange, and Leaf Mineral Nutrient Concentration

HortScience ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Juan Carlos Díaz-Pérez
Keyword(s):  
Gas Exchange ◽  
Plant Growth ◽  
Soil Water ◽  
Leaf Area ◽  
Leaf Gas Exchange ◽  
Bell Pepper ◽  
Mineral Nutrient ◽  
Specific Leaf Weight ◽  
Leaf Weight ◽  
Leaf Transpiration

Use of shading nets helps ameliorate heat stress of vegetable crops. This study evaluated the effects of shade level on microenvironment, plant growth, leaf gas exchange, and mineral nutrient content of field-grown bell pepper crop. Bell pepper cultivars Camelot, Lafayette, Sirius, and Stiletto were grown at 0%, 30%, 47%, 62%, and 80% shade levels. Photosynthetically active radiation and air, leaf, and root zone temperatures decreased as shade level increased. Despite having increased plant leaf area, there was increased soil water content with increased shade level, indicating reduced soil water use. With increased shade level, the total plant leaf area, individual leaf area, and individual leaf weight increased, whereas leaf number per plant and specific leaf weight decreased. In contrast to non-normalized chlorophyll index (CI) values, CI normalized by specific leaf weight were related to leaf nitrogen (N) and increased with increased shade level. Net photosynthesis and stomatal conductance (gS) decreased and leaf transpiration increased with increased shade level, particularly above 47% shade level. Leaf concentrations of N, potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), sulfur (S), aluminum (Al), and boron (B) increased with increased shade level. Relatively few differences in plant growth, leaf gas exchange, and leaf mineral nutrient concentrations were observed among cultivars. In conclusion, morphological changes such as taller plants and thinner and larger leaves likely enhanced light capture under shaded conditions compared with unshaded plants. High shade levels reduced leaf temperature and excessive leaf transpiration but resulted in reduced leaf photosynthesis. Thus, moderate shade levels (30% and 47%) were the most favorable for bell pepper plant growth and function.

scholarly journals Salicylic Acid-Induced Morpho-Physiological and Biochemical Changes Triggered Water Deficit Tolerance in Syzygium cumini L. Saplings

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 491
Author(s):  
Zikria Zafar ◽  
Fahad Rasheed ◽  
Rana Muhammad Atif ◽  
Muhammad Maqsood ◽  
Oliver Gailing
Keyword(s):  
Salicylic Acid ◽  
Water Stress ◽  
Gas Exchange ◽  
Soil Water ◽  
Water Deficit ◽  
Foliar Application ◽  
Leaf Gas Exchange ◽  
Dry Weight ◽  
Soil Water Deficit ◽  
Water Stress Tolerance

Fruit tree culture is at the brink of disaster in arid to semi-arid regions due to low water availability. A pot experiment was carried out to analyze whether foliar application of salicylic acid (SA) can improve water stress tolerance in Syzygiumcumini. Saplings were subjected to control (CK, 90% of field capacity, FC), medium stress (MS, 60% of FC) and high stress (HS, 30% of FC) along with foliar application of 0.5 and 1.0 mM of SA. Results showed that soil water deficit significantly decreased leaf, stem and total dry weight, leaf gas exchange attributes and chlorophyll a, b. However, root dry weight and root/shoot ratio increased under MS and HS, respectively. Contrarily, foliar application of SA significantly improved chlorophyll a, b, leaf gas exchange attributes, and dry weight production under soil water deficit. Concentration of oxidants like hydrogen peroxide and superoxide radicals, along with malondialdehyde and electrolyte leakage increased under soil water deficit; however, decreased in plants sprayed with SA due to the increase in the concentration of antioxidant enzymes like superoxide dismutase, peroxidase, catalase and ascorbate peroxidase. Results suggest that the foliar application of SA can help improve water stress tolerance in Syzygiumcumini saplings; however, validation of the results under field conditions is necessary.

scholarly journals Soil water effect on crop growth, leaf gas exchange, water and radiation use efficiency of Saccharum spontaneum L. ssp. aegyptiacum (Willd.) Hackel in semi-arid Mediterranean environment

2015 ◽  
Vol 10 (4) ◽  
pp. 185 ◽  
Author(s):  
Danilo Scordia ◽  
Giorgio Testa ◽  
Salvatore L. Cosentino ◽  
Venera Copani ◽  
Cristina Patanè
Keyword(s):  
Gas Exchange ◽  
Soil Water ◽  
Biomass Production ◽  
Leaf Gas Exchange ◽  
Irrigation Treatment ◽  
Water Effect ◽  
Mediterranean Environment ◽  
Use Efficiency ◽  
Radiation Use ◽  
Semi Arid

Great effort has been placed to identify the most suited bioenergy crop under different environments and management practices, however, there is still need to find new genetic resources for constrained areas. For instance, South Mediterranean area is strongly affected by prolonged drought, high vapour pressure deficit (VPD) and extremely high temperatures during summertime. In the present work we investigated the soil water effect on crop growth and leaf gas exchange of <em>Saccharum</em> <em>spontaneum</em> L. ssp. <em>aegyptiacum</em> (Willd.) Hackel, a perennial, rhizomatous, herbaceous grass. Furthermore, the net increase of biomass production per unit light intercepted [radiation use efficiency (RUE)] and per unit water transpired [water use efficiency (WUE)] was also studied. To this end a field trial was carried out imposing three levels of soil water availability (I<sub>100</sub>, I<sub>50</sub> and I<sub>0</sub>, corresponding to 100%, 50% and 0% of ETm restutition) under a semi-arid Mediterranean environment. Leaf area index (LAI), stem height, biomass dry matter yield, CO<sub>2</sub> assimilation rate, and transpiration rate resulted significantly affected by measurement time and irrigation treatment, with the highest values in I<sub>100</sub> and the lowest in I<sub>0</sub>. RUE was the highest in I<sub>100</sub> followed by I<sub>50</sub> and I<sub>0</sub>; on the other hand, WUE was higher in I<sub>0</sub> than I<sub>50</sub> and I<sub>100</sub>. At LAI values greater than 2.0, 85% photosynthetically active radiation was intercepted by the <em>Saccharum</em> stand, irrespective of the irrigation treatment. <em>Saccharum</em> <em>spontaneum</em> spp. <em>aegyptiacum</em> is a potential species for biomass production in environment characterized by drought stress, high temperatures and high VPD, as those of Southern Europe and similar semi-arid areas.

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