scholarly journals Comparative Study of the Effects of Salinity on Growth, Gas Exchange, N Accumulation and Stable Isotope Signatures of Forage Oat (Avena sativa L.) Genotypes

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1025
Author(s):  
Syed Sadaqat Shah ◽  
Zhijian Li ◽  
Hong Yan ◽  
Lianxuan Shi ◽  
Bangwei Zhou
Keyword(s):  
Salinity Tolerance ◽  
Avena Sativa ◽  
Plant Biomass ◽  
Water Status ◽  
Growth Cycle ◽  
Shoot Biomass ◽  
Saline Stress ◽  
N Accumulation ◽  
Forage Type ◽  
Four Levels

Identifying suitable salt stress-tolerant phenotypes based on their agronomic and physiological traits remains a herculean task in forage-type oat (Avena sativa L.) breeding. This study examined the responses of six forage-type oat cultivars under four levels of saline stress over the vegetative growth cycle. Crop growth, water status-related traits and nitrogen status-related traits were analyzed in different plant parts to evaluate effective approaches for identifying salt tolerance. Plant biomass, height, tiller number and culm thickness changed substantially during salinity, but they were not precise enough for use in estimating genotypic salinity tolerance during long-term stress. Genotypes bearing larger numbers of tillers showed greater sensitivity to salinity due to its effects on biomass loss. Tolerant genotypes exhibited higher relative shoot biomass together with higher water use efficiency. The concentrations of Na+, K+ and their ratio, combined with the δ13C in shoots and roots were effective indicators for estimating tolerant genotypes through better water maintenance. N concentrations of shoots were the most efficient for evaluating genotypic tolerance. Low nitrate reductase (NR) and glutamine synthetase (GS) activity might be key factors limiting N accumulation. Chlorophyll (Chl) content and net photosynthetic rate, as well as stomatal conductance and evaporation, were useful for identifying salinity tolerance physiological mechanisms, but the effectiveness was low for genotypic tolerance testing for forage type oats due to the interaction between genotypes and salinity levels. The selection of high salinity-tolerant genotypes should focus on genotypes with photosynthetic resilience to salt, followed by high N metabolism (higher NR and GS activities) to ensure accumulation of more N in the shoot dry matter.

scholarly journals Evaluation of salinity tolerance indices in North African barley accessions at reproductive stage

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 61-69 ◽  
Author(s):  
Dorsaf Allel ◽  
Anis BenAmar ◽  
Mounawer Badri ◽  
Chedly Abdelly
Keyword(s):  
Salt Tolerance ◽  
Grain Yield ◽  
Salinity Tolerance ◽  
Selection Criteria ◽  
Reproductive Stage ◽  
Shoot Biomass ◽  
Salt Tolerant ◽  
North African ◽  
Grain Number ◽  
Selection Indices

Soil salinity is one of the main factors limiting cereal productivity in worldwide agriculture. Exploitation of natural variation in local barley germplasm is an effective approach to overcome yield losses. Three gene pools of North African Hordeum vulgare L. grown in Tunisia, Algeria and Egypt were evaluated at the reproductive stage under control and saline conditions. Assessment of stress tolerance was monitored using morphological, yield-related traits and phenological parameters of reproductive organs showing significant genetic variation. High heritability and positive relationships were found suggesting that some traits associated with salt tolerance could be used as selection criteria. The phenotypic correlations revealed that vegetative traits including shoot biomass, tiller number and leaf number along with yield-related traits such as spike number, one spike dry weight, grain number/plant and grain number/spike were highly positively correlated with grain yield under saline conditions. Hence, these traits can be used as reliable selection criteria to improve barley grain yield. Keeping a higher shoot biomass and longer heading and maturity periods as well as privileged filling ability might contribute to higher grain production in barley and thus could be potential target traits in barley crop breeding toward improvement of salinity tolerance. Multiple selection indices revealed that salt tolerance trait index provided a better discrimination of barley landraces allowing selection of highly salt-tolerant and highly productive genotypes under severe salinity level. Effective evaluation of salt tolerance requires an integration of selection indices to successfully identify and characterize salt tolerant lines required for valuable exploitation in the management of salt-affected areas.  

scholarly journals Root Response to Soil Water Status via Interaction of Crop Genotype and Environment

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 708
Author(s):  
Phanthasin Khanthavong ◽  
Shin Yabuta ◽  
Hidetoshi Asai ◽  
Md. Amzad Hossain ◽  
Isao Akagi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Root Distribution ◽  
Water Status ◽  
Soil Layer ◽  
Shoot Biomass ◽  
Soil Conditions ◽  
Crop Adaptation ◽  
Soil Moisture Status ◽  
Root Distributions

Flooding and drought are major causes of reductions in crop productivity. Root distribution indicates crop adaptation to water stress. Therefore, we aimed to identify crop roots response based on root distribution under various soil conditions. The root distribution of four crops—maize, millet, sorghum, and rice—was evaluated under continuous soil waterlogging (CSW), moderate soil moisture (MSM), and gradual soil drying (GSD) conditions. Roots extended largely to the shallow soil layer in CSW and grew longer to the deeper soil layer in GSD in maize and sorghum. GSD tended to promote the root and shoot biomass across soil moisture status regardless of the crop species. The change of specific root density in rice and millet was small compared with maize and sorghum between different soil moisture statuses. Crop response in shoot and root biomass to various soil moisture status was highest in maize and lowest in rice among the tested crops as per the regression coefficient. Thus, we describe different root distributions associated with crop plasticity, which signify root spread changes, depending on soil water conditions in different crop genotypes as well as root distributions that vary depending on crop adaptation from anaerobic to aerobic conditions.

scholarly journals Silicon and the Association with an Arbuscular-Mycorrhizal Fungus (Rhizophagus clarus) Mitigate the Adverse Effects of Drought Stress on Strawberry

Agronomy ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 41 ◽  
Author(s):  
Narges Moradtalab ◽  
Roghieh Hajiboland ◽  
Nasser Aliasgharzad ◽  
Tobias E. Hartmann ◽  
Günter Neumann
Keyword(s):  
Water Content ◽  
Plant Biomass ◽  
Arbuscular Mycorrhizal Fungus ◽  
Water Status ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Stress Factors ◽  
Leaf Water Content ◽  
Rhizophagus Clarus ◽  
Effects Of Drought

Silicon (Si) is a beneficial element that alleviates the effects of stress factors including drought (D). Strawberry is a Si-accumulator species sensitive to D; however, the function of Si in this species is obscure. This study was conducted to examine the effect of Si and inoculation with an arbuscular mycorrhizal fungus (AMF) on physiological and biochemical responses of strawberry plants under D. Plants were grown for six weeks in perlite and irrigated with a nutrient solution. The effect of Si (3 mmol L‒1), AMF (Rhizophagus clarus) and D (mild and severe D) was studied on growth, water relations, mycorrhization, antioxidative defense, osmolytes concentration, and micronutrients status. Si and AMF significantly enhanced plant biomass production by increasing photosynthesis rate, water content and use efficiency, antioxidant enzyme defense, and the nutritional status of particularly Zn. In contrast to the roots, osmotic adjustment did not contribute to the increase of leaf water content suggesting a different strategy of both Si and AMF for improving water status in the leaves and roots. Our results demonstrated a synergistic effect of AMF and Si on improving the growth of strawberry not only under D but also under control conditions.

scholarly journals Evaluating four gap-filling methods for eddy covariance measurements of evapotranspiration over hilly crop fields

2017 ◽  
Author(s):  
Nissaf Boudhina ◽  
Rim Zitouna-Chebbi ◽  
Insaf Mekki ◽  
Frédéric Jacob ◽  
Nétij Ben Mechlia ◽  
...  
Keyword(s):  
Time Series ◽  
Linear Regression ◽  
Eddy Covariance ◽  
Water Status ◽  
Growth Cycle ◽  
Filling Rate ◽  
Gap Filling ◽  
Crop Fields ◽  
Downslope Winds ◽  
Aerodynamic Properties

Abstract. Estimating evapotranspiration in hilly watersheds is paramount for managing water resources, especially in semi-arid regions. Eddy covariance (EC) technique allows continuous measurements of latent heat flux LE. However, time series of EC measurements often experience large portions of missing data, because of instrumental dysfunctions or quality filtering. Existing gap-filling methods are questionable over hilly crop fields, because of changes in airflow inclination and subsequent aerodynamic properties. We evaluated the performances of different gap-filling methods before and after tailoring to conditions of hilly crop fields. The tailoring consisted of beforehand splitting the LE time series on the basis of upslope and downslope winds. The experiment was setup within an agricultural hilly watershed in northeastern Tunisia. EC measurements were collected throughout the growth cycle of three wheat crops, two of them located in adjacent fields on opposite hillslopes, and the third one located in a flat field. We considered four gap-filling methods: the REddyProc method, the linear regression between LE and net radiation Rn, the multi-linear regression of LE against the other energy fluxes, and the use of evaporative fraction EF. Regardless of method, the splitting of the LE time series did not impact the gap filling rate, and it might improve the accuracies on LE retrievals in some cases. Regardless of method, the obtained accuracies on LE estimates after gap filling were close to instrumental accuracies, and were comparable to those reported in previous studies over flat and mountainous terrains. Overall, REddyProc was the most appropriate method, for both gap filling rate and retrieval accuracy. Thus, it seems possible to conduct gap-filling for LE time series collected over hilly crop fields, provided the LE time series are beforehand split on the basis of upslope / downslope winds. Future works should address consecutive vegetation growth cycles for a larger panel of conditions in terms of climate, vegetation and water status.

scholarly journals Effect of Biochar and Irrigation on Soybean-Rhizobium Symbiotic Performance and Soil Enzymatic Activity in Field Rhizosphere

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Ma ◽  
Egamberdieva ◽  
Wirth ◽  
Bellingrath-Kimura
Keyword(s):  
Plant Biomass ◽  
N Uptake ◽  
Critical Factor ◽  
Hydrolytic Activity ◽  
N Fertilizer ◽  
Nutrient Concentrations ◽  
Shoot Biomass ◽  
Soil Enzymatic Activity ◽  
Nodule Number ◽  
Soil Variables

Nitrogen (N) in soybean (Glycine max L.) plants derived from biological nitrogen fixation was shown to be a sustainable N resource to substitute for N fertilizer. However, the limited water supply in sandy soil is a critical factor for soybean nodulation and crop growth. This study investigated the potential mechanism of the effect of biochar and irrigation on the soybean-Rhizobium symbiotic performance and soil biological activity in a field trial. In the absence of N fertilizer, 10 t ha−1 of black cherry wood-derived biochar were applied under irrigated and rainfed conditions on an experimental, sandy field site. The plant biomass, plant nutrient concentrations, nodule number, nodule leghemoglobin content, soil enzyme activities, and soil-available nutrients were examined. Our results show that biochar application caused a significant increase in the nodule number by 35% in the irrigated condition. Shoot biomass and soil fluorescein diacetate hydrolytic activity were significantly increased by irrigation in comparison to the rainfed condition. The activity of soil protease reduced significantly, by 8%, with the biochar application in the irrigated condition. Further, a linear correlation analysis and redundancy analysis performed on the plant, nodule, and soil variables suggested that the biochar application may affect soybean N uptake in the sandy field. Nodulation was enhanced with biochar addition, however, the plant N concentration and nodule Lb content remained unaffected.

scholarly journals Agronomic characteristics of the Pennisetum glaucum submitted to water and saline stresses

2020 ◽  
Vol 43 ◽  
pp. e50468
Author(s):  
Mirna Clarissa Rodrigues de Almeida ◽  
Mauricio Luiz de Mello Vieira Leite ◽  
Luciana Sandra Bastos de Souza ◽  
Vicente José Laamon Pinto Simões ◽  
Luiz Guilherme Medeiros Pessoa ◽  
...  
Keyword(s):  
Arid Regions ◽  
Pennisetum Glaucum ◽  
Block Design ◽  
Salt Content ◽  
Morphological Characteristics ◽  
Saline Stress ◽  
Initial Growth ◽  
Randomized Block Design ◽  
High Salt Content ◽  
Four Levels

Agricultural production in semi-arid regions is limited due to water availability. In addition, the water quality available for irrigation is often compromised due to the high salt content present. Millet is a forage species considered tolerant to water deficit and moderately salt tolerant. In view of the above, the objective was to evaluate the growth of millet under water and saline stress associates. The experiment was carried out in a randomized block design, in a 4x3 factorial scheme, composed of four levels of water replacement, based on crop evapotranspiration (ETc): 25%.ETc, 50%.ETc, 75%.ETc and 100%.ETc and three levels of water salinity (0.03, 2.0 and 4.0 dS m-1). With 25%.ETc independent of salinity, all morphological characteristics of millet were affected, occurring death of plants in the initial growth phase. In the absence of salt and greater availability of water, greater plant growth occurred. With respect to salinity, there was a reduction in the increment of all variables evaluated, with the highest reduction at the highest saline level (4.0 dS m-1). Water and salt stresses, when associated, reduce the growth of millet, since concentrations above 2.0 dS m-1 and less than 50%.ETc compromise its full development, providing declines in yield.

scholarly journals Effects of earthworms and mycorrhizal fungi on the growth of the medicinal herb Calendula officinalis (Asteraceae)

2011 ◽  
Vol 57 (No. 11) ◽  
pp. 499-504 ◽  
Author(s):  
J.G. Zaller ◽  
F. Saccani ◽  
T. Frank
Keyword(s):  
Biomass Production ◽  
Mycorrhizal Fungi ◽  
Plant Biomass ◽  
Arbuscular Mycorrhizal ◽  
Lumbricus Terrestris ◽  
Leaf Length ◽  
Stem Length ◽  
Shoot Biomass ◽  
Calendula Officinalis ◽  
Amf Inoculation

  Both earthworms and symbiotic arbuscular mycorrhizal fungi (AMF) often co-occurr in ecosystems, however very little is known on their interrelationships. Here we tested to what extent earthworms (Annelida) or AMF (Glomales) separately or in combination affect the growth of the pharmaceutical plant species, pot marigold (Calendula officinalis, Asteraceae). We conducted a greenhouse experiment using non-sterilized field soil where we manipulated the factors earthworms (addition/no addition of the vertical burrowing species Lumbricus terrestris) and AMF (addition/no addition of a mix of the four Glomus taxa G. geosporum, G. mosseae, G. intraradices, G. claroideum). Leaf length and flower stem length was significantly increased by earthworms but remained unaffected by additional AMF. The longest leaves and flower stems were observed in pots containing earthworms but no additional AMF. The number of flower buds was unaffected by earthworms but marginally significantly increased by AMF. Plant shoot biomass production was significantly higher when earthworms were present; AMF inoculation had no effect on biomass production. Root biomass production and total plant biomass production remained unaffected by earthworms or AMF. These results indicate that in soil already containing AMF earthworm addition primarily affects vegetative growth while additional AMF inoculation tended to affect reproductive plant parts.

scholarly journals Overexpression of GSK3-like Kinase 5 (OsGSK5) in rice (Oryza sativa) enhances salinity tolerance in part via preferential carbon allocation to root starch

2017 ◽  
Vol 44 (7) ◽  
pp. 705 ◽  
Author(s):  
Maysaya Thitisaksakul ◽  
Maria C. Arias ◽  
Shaoyun Dong ◽  
Diane M. Beckles
Keyword(s):  
Oryza Sativa ◽  
Salt Stress ◽  
Salinity Tolerance ◽  
Carbon Allocation ◽  
Oryza Sativa L ◽  
Rice Seedling ◽  
Shoot Biomass ◽  
Salt Shock ◽  
Seedling Roots ◽  
Root Starch

Rice (Oryza sativa L.) is very sensitive to soil salinity. To identify endogenous mechanisms that may help rice to better survive salt stress, we studied a rice GSK3-like isoform (OsGSK5), an orthologue of a Medicago GSK3 previously shown to enhance salinity tolerance in Arabidopsis by altering carbohydrate metabolism. We wanted to determine whether OsGSK5 functions similarly in rice. OsGSK5 was cloned and sequence, expression, evolutionary and functional analyses were conducted. OsGSK5 was expressed highest in rice seedling roots and was both salt and sugar starvation inducible in this tissue. A short-term salt-shock (150 mM) activated OsGSK5, whereas moderate (50 mM) salinity over the same period repressed the transcript. OsGSK5 response to salinity was due to an ionic effect since it was unaffected by polyethylene glycol. We engineered a rice line with 3.5-fold higher OsGSK5 transcript, which better tolerated cultivation on saline soils (EC = 8 and 10 dS m–2). This line produced more panicles and leaves, and a higher shoot biomass under high salt stress than the control genotypes. Whole-plant 14C-tracing and correlative analysis of OsGSK5 transcript with eco-physiological assessments pointed to the accelerated allocation of carbon to the root and its deposition as starch, as part of the tolerance mechanism.

Yield Stability of Cassava During Prolonged Mid-Season Water Stress

1992 ◽  
Vol 28 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Mabrouk A. El-Sharkawy ◽  
Anna Del Pilar Hernández ◽  
Clair Hershey
Keyword(s):  
Water Stress ◽  
Growth Cycle ◽  
Yield Stability ◽  
High Yield ◽  
Shoot Biomass ◽  
Deep Soil ◽  
Leaf Formation ◽  
Plant Characteristics ◽  
Moisture Conditions ◽  
Field Drainage

SUMMARYYield stability in cassava requires genotypes that produce well under the variable moisture conditions encountered during the growth cycle. Plant characteristics related to yield stability were studied in two cassava clones subjected to 105 days of water stress in a field drainage lysimeter. Stress conditions commenced 117 days after planting, and the plants were allowed to recover at the end of the stress period for the rest of the growth cycle. Water stress restricted the growth of leaves and stems, but root yields were increased or remained unaffected. Leaf water potential varied little with stress, but gas exchange rates were about 75% those of the control throughout the stress period in both cultivars. Under stress, the plants partially closed their stomata and extracted deep soil moisture slowly. A high yield in both wet and stressed environments was associated with high mean LAI, better leaf retention, and greater partitioning of shoot biomass into leaf formation.

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