Mineral Nutrient Concentrations Research Articles

Research progress of the response mechanism of wheat growth to waterlogging stress and the related regulating managements.

The frequency of waterlogging events is increasing in recent years due to climate change. Wheat, a dryland crop, is particularly sensitive to waterlogging. Moreover, waterlogging stress is especially serious in the main wheat-producing regions at the middle and lower reaches of the Yangtze River as influenced by regional climate, soil, rotating system and other factors. Oxygen content in soil decreases under waterlogging condition, which inhibits root growth, restricts plant growth, and eventually reduces wheat yield and grain quality. In the present study, we reviewed the current national and international research progress in the underlying physiological mechanisms of inhibitory wheat growth by waterlogging stress, from the aspects of root respiration, water transport, mineral nutrient absorption, photosynthesis, redox metabolism. We discussed the physiological adaptions of wheat to waterlogging, including maintaining energy supply through anaerobic respiration and oxygen supply through changes of root morphology. We listed the application of cultivation measures such as fertilizer regulation, growth regulator regulation and stress memory in improving waterlogging stress-tolerance in wheat with the underlying physiological mechanisms summarized. We also prospected the future study on waterlogging stress-tolerance in wheat, aiming to provide theoretical foundation for waterlogging-tolerant cultivation and maintaining high yield of wheat.

Eco-Physiological Properties of Open-Field Cucumbers Responded to Organic Liquid Fertilizers

This study was initiated to determine the effect of organic farm-derived liquid fertilizer (LF) on (1) the performance of open-field cucumbers (Cucumis sativus L.) and (2) the soil environment. Treatments included fertigation with a 0.2% solution of an equal T-N concentration on each LF, including long-term non-treatment (LNT, groundwater), non-treatment (NT, groundwater), oil cake (OC), bone meal + fish residue (BF), fish extract + active phosphoric acid (FP), sesame oil (SO), and starfish (SF). Electrical conductivity (EC) in LF was increased in the SF or BF, with high concentrations of T-C observed in the OC and BF and high P in the SO. LNT treatment decreased soil mineral nutrient concentrations and numbers of bacterial operational taxonomic units, invertebrates, and earthworms, significantly increasing infection of powdery mildew and downy mildew for the plants but reducing foliar concentrations of T-N, P, Ca, and SPAD values, and vegetative growth parameters. Soil bulk density decreased in the SF and SO plots. Total fruit yield and fruit yield efficiency were enhanced by BF, FP, SO, and SF treatments, with the highest top grade values observed on the FP- and SO-fruit. Overall, all the organic LF, in particular the SO treatment, would have improved eco-physiological sustainability and provided an alternative organic fertilizer for a short growing period.

Impact of Phosphorus on Cannabis sativa Reproduction, Cannabinoids, and Terpenes

Many abiotic factors, such as mineral nutrients—including phosphorus (P)—fertility, can impact the yield and growth of Cannabis sativa. Given the economic portion of C. sativa is the inflorescence, the restriction of P fertility could impact floral development and quality could be detrimental. This study sought to track the impacts of varying P concentrations (3.75, 7.50, 11.25, 15.0, 22.50, and 30.0 mg·L−1) utilizing a modified Hoagland’s solution. This experiment examined plant height, diameter, leaf tissue mineral nutrient concentrations, and final fresh flower bud weight as well as floral quality metrics, such as cannabinoids and terpenes. The results demonstrated that during different life stages (vegetative, pre-flowering, flowering), P concentrations impact C. sativa growth and development and yield. Regarding the cannabinoid pools, results varied for the individual cannabinoid types. For the acid pools, increasing fertility concentrations above 11.25 mg·L−1 P did not result in any increase in cannabinoid concentrations. These results indicate that, if a crop is being produced under greenhouse conditions, specifically for cannabinoid production, an excessive P supply did not result in higher cannabinoid production. However, plants grown with a higher rate of P fertility (30.0 mg·L−1) had greater plant width and may result in more buds per plant.

Restricting Phosphorous Can Manage Growth and Development of Containerized Sweet Basil, Dill, Parsley, and Sage

The objective of this research was to quantify the effects of phosphorous (P) concentrations on the growth, development, and tissue mineral nutrient concentrations of four popular culinary herbs commonly grown in containers. Seedlings of sweet basil (Ocimum basilicum ‘Italian Large Leaf’), dill (Anethum graveolens ‘Fernleaf’), parsley (Petroselinum crispum ‘Giant of Italy’), and sage (Salvia officinalis) were individually transplanted to 11.4-cm-diameter containers filled with soilless substrate comprising canadian sphagnum peatmoss and coarse perlite. Upon transplanting and throughout the experiment, seedlings were irrigated with solutions containing 0, 5, 10, 20, or 40 mg·L−1 P; all other macro- and micronutrient concentrations were the same across P concentrations. Plants were grown for 4 weeks in a greenhouse; after that time, data were collected. Relationships between height and width and P concentrations were nonlinear for all four species; height and width increased as P increased to more than 0 mg·L−1 until the species-specific maxima; after that time, no further increase occurred. The same trend was observed for the branch length of sweet basil and sage, and for internode length, leaf area, and shoot dry mass of all four species. Although visible P deficiency symptoms were observed for plants provided with 0 mg·L−1 P, there were no signs of P deficiency for plants provided with ≥5 mg·L−1 P, even though tissue P concentrations were below the recommended sufficiency ranges. As a result of this research, containerized sweet basil, dill, parsley, and sage can be provided with 5 to 10 mg·L−1 P during production to limit growth and produce plants without visible nutrient deficiency symptoms that are proportional to their containers.

Effects of drip irrigation and topdressing on dry matter weight, mineral nutrient absorption and yield of pod-bearing stage in peanut

Effects of drip irrigation and topdressing on dry matter weight, mineral nutrient absorption and yield of pod-bearing stage in peanut

Control of in vitro shoot tip necrosis in Carob Ceratonia siliqua L.

Shoot tip necrosis (STN) is a physiological abnormality whereby the apical shoot initially becomes necrotic and subsequently dies leading to considerable loss of shoots and hampering any commercial application of carob (Ceratonia siliqua L.) micropropagation. The objective of the present study is the optimization of a method to alleviate STN during in vitro multiplication of carob dealing with a range of culture media compounds. Obtained results showed that macroelement strength of the culture medium as well as cytokinin and calcium concentrations were the most important factors in controlling STN incidence in carob. In fact, Zimmerman macroelements are most efficient in terms of STN reduction (only 5% STN observed) and shoot multiplication (28.75 shoots with 26.8 leaves and 4.73 cm length). Moreover, shoots cultured on Zimmerman or Ca enriched ½MS showed higher mineral nutrient contents than those cultured on low Ca media. On the other hand, most shoots recovered from STN have produced roots in presence of 1 mg.L-1 IAA (70%) and 83% survived after transfer to ex vitro conditions. The performance of Zimmerman macroelements is most likely due to its high Ca concentration (7.3 mM) compared to the other media. This is confirmed by the steep reduction of STN intensity obtained on ½MS enriched with Ca.

Rapid Determination of Nutrient Concentrations in Hass Avocado Fruit by Vis/NIR Hyperspectral Imaging of Flesh or Skin

Fatty acid composition and mineral nutrient concentrations can affect the nutritional and postharvest properties of fruit and so assessing the chemistry of fresh produce is important for guaranteeing consistent quality throughout the value chain. Current laboratory methods for assessing fruit quality are time-consuming and often destructive. Non-destructive technologies are emerging that predict fruit quality and can minimise postharvest losses, but it may be difficult to develop such technologies for fruit with thick skin. This study aimed to develop laboratory-based hyperspectral imaging methods (400–1000 nm) for predicting proportions of six fatty acids, ratios of saturated and unsaturated fatty acids, and the concentrations of 14 mineral nutrients in Hass avocado fruit from 219 flesh and 194 skin images. Partial least squares regression (PLSR) models predicted the ratio of unsaturated to saturated fatty acids in avocado fruit from both flesh images (R2 = 0.79, ratio of prediction to deviation (RPD) = 2.06) and skin images (R2 = 0.62, RPD = 1.48). The best-fit models predicted parameters that affect postharvest processing such as the ratio of oleic:linoleic acid from flesh images (R2 = 0.67, RPD = 1.63) and the concentrations of boron (B) and calcium (Ca) from flesh images (B: R2 = 0.61, RPD = 1.51; Ca: R2 = 0.53, RPD = 1.71) and skin images (B: R2 = 0.60, RPD = 1.55; Ca: R2 = 0.68, RPD = 1.57). Many quality parameters predicted from flesh images could also be predicted from skin images. Hyperspectral imaging represents a promising tool to reduce postharvest losses of avocado fruit by determining internal fruit quality of individual fruit quickly from flesh or skin images.

The mitigation effects of exogenous dopamine on low nitrogen stress in Malus hupehensis

Dopamine plays numerous physiological roles in plants. We explored its role in the regulation of growth, nutrient absorption, and response to nitrogen (N) deficiency in Malus hupehensis Rehd. Under low N condition, plant growth slowed, and the net photosynthetic rates, chlorophyll contents, and maximal quantum yield of PSII (Fv/Fm) decreased significantly. However, the application of 100 μmol L−1 exogenous dopamine significantly reduced the inhibition of low N stress on plant growth. In addition to modifying root system architecture under low N supply, exogenous dopamine also changed the uptake, transport, and distribution of N, P, and K. Furthermore, exogenous dopamine enhances the tolerance to low nitrogen stress by increasing the activity of enzymes (nitrate reductase, nitrite reductase, glutamic acid synthase and glutamine synthetase) involved in N metabolism. We also found that exogenous dopamine promoted the expression of ethylene signaling genes (ERF1, ERF2, EIL1, ERS2, ETR1, and EIN4) under low N stress. Therefore, we hypothesized that ethylene might be involved in dopamine response to low N stress in M. hupehensis. Our results suggest that exogenous dopamine can mitigate low N stress by regulating the absorption of mineral nutrients, possibly through the regulation of the ethylene signaling pathway.

Long-term effects of mixed planting on arbuscular mycorrhizal fungal communities in the roots and soils of Juglans mandshurica plantations

BackgroundEstablishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management.ResultsGlomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil.ConclusionsMixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

Разработка технологии производства запеченного карбонада

Aim. Development of technology and optimization of the recipe for baked carbonade with improved consumer properties. Material and Methods. The production of the studied samples of carbonade was carried out in accordance with the current regulatory and technical documentation (GOST R 55795-2013). Formulation optimization was performed using Excel. Sampling and preparation of samples for laboratory research was carried out according to a unified methodology in accordance with the requirements of GOST R 51447-99 (ISO 3100-1-91). Determination of organoleptic characteristics was carried out according to the requirements of GOST 9959-91; GOST R 53159-2008; GOST R 53161-2008. The mass fraction of fat was determined according to GOST 23042-86; protein – according to GOST 25011-81. Results. In the process of research, a recipe for baked carbonade was developed. It was revealed that with the introduction of apple pectin into the formulation of baked carbonade, the content of miner-al nutrients increases, and the content of vitamins significantly increases. For the production of baked carbonade, the following salting method was chosen: raw material was injected by brine in an amount of 10% by weight. Then the raw material is massaged in a massager with a drum rotation frequency of 16 rpm for 15 minutes. Heat treatment consists in baking. The carbonade is baked at 100-120 oC for 1-2 hours. The carbonade is considered ready when the temperature in its thick-ness reaches 70-72 oC. The finished product is sent for cooling to the chambers until the temperature reaches 8 oC in the thickness of the product. The developed product was distinguished by high organoleptic and stable physicochemical and mi-crobiological indicators, corresponding to the current regulatory and technical documentation for this type of product. The prime cost of baked carbonade is 439.69 rubles / kg, which at the moment, taking into account the costs of the manufacturer and the distribution network, is the average price in the market. Conclusion. A technology has been developed for the production of baked pork carbonade with high consumer properties, which contributes to the expansion of the range of functional meat products. The product is recommended for a wide range of consumers of different age groups.

Regulation of Sulfate Uptake and Assimilation in Barley (Hordeum vulgare) as Affected by Rhizospheric and Atmospheric Sulfur Nutrition.

To study the regulation of sulfate metabolism in barley (Hordeum vulgare), seedlings were exposed to atmospheric hydrogen sulfide (H2S) in the presence and absence of a sulfate supply. Sulfate deprivation reduced shoot and root biomass production by 60% and 70%, respectively, and it affected the plant’s mineral nutrient composition. It resulted in a 5.7- and 2.9-fold increased shoot and root molybdenum content, respectively, and a decreased content of several other mineral nutrients. Particularly, it decreased shoot and root total sulfur contents by 60% and 70%, respectively. These decreases could be ascribed to decreased sulfate contents. Sulfate deficiency was additionally characterized by significantly lowered cysteine, glutathione and soluble protein levels, enhanced dry matter, nitrate and free amino acid contents, an increased APS reductase (APR) activity and an increased expression and activity of the root sulfate uptake transporters. When sulfate-deprived barley was exposed to 0.6 µL L−1 atmospheric H2S, the decrease in biomass production and the development of other sulfur deficiency symptoms were alleviated. Clearly, barley could use H2S, absorbed by the foliage, as a sulfur source for growth. H2S fumigation of both sulfate-deprived and sulfate-sufficient plants downregulated APR activity as well as the expression and activity of the sulfate uptake transporters. Evidently, barley switched from rhizospheric sulfate to atmospheric H2S as sulfur source. Though this indicates that sulfate utilization in barley is controlled by signals originating in the shoot, the signal transduction pathway involved in the shoot-to-root regulation must be further elucidated.

Boron modulates the plasma membrane H+‐ATPase activity affecting nutrient uptake of Citrus trees

AbstractBoron (B) affects plasma membrane (PM) integrity and consequently modulates the P‐type PM H+‐ATPase activity creating a driving force for nutrient influx at the root level. Because citrus rootstocks respond differently to B supply, we hypothesised that PM H+‐ATPase activity of varieties contrasting in horticultural traits would affect nutrient uptake by trees. Sweet orange (Citrus sinensis) trees grafted onto Rangpur lime (RL; Citrus limonia) or Swingle citrumelo (SW; Citrus paradisi × Poncirus trifoliata) were grown in nutrition solution with four B concentrations (0 [control concentration], 46, 230 and 460 μM B, as H3BO3) up to 7 days of treatment imposition after plant adaptation into the hydroponic condition. SW exhibited higher B absorption, leaf B and enzyme activity than RL. The highest enzyme activity was achieved with 230 μM of B 1 day after treatment imposition (ATI), whereas B excess impaired the PM H+‐ATPase in all periods evaluated. Absorption of mineral nutrients correlated with PM H+‐ATPase activity, with greater nutrient uptake per root unit in SW compared to RL. Leaf and root nutrient concentrations were equivalent to amounts absorbed and enzyme activity, with greater increments exhibited by trees grafted onto SW compared to RL. Effects of B supply on PM H+‐ATPase activity explain distinct nutrient uptake patterns by trees, what supports fine‐tuning fertilisation guidelines of citrus taking into account rootstock varieties.

Influence of a plant biostimulant on the uptake, distribution and speciation of Se in Se-enriched wheat (Triticum aestivum L. cv. Pinzón)

Selenium (Se) can induce stress in plants. Our main purpose is to assess the effect of a biostimulant, based on hetero-polyoxometalates mixed with humic acids, on Se bio-fortified wheat plants. Secondly, to evaluate a possible modification of the Se species in the plant tissues and to investigate the response of phytohormones. Wheat plants were grown hydroponically and exposed to either selenite (Se(IV)), selenate (Se(VI)) or a mixture of both species (Se(MIX)) in the presence or absence of the biostimulant (foliar, FA; or root application, RA). Biomass, mineral nutrient concentration, phytohormones and Se speciation were investigated. The biostimulant FA did not modify the plant biomass but RA significantly increased the root biomass in all treatments as well as the shoot biomass of plants exposed to Se(VI) and Se(MIX) even when both modes of application caused a severe reduction of IAA levels in shoots. The biostimulant accelerated the translocation of Se from roots to shoots in the presence of Se(VI) and Se(MIX), and it only had a noticeable influence on the Se speciation in roots, but not significant in shoots. X-ray absorption spectroscopy allowed to identify organic Se as the main Se species formed in the shoots. The biostimulant has a mild effect on the Se speciation. The biostimulant has a remarkable influence on both the uptake and accumulation of certain mineral nutrients and the plant metabolism by increasing the biomass under Se exposure. This indicates the potential of this biostimulant that also will prevent the possible Se-induced plant stress.

Morphophysiological responses, bioaccumulation and tolerance of Alternanthera tenella Colla (Amaranthaceae) to excess copper under in vitro conditions

Copper (Cu) is an essential metal and both its deficiency and excess has negative effects on the growth and physiology of plants. Some plant species can tolerate high Cu concentrations due to their anatomical and physiological strategies. These plants can avoid absorption or accumulate this element in their biomass. Thus, the aim was to analyze the anatomical and physiological changes of Alternanthera tenella in response to excess Cu under in vitro conditions. A. tenella plants, previously established in vitro, were transferred to culture media containing 0, 25, 50, 100 or 200 µM Cu. At 30 days of culture, the stem and leaf anatomy, contents of photosynthetic pigments mineral nutrients, chlorophyll fluorescence, and, growth were analyzed. The excess Cu induced lower biomass accumulation. Plants also presented a decline in cell sizes of stem and leaf tissues under high Cu concentrations. Greater formation of druse crystals and lower number of active reaction centers (RC/CSM) were observed with 200 μM Cu. The Cu treatments modulated the contents of mineral nutrients and photosynthetic pigments of the plants. Plants cultured in media with Cu absence or excess (200 μM Cu) presented partial inhibition of electron transport and photochemical activity of photosystem II. Even though A. tenella plants showed clear signs of stress under Cu excess, they also have a strong capacity for Cu bioaccumulation and tolerance. A. tenella plants can be used for phytoremediation or bioindication due to their tolerance and high Cu bioaccumulation capacity. Copper can modulate the morphophysiology of A. tenella under in vitro conditions. A. tenella can be used for phytoremediation or bioindication due to its tolerance and high copper bioaccumulation capacity.

Interactive Effects of N Form and P Concentration on Growth and Tissue Composition of Hybrid Napier Grass (Pennisetum purpureum × Pennisetum americanum).

This study aimed to assess effect of nitrogen (N) form and phosphorus (P) level on the growth and mineral composition of hybrid Napier grass. Experimental plants were grown with different N forms (NO3−, NH4NO3, and NH4+; 500 µM) and P concentrations (100 and 500 µM) under greenhouse conditions for 42 days. Growth rate, morphology, pigments, and mineral nutrients in the plant tissue were analysed. At the low P concentration, the better growth was found in the plants supplied with NH4+ (relative growth rate (RGR) = 0.05 g·g−1·d−1), but at the high P concentration, the NH4+-fed plants had 37% lower growth rates and shorter roots and stems. At the high P level, the NH4NO3−-fed plants had the highest RGR (0.04 g·g−1·d−1). The mineral nutrient concentrations in the plant tissues were only slightly affected by N form and P concentration, although the P concentrations in the plant tissue of the NO3−-fed plants supplied with the high P concentration was 26% higher compared to the low P concentration plants. The N concentrations in the plant tissues did not vary between treatments. The results showed that the optimum N form for the plant growth and biomass productivity of hybrid Napier grass depends on P level. Hybrid Napier grass may be irrigated by treated wastewater containing high concentrations of N and P, but future studies are needed to evaluate biomass production and composition when irrigating with real wastewater from animal farms.

Physiological Performance of a Coastal Marsh Plant Hydrocotyle vulgaris in Natural Conditions in Relation to Mineral Nutrition and Mycorrhizal Symbiosis

Abstract Fluctuating soil salinity and competition for light are the main factors affecting plant distribution and performance in coastal salt marshes. The aim of the present study was to assess plant performance by means of non-destructive instrumental methods in a highly heterogeneous natural habitat. More specifically, environmental factors affecting growth and physiological performance of a clonal plant Hydrocotyle vulgaris L. were investigated. Changes in soil salinity, soil mineral characteristics, leaf nutrient concentrations, morphological parameters, chlorophyll fluorescence, and mycorrhizal symbiosis were analysed in different experimental plots of naturally growing H. vulgaris plants. The dynamic nature of interaction between sea water flooding-affected changes in soil salinity and competition-dependent changes in light availability led to micro-environmental heterogeneity differentially affecting physiological performance and growth of H. vulgaris in natural conditions. Plant growth was mostly affected by intensity of photosynthetically active radiation in the respective plots. Increased growth rate in shaded conditions specifically pointed to shade tolerance strategy of H. vulgaris. High heterogeneity of mineral nutrients between the plots was established. However, considerable plasticity of metabolism in respect to highly variable soil concentration of mineral nutrients together with effective mineral adaptation mechanisms ensured optimal supply of material for growth. Photochemistry of photosynthesis was only marginally affected by differences in microenvironmental conditions as shown by respective changes in chlorophyll a fluorescence parameters. Mycorrhizal symbiosis was stimulated by moderately increasing soil salinity and suppressed by relatively high salinity. When the effect of soil salinity was omitted, intensity of mycorrhizal symbiosis was positively associated with intensity of photo-synthetically active radiation. In general, a relatively high stable level of photosynthetic performance across a wide range of micro-environmental conditions indicates an adequate level of physiological adaptation of H. vulgaris to conditions of a coastal salt marsh. The present data clearly reflect complex interactions between environmental factors and plastic physiological responses of H. vulgaris.

Physiological Aspects of Melon (Cucumis melo L.) as a Function of Salinity

This study evaluated the effect of saline water irrigation (4.5 dS m−1) on growth, gas exchange and mineral nutrient content in eight melon accessions and two cultivars classified as tolerant (Sancho) and susceptible (Caribbean Gold) to salinity. Results showed saline water irrigation reduced stomatal conductance, which consequently decreased transpiration and photosynthesis. Also, plants became more efficient in water use under salinity and increased K+/Na+ in leaves as a mechanism to mitigate the ionic stress caused by Na+ and Cl−. Moreover, the accessions responded differently from cultivars to saline water irrigation. However, we found accessions more efficient in water use, with more K+/Na+ content and higher photosynthesis rate than Sancho under saline and non-saline water irrigation. Due to these traits, these accessions were more productive than Sancho under salinity.

Sole-Source LED Lighting and Fertility Impact Shoot and Root Tissue Mineral Elements in Chinese Kale (Brassica oleracea var. alboglabra)

The current study investigated the impacts of light quality and different levels of fertility on mineral nutrient concentrations in the shoot and root tissues of Chinese kale (Brassica oleracea var. alboglabra). “Green Lance” Chinese kale was grown under: (1) fluorescent/incandescent light; (2) 10% blue (447 ± 5 nm)/90% red (627 ± 5 nm) light emitting diode (LED) light; (3) 20% blue/80% red LED light; and (4) 40% blue/60% red LED light as sole-source lighting at two different levels of fertility. All plants were harvested 30 days after seeding and shoot and root tissues were analyzed for mineral nutrients. Lighting and fertility interacted to influence kale shoot and root mineral nutrient concentrations. The results indicate that sole-source LED lighting used in production can impact the mineral nutritional values of baby leafy greens now popular for the packaged market. This is evident in the current and previous studies in which lighting affects biomass and indirectly affects mineral nutrient concentrations.

Determination of Mineral Nutrient Concentrations in Fish Growing Water and Lettuce Leaf for Hydroball Aquaphonics

Determination of Mineral Nutrient Concentrations in Fish Growing Water and Lettuce Leaf for Hydroball Aquaphonics

Effect of foliar application of amino acids on the salinity tolerance of tomato plants cultivated under hydroponic system

Salinity is one of the most critical problems faced by agriculture in all the arid and semi-arid climates in the world. Many biostimulant-producing companies utilize different raw materials to palliate the negative effects of salinity on crops. Some of these active materials are amino acids (AAs). In this study, the effect of the foliar application of free amino acids or as a mixture of them was studied in tomato plants cv “Optima”, grown in a controlled environment growth chamber in a hydroponic system with Hoagland’s solution with added 50 mM NaCl. The following treatments were applied: i) Control (-salt), ii) salt (+salt), and the salt treatments with amino acids (AAs + salt): iv) L-Arg, v) L-Pro, vi) Glu, vii) L-Trp, viii) L-Met + L-Arg, ix) L-Met + L-Trp, x) Glu + L-Pro. At the end of the assay, vegetative growth parameters, relative water content, mineral nutrient content, carbohydrates and organic solutes and chlorophylls were measured. The results showed that salinity decreased the growth of the plants, but those treated with the L-Met, Pro + Glu and Met + Trp reversed the negative effect of salinity. Also, this result was not due to differences in the concentration of Cl- or Na+ in the leaves, or to changes in the water status of the plants, but to a greater accumulation of total soluble sugars induced by the application of AAs, which could have de-activated the reactive oxygen species created by the toxicity of these ions. The results of this experiment also highlight the antagonistic or synergistic effects between the AAs, which should be taken into account by fertilizer producers.