Search

Phosphorus (P) use efficiency is crucial for sorghum production. P acquisition efficiency is the most important component of P use efficiency. The early-stage evaluation of plant development is a useful tool for identifying P-efficient genotypes. This study aimed to identify sorghum hybrids that are efficient in P use efficiency and assess the genetic diversity among hybrids based on traits related to P acquisition efficiency. Thus, 38 sorghum hybrids and two inbred lines (checks) were evaluated under low and high P in a paper pouch system with nutrient solution. Biomass and root traits related to P efficiency were measured. There was no interaction between genotypes and P levels concerning all evaluated traits. The biomass and root traits, except root diameter, presented smaller means under low P than high P. Efficient and inefficient hybrids under each P level were identified. The genetic diversity assessment grouped these genotypes in different clusters. The hybrids AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540, and DKB 590 were superior under low-P and high-P. Hybrids SC121, 1236020 e 1167017 presented the lowest means than all other hybrids, under both conditions. The evaluated hybrids showed phenotypic diversity for traits related to P acquisition, such as root length and root surface area, which can be useful for establishing selection strategies for sorghum breeding programs and increasing P use efficiency. Resumo A eficiência do uso do fósforo (P) é fundamental para a produção de sorgo. A avaliação no estágio inicial do desenvolvimento da planta é uma ferramenta útil para a identificação de genótipos eficientes de P. Este trabalho teve como objetivo identificar híbridos de sorgo que sejam eficientes ao uso de P e avaliar a diversidade genética entre os híbridos com base em características relacionadas à eficiência de aquisição de P. Assim, 38 híbridos de sorgo e duas linhagens (testemunhas) foram avaliados sob baixo e alto P em sistema de pastas de papel com solução nutritiva. Características de biomassa e de raiz relacionadas à eficiência de P foram mensuradas. Não houve interação entre genótipos e níveis de P em todas as características avaliadas. As características de biomassa e raiz, exceto o diâmetro da raiz, apresentaram médias menores sob baixo P em comparação com alto P. Híbridos eficientes e ineficientes sob cada nível de P foram identificados e agrupados quanto à diversidade genética. Os híbridos AG1090, MSK326, AG1060, 1G100, AS 4639, DKB 540 e DKB 590 foram superiores sob baixo-P e alto-P. Os híbridos SC121, 1236020 e 1167017 apresentaram as menores médias que todos os outros híbridos, em ambas condições. Os híbridos avaliados apresentaram diversidade fenotípica para características relacionadas à aquisição de P, como comprimento e área superficial da raiz, o que pode ser útil para estabelecer estratégias de seleção para programas de melhoramento de sorgo e aumentar a eficiência de uso do P.

The aim of Sustainable Development Goal 2 (SDG2) is to end hunger, improve food security and nutrition and promote sustainable crop production by 2050. However, climate change, increasing soil salinization and the inadequate availability of fresh water have negatively affected crop production around the world including South Africa, making it difficult to meet the required target. This necessitates the use of wild edible plants that are adapted to adverse conditions such as drought and salinity in order to mitigate this problem. The genus Trachyandra (Asphodelaceae) consist of three edible species (T. ciliata, T. divaricata and T. falcata) which are native to the dry saline environments of the western Cape coastal sand dunes. The genus is less studied with no record of cultivated species, although the existing literature states that T. ciliata, (wild cabbage) was originally used as a food source by the indigenous Khoi-san people who lived on the South African Cape coast. Colonization and removal of indigenous people from cultural lands led to erosion and detachment from the knowledge of the land and its useful plants. The species is used in selected restaurants where the inflorescence is steamed and eaten as a vegetable or added into a stew. This review explores the importance of Asphodelaceae family, T. ciliata as a vegetable crop and its potential as a pharmaceutical candidate. Furthermore, this review examines potential technological advances such as hydroponics that could be used for sustainable crop production of T. ciliata. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was utilized in the selection of articles in this review. The existing literature provided useful information on the potential of T. ciliata as a vegetable crop and the importance of using halophytes to achieve food security. This appraisal is expected to serve as a template for researchers, food enthusiasts, potential farmers and policy makers who may be keen in exploring further nutritional composition and medicinal potential of this plant.&nbsp

Nickel is an essential element as the cofactor in the enzyme urease, and pecan (Carya illinoinensis (Wangenh.) K. Koch) is known to suffer from commercially important nickel deficiency manifested in “mouse-ear” disease. Foliar application of nickel has been shown to increase foliar nickel concentrations and foliar urease activity and to cure the nickel deficiency syndrome. However, there is currently no detailed knowledge on the uptake pathways of nickel into pecan leaves and subsequent internal redistribution of nickel after foliar application. In this study, we cultivated pecan seedlings for a period of 6 months after germination (growing to 250–350 mm tall with mature compound leaves) under low nickel availability in hydroponics solutions. The solution was purified to < 0.001 mg L−1 of nickel, and plants displayed severe “mouse-ear” deficiency symptoms. Half of the plants were then treated with a foliar nickel spray (100 mg L−1 nickel), and leaves were analysed using instrumental micro-X-ray fluorescence (µXRF) analysis, and total leaf nickel concentrations and urease activities were determined. The results show that nickel is rapidly taken up in the leaf and distributed into the vascular bundles. Application of nickel leads to a major increase in urease activity as well as in leaf nickel concentrations, and young emerging growth no longer display deficiency symptoms. The uptake pathway of nickel following foliar application is via the main vein into the secondary veins towards other tissues.

The overexploitation of the O horizon, or the litter layer of the soil profile, in the production of ornamental plants, causes the disintegration of the landscape and the loss of soil productivity in preserved areas, which calls for new approaches to address the need for substrates in soilless culture systems. Thus, this study examined the construction of purpose-designed Technosols from construction waste as substrates in the production of ornamental plants. The evaluated treatments were as follows: (CCW) 40% concrete waste, 30% compost, 30% wood chips; (ECW) 40% excavation waste, 30% compost, 30% wood chips; and (AOW) 40% compost, 60% wood chips. A control treatment (CTL) was composed of 50% compost and 50% natural exported soil. The plant species used were Heliotropium arborescens, Lobularia maritima, and Lavandula angustifolia, which were grown for one cycle in an 8-week greenhouse experiment. The pH, electrical conductivity (EC), carbon and nutrient (N, P, and exchangeable cations) contents, and water availability of the Technosols and control treatment, as well as the survival rate, presence of flowers, number of flowers per plant and shoot diameter of the ornamental plants, were evaluated over the experimental period. All treatments had slightly alkaline pH, yet their EC decreased to the levels recommended for growing media considering the evaluated species. The AOW presented the highest initial contents of total C, total N, and available P, and the highest concentration of DOC at the end of the experiment, followed by the CCW Technosol. There were no differences within treatments regarding their initial and final available P contents, and the final available P and mineral N contents in Technosols and control did not differ, thus showing their ability to supply both N and P adequately to plants. A high plant survival rate was observed throughout the experimental period, and the frequency of blooming plants increased for all species regardless of the treatment. The Technosols produced from construction and excavation waste had been shown to provide favorable chemical, physical, and physicochemical conditions for the vegetative development and blooming of ornamental plants with different fertilization requirements and, thus, could be used as alternative to reduce the exploitation of exported natural soils. The plants used in the study had different nutritional requirements, yet they all grew adequately. The Technosol made from concrete waste had the most promising outcome in terms of C and available nutrients (N, P and exchangeable cations) as well as water retention and availability to plants compared to the excavation-based Technosol, besides having comparable results with the control treatment that is commonly used by the producers to grow ornamental and flower plants. Considering that no mineral fertilization was used in this study, further research may assess the use of a controlled fertilization schedule in order to reduce and optimize the use of agrochemical inputs, from small to large-scale growers of flower plants.

Uranium (U) is difficult to be transported from roots to leaves, but it has been reported to inhabit photosynthesis in leaves, so how does this work? In the present study, the effects of U (0-25 μM) on the development and photosynthesis in V. faba seedlings were studied under hydroponics. The results showed that U significantly inhibited the growth and development of V. faba plants, including decreased biomass, water content, lateral root number and root activity. U also led to a large accumulation of reactive oxygen species (ROS) in the leaves which affects leaf structural traits (e.g., decreased leaf area and chlorophyll a content). When U concentration was 25 μM, the net photosynthetic rate (Pn) and transpiration rate (Tr) were inhibited, which were only 66.53% and 41.89% of the control, respectively. Further analysis showed that the stomatal density of leaves increased with the increase of U concentration, while the stomatal aperture and stomatal conductance (Gs) were on the contrary. The results of chlorophyll fluorescence showed that the non-photochemical quenching coefficient (NPQ) increased and the electron transfer rate (ETR) decreased after U exposure, but fortunately, photosystem II (PSII) suffered little damage overall. In conclusion, the accumulation of U in the roots inhibited the root activity, resulting in water shortage in the plants. To prevent water loss, leaves have to regulated stomatal closure at the cost of weakening photosynthesis. These results provide a new insight into the mechanism by which U affects plant photosynthesis.

Boron (B) deficiency influences sugar beet development and productivity. A hydroponic set up of experiment was conducted by utilizing different B concentrations to study the impact of different morphological and physiological responses of sugar beet seedlings under B deficiency. The results showed that B deficiency (14 days of stress) inhibited the growth of different plant parts of sugar beet. The B deficiency significantly increased the leaf specific weight (SLW) and the root-shoot ratio of sugar beet seedlings. The activities of peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) showed a decreasing tendency under B deficiency, while the contents of hydrogen peroxide (H2O2) and superoxide (O2−) increased with B concentration. Malonaldehyde (MDA) and proline contents were induced at B deficiency. In conclusion, B deficiency significantly reduced dry weight and leaf area, resulting in stunted sugar beet seedlings. It was manifested by a significant decrease in antioxidant enzyme activities and accumulation of ROS in the plant cells, inducing oxidative stress. The current study revealed that B deficiency affects plant growth and various morpho-physiological processes.

In this research, it was aimed to use the Chlorella Vulgaris algae, and eggshell waste (ESW) as different mineral sources for tomato plant nutrition in soilless culture. Algae is seen as safe, sustainable energy source. Egg shell waste is known to be valuable for high calcium content and minerals therefore, has been considered as mineral enrichment source. Although there are several papers on the soil nutrition, there is not as much information on eggshell waste and algae use for plant production in soilless culture. In the controlled atmosphere of the laboratory, a set-up was constructed for pumping the liquid medium (hydroponics) circulating in the tubes holding the tomato plantlets. The liquid nutrient solutions used for soilless culture treatments were media enriched with algae, enriched with ESW and blank (hydroponic only). Research was conducted for 3 months, the final weight of harvested tomatoes and mineral uptake of the plant (stalk and tomato) for different treatments were measured. Algae added medium gave higher results in tomato weight, than ESW added and blank treatments. Results showed that algae and ESW addition led to increased Ca content in harvested tomato, as well as minerals such as B, K, Mg, and Zn. The results were as expected in terms of increase in mineral contents, but the statistics showed no significant difference between treatments.

In the Netherlands recirculation of the nutrient solution is statutory required in soilless culture systems. The goal is to achieve a zero liquid discharge, it means no solution with fertilizers, pesticides and/or cleansing products are allowed to be discharged to surface or ground water or the sewage system. It also means that products added to the system should be taken up by the plants or broken down. The objectives of this research were to investigate i) if frequently used cleansing products accumulate in the nutrient solution and may harm growth of the plants, and ii) if the used concentrations of cleansing products were able to eliminate pathogens in the circulating nutrient solution. Gerbera was used as a pilot crop. The research was divided in four steps. As a first step growers and consultants were inquired (1) about the use of cleansing products additional to the traditional disinfection methods. It was followed by laboratory experiments (2) to test a few cleansing products in various concentrations against plant pathogens. A next step was a greenhouse experiment in which gerbera plants were infected with Fusarium oxysporum (3). Finally sampling at commercial farms (4) was performed to investigate if accumulation did really appear. The inquiry showed that nearly all growers were using, additional to UV or heat treatment for disinfection, cleansing products such as hydrogen peroxide, bleach, chlorine dioxide or ECA water. They were mainly used for cleaning of the pipework. From the laboratory experiments it appeared that the concentration to eliminate the pathogen was much higher as the concentration used to clean the pipe work. In the greenhouse experiment two cleansing products (hydrogen peroxide, chlorine dioxide) were added in five concentrations with two replicates and compared with a control. All treatments were infested with F. oxysporum, except for the control. During the short growing cycle there were no symptoms of F. oxysporum at the plants. However, it appeared that the higher the concentration of added cleansing products the worse the state of the plants, decreasing plant growth. Additionally, bleach showed high sodium concentrations, while the iron chelate was broken down by the hydrogen peroxide. Looking to the cleansing products at commercial farms hardly any accumulation could be measured. It was concluded that the low concentrations applied in commercial practice do not accumulate to toxic levels while a side effect of cleansing products against pathogens cannot be expected.

Silicon (Si) absorption is highly variable among different plant types; however, few studies have examined variations among different cultivars within a single species. In this study, 10 different tomato cultivars, including determinants and indeterminants as well as hybrids and heirlooms, were hydroponically grown in the presence or absence of Si to determine the absorption and distribution of the nutrients in roots, stems, petioles, and leaves. A total elemental analysis revealed that Si concentrations significantly increased with Si treatment, and that root concentrations were significantly higher than those in leaves. Although a few species showed differences in carbon, nitrogen, and calcium concentrations in roots and leaves with Si treatment, many of the macronutrients and micronutrients were unaffected. These data suggest that tomato plants absorb Si within the macronutrient range and restrict its movement from roots to shoots.

Lettuce has a predisposition to nitrate accumulation and has led many researchers to develop research to reduce this accumulation. The objective of this study was to evaluate the effect of nitrate concentration (NO3-) and nitrate/ammonium ratio (NO3-:NH4+) on growth, production and accumulation of these nitrogen compounds in lettuce grown in a hydroponic system in southern Amazon. There were performed two experiments with Iceberg lettuce type, in a floating-hydroponic system under protected cultivation. In the first experiment, five nitrate concentrations (2.5, 5.0, 7.5, 10.0 and 15.0 mmol L-1) were evaluated. In the second experiment, the best NO3- : NH4+ ratio was evaluated with five proportions 0:100, 25:75, 50:50, 75:25 and 100:0 in the nutrient solution. At 35 days after transplanting, the evaluations were performed. The nutrient solution containing nitrogen (N) as nitrate source in the concentration of 15.0 mmol L-1 contributed to higher lettuce productivity, being the concentration recommended for hydroponic grown system in southern Amazon. It is recommended to use about 23% of the N in nutrient solution in ammonium form, where higher N-ammonium concentrations are not indicated for Icebeg lettuce type because it reduces the productivity of this green leaf vegetable, causing toxicity symptoms. Key words: Nitrogen, vegetable, nutrient solution, food security.

Cadmium (Cd) is one of the most important heavy metals in the environment which has several effects on the morphology, physiology, and anatomy of plants. It is a mobile heavy metal that can be transferred easily into plants, thus entering into the human food chain. Chamomile (Matricaria chamomilla L.) as an important medicinal plant can uptake and accumulate Cd in its root and aerial organs. In this research, the effects of different concentrations of Cd (90, 180, and 360 μM) were investigated on the growth parameters, anatomical features, and enzymatic antioxidant activities in flowers of chamomile after 7 days of exposure. The content of apigenin, a flavone compound mostly synthesizing in chamomile flowers, was also analyzed after 72 h from Cd treatment. The results showed that all concentrations of Cd reduced the length and biomass of roots and shoots, the diameter of flowers, as well as the number of pollen grains in tubular florets, while increased trichome density on the florets. Cd-treated plants showed an increase in antioxidant enzymes, superoxide dismutase (SOD), and peroxidase (POX) activities. After 7 days of treatment to Cd major concentration, flowers accumulated Cd and enhanced the apigenin production with the increase of Cd contamination in hydroponic solution. This increase of apigenin is most likely due to its antioxidant and sequestering property as a resistance response to Cd excess.

The legume plant alfalfa (Medicago sativa L.) is a widely cultivated perennial forage due to its high protein content, palatability, and strong adaptability to diverse agro-ecological zones. Alfalfa is a self-incompatible cross-pollinated autotetraploid species with tetrasomic inheritance. Therefore, maintaining excellent traits through seed reproduction is a prime challenge in alfalfa. However, the cutting propagation technology could enable consistent multiplication of quality plants that are genetically identical to the parent plant. The current study aimed to develop a simple, cost-effective, reproducible, and efficient hydroponic cutting method to preserve alfalfa plants and for molecular research. In this study, alfalfa landrace ‘Wudi’ was grown in hydroponics for 30 days and used as source material for cuttings. The top, middle and bottom sections of its stem were used as cuttings. The rooting rate, root length, and stem height of the different stem sections were compared to determine the best segment for alfalfa propagation in four nutrient treatments (HM, HM + 1/500H, HM + 1/1000H and d HM + 1/2000H). After 21 days of culture, the rooting rates of all the three stem types under four cutting nutrient solutions were above 78%. The rooting rate of the middle and bottom parts in HM + 1/1000 H and HM + 1/2000 H nutrient solutions reached more than 93%, with a higher health survey score (> 4.70). In conclusion, this study developed a de novo cutting propagation method that can be used to conserve and propagate germplasm in breeding programs and research. This method is a new report on the cutting propagation of alfalfa by hydroponics, which could supplement the existing cutting propagation methods.

Salinity is a significant constraint for plant survival and productivity. Therefore, an immediate solution to this problem is sought to meet the human population's food demands. Recently, Menadione sodium bisulphite (MSB) has emerged as a significant regulator of plant defense response under abiotic stress. Studies on MSB are scarce, and a few reports on salinity (Arabidopsis and okra) and cadmium stress (okra) are present in the literature. However, these studies did not include the impact of MSB on physiological and plant water relation attributes, critical mediators of plant survival, and yield production under stress. Our results studied the impact of MSB on wheat administered to NaCl salinity in hydroponics medium. We used two wheat cultivars (salt-sensitive MH-97 and salt-tolerant Millat-2011, based on our pre-experimental studies). Seeds were primed in different MSB doses [control (unprimed), hydroprimed, 5, 10, 20, and 30 mM]. Salinity significantly diminished growth, chlorophyll molecules, photosynthesis, total free amino acids, water and turgor potentials, K, Ca, and P contents of wheat when administered NaCl salinity in the nutrient solution. Besides, a noteworthy accretion was present in oxidative stress markers [hydrogen peroxide & malondialdehyde], proline, ascorbic acid, antioxidant enzyme activities, and Na+ accumulation under salinity. Moreover, MSB noticeably enhanced chlorophyll molecules, proline, and oxidative defense to improve photosynthesis, plant water relations, and diminish specific ions toxicity. Our results manifested better defense regulation in salt-administered plants primed with 5 and 10 mM MSB. Our findings strongly advocated the use of MSB in improving plant salinity tolerance, particularly in wheat.

Currently, in critical times of confinement, hydroponics is a viable alternative that allows the production of plant biomass derived from the initial development of plants in the stages of germination and early growth of seedlings from feasible seeds, it is the sowing of soilless cultivation, this method facilitates the productive, sustainable, and ecological development of plants. Hydroponic crops are developed in a medium or culture system fed by a nutrient solution that offers the precise food for the entire period of growth of the forages, free of pesticides andfungicides with this we get healthy food for the feeding of domestic animals. In addition, it allows the use of simple or complex structures to produce fodder, taking advantage of spaces or areas such as terraces, infertile soils, rugged terrain, technical or traditional greenhouses. Based on this idea, techniques were deployedthat are supported by using substrates, or methods with contributions of nutrient solutions, always considering the needs of the plant such as temperature, humidity, water, and nutrients. Based on prac-tice, the benefits per unit of planted area are high due to greater consistency, productivity, safety, and effi-ciency in the use of water, light, and nutrients, and it is also economically viable that deserves to be considered by small and medium- sized companies. rural producers of domestic animals.

Soil bioavailability of phosphorus (P) is a major concern for crop productivity worldwide. As phosphatic fertilizers are a non-renewable resource associated with economic and environmental issues so, the sustainable option is to develop P use efficient crop varieties. We phenotyped 82 diverse wheat (Triticum aestivum L.) accessions in soil and hydroponics at low and sufficient P. To identify the genic regions for P efficiency traits, the accessions were genotyped using the 35 K-SNP array and genome-wide association study (GWAS) was performed. The high-quality SNPs across the genomes were evenly distributed with polymorphic information content values varying between 0.090 and 0.375. Structure analysis revealed three subpopulations (C1, C2, C3) and the phenotypic responses of these subpopulations were assessed for P efficiency traits. The C2 subpopulation showed the highest genetic variance and heritability values for numerous agronomically important traits as well as strong correlation under both P levels in soil and hydroponics. GWAS revealed 78 marker-trait associations (MTAs) but only 35 MTAs passed Bonferroni Correction. A total of 297 candidate genes were identified for these MTAs and their annotation suggested their involvement in several biological process. Out of 35, nine (9) MTAs were controlling polygenic trait (two controlling four traits, one controlling three traits and six controlling two traits). These multi-trait MTAs (each controlling two or more than two correlated traits) could be utilized for improving bread wheat to tolerate low P stress through marker-assisted selection (MAS).

This study was undertaken to determine the effect of potassium silicate (K2SiO3) on the physiological and growth characteristics and elemental composition of barley plants. Hydroponically grown barley (Hordeum vulgare L.) var. Wilma was exposed to four different levels of Si in the form of K2SiO3 at concentrations of 0 (Si0), 0.5 (Si0.5), 1 (Si1) or 1.5 (Si1.5) mM Si. Plants were analyzed for root length, number of dry leaves, number of trichomes, electron transport system activity in mitochondria (ETS), leaf pigment content and elemental composition of roots and leaves. Treatment with Si0.5 significantly increased the concentration of total chlorophylls, root length and ETS activity in barley. Plants with no Si added to the nutrient solution had significantly more dry leaves than plants from all Si-treated groups. Necrosis was observed in Si0 plants, while leaf damage was not visible in treated plants. According to the results of the study, we evidenced that plants were stressed due to Si deficiency. The addition of K2SiO3 significantly affected the concentration of Si, K, Ca, Cl, S, Mn, Fe and Zn in roots and leaves of barley. In barley treated with Si0.5, plants showed the best performance in terms of their physiological characteristics and growth.

Humic substances (HS) are the most important natural biostimulant of plants. However, the relationship between their structure and biological activity in plants is still not well recognized. The objective of this paper was to assess the influence of molecular fractions of humic acids (HA) (HA < 30 kDa and HA > 30 kDa) on reducing negative effects of drought stress in soybean (Glycine max (L.) Merr.) seedlings of Progres and Nawiko cultivars. Drought stress was induced in laboratory conditions by the addition of polyethylene glycol 6000 (PEG 6000) to make a water potential of −0.5 MPa. HA were extracted according to the International Humic Substances Society procedure, and then were separated into two molecular fractions by membrane filtration. The following physiological and biometric parameters were determined: chlorophyll content, photosynthesis activity, electrical conductivity, fresh and dry mass of overground and roots, and plant length. The enzyme activity and ion contents were also measured. Differences in response to drought stress with the addition of HA < 30 kDa and HA > 30 kDa or not to the Hoagland’s solution were observed among studied cultivars. Drought stress caused a decrease in the most physiological parameters and increase in peroxidase activity in the case of both studied cultivars. However, the results of biometric measurements showed that the Progres cultivar appears to have better tolerance to drought stress. The significant influence of water deficit on most macroelement content in dry matter leaves of both studied cultivars was not observed, while its effect on microelement uptake by soybean plants was concluded. In the case of the Progres cultivar, the results showed a significant decrease in microelement content in the dry matter of leaves, whereas in the leaves of Nawiko cultivar there was a significant increase. The influence of HA > 30 kDa and HA < 30 KDa fractions on physiological features of both studied cultivars was varied. HA > 30 kDa fraction better up-regulated the antioxidant defense system. Unfortunately, no effect of either HA fraction on the macro- and micronutrients uptake system of both studied cultivars was observed.

Imidaclothiz is a novel and systemic neonicotinoid pesticide with excellent insecticidal efficacy. However, knowledge of its uptake, translocation, and biotransformation within plants is still largely unknown, restricting work on its accurate and comprehensive risk assessment. Here, we systematically investigated the behavior of imidaclothiz in three plant-water systems via hydroponic experiments. The results showed that imidaclothiz was readily taken up by plant roots and translocated upward, resulting in relative enrichment in leaves. The recoveries of imidaclothiz in plant-water systems decreased with increasing exposure time, and approximately 31.8-45.6% mass loss was measured at the end of exposure. Ultimately, imidaclothiz yielded five products in celery leaves, three products in lettuce leaves, and two products in radish leaves. Multiple metabolic reactions including hydroxylation, hydrolysis of nitrate ester, and methylation occurred within plants. This is the first report on the fate of imidaclothiz within plants and suggests increasing concerns about the risk assessment of imidaclothiz.

Yellowing and wilting of black pepper vines is a serious concern in many black pepper growing tracts where Pythium deliense was recently emerged as a pathogen from the rhizosphere of affected vines, which is proved to be pathogenic by Koch's postulates. As a measure to manage the symptoms, bioagents were evaluated against infection by P. deliense. Among the seven bioagents tested, Trichoderma harzianum and Streptomyces albulus showed 100% inhibition in vitro followed by one Streptomyces sp. and S. rimosus (75.33%). The potential ones were further evaluated under the hydroponic system in vivo by challenge inoculation. No root infection was noticed with T. harzianum and S. albulus inoculation, instead, the inoculated plants showed root regeneration. This suggests the efficiency of these bioagents on plant growth promotion as well as on disease suppression. Biochemical analysis of the hydroponic medium showed an increase in membrane conductivity in all the treatments except in T. harzianum. The release of phenolic compounds into the medium was lowest with T. harzianum indicating the prevention of pathogen invasion. In planta evaluation under greenhouse condition and field evaluation also showed the protective effect of T. harzianum and S. albulus with a reduction in the intensity of yellowing to an extent of 73.1% and 71.2%, respectively. The study revealed that T. harzianum and the actinomycete S. albulus had the potential to prevent the root rot caused by P. deliense.

Messina (Melilotus siculus) is a new annual pasture legume with better combined waterlogging and salt tolerance than other annual legumes. Messina cv. Neptune and a new salt-tolerant rhizobial symbiont (Sinorhizobium medicae SRDI-554) were made available to Australian growers in 2017. Messina is related to the annual medics (Medicago spp.) that are nodulated by the same genus of rhizobia and regarded as sensitive to soil acidity. Because some saltland soils are acidic, it is important to understand the sensitivity of messina to soil acidity in order to avoid failures during early adoption. Acidity tolerance of the messina–Sinorhizobium symbiosis was investigated in a hydroponic experiment (inoculation with SRDI-554, or the salt-intolerant strain WSM-1115 recommended for medics), and in three acidic soils (pHCa 4.3–5.5) (inoculation with SRDI-554 ± lime pelleting of seed), in the greenhouse. In the hydroponic experiment, the percentage of messina plants (with SRDI-554) that formed nodules declined at pH levels between 5.7 (43%) and 5.5 (4%). Strain SRDI-554 was slightly more sensitive to acidity than strain WSM-1115. In the acidic soils, more plants formed nodules than in the hydroponic experiment at similar pH levels; however, without lime pelleting, nodule number was inadequate at soil pHCa

Microbial-inoculated phospho-feather compost (PIFRM) was manufactured by inoculating Arthrobacter ureafaciens K10 and Streptomyces sp. CP3 into compost composed of spent mushroom waste (SMW), duck ...

Elevated CO2 interactions with other factors affects the plant performance. Regarding the differences between cultivars in response to CO2 concentrations, identifying the cultivars that better respond to such conditions would maximize their potential benefits. Increasing the ability of plants to benefit more from elevated CO2 levels alleviates the adverse effects of photoassimilate accumulation on photosynthesis and increases the productivity of plants. Despite its agronomic importance, there is no information about the interactive effects of elevated CO2 concentration and plant growth regulators (PGRs) on potato (Solanum tuberosum L.) plants. Hence, the physiological response and source-sink relationship of potato plants (cvs. Agria and Fontane) to combined application of CO2 levels (400 vs. 800 µmol mol−1) and plant growth regulators (PGR) [6-benzylaminopurine (BAP) + Abscisic acid (ABA)] were evaluated under a controlled environment. The results revealed a variation between the potato cultivars in response to a combination of PGRs and CO2 levels. Cultivars were different in leaf chlorophyll content; Agria had higher chlorophyll a, b, and total chlorophyll content by 23, 43, and 23%, respectively, compared with Fontane. The net photosynthetic rate was doubled at the elevated compared with the ambient CO2. In Agria, the ratio of leaf intercellular to ambient air CO2 concentrations [Ci:Ca] was declined in elevated-CO2-grown plants, which indicated the stomata would become more conservative at higher CO2 levels. On the other hand, the increased Ci:Ca in Fontane showed a stomatal acclimation to higher CO2 concentration. The higher leaf dark respiration of the elevated CO2-grown and BAP + ABA-treated plants was associated with a higher leaf soluble carbohydrates and starch content. Elevated CO2 and BAP + ABA shifted the dry matter partitioning to the belowground more than the above-media organs. The lower leaf soluble carbohydrate content and greater tuber yield in Fontane might indicate a more efficient photoassimilate translocation than Agria. The results highlighted positive synergic effects of the combined BAP + ABA and elevated CO2 on tuber yield and productivity of the potato plants.

Analyses of metabolite secretions by field-grown plants remain scarce. We analyzed daidzein secretion by field-grown soybean. Daidzein secretion was higher during early vegetative stages than reproductive stages, a trend that was also seen for hydroponically grown soybean. Daidzein secretion was up to 10 000-fold higher under field conditions than hydroponic conditions, leading to a more accurate simulation of rhizosphere daidzein content.

Palm oil can produce high productivity which must be supported from several aspects, one of them is a good and correct nursery. Palm oil nursery isusually carried out conventionally, namely planting using soil media. Hydroponic research using cocopeat and rice husks planting media on the growth of palm oil seeds in pre nursery has never been carried out. The objective of this study was to determine the growth of palm oil seedlings using the hydroponic method. This research was conducted in the STIPAP Medan greenhouse. This research was conducted from April to July 2018. This research was a non-factorial RAK, which consisted of four treatments, namely M0 (top soil), M1 (Cocopeat), M2 (rice husks), M3 (combination). Height, stem, number of leaves, dry and wet weight of roots and plants, root length were observed. Then data analysis with ANOVA with the continued test of 5% Duncan was performed. The results of the effect of cocopeat and rice husk media was there was no a significant effect on the treatment parameters of seed height, number of leaves, dry and wet weight of roots and plants, and root length.

Root system architecture (RSA) is a key factor in the efficiency of nutrient capture and water uptake in plants. Understanding the genetic control of RSA will be useful in minimizing fertilizer and water usage in agricultural cropping systems. Using a hydroponic screen and a gel-based imaging system, we identified a rice (Oryza sativa) gene, VAP-RELATED SUPPRESSOR OF TOO MANY MOUTHS1 (OsVST1), which plays a key role in controlling RSA. This gene encodes a homolog of the VAP-RELATED SUPPRESSORS OF TOO MANY MOUTHS (VST) proteins in Arabidopsis (Arabidopsis thaliana), which promote signaling in stomata by mediating plasma membrane–endoplasmic reticulum contacts. OsVST1 mutants have shorter primary roots, decreased root meristem size, and a more compact RSA. We show that the Arabidopsis VST triple mutants have similar phenotypes, with reduced primary root growth and smaller root meristems. Expression of OsVST1 largely complements the short root length and reduced plant height in the Arabidopsis triple mutant, supporting conservation of function between rice and Arabidopsis VST proteins. In a field trial, mutations in OsVST1 did not adversely affect grain yield, suggesting that modulation of this gene could be used as a way to optimize RSA without an inherent yield penalty.

The aim of the study was to understand the hydraulic response to salt stress of the root system of the comparatively salt-tolerant crop barley (Hordeum vulgare L.). We focused on the transcellular path of water movement across the root cylinder that involves the crossing of membranes. This path allows for selective water uptake, while excluding salt ions. Hydroponically grown plants were exposed to 100 mM NaCl for 5-7 days and analysed when 15-17 days old. A range of complementary and novel approaches was used to determine hydraulic conductivity (Lp). This included analyses at cell, root and plant level and modelling of water flow. Apoplastic barrier formation and gene expression level of aquaporins (AQPs) was analysed. Salt stress reduced the Lp of root system through reducing water flow along the transcellular path. This involved changes in the activity and gene expression level of AQPs. Modelling of root-Lp showed that the reduction in root-Lp did not require added hydraulic resistances through apoplastic barriers at the endodermis. The bulk of data points to a near-perfect semi-permeability of roots of control plants (solute reflection coefficient σ ~1.0). Roots of salt-stressed plants are almost as semi-permeable (σ > 0.8).

The synthesized α-MoO3 and MoS2 NPs had nanosheet and nanoflower-like structures with crystallite size of 21.34 nm and 4.32 nm, respectively. The uptake, bioaccumulation, and impact of these two Mo-NPs were studied in rice (Oryza sativa L) cv. HUR 3022 seedlings exposed to 100, 500, and 1000 ppm concentrations in hydroponics for 10 days in the growth medium. The uptake of α-MoO3 and MoS2 NPs by rice exposed to 100 ppm concentrations of NPs led to the accumulation of 7.32 ppm/4.55 ppm and 1.84 ppm/1.19 ppm in roots/shoots, respectively, as compared to controls. Unlike MoO3, more accumulation of MoS2 in roots reflect less translocation of this NP from roots to shoots. Results suggest tissue-specific distribution of NPs in rice seedlings. The increased growth and elevated protein levels in rice seedlings at 100 ppm concentrations of nanoparticles imply a stimulation in the repair mechanism at low doses indicating hormesis. MoS2 NPs treatments led to increased chlorophyll a levels suggesting it to be non-compromising with photosynthetic process in rice. The high malondialdehyde levels and altered activities of antioxidant enzymes GPX, APX, and CAT in rice seedlings exposed to α-MoO3 or MoS2 NPs indicate oxidative imbalance. Between α-MoO3 and MoS2 NPs, the former shows toxic effects as reflected from the decreased levels of photosynthetic pigments at all concentrations; however, an activation of chloroplast ROS detoxification is evident in the presence of MoS2 NPs. The BCF > 1 for both α-MoO3 and MoS2 NPs and TF of 0.6-2.0 and 0.42-0.65 suggest the latter to be more environmentally safe. In conclusion, a100 ppm MoS2 NPs concentration has low translocation and less accumulation with no significant impact on growth of rice cv. HUR 3022 seedlings and appears to be environmentally safe for future applications.

Freshwater resources comprise only 2.5–2.75% of all water on the Earth, 1.75–2% from them are frozen. We urgently desperately need to conserve water and find an effective alternative agriculture system. Other techniques-agricultural practices and food sources must be used to avoid disasters. We aimed to compare two farming systems (hydroponic with microbubbles or macrobubbles and sand soil) and to find the best system with the lowest cost and high production of low-water plants. We used three hydroponic system: (i) without the application of bubbles (T1), (ii) with the application of microbubbles (T2), (iii) macrobubbles (T3), and the conventional cultivation-based soil (T4). The results show significant differences in the morphological and biochemical parameters of lettuce plants grown in the hydroponic system and conventional cultivation-based soil. The morphological characteristic, chlorophyll, phenol, flavonoid content, enzymatic and non-enzymatic antioxidants, mineral content, and dissolved oxygen were significantly greater in plants grown in the microbubble hydroponic system. In addition, total soluble sugars, proline, and MDA content were significantly greater in plants grown in sand soil (T4) as compared to the plants grown in different hydroponic systems (T1, T2, T3). The results show that the water consumed in the hydroponic system is lower than used in sandy soil. Our findings suggest that the hydroponic system can increase income and reduce the amount of water consumed; therefore, plants grown in hydroponic systems with microbubbles have achieved the best plant growth, secondary metabolites, and antioxidants compared to plants grown in other systems.

Sweet basil (Ocimum basilicum L.) is a globally cultivated and consumed herb known for its unique aroma and flavor. Sweet basil grows best in warm temperatures, and productivity and marketability decrease when grown under cool conditions (

Hydroponics is a modern way of growing plants in special solutions. Using this method, plants dispense with soil, are in the substrate, which serves as a support for the root system and receive the necessary nutrients from the solution. It for each plant, depending on the species, is selected individually. The hydroponic method is of two types: open systems and closed. Most industrial plants are simple open systems. Plants are grown on a mineral wool slab; the nutrient solution circulates several times a day, according to the ambient temperature, and then after each watering 25-30% of the nutrient solution is discharged into the ground. This is to prevent the deposition of salts on the substrate.There are also closed systems where the nutrient solution circulates from the tank to the plants and back to the tank. In this case, all the consumed water is absorbed and evaporated by the plant, thereby increasing the efficiency of water consumption. In addition, the nutrient solution does not come into contact with the soil and does not contaminate the soil, and unwanted nutrients do not enter the groundwater. System closure solves the problem of water loss. Peppermint culture was grown using a closed type of hydroponic system. Passiflora seeds were grown using mineral wool.

A total of four Capsicum annuum L. genotypes (‘Caro F1’, ‘Berenyi F1’, ‘Somborka’ and ‘Novosadka’) were exposed to two intensities of salt stress. We observed a significant decrease in the sugar content in all salt stressed treatments, except for the sucrose content of the pericarp of the ‘Caro F1’ cultivar. Salt stress had a largely negative effect on the total and individual organic acid content, although the effect differed among cultivars. Using high performance liquid chromatography coupled with a mass spectrometer, most phenolics were identified in the pericarp (18), followed by the placenta (7) and seeds (8). Treatment with 40 mM NaCl caused the highest increase in individual phenols, followed by treatment with 20 mM NaCl. The cultivar ‘Berenyi F1’ was less affected by salt stress treatment than the other three cultivars in terms of content of individual and total phenols. Salt stress increased the content of capsaicinoids in all the cultivars. The pericarp of the cultivar ‘Novosadka’ showed 17.5 and 50 times higher total capsaicinoid content than the control in the 20 mM and 40 mM NaCl, respectively. With the results of several metabolite groups, we confirmed that the reaction and metabolic content to salt stress within the genus Capsicum is genotype-, fruit part-, and salinity level-dependent.

Aquaponics combines raising fish and growing plants by recycling water and nutrients to reduce water consumption and reliance on chemical fertilizers. Coupled aquaponics systems recirculate water between fish and plant crops, whereas decoupled systems send mineralized fish effluent and wastewater unidirectionally to an independent hydroponic loop. Decoupling enables changes to the water, such as pH adjustments and complementary nutrient additions, to promote plant performance. In this study, basil, Ocimum basilicum (L.), was transplanted into 4 L containers filled with decoupled aquaponic (DAP), nutrient-complemented decoupled aquaponic (DAP+), or chemical-based conventional hydroponic (CON) nutrient solutions and grown for 21 days at pH 5.8. Plants grown in DAP+ and CON had greater biomass, height, and Soil Plant Analysis Development (SPAD) chlorophyll index and lower root:shoot biomass ratios than those in DAP. Shoot fresh and dry biomass was 11% greater for CON than DAP+, while height, SPAD chlorophyll index, and root:shoot ratio did not differ. We concluded that added nutrients in DAP+ enhanced performance compared to DAP, and the biologically derived nutrition in DAP+ enhanced performance to be similar, but not equal, to CON. We cannot recommend specific adjustments to the targeted blend of complementary nutrients tested, but findings suggest that complementary nutrients are effective in decoupled aquaponics.

BACKGROUND Beyond nutrition, fruits and vegetables can be considered as natural sources of bioactive molecules, for which beneficial effects on human health are widely recognised. To improve food quality, soilless growing systems could represent a good strategy for promoting a sustainable food production chain, although the nutritional and nutraceutical properties of their products should be investigated in depth. The main quality traits and the volatile and non-volatile secondary metabolites of Solanum lycopersicum L., Petroselinum crispum (Mill.) Fuss and Ocimun basilicum L. grown in an aquaponics system and in organic farming were quantified and compared. RESULTS On a fresh basis, soil-grown P. crispum and O. basilicum showed significantly higher total phenolics and antioxidant activity compared to aquaponic crops, whereas, on a dry basis, both plants showed opposite results. Soil-grown S. lycopersicum was significantly richer in total phenolics, whereas the aquaponic type showed a higher antioxidant activity. Aquaponics induced the accumulation of resveratrol in P. crispum, rosmarinic acid and myricetin in O. basilicum, and lycopene in S. lycopersicum. Among the volatile compounds, in O. basilicum, linalool was the main constituent in both treatments, whereas τ-cadinol represented the second constituent in aquaponic crops. The volatile profiles of P. crispum did not differ significantly between the two cultivation methods. CONCLUSION The overall quality of organic and aquaponics cultures appeared to be comparable. The results showed that aquaponic farming method can be an innovative, rapid and sustainable way of producing quality food. © 2021 Society of Chemical Industry.

An experiment was conducted to study the influence of combinations of different fodder crops on nutritional quality under hydroponic condition at Agronomy field unit, Zonal Agricultural Research Station, Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore during the year 2018. The experiment was conducted with 13 treatment combinations involving maize, finger millet, little millet and cowpea at different proportions by using completely randomised design (CRD) and repeated three times. The results revealed that the crude protein and carbohydrate yield was highest in 100% Cowpea and 25% Cowpea + 75% Maize treatments compared to other treatments.

Since arsenic (As) exposure is largely due to geochemical contamination, this study focused on the remediated area of Santana do Morro, a district of Santa Barbara, Minas Gerais, Brazil, which was previously contaminated with As due to gold mining. Total As concentrations in sediment, soil and plants were determined, next to As species, anionic arsenic compounds As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), in plants samples. Total As concentrations in soil and sediments were slightly elevated (16-18 µg g -1 ) and most of the plants contained low levels of As (< 1 µg g -1 ). The exception was a native plant Eleocharis geniculata (L.) which contained elevated levels of As (4 µg g -1 ). The exposure of this plant to As under controlled conditions (hydroponics) indicated its possible tolerance to elevated As levels and suggesting its potential use in phytomonitoring of As-contaminated sites. This plant is able to metabolize arsenate to arsenite and contained MMA and DMA, both in its natural habitat and under controlled conditions.

Drought is the major constraint, adversely affecting the rice productivity in India. Emerging climate change scenario demands potential donors to develop climate resilient genotypes in order to increase the productivity of rice. In the present study, 85 traditional rice landraces and 15 improved cultivars were screened for drought tolerance potential under hydroponics, along with IR 64 and IR 64 Drt 1 as drought susceptible and tolerant checks respectively. Moisture stress was induced using PEG 6000 over a range of osmotic potentialsviz.,(-) 1.0 Mpa, (-) 1.25 Mpa and (-)1.5 Mpafor a period of 30 days. Fifty two landraces survived under maximum osmotic potential of (-) 1.5 Mpa. Based on the phenotypic scores, six genotypes viz., Kuliyadichan, Rajalakshmi, Sahabhagidhan, Nootripathu, Chandaikar and Mallikar were identified to have higher degree of drought tolerance .. The investigation concluded that these six genotypes can serve as potential donors for developing drought resilient rice cultivars.

Drought resistance mechanisms of sugarcane (Saccharum officinarum L.) vary with different conditions and locations. Understanding physiological and morphological responses of sugarcane cultivars grown under uniform and controllable conditions needs to be established. Therefore, the objective of this study was to investigate the mechanisms of drought responses of sugarcane cultivars grown under low water potential conditions via polyethylene glycol (PEG) induction. The hydroponic experiment was conducted under open greenhouse conditions. A split-plot in a randomised complete block design with three replicates was used. The PEG rates (0% and 1%) were assigned as main factor. Six sugarcanes cultivars differing in drought-resistance levels were sub-plot factors. To understand drought mechanisms, physiological and morphological traits were measured during stress and recovery periods. Drought mechanisms clearly evidenced only low water potentials at early growth stages, but not terminal drought stress. The six cultivars used in this study could be classified into two groups based on responses of shoot mass after exposure to early drought, consisting of reduced shoot dry weight when exposed to early drought stress and insensitive to early drought stress. In recovery phase, shoot DM of reduced shoot dry weight cultivar (‘KKU99-03’) was 754.6 and 499.5 g pl-1 under control and PEG treatments, respectively, whereas shoot DM of insensitive group did not differ from control conditions. Drought resistance mechanisms, which can maintain aboveground DM of sugarcane cultivars under this condition, varied. Good adaptations for maintenance shoot mass under hydroponics were photosynthesis, stomatal conductance, partitioning of dry weight, root dry weight and green leaf number proportions. The ability to perform well with acclimation of these traits might be useful for improving drought resistance genotypes in the future.

Selenium (Se) is an essential element for humans. Its consumption comes from food of animal or vegetal origin; whose content varies widely depending on its availability in soil or anthropogenic sources. Biofortification improves food nutritional quality, and its consumption has a positive influence in human health. Thus, the objective of this research was to assess agricultural biofortification with Se in tomato fruit and its effects on yield, nutraceutical quality, and antioxidant capacity. Five Se doses (0, 2, 4, 6, and 8 mg L-1) in the form of sodium selenite (Na2SeO3) were added in a nutritional solution in a hydroponic system. The results obtained indicated that agricultural biofortification with Se applied in the nutritional solution improved yield, nutraceutical quality, and Se concentration in tomato fruit. The optimum Se dose that maximized yield and nutraceutical quality, as well as the recommended consumption concentration in tomato fruit in this study was 2 mg L-1 (Na2SeO4) because higher doses decreased yield and bioactive compound biosynthesis. Incorporating Se in the nutritional solution is an alternative to increase phytochemical compound biosynthesis in tomato fruit and yield with the possibility of improving public health with its consumption.

The aquaponic system is an alternative strategy to treat aquaculture waste and achieve food independence. Bacteria play vital roles in the aquaponic system as they can transform ammonia or ammonium into nitrite and then into nitrate, which is more favorable for bacteria, fish, and plants. The objective of this study was to determine the effect of nitrifying bacteria (Nitrosomonas europaea Winogradsky and Nitrobacter winogradskyi Winslow) on the aquaponic system in terms of water quality, nutrient availability, and productivity of carp (Cyprinus carpio), lettuce (Lactuca sativa var. crispa), and vetiver grass (Chrysopogon zizanioides L.). The experiment consisted of four treatments: aquaculture of carp as a control for fish (A), hydroponic of lettuce and vetiver grass without nutrient addition as a control for plants (B), aquaponic (carp, lettuce, vetiver grass) (C), and aquaponic with nitrifying bacteria addition (D). The results showed nitrifying bacteria addition had a significant effect on daily growth rate (DGR) and relative growth rate (RGR) of lettuce within a treatment; on the other hand, the nitrifying bacteria did not give a significant effect to RGR of vetiver grass. The growth rate, specific growth rate, and survival rate of the carp in aquaculture treatment (A) were lower than in both aquaponic treatments (C and D). Nitrifying bacteria addition in the aquaponics system had a significant effect of increasing the orthophosphate concentration. Water quality was also indicated to be better in the aquaponic system than in the aquaculture system. The integration of aquaculture and hydroponics with the addition of nitrifying bacteria enables the formation of microorganism communities, nitrate, and orthophosphate, which lead to the improvement of water quality, nutrient availability, and plant growth.

The development of the Hydroponic Planting Technique for Medicinal Planting in the Central Java Josroyo Housing was carried out with the aim of improving the quality of health and the economy of the community. Pollution is a daily consumption for residents living in big cities and densely populated settlements. On free roads, motor vehicle fumes mixed with cigarette smoke are almost inevitable. Health research about cigarette smoke that causes lung cancer is not new and widely reported by researchers. Hydroponics is a method of planting that is positive for health. Consuming vegetables and medicinal plants hydroponics is better than conventional vegetables and free of pesticides so it is healthy. Vegetables and medicinal hydroponic drugs are fresher and tastier than similar products from the market or vegetable vendors. The durability of vegetables and hydroponic medicinal plants is recognized relatively longer than vegetables grown above ground. The advantages of hydroponic planting methods are saving land, saving water, without pesticides, free of weed disturbances, on-target nutrition as well as saving land and labor so as to answer the problem of planting in Josroyo housing

It was shown that the preparation “Immunact-GK” based on β-1,3-glucan exerts a multilateral positive effect on tomato plants grown under conditions of low-volume hydroponics in protected ground. In particular, it has a stimulating effect on the biosynthesis of photosynthetic pigments and the photochemical activity of PS II in chloroplast membranes, induces the accumulation of phenolic compounds, promotes the generation of ROS, which perform a signaling function and start a natural internal defense mechanisms, contributes to stabilize the level of oxidative processes in tomato leaves. It has been established that under manufacturing conditions, the preparation “Immunact-GK” provides an increase in tomato yield up to 5 kg/m 2 and exceeds the efficiency of the native growth regulator “Ecosil”.

Rice genotype (cv. Swarna Sub1) was compared with cv. Swarna with respect to salinity stress. The modality of sub1A traits, which is primarily linked to submergence tolerance, was monitored as to its sensitivity to salinity. Proline and electrolyte leakage were not significantly changed in cv. Swarna Sub1 as compared to cv. Swarna. However, the effects of silver ions through individual, hydroponics and pre-treatment distinctly varied between two cultivars. Silver absorption distinctly varied with 45.01-fold rises in cv. Swarna against control, whereas for sodium cv. Swarna Sub1 scored the highest accumulation by 3.03-fold. Potassium depletion in plants recorded a significant down-regulation for both the genotypes, maximally under salinity by 43.78 and 22.33%, respectively. Plants exhibited a significant suppression of shoot and root length which finally manifested in dry matter accumulation by 93.95 and 89.24%, respectively, for cv. Swarna and Swarna Sub1 under pre-treatment. Chlorophyll content significantly varied among the treatments as well as between the cultivars. Carotenoids and lycopene though depleted but had not any significant variation between the cultivars. NADP(H)-oxidase was distinctly overexpressed for cv. Swarna Sub1 by 1.16-fold under salinity than cv. Swarna (1.22-fold). Still, pre-treatment with silver has maximally induced superoxide content establishing oxidative sensitivities with a peak rise of 3.07 and 2.44-fold for two genotypes. Therefore, the significant traits linked to sub1A QTL would be the selection markers or to overexpress in susceptible genotypes under the condition of salinity for better sustenance.

Yield reduction resulting from high temperatures and tipburn are common issues during the summer for hydroponically grown lettuce using the nutrient–film technique (NFT). We investigated the yield and degree of tipburn of lettuce ‘Red Butter’, ‘Green Butter’, and ‘Red Oakleaf’ of the Salanova® series under different-solution electrical conductivity (EC) and pH levels. We also quantified the effect of foliar spray application of calcium chloride (CaCl2) on the yield and degree of tipburn using the lettuce cultivar Green Butter. For the EC experiment, the plants were grown at four EC levels (1.4, 1.6, 1.8, or 2.0 mS·cm–1) and a constant pH of 5.8. For the pH experiment, the plants were grown at and four pH levels (5.8, 6.0, 6.2, or 6.4) and a constant EC of 1.8 mS·cm–1. For the foliar spray experiment, CaCl2 was applied 1 week after transplanting into NFT channels at three different concentrations: 0, 200, 400, or 800 mg·L calcium (Ca). During the EC trial, the maximum yields were observed at or more than 1.8 mS·cm–1 for ‘Green Butter’ (263 ± 14 g/head) and ‘Red Butter’ (202 ± 8 g), and more than 1.6 mS·cm–1 for ‘Red Oakleaf’ (183 ± 6 g). The yield of ‘Green Butter’ was 75 g less at 1.4 mS·cm–1 compared with 1.8 mS·cm–1. Tipburn symptoms were less at 1.4 mS·cm–1 for ‘Green Butter’ whereas other cultivars were not highly susceptible. In pH trials, the maximum yield for all cultivars was found at pH 6.0 and 6.2. There were no differences in tipburn symptoms among all pH levels. The foliar spray treatment, twice a week at 400 or 800 mg·L–1 Ca, provided improved tipburn control, as the tipburn symptoms were minimal and the impact on yield was minor compared with reducing EC. This series of experiments found evidence in proper EC and pH management for optimum yield and tipburn control in NFT lettuce grown in summer conditions.

Improving salinity tolerance in the most widely cultivated cereal, bread wheat (Triticum aestivum L.), is essential to increase grain yields on saline agricultural lands. A Portuguese landrace, Mocho de Espiga Branca accumulates up to sixfold greater leaf and sheath sodium (Na+) than two Australian cultivars, Gladius and Scout, under salt stress in hydroponics. Despite high leaf and sheath Na+ concentrations, Mocho de Espiga Branca maintained similar salinity tolerance compared to Gladius and Scout. A naturally occurring single nucleotide substitution was identified in the gene encoding a major Na+ transporter TaHKT1;5‐D in Mocho de Espiga Branca, which resulted in a L190P amino acid residue variation. This variant prevents Mocho de Espiga Branca from retrieving Na+ from the root xylem leading to a high shoot Na+ concentration. The identification of the tissue‐tolerant Mocho de Espiga Branca will accelerate the development of more elite salt‐tolerant bread wheat cultivars., A bread wheat (Triticum aestivum L.) landrace Mocho de Espiga Branca maintained similar salinity tolerance compared to commercial cultivars despite accumulating high leaf sodium. An impaired sodium transporter TaHKT1;5‐D was shown to be responsible for the increased shoot sodium in this landrace.

Tomato fruits are a unique functional food and a natural reservoir of nutrients, antioxidants, vitamins and bioactive compounds that improve nutrition and human health. As an important vegetable throughout the world, tomatoes have attracted the attention of researchers to carry out various strategies to improve the functionality of this food aimed at the prevention of diseases, health and global well-being. An agronomic strategy in this study was to evaluate the influence of the application of "salicylic acid (SA)" on the yield and nutraceutical quality of the tomato crop, produced under hydroponic conditions. A completely randomized experimental design with six repetitions was used. SA at five doses (0.025, 0.05, 0.075, 0.1 and 0.125 mM) and one control were applied every 15 days in the nutritive solution under a hydroponic system on tomato plants. The evaluated variables were yield (total fruit weight per plant), fruit parameters (weight, diameter, firmness, and total soluble solids), percentage of weight loss and nutraceutical quality of tomato. The results obtained indicate that the addition of salicylic acid in nutritive solution increased the yield and biosynthesis of phytochemical compounds in tomato fruits, in relation to the control without application. In conclusion, to obtain a higher nutraceutical quality without affecting the tomato fruit yield, it is recommended to use the average concentration (0.125 mM) of SA.

A new type of mesoionic insecticide triflumezopyrim is mainly used to control rice planthoppers, leafhoppers, etc. In order to study the uptake and translocation characteristics of this new insecticide in rice (

Bacillus methylotrophicus has been demonstrated to promote growth of various plants, whereas the promoting effect of B. methylotrophicus on rice growth has been rarely reported. In this study, B. methylotrophicus DD-1, capable of efficiently promoting the growth of rice, was isolated from the root soil of rice plants. The isolate exhibited potassium-solubilizing (1.18 mg/L), Indole-3-acetic acid (IAA) (87.26 mg/L), Gibberellic acid (GA) (25.91 mg/L) and Siderophore production activity (52.32%). As indicated from the result, plant growth parameters (e.g., dry weight, tiller number, root and shoot length) of rice seedlings treated with the isolate DD-1 were more effective than those of the control group in pot and soilless culture experiments. Moreover, the adsorption capacity of rice roots which were soaked in the bacterial suspension of isolate increased with the increase in concentration and absorption time. In sterilized and unsterilized soil, conformation of root colonization activity by bacterial isolate established by its nearer existence to the rice root. Thus, the B. methylotrophicus DD-1 enhances plant growth promotion by multifarious growth promoting and root colonization traits, thereby augmenting potassium level in soil. Henceforth, the potential bacterium could be exploited for the development of biological fertilizer, leading towards sustainable agronomy.

The rising demand for agricultural commodities in developing countries has put increasing pressure on land resources for higher yields, with associated growth in the demand for phosphate fertilizers. However, there are a number of adverse environmental impacts associated with the use of inorganic P fertilizers that is pushing global fertilizer prices up. In this context, phosphate solubilizing microorganisms, such as Bacillus, are the most eco-friendly and inexpensive option for enhancing P availability for plants, once they are capable of transforming insoluble P into soluble (plant accessible) forms and are regarded as plant growth-promoting microorganisms. This work aimed to understand the effect of tropical Bacillus strains on maize root morphology and growth using a hydroponic system and to evaluate their performance under two phosphorus fertilization conditions in the field. Maize root was inoculated separately with six Bacillus strains and grown in nutrient solution. Several root traits, dry weight and nutrient content were measured in maize seedlings. Moreover, we measured bacterial IAA-like molecules in vitro production and evaluated inoculated maize performance under field conditions with no P added (P0) and triple superphosphate (TSP) soil fertilization. All the Bacillus strains increased shoot and total dry weight and strains B2084, B119 and B32 had the greatest performance, producing the highest biomass, shoot nutrient content and root surface area compared to other strains in hydroponics. All strains that produced IAA-like molecules demonstrated a positive effect on plant growth by stimulating root elongation. In the field experiments, strain B116 inoculation increased maize yield and P grain accumulation by around 36% and 58%, respectively, and B119 increased P grain in 21% in soils with no P added. Even in soils fertilized with TSP, maize yield increase and P grain accumulation was around 20% after inoculation with these two strains comparing to non-inoculated control. Our results indicated that maize plants inoculated with Bacillus strains capable of producing IAA-like molecules and solubilizing phosphate, presented enhanced root system, dry matter and nutrient accumulation in hydroponics and higher yield and grain P content with and without addition of phosphate fertilizer under field conditions.

Acclimatization of tissue cultured plants to greenhouse or field conditions is the final and most crucial step of micropropagation. Hydroponic system has the potential to harden in vitro plants in an efficient and convenient way. Herein, in vitro regenerated plants of Trichosanthes kirilowii were cultured in 1/4, 1/2 and full strength Hoagland nutrient solution under a simple hydroponic system during acclimatization, respectively, and soil culture was prepared as a control. Morphological, physiological, anatomical and histochemical alterations of the plants treated by different concentrations of nutrient solution and soil conditions were analyzed after 30 days of growth. Results showed that all the three concentrations of nutrient solution significantly improved the survival rate, plant growth, pigment content, photosynthesis capacity, and stomatal density compared with those grown in soil, and there were no significant differences of the plant morphological parameters and the stomatal characteristics among the three hydroponic treatments. The plants grown in the 1/4 Hoagland solution yielded the highest net photosynthesis rate, transpiration rate and stomatal conductance, as might be attributed to their highest photosynthetic pigment content among the treatments. Anatomical and histochemical studies revealed that enlarged air spaces, multiple lignified Φ thickenings, and heavier suberin and lignin were formed in the cortex of the adventitious roots grown in 1/4 Hoagland nutrient solution as compared with those cultured in soil conditions, indicating that T. kirilowii had enough phenotypic plasticity in the root structure to grow in hydroponic conditions by formation of larger aerenchyma spaces and apoplastic barriers. This study clearly demonstrates that hydroponics is an alternative for the tissue cultured plants of T. kirilowii to adapt to great environmental changes during acclimatization. Micropropagated plants of T. kirilowii can adapt to hydroponic conditions through changes in plant morphological, physiological and stomatal characteristics, and anatomical and histochemical features of roots during acclimatization.

Zinc (Zn) is an important essential micronutrient for plants and humans; however, the exact transporter responsible for root zinc uptake from soil has not been identified. Here, we found that OsZIP9, a member of the ZRT–IRT-related protein, is involved in Zn uptake in rice (Oryza sativa) under Zn-limited conditions. OsZIP9 was mainly localized to the plasma membrane and showed transport activity for Zn in yeast (Saccharomyces cerevisiae). Expression pattern analysis showed that OsZIP9 was mainly expressed in the roots throughout all growth stages and its expression was upregulated by Zn-deficiency. Furthermore, OsZIP9 was expressed in the exodermis and endodermis of root mature regions. For plants grown in a hydroponic solution with low Zn concentration, knockout of OsZIP9 significantly reduced plant growth, which was accompanied by decreased Zn concentrations in both the root and shoot. However, plant growth and Zn accumulation did not differ between knockout lines and wild-type rice under Zn-sufficient conditions. When grown in soil, Zn concentrations in the shoots and grains of knockout lines were decreased to half of wild-type rice, whereas the concentrations of other mineral nutrients were not altered. A short-term kinetic experiment with stable isotope (67)Zn showed that (67)Zn uptake in knockout lines was much lower than that in wild-type rice. Combined, these results indicate that OsZIP9 localized at the root exodermis and endodermis functions as an influx transporter of Zn and contributes to Zn uptake under Zn-limited conditions in rice.