Search Results (553)

Cajanus cajan (L.) Huth (Fabaceae) is a food legume of considerable nutritional and functional significance. This study examined the comparative effects of salt stress on seed germination, hydroponic growth, and phytochemical accumulation across two developmental stages: 10-day-old germinated seeds and 45-day-old hydroponically grown plants, using NaCl solutions at concentrations of 0, 25, 50, 75, 100, and 150 mM. Both germination rate and growth were greatest at 0–25 mM NaCl, with performance declining at higher concentrations. LC–MS/MS analysis of free amino acids in 10-day-germinated seeds revealed a salt-induced metabolic shift. Proline, leucine, and phenylalanine were the dominant free amino acids and increased progressively with rising NaCl concentrations. Phytochemical profiling by HPLC identified gallic acid, catechin, and genistin as the major compounds, with increased levels under salinity stress. Germinated seeds at 150 mM NaCl, germinated seeds exhibited the highest phytochemical accumulation, with total phenolic content (TPC), total flavonoid content (TFC), and DPPH activity reaching 18.192 ± 0.020 mg GAE/g extract, 8.519 ± 0.026 mg QE/g extract, and 11.623 ± 0.284 mg AAE/g extract, respectively. Phytochemical responses in 45-day hydroponic plants varied by tissue type. Leaves exhibited declining TPC and TFC with increasing NaCl (from 29 to 16 mg GAE/g and 41 mg QE/g extract), while stems showed the opposite trend, reaching 18 mg GAE/g and 21 mg QE/g extract at 50 mM. Root tissues maintained comparatively low phytochemical levels throughout. Notably, DPPH scavenging capacity increased across all tissues under salt stress, with peak values of 12–13 µg AAE/g extract recorded at 50 mM NaCl. These results indicate that salt stress exerts stage- and organ-dependent effects on phytochemical accumulation in C. cajan. High salinity during germination stimulates bioactive compound production, whereas moderate salinity appears to be the threshold at which antioxidant capacity is maximized in hydroponic systems. These observations point to the practical utility of controlled salt elicitation as a strategy for enriching pigeon pea with health-promoting phytochemicals, reinforcing its potential as a functional food crop. Full article

Background/Objectives: With the acceleration of global industrialization and continuous population growth, the world is increasingly confronted with the dual challenges of food insecurity and cultivated land contamination. The screening and breeding of rice varieties with superior agronomic traits and low heavy metal accumulation have therefore become important strategies for ensuring food safety and sustainable agricultural production. Methods: In this study, rice varieties carrying the Gn1a-i gene and exhibiting specific cadmium (Cd) accumulation characteristics were screened using a combination of molecular marker detection and cadmium accumulation evaluation. Specific loop-mediated isothermal amplification (LAMP) primers targeting the Gn1a-i gene were designed and combined with a lateral flow dipstick (LFD) assay to enable rapid genetic screening of rice varieties. A six-day hydroponic experiment under cadmium stress was conducted across three temperature ranges (15–20 °C, 22–27 °C, and 30–35 °C), and cadmium accumulation in different plant organs (roots, stem sheath, and leaves) was analyzed. Results: Seven varieties carrying the Gn1a-i gene, including Xiangwanxian 12, were identified among ten tested rice varieties. Xiangwanxian 12 was subsequently selected for further evaluation, with the high-cadmium-accumulating variety Yuzhenxiang used as a control. At 144 h, the total Cd content in the measured organs of Xiangwanxian 12 was 9.6%, 4.0%, and 23.2% lower than that of Yuzhenxiang under low, medium, and high temperatures, respectively (one-tailed t-test, p < 0.01 for all three temperatures). Conclusions: The integration of LAMP-based genotyping and physiological evaluation provides a novel and reliable strategy for identifying low-Cd rice germplasm. Xiangwanxian 12, which carries the Gn1a-i allele and exhibits consistently lower Cd accumulation than Yuzhenxiang, suggests potential as a candidate for breeding high-yield, low-Cd rice cultivars. Full article

Hydroponic cultivation is expanding rapidly as a resource-efficient alternative to soil-based farming, but challenges related to nutrient management, abiotic or biotic stresses, and organic production still limit the system’s performance and efficiency. Biostimulants are increasingly being explored as a promising strategy to support productivity and sustainability in soilless systems. This review summarizes the current evidence on the use of plant biostimulants to support crop performance in hydroponic systems. Microbial biostimulants, such as plant growth promoting rhizobacteria, Arbuscular Mycorrhizal Fungi, and Trichoderma spp., have been reported to promote root growth by synthesizing phytohormones, enhance nutrient uptake, and reduce the impacts of salt and heat stress, with reported improvements in biomass and nutrient use efficiency. Seaweed extracts and protein hydrolysates modulate plant hormonal balance, improve antioxidant defense, and have been associated with improvements in yield and quality. Humic and fulvic acids increase micronutrient bioavailability through chelation and stimulate root activity through auxin-like effects. In organic hydroponics, biostimulants may help address the nutrient gap by accelerating organic matter mineralization. Existing key challenges include the lack of hydroponic-specific dosage guidelines and high commercialization costs. Future efforts should further evaluate system-specific strategies, including emerging tools such as artificial intelligence-optimized strategies and the use of clustered regularly interspaced short palindromic repeats-edited microbes to support the long-term sustainability of controlled environment agriculture. Full article

Toxic aluminum (Al) and iron (Fe) alter the hormonal balance of plants, leading to metabolic disorders and growth inhibition. Plants adapt to abiotic stress by optimizing phytohormone biosynthesis. However, the impact of toxic Al and Fe on plant hormonal status is poorly understood. Pea cultivar Sparkle and its mutant E107 (brz), accumulating Al and Fe due to disfunction of metal transporter gene OPT3, were cultivated in hydroponics supplemented or not with 80 µM of AlCl₃ or 300 µM of FeCl₃. Root and shoot biomass of E107 decreased due to Al or Fe treatments approximately by 30%, whereas growth of Sparkle was not affected. The Al and Fe content in the roots and shoots of the metal-treated mutant was circa twice that of Sparkle. Treatment with Al and Fe reduced the content of nutrients (Ca, K, Mg, S) in roots and/or shoots in both genotypes. Compared with Sparkle, untreated E107 possessed lower IAA and higher ethylene and tZR contents in roots but lower GA3, DHZ and tZ content in shoots. Mutant E107 had: lower GA3 and ethylene but higher DHZ, tZ and tZR contents in Al-treated roots; higher ABA, SA, IAA, GA3, DHZ, and tZ contents in Al-treated shoots; lower ABA and SA but higher JA, GA3, DHZ and ethylene contents in Fe-treated roots; higher ABA, SA, IAA, GA3, DHZ, and tZ contents in Al-treated shoots; higher ABA, JA, and GA3 but lower ethylene and tZR contents in Fe-treated shoots. Metal toxicity mainly reduced the content of phytohormones in roots and increased it in shoots. Hormonal disturbances were more significant in E107 than in Sparkle, and the effect of Al was stronger than Fe. Thus, toxic Al and Fe lead to complex, metal- and organ-specific changes in the hormonal status of E107. Hormonal changes might be associated with both defense reactions and the toxic effects of metals on plants. Full article

Efficient water management is essential for sustainable agriculture, particularly for crops like carrots that are traditionally grown in soil systems with high water consumption, averaging 4500–6000 m³/ha. Hydroponics offers a potential alternative due to its higher water-use efficiency, yet root crops have been understudied because of system design and economic challenges. This study evaluated the effects of different hydroponic solution volumes on the growth of carrots (Daucus carota cv. Mokum) in a Deep-Water Culture (DWC) system to address knowledge gaps regarding their feasibility in soilless production. Experiments were conducted in a controlled greenhouse using three solution volume treatments (50% with 10.75 L, 75% with 16.13 L, and 100% with 21.50 L) applied to 12 plants per treatment across two repeated experiments. Biomass production, water use efficiency, and total carotenoid concentration were assessed after eight weeks. The 100% (21.50 L) volume treatment produced the greatest shoot and root biomass, whereas the 50% (10.75 L) volume treatment significantly increased total carotenoid concentration, particularly in the second trial. Despite lower water inputs, water use efficiency did not differ statistically among treatments. These results indicate that carrots can be successfully cultivated in DWC systems, though further optimization, such as using narrower containers, may be required to improve efficiency and competitiveness with soil-based production. Full article

This study investigated the effects of four LED light qualities, red+blue+far-red (WRS-LED), blue+red (BR-LED), blue (B-LED), and red (R-LED), and exogenous L-glutamic acid at 10 ppm on the growth and quality of red mustard spinach (Brassica rapa var. perviridis) cultivated in a plant factory using a recirculating deep-flow hydroponic system. Plants were exposed to four LED light quality treatments at 180 ± 10 μmol·m⁻²·s⁻¹ PPFD for 28 days after transplanting. L-glutamic acid at 10 ppm was applied once to the recirculating nutrient solution 15 days after transplanting, resulting in 13 days of exposure prior to final harvest on day 28. All growth and quality parameters were measured at the final harvest after 28 days of cultivation. WRS-LED promoted the greatest biomass production. Additionally, vitamin C content, DPPH radical scavenging activity, and total phenolic content were highest under BR-LED and B-LED conditions. Notably, under B-LED, L-glutamic acid treatment increased total phenolic content to approximately twice that of the control. Leaf redness, expressed as Hunter a* values, was observed exclusively under BR-LED. Principal component analysis revealed that LED light quality was the primary determinant of treatment responses, with growth-related traits associated with WRS-LED and R-LED, and quality-related traits with B-LED and BR-LED. Overall, BR-LED combined with L-glutamic acid represents the most suitable treatment for red mustard spinach cultivation in plant factories, achieving a favorable balance between growth and nutritional quality. Full article

The increasing demand for sustainable food production has intensified interest in controlled-environment agriculture and soilless cultivation systems. This study evaluated the performance of local chicory (Cichorium intybus L., cultivar “Otrantina”) grown for 45 days in soil, hydroponics, and decoupled aquaponics under two different environments: a fully controlled growth chamber and a naturally variable greenhouse. Morphological, anatomical, biochemical, and physiological traits were analyzed to assess the combined influence of growth environment and cultivation system on plant development and nutritional quality. Across all parameters, the growth environment emerged as the main driver of plant performance. Greenhouse-grown plants exhibited greater leaf expansion, enhanced mesophyll and vascular development, and higher fresh and dry biomass than those cultivated in the growth chamber. Within each environment, hydroponics consistently supported vigorous growth, whereas aquaponics produced smaller leaves and pronounced root elongation, likely reflecting nutrient and pH instability in the decoupled system. Biochemical analyses revealed system-specific adaptive responses. Soilless cultivation promoted higher lipid accumulation and, under growth chamber conditions, increased protein content. Aquaponically grown plants, particularly in the greenhouse, accumulated elevated levels of soluble sugars and phenolic antioxidants, consistent with stress-related metabolic activation. In contrast, soil-grown plants displayed the highest flavonoid concentrations, suggesting a prominent role of rhizosphere–microbiome interactions in modulating secondary metabolism. Overall, these results indicate that, under the tested conditions, environmental control exerts a stronger influence than cultivation systems on chicory growth and metabolism. Hydroponics proved to be the most efficient system for biomass production, whereas aquaponics requires improved nutrient management to ensure stable growth and quality. The distinct metabolic profiles associated with each cultivation system highlight opportunities to tailor chicory nutraceutical traits within sustainable controlled-environment agriculture. Full article

Brackish aquaponics is expected to be a promising approach to sustainable food production, integrating saline water resources with simultaneous co-cultivation of fish and halophytes. The present study investigated the effects of three feeding ratios (FR1.5: 1.5%, FR3: 3%, and FR6: 6% b.w/d) on the growth performance of European sea bass (Dicentrarchus labrax) and glasswort (Salicornia europaea) co-cultured in three autonomous one-loop recirculation aquaponic systems (180 L each) at 20 ppt salinity over 78 days. Each system comprised three fish-rearing tanks connected to a two-stage sump filter and a nutrient film technique (NFT) hydroponic subsystem. Sea bass fed at FR3 achieved significantly higher weight gain, specific growth rate, and feed conversion efficiency than FR1.5. At FR6, feed consumption nearly doubled compared to FR3 (3.79 vs. 1.91 g), yet the feed conversion ratio increased from 0.79 to 1.65, and protein efficiency ratio declined from 3.80 to 1.91, indicating overfeeding effects. Regarding glasswort, FR6 produced significantly higher chlorophyll a content and plant biomass, whereas FR1.5 showed superior ammonia removal efficiency. Overall, FR3 provided the best balance between fish growth, plant yield, and water quality maintenance. These findings highlight the critical role of feeding management in brackish aquaponics in order to optimize nutrient coupling between fish and halophyte production. Full article

Controlled Environment Agriculture (CEA) has become a key driver of vertical farming (VF), offering innovative solutions for the sustainable production of ornamental plants in urban environments with limited arable land. This review examines recent advances in VF technologies and their applications in foliage and flowering ornamental plant production. The literature indicates that precise environmental control, including optimized LED lighting spectra, hydroponic and aeroponic nutrient delivery, and automated climate regulation, can significantly enhance plant growth, morphological characteristics, color intensity, and overall market quality of ornamental species. In addition, VF systems demonstrate substantial reductions in water consumption, pesticide use, and land requirements compared with conventional cultivation methods. However, several challenges remain, including high-energy demand, economic feasibility, and the need for crop-specific environmental optimization for different ornamental species. This review synthesizes current research on VF systems, highlights the integration of emerging technologies such as the Internet of Things (IoT), artificial intelligence (AI), and data-driven management tools, and evaluates their potential to improve production efficiency and sustainability in ornamental horticulture. Overall, vertical farming represents a promising approach for high-quality ornamental plant production, although further research is required to optimize energy efficiency and cultivation protocols for diverse ornamental crops. Full article

This study evaluated the effects of various LED spectra—white (W), red and blue (RB), W plus far-red (FR), and RB plus FR—on the growth, fruit quality, and phytochemical accumulation of greenhouse-grown hydroponic watermelon. Watermelons were cultivated with controlled temperature and humidity and subjected to four LED treatments at an equivalent PPFD of 200 ± 3 µmol·m⁻²·s⁻¹ and a 15 h light period for 43 days, with sunlight as a control. The photosynthetic rate and stomatal conductance were significantly higher in the RB LEDs than in all other treatments. Fv/Fm and PIABS exhibited time-dependent differences among treatments after 13:00, with all LED treatments showing higher values than the control, except for the Fv/Fm of RB LEDs. SPAD, chlorophyll, and carotenoid contents were the highest in the RB LEDs, and 40%, 30%, and 19% higher than those in the control group, respectively. Growth characteristics, such as plant height and node and leaf number, were highest in the control group and were significantly higher than the RB LEDs. Petiole length tended to increase in LEDs treated with FR. Sweetness was the highest in W LEDs. Therefore, supplemental LED lighting can potentially improve the production and fruit quality of greenhouse watermelons. Full article

Light quality is a crucial factor influencing plant growth and physiological quality in controlled-environment agriculture (CEA). This study examined how different LED light spectra affect the growth and internal quality of Ligularia stenocephala cultivated in a plant factory. The plants were grown under five types of LED light: monochromatic red, monochromatic blue, a combination of blue and red, white LEDs, and quantum dot (QD) LEDs. We evaluated various growth parameters, biomass accumulation, chlorophyll indices, and antioxidant capacity. Monochromatic red LEDs promoted rapid early growth and stem elongation but led to lower chlorophyll accumulation and antioxidant capacity. In contrast, monochromatic blue LEDs increased chlorophyll content, leaf thickness, dry matter accumulation, and antioxidant capacity, although they limited leaf expansion and shoot biomass. Composite-spectrum LEDs displayed distinct trade-offs between growth and quality parameters. QD LEDs maximized shoot biomass accumulation while maintaining moderate internal quality, whereas Blue+Red LEDs provided a balanced combination of significant biomass and enhanced phytochemical content. Principal component analysis indicated a fundamental trade-off between quality-related (PC1: 57.6%) and growth-related (PC2: 22.7%) parameters, showing that no single LED spectrum could optimize all cultivation factors simultaneously. Therefore, LED selection should align strategically with specific cultivation goals: use QD LEDs for volume-based production, Blue+Red LEDs for balanced premium markets, and blue LEDs for specialty functional vegetables. These findings underscore the importance of context-dependent lighting optimization strategies in plant factory systems and offer a framework for selecting the most effective LED spectra to enhance crop performance in CEA. Full article

Sustainable agricultural techniques can ensure food security around the world. Hydrogel based soilless culture is an ecological and efficient alternative compared to conventional agriculture. Here, a multi-component hydrogel (pectin, Kelcogel, and chitosan/Se hydrogel, PKCH) was prepared by synthesizing natural biomolecules to cultivate dandelion for stimulate dandelion growth and improve nutritional value. The germination percentage of dandelion on PKCH (88.89%), was significantly higher than that in traditional hydroponics and pure Kelcogel (p < 0.05). Compared with hydroponics, the long-term dandelion cultivation experiments demonstrated that the PKCH cultivation mode enhanced root vitality, further increasing the growth and yield of dandelions (shoot length: 18.36 ± 0.30 cm, root length: 9.28 ± 0.21 cm, main root diameter: 0.94 ± 0.02 cm). The hydrogel substrate was associated with improved nutrient solubilization and sustained release, which may be linked to the accumulation of low-molecular-weight organic acids in the rhizosphere. Exogenous Se was effectively assimilated and transported to the above-ground parts of dandelion, which stimulated the photosynthetic efficiency and nutritional accumulation of dandelion. The polysaccharide content of dandelion reached 69.40 ± 0.13% (expressed as glucose-equivalent total sugars), which demonstrated the potential antioxidant properties and medicinal value. Technical economic analysis revealed the cost-effectiveness of PKCH synthesis and application. This study enriches the application of hydrogels in dandelion cultivation and provides an alternative approach for cultivating dandelion in soilless environments and medicinal crop production techniques. Full article

This study presents an Internet of Things (IoT)-assisted semi-open hydroponic system for cultivating Andrographis paniculata under tropical conditions, aiming to enhance biomass productivity, andrographolide (AG) yield, and production efficiency. IoT-assisted hydroponics, non-IoT hydroponics, and soil-based cultivation were compared in 10 m² greenhouses. The IoT system enabled real-time monitoring and adaptive regulation of temperature, relative humidity, light intensity, nutrient solution pH, and electrical conductivity (EC). IoT-assisted hydroponics achieved earlier harvest (≈90 days) and the highest fresh biomass yield (0.409 ± 0.014 kg m⁻²) while maintaining per-plant productivity (15.74 ± 0.54 g plant⁻¹) comparable to soil-based cultivation. Andrographolide concentration reached 25.58 ± 3.36 mg g⁻¹ DW (2.56% w/w), meeting pharmacopeial requirements. Owing to stable environmental regulation and tolerance to high planting density, the IoT system produced the highest areal AG productivity (209.5 mg m⁻²), representing a four- to tenfold increase over the other systems. Despite higher operational costs, IoT-assisted hydroponics achieved the lowest AG unit cost (≈6.77 USD g⁻¹). While most previous studies emphasize tissue-level AG concentration, system-level productivity and cost efficiency under realistic cultivation conditions remain insufficiently explored. Overall, IoT-enabled semi-open hydroponics provides a scalable and economically viable approach for medicinal plant production, bridging the gap between open-field cultivation and fully controlled plant factory systems. Full article

Light quality is a critical regulatory factor for the growth and nutritional quality of hydroponic lettuce (Lactuca sativa L.), and red–blue combined light serves as a key artificial light source for protected horticulture. This study aimed to investigate the effects of different red–blue (R:B) light ratios on the growth, photosynthetic pigment content, nutritional quality, antioxidant capacity, and mineral nutrient content and accumulation of hydroponic lettuce. Lettuce was cultivated under four R:B light treatments (CK: pure red light, 100:0; T1: 90:10; T2: 80:20; and T3: 60:40) with a uniform photosynthetic photon flux density of 350 µmol m⁻²s⁻¹ and a 12 h photoperiod. The results showed that all red–blue combined light treatments significantly improved the above physiological and nutritional indices compared with monochromatic red light (CK), with the fresh weight increased by 0.73 to 0.78 times and different R:B ratios inducing distinct tissue-specific and element-specific responses in lettuce. Specifically, T3 (60:40) exhibited the highest root dry weight (0.57 ± 0.02 g plant⁻¹), inhibited excessive leaf elongation to form a compact plant architecture, and its chlorophyll a and b contents increased significantly by 1.6 and 2.25 times compared with CK, respectively. Furthermore, T3 markedly enhanced the accumulation of soluble sugar (0.36 times higher), soluble protein (1.16 times higher), and vitamin C (4.09 times higher), reduced the nitrate content to 0.58 times that of CK, and showed the highest antioxidant capacity (polyphenol content and DPPH free radical scavenging rate), with antioxidant traits positively correlated with the blue light proportion. In contrast, T2 (80:20) effectively promoted plant biomass accumulation and exhibited the most balanced mineral nutrient profile, with significant increases in nitrogen, calcium, and magnesium accumulation, and it also upregulated chlorophyll synthesis to enhance carbon assimilation. T1 (90:10) had moderate regulatory effects on both lettuce growth and nutritional quality and was favorable for potassium accumulation in lettuce tissues. These findings clarify the differential regulatory mechanisms of red–blue light ratios on hydroponic lettuce and provide a theoretical basis for the precise configuration of LED lighting in greenhouse lettuce production. Lettuce producers can select specific R:B ratios according to actual cultivation demands, and the regulatory effects of such light ratios on red leaf lettuce varieties merit further exploration. Full article

Legumes are among the most important plants capable of biological nitrogen fixation. However, there is a significant knowledge gap regarding the specifics of cultivating legumes in hydroponic systems under controlled environment conditions, particularly nitrogen metabolism at different growth stages, which this study addressed. Chickpeas, faba beans, lentils, soybeans, and sugar peas were cultivated in deep-water hydroponics without rhizobia, with a nutrient solution as the nitrogen source. The legumes displayed significant variations in growth patterns and nitrogen dynamics. Among them, soybeans had the longest growth cycle, characterised by extended vegetative and early reproductive phases, while sugar peas developed the fastest. In all species, nitrate was the dominant form of nitrogen found in the roots, stems, and leaves, followed by ammonium (NH₃–N) and nitrite (NO₂⁻). The levels of NH₃–N varied among species, peaking early in faba beans and later in chickpeas. NO₂⁻ concentrations were low and decreased with development. The activities of nitrate reductase and nitrite reductase also varied across species, plant organs, and growth stages. The highest enzyme activity was consistently observed in the leaves. Notably, peas exhibited high enzyme activity across all organs, while the leaves of soybeans showed the highest activity in the studied legumes. Full article