This study evaluated the growth performance and physiological responses of 24 Korean landrace accessions of pak choi (Brassica rapa subsp. chinensis) under polyethylene glycol (PEG)-induced drought stress to identify indicators for selecting drought-resistance genotypes. Electrolyte leakage (EL) and chlorophyll fluorescence (Fv/Fm) analyses showed that resistance accessions (IT262109(11), IT279432(12), IT293143(20)) had minimal increases in EL and maintained high Fv/Fm values under stress, indicating superior membrane stability and photosystem II activity. In contrast, sensitive accessions exhibited a sharp rise in EL and a decline in Fv/Fm to approximately 0.3 under 25% PEG treatment, reflecting severe physiological damage. Principal component analysis (PCA) biplot based on integrated growth and photosynthetic parameters differentiated resistance and sensitive groups, with PC1 representing photosynthetic efficiency versus membrane injury. Growth trait responses interaction analysis using GGE biplot of six representative accessions (three resistance, three sensitive) demonstrated that resistance genotypes had smaller positional shifts across treatments, indicating greater growth stability, while sensitive genotypes showed pronounced variability and environment-specific responses. This study provides a framework integrating growth and physiological indicators for identifying drought-resistance pak choi accessions, offering valuable implications for breeding programs aimed at climate-resilient cultivar development.

Drainage recycling management in recycling hydroponic systems affects root-zone conditions and fruit metabolism. However, its interaction with fruit developmental stages on strawberry biochemical quality and mineral content is unclear. Therefore, this study investigated how developmental stages and drainage recycling ratio influence antioxidant properties, pigment contents, carbohydrate accumulation, and mineral composition in hydroponically grown 'Seolhyang' strawberry. The experiment was conducted from 20 September 2024 to 31 March 2025 in a smart greenhouse. Plants were grown in coconut coir in a closed hydroponic system with 30%, 50%, 70% and 100% (open-system) drainage recycling ratios. Fruits were harvested at green, white, turning, and red stages on March 11, 2025. Fruit developmental stages primarily determined biochemical composition, while drainage recycling ratio modified traits in a stages-dependent way. Antioxidant properties including total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazy (DPPH) radical-scavenging activity were highest in green fruit, especially under 30% drainage, reaching 45.8 mg GAE g⁻¹ FW for TPC and 5.5 mg QE g⁻¹ FW for TFC. Conversely, anthocyanin and soluble sugar accumulation increased during ripening, with 50% drainage recycling yielding the highest concentrations in red fruit (30.0 and 17.8 mg g⁻¹ DW, respectively) and lower starch accumulation. Chlorophyll a, chlorophyll b, and total chlorophyll were also highest in green fruit and enhanced by 30% drainage. Mineral responses were less pronounced and primarily driven by developmental stages. Correlation analysis showed associations among phenolic compounds, antioxidant capacity, pigments, Ca, and Mg, while soluble sugars were negatively associated with early-development traits. Partial least squares analysis identified DPPH, TPC, TFC, FRAP, and anthocyanins as key variables distinguishing developmental stages and drainage recycling treatments. Drainage recycling management does not have a single optimum for strawberry fruit quality; its effects depend on the developmental target. A 30% drainage recycling regime favored phenolic-antioxidant characteristics in early-stages fruit, while 50% drainage recycling enhanced sugar accumulation and pigmentation at full ripeness. In contrast, a 70% drainage recycling ratio promotes the accumulation of Na⁺, Cl⁻, and SO₄²⁻, disrupts nutrient balance, whereas an open system showed lower phytochemical accumulation. This stages-specific response helps guide drainage recycling management based on the harvest goals and shows that immature strawberries may be a useful source of phytochemicals.

Tomato yellow leaf curl virus (TYLCV) is one of the most destructive viral diseases causing severe yield losses in tomato production worldwide. This study investigated the effects of TYLCV infection on plant growth, photosynthetic physiological responses, and yield formation in greenhouse-grown tomatoes and evaluated the applicability of physiological trait-based yield prediction models. Two large-fruited tomato cultivars widely cultivated in Korean protected horticulture systems, ‘Daphnis’ and ‘Pink Star’, were inoculated with TYLCV under greenhouse conditions, and their growth, physiological responses, and yield characteristics were compared under high- and low-temperature growing seasons. TYLCV infection significantly reduced leaf length, leaf width, and leaf area index (LAI), and decreased both flowering truss number and fruit-setting truss number, resulting in reduced total yield. Physiological analyses showed that infected plants exhibited decreases in the OJIP fluorescence rise curve and Fv/Fm values, indicating a reduced photochemical efficiency in photosystem II. In addition, A–Ci response curve analysis revealed a reduction in net photosynthetic rate, suggesting limited carbon assimilation capacity. Total yield showed significant positive correlations with maximum net photosynthetic rate (Amax), Fv/Fm, and Ci300. GGE and GT biplot analyses further indicated that yield was closely associated with photosynthetic performance and canopy development traits. A multiple regression model based on physiological traits and virus infection status explained a significant proportion of the variation in tomato yield (R² = 0.367), indicating that TYLCV infection acts as a key limiting factor for yield reduction. These findings demonstrate that TYLCV infection restricts tomato productivity through reduced photosynthetic efficiency and altered canopy structure. Moreover, physiological trait-based yield prediction approaches may provide a useful framework for evaluating productivity under viral infection conditions and for developing data-driven crop management strategies in greenhouse tomato production systems.

This study investigated how different LED spectral compositions affect seed germination, early growth, photosynthetic efficiency, and the postharvest quality and microbiological stability of Ipomoea aquatica Forsk. cultivated in a plant factory system, aiming to propose an integrated management strategy for stable year-round production. Five LED light treatments with varying red and blue light ratios (R10, R7B3, R5B5, R3B7, and B10) were applied during cultivation. After harvest, the plants were stored under low-temperature conditions using either carton box packaging or modified atmosphere packaging (MAP) to evaluate postharvest quality and microbial changes. Germination analysis indicated that red-dominant treatments (R10 and R7B3) significantly enhanced germination percentage, rate, and uniformity. These treatments also promoted greater plant height and fresh biomass accumulation during early growth while maintaining a higher maximum quantum yield of photosystem II (Fv/Fm), indicating improved photochemical efficiency. In contrast, blue-dominant treatments led to reduced growth performance and lower Fv/Fm values. Postharvest quality and microbiological stability were more significantly affected by the packaging method than by the LED light treatment. MAP effectively minimized fresh weight loss and inhibited the growth of aerobic bacteria, Escherichia coli, total coliforms, and yeast and mold during storage. Overall, the findings demonstrate that red-centered LED spectra are optimal for enhancing early growth and physiological stability of I. aquatica, while MAP is crucial for preserving postharvest quality and microbial safety. This study underscores the synergistic potential of combining LED spectral management during cultivation with optimized packaging strategies to achieve stable year-round production and extended shelf life of I. aquatica in controlled plant factory systems.