Chlorophyll Content Research Articles

Smartphone-Based Leaf Colorimetric Analysis of Grapevine (Vitis vinifera L.) Genotypes

Leaf chlorophyll content is a key indicator of plant physiological status in viticulture; therefore, regular evaluation to obtain data for nutrient supply and canopy management is of vital importance. The measurement of pigmentation is most frequently carried out with hand-held instruments, destructive off-site spectrophotometry, or remote sensing. Moreover, smartphone-based applications also ensure a promising way to collect colorimetric information that could correlate with pigmentation. In this study, four grapevine genotypes were investigated using smartphone-based RGB (Red, Green, Blue) and CIE-L*a*b* colorimetry and a portable chlorophyll meter. The objective of this study was to evaluate the correlation between leaf chlorophyll concentration and RGB- or CIE-L*a*b*-based color indices. A further aim was to find an appropriate model for discriminating between the genotypes by leaf coloration. For these purposes, fully developed leaves of ‘Chardonnay’, ‘Sauvignon blanc’, and ‘Pinot noir’ clones 666 and 777 were investigated with the Color Grab smartphone application to obtain RGB and CIE-L*a*b* values. Using these color values, chroma, hue, and a further 31 color indices were calculated. Chlorophyll concentrations were determined using an Apogee MC100 device, and the values were correlated with color values and color indices. The results showed that the chlorophyll concentration and color indices significantly differed between the genotypes. According to the results, certain color indices show a different direction in their relationship with leaf pigmentation for different grapevine genotypes. The same index showed a positive correlation for the leaf chlorophyll concentration for one variety and a negative correlation for another, which raises the possibility that the relationship is genotype-specific and not uniform within species. In light of this result, further study of the species specificity of the commonly used vegetation indices is warranted. Support Vector Machine (SVM) analysis of the samples based on color properties showed a 71.63% classification accuracy, proving that coloration is an important ampelographic feature for the identification and assessment of true-to-typeness.

Photosystem rearrangements, photosynthetic efficiency, and plant growth in far red-enriched light.

Arabidopsis plants were grown in white light (400-700 nm) or in white light supplemented with far-red (FR) light peaking at 730 nm. FR-enriched light induced the typical shade avoidance syndrome characterized by enhanced length of seedling hypocotyl and leaf petiole. FR supplementation also caused a noticeable decrease in the carotenoid and chlorophyll content that was attributable to a block of pigment accumulation during plant development. The carotenoid decrease resulted from a downregulation of their biosynthesis pathway rather than carotenoid degradation. The losses of photosynthetic pigments are part of structural and functional rearrangements of the photosynthetic apparatus. The plastoquinone pool was chronically more oxidized in plants acclimated to white + FR light compared to white light-grown plants. Growth in FR-enriched light was associated with a higher photochemical efficiency of PSII compared to growth in white light and with a substantial increase in root and shoot biomass production. Light distribution between the photosystems was modified in favor of PSII by an increase in the PSII/PSI ratio and an inhibition of state transitions. Neither LHCII abundance nor nonphotochemical energy dissipation in the PSII chlorophyll antennae were modified significantly by the addition of FR light. A PSI supercomplex, not previously observed in Arabidopsis, was specifically found in plants grown in FR-enriched light. This large PSI complex contains a supplementary Lhca1-4 dimer, leading to a total of 6 LHCI antennae instead of 4 in the canonical PSI. Through those photosystem rearrangements and the synergistic interaction with white light, FR light is photosynthetically active and can boost photosynthesis and plant growth.

Combining UAV Multispectral and Thermal Infrared Data for Maize Growth Parameter Estimation

The leaf area index (LAI) and leaf chlorophyll content (LCC) are key indicators of crop photosynthetic efficiency and nitrogen status. This study explores the integration of UAV-based multispectral (MS) and thermal infrared (TIR) data to improve the estimation of maize LAI and LCC across different growth stages, aiming to enhance nitrogen (N) management. In field trials from 2022 to 2023, UAVs captured canopy images of maize under varied water and nitrogen treatments, while the LAI and LCC were measured. Estimation models, including partial least squares regression (PLS), convolutional neural networks (CNNs), and random forest (RF), were developed using spectral, thermal, and textural data. The results showed that MS data (spectral and textural features) had strong correlations with the LAI and LCC, and CNN models yielded accurate estimates (LAI: R2 = 0.61–0.79, RMSE = 0.02–0.38; LCC: R2 = 0.63–0.78, RMSE = 2.24–0.39 μg/cm2). Thermal data reflected maize growth but had limitations in estimating the LAI and LCC. Combining MS and TIR data significantly improved the estimation accuracy, increasing R2 values for the LAI and LCC by up to 23.06% and 19.01%, respectively. Nitrogen dilution curves using estimated LAIs effectively diagnosed crop N status. Deficit irrigation reduced the N uptake, intensifying the N deficiency, while proper water and N management enhanced the LAI and LCC.

Evaluation of cultivation technology package and corn variety based on agronomy characters and leaf green indices

Abstract This study aimed to identify the best combination of corn technologies and varieties to increase yield, a study case in Torowang, South Sulawesi. The findings of this study used a split-plot design with three replications. The cultivation technology package is composed of planting spacing, chemical fertilizer, and biofertilizer, with three levels of treatment. Meanwhile, varieties treatment as subplot consisted of six varieties of treatment: Nasa 29, Bisi 18, Sinhas 1, NK7328, Pioneer 27, and ADV 313. The study determined the effectiveness of six agronomy and three chlorophyll pigment characters. Based on the results, varietal diversity dominates the differences in growth traits, both morphological and physiological. Varietal potential differs from the diversity of crop technology packages, which show no significant effect on all growth traits. However, the interaction between the growth package and varieties shows a significant effect, indicating that the crop technology package significantly affects the growth response. Yield was significantly correlated with plant height, 1,000 grain weight, peeled ear weight, chlorophyll content meter (CCM) chlorophyll, and NDVI-UAV. The total chlorophyll trait based on CCM showed a significant correlation with yield but did not correlate with NDVI-UAV. The study concluded that Pioneer 27 and ADV 313 varieties are recommended for cultivation in Takalar, with the combination of planting space of 75 × 20 cm + N:P:K fertilizer dose of 200:100:50 kg ha−1 + 25 kg of KNO3 + 5 cc L−1 of Eco-Farming fertilizer to Pioneer 27 (Pc2V5) recommended. Further dissemination is required in other regions.

The Impact of Grafting with Different Rootstocks on Eggplant (Solanum melongena L.) Growth and Its Rhizosphere Soil Microecology

This study investigated the effects of grafting on eggplant growth, yield, and disease resistance, with a focus on microbial dynamics in the rhizosphere. Eggplant scions were grafted onto rootstocks of wild eggplant and tomato, with self-rooted eggplants serving as controls. Greenhouse experiments were conducted over an eight-month growing period, using standard field practices such as film mulching and integrated water–fertilizer management. High-throughput sequencing was used to analyze the biological properties and microbial community of the rhizosphere soil. Results showed that plants grafted onto ‘Huimei Zhenba’ and ‘Torvum’ rootstocks yielded up to 36.89% more than self-rooted controls, achieving yields of 4619.59 kg and 4399.73 kg per 667 m², respectively. The disease incidence of bacterial wilt was reduced to as low as 3.33% in the ‘Huimei Zhenba’ treatment, compared to 55.56% in non-grafted controls. Additionally, grafted plants exhibited increased stem diameter and chlorophyll content, with the TL/HM combination reaching 54.23 ± 3.17 SPAD units. The enhanced microbial biomass of carbon, nitrogen, and phosphorus, particularly in the TL/HM treatment (377.59 mg/kg, 28.31 mg/kg, and 36.30 mg/kg, respectively), supports a more nutrient-rich rhizosphere environment. Moreover, soil enzyme activities, such as β-glucosidase and phosphatase, were significantly higher in grafted plants, enhancing nutrient cycling and potentially increasing resistance to pathogens. Overall, grafted eggplants demonstrated enhanced soil microbial biomass, enzyme activity, and a more diverse microbial community, which are critical factors contributing to the improved yield and disease resistance observed in grafted crops.

Effect of Different Zn Concentrations on Crop Growth and Root Nodulation in Yard-Long Bean (Vigna unguiculata L.)

An experiment was conducted to study the effect of Zinc (Zn) as a micronutrient on growth and nodulation in Vigna unguiculata L. The experiment was carried out as a pot experiment in the Crop Farm, Faculty of Agriculture, Palachcholai, Eastern University, Sri Lanka from August to November 2023. The experiment was laid out in Complete Randomized Design with six treatments and four replicates. The treatments are T1 (Control), T2 (50 mg ZnSO4/kg soil), T3 (100 mg ZnSO4/kg soil), T4 (150 mg ZnSO4/kg soil), T5 (200 mg ZnSO4/kg soil) & T6 (250 mg ZnSO4/kg soil). The experiment used source of Zinc in the form of Zinc Sulphate (ZnSO4,5H2O) which yard-long bean plants can grow. The experiment results showed that, T2 treatment, the soil treated with 50 mg ZnSO4/kg soil significantly increase the Plant height, Chlorophyll content, Leaf area, Fresh weight of shoot & root, Dry weight of shoot & root, Number of nodules, Effective nodule percentage, as well as Soil respiration compared to the other treatments. However, beyond the level of 200 mg ZnSO4/kg soil, reduces the growth & nodulation of Vigna unguiculata L. and this shows that the level 200 mg ZnSO4/kg soil and beyond that level were the toxic level to the Vigna unguiculata L. Accordingly, the treatment T2 (50 mg ZnSO4/kg soil) was at the micronutrient level of Zn concentration which involved in many key cellular functions and show the best positive effect on growth and nodulation in Vigna unguiculata L. The results clearly indicate that, Zn can be use as a micronutrient up to a trace level in inducing plant growth and nodulation. However, at higher levels of Zn may act as heavy metal and cause phyto-toxicity in plants.

The Effect of Biochar on Tomato (Solanum lycopersicum) Cultivar Micro-Tom Grown under Continuous Light

AbstractContinuous lighting (CL) has the potential to increase crop yield in greenhouse production. Tomato plants, however, when exposed to CL develop inter-vascular chlorosis, a leaf injury which causes a reduction in chlorophyll content and necrosis. The application of biochar can reduce physiological stress in plants, we examine if biochar also reduces necrosis in tomatoes when grown under CL. Faecal sludge biochar was applied to an acidic soil to examine plant growth and yield in Micro-Tom tomato plants grown under continuous light. We examined soil and plant growth properties of three soil application treatments: a control soil, biochar treatment (4%w/w) (Biochar), and a combined biochar (2% w/w) and fertilizer (2% w/w) treatment (Biochar + Fert). Faecal sludge biochar addition produced plant heights 216% greater than control and above ground biomass 583% greater than control. The biochar and fertilizer treatment group produced a 487% increase in leaf number compared to biochar. The combined biochar and fertilizer treatment produced a 398% increase in dried above ground biomass and a 177% increase in dried fruit yield compared with biochar. Plants in the biochar and fertilizer treatment group showed less visual evidence of continuous light induced leaf injury.Biochar addition did not limit continuous light induced leaf chlorosis whereas combined biochar and fertilizer treatment resulted in a significant reduction in leaf injury and death. Overall, the application of biochar and biochar and fertilizer combined increased crop yield.

Effect of the Root Endophytic Fungus Piriformospora indica on Strawberry Growth, Fruit Quality and Physiological Traits Under Elevated Electrical Conductivity

Strawberries are sensitive to abiotic stresses such as salinity, high levels of electrical conductivity, and nutrient imbalances. The mutualistic endophytic fungus Piriformospora indica has significant potential to be used in improving crop production under adverse conditions, with a large host range. However, greenhouse production requires novel tactics to improve the efficiency of saline water irrigation in areas with limited freshwater resources. This study was conducted at the National Research and Development Center for Sustainable Agriculture (Estidamah), KSA, to investigate the impact of P. indica colonization on the growth, photosynthesis traits, productivity, and fruit quality of Fragraria x ananassa Duch cv. Festival strawberry grown in pots and irrigated with two electrical conductivity (EC) nutrient solutions of 1.5 and 3.0 dS/m. The results showed that higher-EC-nutrient solution clearly reduced growth and early yield and improved vitamin C, TSS, and anthocyanin of strawberry in comparison to low-EC-nutrient solution. On the other hand, P. indica colonization significantly increased plant height, shoot fresh weight, root length, and early yield of plants grown under high-EC-nutrient solution with no impact on fruit quality. Obviously, the symbiosis between strawberry roots and P. indica enhanced chlorophyll content, photosynthetic rate, stomatal conductance, and transpiration rate, as well as antioxidant activity such as proline, malondialdehyde, catalase, superoxide dismutase, and peroxidase under higher-EC-nutrient solution. Our study indicated that P. indica might be used as a sustainable tool for strawberry production in arid and semiarid zones, to mitigate the negative impacts of higher-EC-nutrient solution.

Respon Pertumbuhan dan Hasil Microgreens Beberapa Varietas Tanaman Caisim (Brassica juncea L.) pada Berbagai Jarak Tanam

The diminishing amount of land available for agriculture and the growing demand for nutritious food have made it necessary to find alternative sources of fresh vegetables. Urban farming, especially the cultivation of microgreens, can help meet this demand. Microgreens offer several advantages, such as time and cost savings, and they require minimal space while growing quickly. However, the optimal spacing for different types of microgreens is not extensively documented, as research on microgreens is still limited in Indonesia. The Brassicaceae family is one of the most commonly cultivated families for microgreens. This study was carried out at Room A, Faculty of Agriculture, Singaperbangsa Karawang University, Campus 2. The experimental method used was a factorial randomized block design (RBD Factorials) with two treatments for varieties and three for spacing, repeated five times, resulting in 30 experimental units. Factor I, Varieties, consisted of v1 (Tosakan) and v2 (Shinta). Factor II, Spacing, consisted of j1 (1 cm x 1 cm), j2 (1 cm x 2 cm), and j3 (2 cm x 2 cm). The data were analyzed using an analysis of variance (Uji F) at a 5% level. If the results of the analysis of variance were significantly different, the study continued with a multiple range test (DMRT) at a 5% level to determine the best-performing treatment. There was an interaction between the treatments for microgreen varieties and spacing on parameters such as plant density, dry weight of the plant, and fresh weight. There was a significant effect of the variety on the parameter of chlorophyll content, and a significant effect of spacing on the parameters of plant growth rate and the age of leaf appearance. Additional types of plants are needed to determine significant differences related to spacing and their interactions.

Comparative study of endophytic bacterial strains from non-host crops for enhancing plant growth and managing early blight in tomato

Bacillus pseudomycoides, Paenibacillus polymyxa, and B. velezensis are potent bacterial endophytes, which typically exhibit host-specific interactions. However, comparative studies of these endophytes in vitro and in planta in non-host crops are lacking. Therefore, in this study, we evaluated the potential of endophytes B. pseudomycoides strain HP3d, P. polymyxa strain PGSS1, B. velezensis strain A6, and P42, isolated from various crop ecosystems in promoting plant growth and inducing systemic resistance against early blight disease in tomato. In vitro, endophytes exhibited 44.44–55.56% and 37.50–87.50% inhibition of Alternaria solani in dual culture and volatilome bioassay, respectively. In the glasshouse, individual and combined applications via seed treatment (ST), seedling dip (SD), and foliar spray (FS) significantly enhanced shoot growth (23.63–57.61%), root growth (43.27–118.23%), number of leaves (77.52–93.58%), number of shoots (33.42–45.28%) and root dry matter (42.17–43.86%), reducing early blight (PDI) by 70.95–76.12% compared to uninoculated control. Enzymatic activities, including such as polyphenol oxidase (30–40 fold), peroxidase (65.00–75.00 fold), superoxide dismutase (34.20–37.20 fold) and phenylalanine ammonia-lyase (44.44–45.56 fold) were elevated post-inoculation in endophytes treated tomato plants challenged with A. solani compared to control treated only with A. solani and declined after the fifth day. The total chlorophyll content declined from the 0th to the 10th day, but endophyte treated plants exhibited lesser reductions (2.03–2.09) than uninoculated control. Field trials confirmed the glasshouse findings, showing reduced early blight and improved growth parameters in tomato where the ST + SD + FS combination emerged as the most effective treatment for all endophytes showing 1.06–1.88 fold increase in fruit yield per plant and 28.92–32.52% decrease in PDI compared to untreated control. Thus, the study highlights the broad-spectrum potential of these strains in promoting plant growth and controlling early blight in tomato, demonstrating non-host specificity. These endophytes offer eco-friendly alternatives to chemical pesticides, supporting sustainable agriculture. Their success in field trials suggests the potential for commercialization and large-scale use across diverse crops and pave the way for further interdisciplinary research to optimize their application in integrated pest management strategies.

Overexpression of SlATG8f gene enhanced autophagy and pollen protection in tomato under heat stress.

Autophagy is a mechanism for the degradation of cellular components in eukaryotes and plays a critical role in plant responses to abiotic stress. As a core member of the autophagy process, ATG8's role in how plants respond to heat stress remains unclear. To investigate the response of the tomato autophagy core member ATG8f to heat stress, we studied the key gene ATG8f and generated tomato lines overexpressing SlATG8f using the recombinant expression vector pBWA(V)HS. We observed that under heat stress, SlATG8f overexpression (OE) plants exhibited decreased heat tolerance compared to wild-type (WT) plants. Specifically, OE plants showed increased relative electrolyte leakage, reduced soluble solid content, elevated chlorophyll content, and higher autophagosome numbers, with less damage to chloroplasts and mitochondria. Additionally, expression of some ATG8 family genes and heat shock protein-related genes was upregulated. Moreover, SlATG8f overexpressing plants had higher pollen vitality and more intact pollen morphology. These results suggest that while SlATG8f overexpression renders plants more sensitive to heat, it helps mitigate high-temperature damage to tomato pollen by maintaining chloroplast integrity and interacting with heat shock proteins to respond to heat stress.

Evaluation of Genotypes against Water Stress and Salinity in Rice (Oryza sativa L.)

Abiotic stresses pose significant challenges to growth, yield and productivity thus threatening food security. Hence, it is essential to develop climate resilient rice varieties that mitigate the impact of abiotic stress. A study on physiological characterization for water and salinity stress was conducted in twenty-eight rice genotypes during kharif 2023 at Regional Agricultural Research Station, Maruteru. Among all the treatments, root length, shoot length, root and shoot dry weight and chlorophyll content was maximum under control followed by 1% mannitol, 2% mannitol and salinity stress. Visual scoring for water stress at seedling stage revealed that under mild water stress (1% M) more than 90% of plants survived in genotypes viz., AC-35678, FL 478, Ravana, Rahaspunjar, AUS 63, AUS 73, Vandana, NICRA 16, NICRA 17, CR-3439-4-E-17-2-1-B-1-S-1, CR-4215-2-5-2-M-4-SUB-2-5-1. Under severe water stress (2% M) more than 70% of the seedlings survived in NICRA 16, CR-4215-2-5-2-M-4-SUB-2-5-1, CRAC-4423-3, IET -18727, IC-516 149, IET-18716, AC-35678, FL 478, AC 85, Rahaspunjar, AUS 100, NICRA 17, CR-3439-4-E-17-2-1-B-1-S-1. Under salinity stress the score 3 was recorded in FL 478, and 5 in Rahaspunjar, IET -18727, NICRA 16, Ravana, NICRA 17. For both combined stresses, FL 478, Rahaspunjar, NICRA 16 and NICRA 17 were identified as tolerant and can be identified as donors for development of rice varieties having climate resilience.

Ethyl methanesulfonate (EMS) mediated dwarfing mutation provides a basis for CaCO3 accumulation by enhancing photosynthetic performance in Ceratostigma willmottianum Stapf.

Ceratostigma willmottianum Stapf is a unique chalk gland (salt-excreting) plant from China, with a salt gland structure that excretes white crystals of calcium carbonate (CaCO3), which has potential biomineralization and carbon sequestration functions. Due to the narrow distribution of wild germplasm resources, there is a lack of diversity of new varieties to satisfy commercial development and scientific exploration. Therefore, we used ethyl methanesulfonate (EMS) mutagenesis to obtain new dwarf mutant germplasm, and analysed it in terms of morphology, growth, photosynthesis, salt glands, and excretion traits. All four dwarfing mutant strains (DM1, DM2, DM3, and DM4) exhibited extreme dwarfing (62.28%, 62.28%, 74.55% and 61.68% reduction in plant height, respectively), faster growth, increased belowground root biomass, and earlier bud differentiation and flowering. Photosynthetic capacity was enhanced: chlorophyll content, maximum quantum yield of PSII (Fv/Fm), effective quantum yield of PSII (ΦPSII), photochemical quenching coefficient (qP), electron transfer rate (ETR), net photosynthesis (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs), and transpiration (Tr), were significantly higher in leaves of DM mutants. The density of salt glands per unit leaf area and average Ca2+ excretion rate of individual salt glands increased significantly (especially in DM2), and CaCO3 accumulation per unit leaf area was 28.57% higher than that of the wild type. Pearson correlation analysis showed that photosynthetic capacity was significantly and positively correlated with CaCO3 excretion. The above study not only provided enriched new germplasm of C. willmottianum, but also important research material for studying the mechanism of CaCO3 excretion by salt glands and carbon sequestration capacity of biomineralization.

Application of Spectral Imaging and Vegetation Index in Latin American Coffee Production: A Systematic Mapping

ABSTRACTCoffee production is a crucial economic, social, and cultural pillar in Latin America, facing numerous challenges, including integrating technological advancements such as multispectral imaging. This approach offers multiple advantages for coffee production; however, a knowledge gap in the domain is the need to methodologically review the available empirical evidence to delineate the field and the study region. Therefore, this systematic mapping aims to map the scientific corpus of multispectral imagery and vegetation index implemented in coffee production in the Latin American region. The study followed the PRISMA protocol; 42 primary studies were analyzed to identify key trends and research gaps. The main result of this research is that NDVI emerged as the most widely used spectral index, with applications in estimating critical biophysical parameters such as biomass and chlorophyll content. Other indices such as GNDVI, NDRE, and SAVI also proved valuable in assessing coffee plant health and development. There was an emerging trend to integrate multispectral imaging with machine learning techniques, promising greater accuracy in data interpretation. The study also revealed a concentration of research efforts in selected Latin American countries, particularly Brazil, indicating opportunities to expand research in other coffee‐producing regions. The study's main conclusion is that multispectral imaging, mainly through vegetation index, has emerged as a valuable tool for phenological monitoring and management of coffee production, offering several advantages over traditional methods. Finally, this review contributes to the existing knowledge base and identifies future research directions for applying multispectral imagery to sustainable coffee production in Latin America.

Synthesis and mechanism of Mg/Al layered double oxides-silica nanocomposites for sustainable multi-nutrient delivery in agricultural applications

Potassium (K), urea (N), phosphate (P), and selenite (Se) are widely used in modern agriculture for improvement of crop yield and quality. However, traditional fertilizer suffers from poor fertilizer utilization efficiency and noncontrollable slow-release behavior. To improve nutrient utilization, we developed a layered double oxides-silica (LDO@Si) based on calcined Mg/Al layered double hydroxide-silica nanocomposites (LDH@Si), for slow release of K, N, P, and Se to crops. In this study, SEM, XRD, FT-IR, XPS, BET, and TGA were employed to analyze the structure, morphology, and microstructures of the samples. Results show that LDH@Si successfully transforms into LDO@Si after calcination, where LDO is mainly connected to silica via M-O-Si bonds. Furthermore, after K, P, and Se loading, the LDH@Si structure was successfully restored, indicating that phosphate and selenite ions have been effectively embedded in the inner layer of LDH. K ions are firmly fixed to the material surface via M-O-K bonds. After urea introducing, the pore structure of the material was completely filled, and excess urea formed a urea layer on the surface of the material. LDO@Si can continuously release nutrients into water through diffusion and LDO@Si dissolution for up to 240 h. Compared with chemical fertilizers, LDO@Si based slow-release fertilizer (CRSF2) significantly improves plant fresh weight, dry weight and chlorophyll content, increasing them by 13.91 %–23.13 %, 18.20 %–34.40 % and 2.24 %–14.81 %, respectively. Furthermore, a modest increase in the levels of nutrients N, P, and K is observed, while the Se concentration in plants treated with CRSF2 demonstrates significant enhancements of 9.57 %, 72.49 %, and 50.97 % compared to control treatments. These results illustrate the potential agricultural application of LDO@Si as a slow-release fertilizer for improving crop yields while minimizing the required amount of fertilizer.

Integrative multi-omics analysis of chilling stress in pumpkin (Cucurbita moschata).

Pumpkin (Cucurbita moschata) is an important vegetable crop that often suffers from low-temperature stress during growth. However, the molecular mechanism involved in its response to chilling stress remains unknown. In this study, we comprehensively investigated the effect of chilling stress in pumpkin seedlings by conducting physiological, transcriptomic, and metabolomic analyses. Under chilling stress, there was an overall increase in relative electrical conductivity, along with malondialdehyde, soluble sugar, and soluble protein contents, but decreased superoxide dismutase and peroxidase activities and chlorophyll contents in seedling leaves compared with controls. Overall, 5,780 differentially expressed genes (DEGs) and 178 differentially expressed metabolites (DEMs) were identified under chilling stress. Most DEGs were involved in plant hormone signal transduction and the phenylpropanoid biosynthesis pathway, and ERF, bHLH, WRKY, MYB, and HSF transcription factors were induced. Metabolomic analysis revealed that the contents of salicylic acid (SA), phenylalanine, and tyrosine increased in response to chilling stress. The findings indicated that the SA signaling and phenylpropanoid biosynthesis pathways are key to regulating the responses to chilling stress in pumpkins. Overall, our study provides valuable insights into the comprehensive response of C. moschata to chilling stress, enriching the theoretical basis of this mechanism and facilitating the development of molecular breeding strategies for pumpkin tolerance to chilling stress.

Effect of a tropical cyclone on the pelagic ecosystem of a continental shelf

AbstractThis study aimed to comprehend the effects of Typhoon Maria on the pelagic ecosystem in the southern East China Sea. Shipboard measurements were conducted at eight sampling stations before (2–4 d) and after (3–6 d) the typhoon, which enabled the evaluation of the potential impacts of the typhoon on this pelagic ecosystem, with particular focus on carbon dynamics. Following the typhoon's passage, there was a slight drop in sea surface temperature. The response of the variables to the typhoon, however, exhibited variations at different sampling stations. For further analysis, t‐tests compared variables, while type II regression assessed the linear correlation between two variables. Overall, during the post‐typhoon period, concentrations of nitrate, chlorophyll a, primary production, bacterial biomass and production, plankton community respiration, and abundance of large phytoplankton (> 2 μm) and the relative abundance of picophytoplankton among larger‐sized picoeukaryotes were higher compared to the pre‐typhoon period. The mean value of fugacity of CO2 was similar to or slightly lower than pre‐typhoon period. Although the typhoon‐induced vigorous primary production might have absorbed a significant amount of CO2, the decrease in fugacity of CO2 could have been offset by the plankton community respiration. The findings suggest that the typhoon enhanced physical disturbance and increased water column mixing, which, in turn, augmented nutrient availability and promoted plankton growth in the shallow water column. Overall, this study sheds light on the complex interactions between typhoons and marine ecosystems and highlights the importance of further investigating these phenomena to better understand their ecological implications.

Exploring the impact of aminoethoxyvinylglycine (AVG) on the ripening behaviour and quality of bananas under different storage conditions

ABSTRACT Bananas rapidly undergo physiological deterioration after harvest owing to their climacteric and perishable nature causing significant economic yield loss. Thus, the adoption of postharvest loss mitigation strategies becomes imperative for enhancing fruit longevity. This study aimed to assess the effect of postharvest treatment with different concentrations of aminoethoxyvinylglycine (AVG) on shelf life extension and quality sustainability of bananas, such as Grand Naine, Poovan and Ney Poovan, kept under ambient (27°C ± 2°C) and cool (17°C) conditions. The findings revealed that AVG-treated bananas reduced weight loss of banana hands (0.655–2.559 kg hand−1) and higher peel thickness (0.86–2.73 mm) and firmness (6.54–12.01 N) over untreated control at ambient storage condition, whereas under cool storage, weight loss of banana hands reduced from 0.761 to 2.579 kg hand−1, while both peel thickness (1.24–2.84 mm) and firmness (7.75–11.45 N) were retained for varieties. The physio-chemical traits of fruit, such as total chlorophyll and starch content, were improved due to AVG treatment under both storage conditions. Among the treatments, postharvest application of AVG at 700 ppm showed better performance in the morphological, physiological and quality characters irrespective of the varieties.

Exogenous Riboflavin Application at Different Growth Stages Regulates Photosynthetic Accumulation and Grain Yield in Fragrant Rice

Fragrant rice has high market value and is popular among consumers because of its pleasant fragrance. Plant growth regulators and trace elements can influence the yield and physiological indices of fragrant rice. Riboflavin, a vital component of plant vitamins, plays a crucial role in plant growth and development, and it is a water-soluble vitamin that is essential for sustaining normal photosynthesis and metabolic processes. However, the effects of riboflavin on nutrient accumulation and yield formation in fragrant rice have rarely been reported. Therefore, to further increase the yield and quality of fragrant rice, this study investigated the impact of the foliar application of riboflavin at different growth stages on nutrient accumulation and yield formation in two different genotypes of fragrant rice via a pot experiment. The experimental design consisted of three treatment groups, i.e., the T0 treatment group (control), which was sprayed with water; the T1 treatment group, which was sprayed at the booting stage; and the T2 treatment group, which was sprayed at the flowering stage; in all of these groups, 20 mg·L−1 riboflavin solution was used. The results revealed that the yields of the T1 and T2 treatments increased by 6.56–7.25% and 10.52–13.80%, respectively, compared with those of T0, which was attributed mainly to the increase in 1000-grain weight and grain filling. Furthermore, foliar spraying of riboflavin significantly increased the chlorophyll content, which resulted in the increased production of more total starch, soluble sugars, and sucrose and facilitated their transportation to the seeds. Moreover, applying riboflavin directly to the leaves increased the activity levels of the sucrose synthase (SS) and sucrose phosphate synthase (SPS) enzymes. Among the three treatments, the T2 treatment had the most pronounced effect. The results revealed that the foliar application of riboflavin could increase photosynthesis and promote the production of nonstructural carbohydrates, thereby increasing the total aboveground biomass of fragrant rice by 17.00–20.91% and 21.07–72.91% under the T1 and T2 treatments, respectively. Additionally, spraying riboflavin promoted rapid increases in the weight of fragrant rice seeds. In conclusion, foliar spraying of riboflavin during the flowering stage of aromatic rice can effectively enhance photosynthetic accumulation and yield, which is a promising physiological regulation strategy and provides new theoretical guidance for high-yield cultivation practices.

Photoperiodic Effect on Growth, Photosynthesis, Mineral Elements, and Metabolome of Tomato Seedlings in a Plant Factory

The duration of light exposure is a crucial environmental factor that regulates various physiological processes in plants, with optimal timing differing between species and varieties. To assess the effect of photoperiods on the growth and metabolites of a specific truss tomato cultivar, three photoperiods (12 h, 16 h, and 20 h) were tested in a plant factory. Growth parameters, including plant height, stem diameter, fresh and dry weights of shoots and roots, photosynthetic characteristics, mineral content, and metabolome profiles, were analyzed under these conditions. The results indicated that prolonged light exposure enhanced plant growth, with the highest photosynthesis and chlorophyll content observed under a 20 h photoperiod. However, no significant correlation was observed between the photoperiod and the mineral element content, particularly for macro minerals. Metabolome analysis revealed that different photoperiods influenced the accumulation of metabolites, particularly in the lipid metabolism, amino acid metabolism, and membrane transport pathways. Long periods of light would enhance photosynthesis and metabolism, improving the rapid growth of tomato seedlings. Overall, this study provides a theoretical basis for understanding the responses of truss tomato cultivars to varying photoperiods in plant factories and proposes an optimizable method for accelerating the progress of tomato seedling cultivation.