Search Results (2,778)

Tomato (Solanum lycopersicum L.) is among the most economically significant and nutritionally valuable vegetable crops grown globally. However, fungal diseases such as Early Blight caused by Alternaria alternata are a major factor limiting yield and fruit quality in tomato production. This study investigates the biocontrol potential of locally isolated rhizobacterium Pseudomonas yamanorum against A. alternata, the causal agent of early blight in tomato, under both in vitro and in planta conditions. In vitro assays demonstrated significant antifungal activity; in the dual confrontation assay, P. yamanorum (10⁸ CFU/mL) reduced A. alternata mycelial growth by 68.7%, while spore germination was inhibited by 88.7%. In planta trials demonstrated that plants treated with P. yamanorum (10⁷ CFU/mL) alone exhibited the lowest disease severity (2.5). The treatments also significantly enhanced plant growth, with shoot length reaching 45 cm versus 26 cm in infected controls. Biochemical analyses revealed increased catalase (94.84 units mg⁻¹ protein min⁻¹), peroxidase (5.83), and ascorbate peroxidase (67.01) activities in treated plants. Total polyphenol and protein contents also increased (0.81 mg/g and 15.82 mg/g, respectively). Furthermore, P. yamanorum treatments maintained fruit quality parameters such as firmness (3.13), sugar content (6.43 °Brix), and juice yield (55.88%), while reducing malondialdehyde (2.02 µmol/g Dry Weight) and electrical conductivity (0.59 mS/cm). These findings highlight P. yamanorum as a promising biocontrol agent and plant growth-promoting bacteria that improve disease resistance, which can be combined with salicylic acid to further enhance crop vigor and fruit quality under biotic stress. Full article

The continued use of agrochemicals in Valle de Arista, SLP, Mexico, has generated loss of effectiveness of active ingredients and impacts on public health and the environment. To identify environmental and socioeconomic impacts, a quantification method was designed using the Kovach Environmental Impact Quotient and environmental accounting of pesticides (Leach and Mumford) that included agricultural diagnosis and identification of agrochemical impacts. Producers, technical advisors and agrochemicals dealers were surveyed as key agents of tomato (Solanum lycopersicum) and chili pepper crops (Capsicum annuum) due to their economic importance. Gower quotation coefficients were calculated to measure similarity of quantitative, qualitative and dichotomous variables with continuous, discrete and binary characteristics. The use of fungicides (carbendazim and chlorothalonil) showed the greatest environmental impact, followed by insecticides (endosulfan and thiametoxam) and herbicides. The negative externality averaged US$15.60 ha⁻¹ annually, corresponding to 50% of tomato, 31.25% of poblano pepper and 18.75% of serrano pepper. Estimated damages due to the use of greenhouses were 37.7% to the consumer, 21.2% to the worker, 14.8% to aquatic life, 3.6% to birds, 9.2% to bees and 3.3% to insects. Full article

Wild potato relatives are vital for breeding programs to tackle rising temperatures. This study proposes a methodological approach based on the examination of genetic variation among 19 accessions belonging to Solanum chacoense and Solanum commersonii from the Embrapa Potato Genebank under heat stress (HS). Heat tolerance coefficient (HTC) was calculated using genotypic values predicted through mixed models. After 15 days of heat stress (DHS), a significant variation in gas exchange and chlorophyll fluorescence indicates strong breeding potential and photosystem resilience. By 35 DHS, increased pigment variation suggests acclimation. Based on predicted genotypic values, S. chacoense outperforms S. commersonii in tuber production and gas exchange under HS, and principal component analysis (PCA) performed using the HTC shows early resistance driven by photosynthesis, mid-term by tuber yield, and long-term by gas exchange and tuber production. Genotypes BRA00167017-3, BRA00167023-1, BRA00167025-6, and BRA00167028-0 excel in heat comprehensive evaluation values (HCEVs)/comprehensive principal component value (F) rankings, demonstrating robust photosynthesis, thermoregulation, and tuber yield. Cluster analysis identifies these as highly tolerant, ideal for breeding heat-resilient potatoes. These PCA-derived weights and genotype clustering system provide a precise tool for selecting heat-tolerant wild potato germplasm, categorizing them into highly tolerant, moderately tolerant, sensitive with late recovery, and highly sensitive groups acquired for specific objectives of the breeding programs to climate change. Full article

Use of dicamba, an auxin-mimic herbicide, has increased in recent years. Both the effects of dicamba on non-target plants and the determination of a biological model to determine the dicamba ecotoxicity dynamics are important to monitor the correct and safe use of this herbicide. The objectives of this study were to determine the effects of low doses (simulating herbicide drift) and to determine the acute toxicity of dicamba to aquatic bioindicator species (Lemna minor, Pomacea canaliculate, Hyphessobrycon eques, and Danio rerio) and terrestrial non-target plants (Cucumis sativus, Solanum lycopersicum, and Lactuca sativa) in tropical conditions. Measurements of acute toxicity of dicamba at the concentrations that cause 50% of symptoms of injury (LC50) and other biometric variables were performed. Dicamba was virtually non-toxic to all aquatic bioindicator species (LC50 > 118.0 mg L⁻¹), while it was highly toxic to all terrestrial non-target plants (LC50 < 0.5 mg L⁻¹). Severe injury symptoms (70% to 100%) caused by application of low doses of dicamba were found for all non-target terrestrial plants. Severe injury symptoms (70% to 100%) caused by volatilization of dicamba were found only for S. lycopersicum. Since S. lycopersicum was found as the most sensitive non-target plant, showing high injury symptoms caused by dicamba and significant injury from volatilized dicamba, this species is suitable for environmental monitoring of dicamba applications. Full article

The joint adoption of agronomic practices has often been employed to maximize the efficiency of production inputs, especially water and nutrients. Potato (Solanum tuberosum) is a highly demanding crop in both water and nutrients. This study aimed to determine the most appropriate strategy for irrigation frequency and planting fertilization depth in potato cultivated in amended soil, in order to maximize plant growth, tuber yield, and tuber quality. Field experiments were conducted over two growing seasons, with irrigation frequencies of daily irrigation and irrigation every 4, 7, and 10 days, and planting fertilization depths of 10 and 20 cm. Irrigation frequency significantly affected agronomic traits, water consumption, potato growth, and tuber quality. Treatments did not influence root development across different soil layers. Irrigation intervals of 1 and 4 days promoted greater plant growth. A 7-day irrigation interval enhanced specific gravity and soluble solids in tubers, while a 10-day interval increased tuber dry matter content by up to 18% compared to daily irrigation (IF1). Decreasing irrigation frequency reduced the irrigation depth without affecting yield and average tuber mass, and improved water productivity. Water productivity increased by up to 32% under the 10 day irrigation interval (IF10) compared to IF1. Therefore, reducing irrigation frequency is a promising strategy to improve water use efficiency in potato cultivation. Full article

The study provides valuable insights into the sustainable utilization of edible tuber peels from the high mountains of the Argentinian Puna, which constitutes promising reserves of bioactive phenolic compounds with the potential to enhance the biofunctional properties of lactic acid bacteria. Thirty-two extracts derived from peels of different varieties of tubers, such as Oxalis tuberosa Mol., Ullucus tuberosus Caldas, and Solanum tuberosum L. were incorporated into lactobacilli cultures and individually evaluated. These selectively enhance the development of the probiotic strain Lactiplantibacillus plantarum ATCC 10241 and of Lacticaseibacillus paracasei CO1-LVP105 from ovine origin, without promoting the growth of a pathogenic bacteria set (Escherichia coli O157:H12 and ATCC 35218, Salmonella enterica serovar Typhimurium ATCC 14028, and S. corvalis SF2 and S. cerro SF16), in small amounts. To determine the main phenolic group concentrated in the phytoextracts, a bio-guided study was conducted. The most significant results were obtained by O. tuberosa phytochemicals added to the culture medium at 50 µg/mL, yielding promising increases in biofilm formation (78% for Lp. plantarum and 43% for L. paracasei) and biosurfactant activity (112% for CO1-LVP105 strain). These adaptive strategies developed by bacteria possess key biotechnological significance. Furthermore, the bio-detoxification capacity of phenol and o-phenyl phenol, particularly of the novel strain CO1-LVP105, along with its mode of action and genetic identification, is described for the first time to our knowledge. In conclusion, lactobacilli strains have potential as fermentation starters and natural products, recovered from O. tuberosa peels, and added into culture media contribute to multiple bacterial biotechnological applications in both health and the environment. Full article

Plant seedlings are sensitive to cultivation environment factors and highly susceptible to pathogenic infections under adverse conditions such as inappropriate light environment. In this study, five kinds of LED lighting sources with different red (R) and blue (B) light combinations were set up: R10B0, R7B3, R5B5, R2B8 and R0B10 (with R:B ratios of 10:0, 7:3, 5:5, 2:8 and 0:10, respectively) to explore their effects on tomato seedlings’ growth, AsA-GSH cycle, endogenous hormones, and resistance to Phytophthora infestans, providing a basis for factory seedling light-quality selection. The results showed that with the increase in the proportion of blue light in the composite light, the growth indicators, photosynthetic characteristic parameters and enzyme activities of tomato seedlings generally increased. The contents of AsA, reduced glutathione, and oxidized glutathione all reached the maximum under high-proportion blue-light treatments (R2B8 and R0B10). The high-blue-light groups (R2B8 and R0B10) had the highest AsA and glutathione contents. The red–blue combinations reduced inhibitory ABA and increased growth-promoting hormones (e.g., melatonin), while monochromatic light increased ABA to inhibit growth. After inoculation with P. infestans, the apoplastic glucose content was the highest under the red–blue-combined treatments (R5B5 and R2B8), while the total glucose content in leaves was the highest under the combined light R2B8 treatment. In conclusion, high-proportion blue-light treatment can greatly promote the photosynthetic process of tomato, enhance the AsA-GSH cycle, and achieve the best effect in improving the resistance of tomatoes to P. infestans. Given these, the optimal light environment setting was R:B = 2:8. Full article

Microviscosity and lipid order are the main parameters characterizing the phase states of the membrane. Variations in microviscosity and lipid composition in a living cell may indicate serious disturbances, including various kinds of stress. In this work, the effect of hyperosmotic stress on the microviscosity of mitochondrial membranes was investigated, using potato (Solanum tuberosum L.) tuber mitochondria. The microviscosity of mitochondrial membranes isolated from check and stressed (9 days at 34–36 °C) tubers was estimated by determining the generalized polarization (GP) values using a Laurdan fluorescent probe in confocal microscopy studies. It was revealed that the GP distribution in mitochondria isolated from stressed tubers contained new component-characterizing membrane domains with an increased lipid order compared to the rest of the membrane. We have mapped the microviscosity of mitochondrial membranes for the first time and observed the dynamics of the membrane microviscosity of an individual mitochondrion. The hyperosmotic stress significantly influences the functional state of potato mitochondria, decreasing the substrate oxidation rate and respiratory control coefficient but increasing MitoTracker Orange fluorescence. Under hyperosmotic stress, the microviscosity of mitochondrial membranes changes, and membrane domains with increased lipid order are formed. The revealed changes open up prospects for further research on the participation of raft-like microdomains of mitochondria in plant resistance to stress factors. Full article

Arbuscular Mycorrhizal Fungi (AMF) can form symbiotic relationships with most plants. They can alleviate the toxic effects of heavy metals on plants. This study analyzed the effects of AMF (Diversispora versiformis, D.v.) on the physiological responses and root organic acid secretion of tomato (Solanum lycopersicum L.) under cadmium (Cd) stress, in order to elucidate how AMF enhance Cd tolerance. The results indicated that when the AMF inoculation rate of tomato seedlings ranged from 26.75% to 38.23%, the AMF treatment significantly promoted tomato growth. Cd significantly reduced the agronomic traits of tomato. However, AMF inoculation dramatically lowered the Cd level from 19.32 mg/kg to 11.54 mg/kg in tomato roots, and effectively reduced the negative effect of Cd toxicity on seedling growth. Cd stress also significantly reduced the chlorophyll fluorescence parameters, chlorophyll contents, and photosynthetic intensity parameters in seedling leaves, while the AMF treatment significantly increased these indicators. Under Cd stress, the AMF treatment significantly increased the activities of SOD, POD, and CAT, and reduced the levels of reactive oxygen species and the contents of osmotic regulatory substances in roots. Under Cd stress conditions, the AMF treatment also significantly increased the auxin level (57.24%) and reduced the abscisic acid level (18.19%), but had no significant effect on trans-zeatin riboside and gibberellin contents in roots. Cd stress markedly reduced the content of malic acid and succinic acid by 17.28% and 25.44%, respectively; however, after the AMF inoculation, these indicators only decreased by 2.47% and 2.63%, respectively. Under Cd stress, AMF could increase tomato roots’ antioxidant capacity to reduce ROS level, thereby alleviating the toxicity induced by ROS and maintaining reactive oxygen metabolism, enhancing the plant’s stress resistance. In summary, the AMF treatment enhances the osmotic regulation capacity and maintains the stability of cell membranes by reducing the levels of osmotic regulatory substances in roots. It also enhances the Cd tolerance of tomato plants by regulating the contents of root hormones and aerobic respiration metabolites, among other pathways. Therefore, inoculating plants with AMF is a prospective strategy for enhancing their adaptive capacity to Cd-polluted soils. Full article

As climate extremes increasingly threaten global food security, precision tools for early detection of crop stress have become vital, particularly for root crops such as potato (Solanum tuberosum L.) and sweet potato (Ipomoea batatas L. Lam.), which are especially susceptible to environmental stressors throughout their life cycles. In this study, plants were monitored from the initial onset of seasonal stressors, including spring drought, heat, and episodes of excessive rainfall, through to harvest, capturing the full range of physiological and biochemical responses under seasonal, simulated conditions in greenhouses. The spectral data were obtained from regions of interest (ROIs) of each cultivar’s leaves, with over 3000 data points extracted per cultivar; these data were subsequently used for model development. A comprehensive classification framework was established by employing machine learning models, Support Vector Machine (SVM), Linear Discriminant Analysis (LDA), and Partial Least Squares-Discriminant Analysis (PLS-DA), to detect stress across various growth stages. Furthermore, severity levels were objectively defined using photoreflectance indices and principal component analysis (PCA) data visualizations, which enabled consistent and reliable classification of stress responses in both individual cultivars and combined datasets. All models achieved high classification accuracy (90–98%) on independent test sets. The application of the Successive Projections Algorithm (SPA) for variable selection significantly reduced the number of wavelengths required for robust stress classification, with SPA-PLS-DA models maintaining high accuracy (90–96%) using only a subset of informative bands. Furthermore, SPA-PLS-DA-based chemical imaging enabled spatial mapping of stress severity within plant tissues, providing early, non-invasive insights into physiological and biochemical status. These findings highlight the potential of integrating hyperspectral imaging and machine learning for precise, real-time crop monitoring, thereby contributing to sustainable agricultural management and reduced yield losses. Full article

Bacterial wilt, caused by Ralstonia solanacearum, is a major constraint to tomato production globally. To uncover resistance loci and develop efficient molecular tools for breeding, we conducted disease phenotyping over two growing seasons, which revealed consistent variation in resistance and moderate broad-sense heritability (H² = 0.22–0.28), suggesting a genetic basis. A genome-wide association study (GWAS) was performed on a diverse panel of 267 tomato accessions, evaluated against two R. solanacearum strains. A major resistance locus was identified on chromosome 12, with the strongest association observed at SNP S12_2992992, located within a gene encoding a leucine-rich repeat (LRR) receptor-like protein. Haplotype analysis indicated that the resistance-associated allele is relatively rare (~13.5%) in the population, underscoring its potential value in breeding programs. Functional validation in an F₂ population derived from a cross between the susceptible ‘Seedathip6’ and the resistant ‘Hawaii 7996’ confirmed that the TT genotype at S12_2992992 was significantly associated with enhanced resistance. A Kompetitive Allele Specific PCR (KASP) marker was developed for this SNP, facilitating cost-effective and high-throughput selection. Collectively, these findings establish S12_2992992 as a robust and functionally informative marker, offering a valuable tool for accelerating bacterial wilt resistance breeding in tomato through marker-assisted selection. Full article

Edible composite coatings represent an alternative approach to reducing postharvest losses and extending the shelf life of perishable fruits. This study developed a nano-biopolymer coating by integrating pullulan (PUL), nano-silica (Nano-SiO₂), and tea polyphenols (TP) to retard deterioration in cherry tomatoes (Solanum lycopersicum var. cerasiforme). Optimized through response surface methodology (0.06% Nano-SiO₂, 0.1% TP, 1.8% PUL, 0.77% glycerol), the resulting Nano-SiO₂/PUL/TP composite film showed improved barrier properties (water vapor permeability, WVP: 0.2063 g·mm·m⁻²·h⁻¹·kPa⁻¹) and increased mechanical strength (tensile strength, TS: 2.62 MPa; elongation at break, EB: 67.67%), which may be attributed to a homogeneous microstructure stabilized via intermolecular hydrogen bonding. The composite coating exhibited significant (p < 0.05) antioxidant activity (59.04% DPPH·scavenging) compared to the PUL film (1.17%) and showed efficacy against S. aureus. When applied to cherry tomatoes stored at 4 °C for 15 days, the coating contributed to improved postharvest quality by reducing weight loss (−27.6%) and decay incidence (−32.3%), delaying firmness loss (2.40 vs. 0.54 N in uncoated group, CK), suppressing respiration rate (−38.8%), and enhancing the retention of total acidity (+9.7%), vitamin C (+49.6%), and total soluble solids (+48.6%) compared to the CK (p < 0.05). Principal component analysis supported sensory evaluation results, indicating the coating helped maintain sensory quality (scores > 6.0) and commercial value while extending shelf life from 9 to 15 days. These results suggest that the Nano-SiO₂/TP/PUL composite coating may serve as a preservative for extending the shelf-life of cherry tomatoes by effectively reducing decay and mitigating quality degradation. Full article

The early stages of plant–microbe interaction are critical for establishing beneficial symbioses. We investigated how the endophytic fungus Fusarium solani strain FsK modulates tomato (Solanum lycopersicum) development and hormone pathways during in vitro co-cultivation. Seedlings were sampled at three early interaction stages (pre-contact, T1; initial contact, T2, 3 days post-contact, T3). Root traits and root and leaf transcripts for abscisic acid (ABA) and ethylene (ET) pathways were quantified, alongside fungal ET-biosynthesis genes. FsK altered root system architecture, increasing root area, lateral root number, root-hair length, and fresh biomass. These morphological changes coincided with tissue- and time-specific shifts. In leaves, FsK broadly affected ABA biosynthetic and homeostasis genes (ZEP1, NCED1, ABA2, AAO1, ABA-GT, BG1), indicating reduced de novo synthesis with enhanced deconjugation of stored ABA. ET biosynthesis was curtailed in leaves via down-regulation of ACC oxidase (ACO1–3), with isoform-specific changes in ACC synthase (ACS). The ET receptor ETR1 was transiently expressed early (T1–T2). FsK itself showed staged activation of fungal ET-biosynthesis genes. These results reveal coordinated fungal–plant hormone control at the transcriptional level that promotes root development during early interaction and support FsK’s potential as a biostimulant. Full article

The human gut microbiota plays a critical role in health throughout life. While fruits and vegetables are well-known sources of nutrients and prebiotics, recent studies suggest they may also contribute viable microorganisms to the gut microbiome, particularly when consumed raw. However, the impact of agricultural practices—such as the use of microbial biostimulants or exposure to salt stress—on the composition of the edible plant microbiome remains poorly understood. In this study, we performed a comprehensive metataxonomic analysis of the endophytic microbiome in the edible tissues (leaves or fruits) of lettuce (Lactuca sativa) and tomato (Solanum lycopersicum), cultivated under standard conditions with or without microbial biostimulants and salt stress. Our results show that microbial biostimulants—Priestia megaterium (PGPB) and Rhizophagus irregularis (AMF)—as well as moderate salt stress, significantly reshape the composition and diversity of endophytes in both crops. Notably, the PGPB and NaCl treatments enhanced the abundance of bacterial genera such as Pantoea, Stenotrophomonas, and Massilia, which are associated with plant health and may have probiotic potential. Salt stress also increased alpha-diversity indices and favored the presence of Firmicutes and Bacteroidota, phyla commonly linked to a healthy human gut microbiome. Agronomic inputs used in organic and conventional farming, such as microbial biostimulants or controlled salt exposure, may represent novel strategies to enhance the microbial quality of fresh produce and promote gut microbial diversity through diet. Full article

Efficient water and nitrogen (N) management are essential for sustaining potato (Solanum tuberosum L.) production under limited resource conditions. This study investigated the effects of deficit irrigation and reduced N application on tuber quality parameters including specific gravity (SG), starch content (SC), and tuber dry matter (TDM) as well as agronomic water use efficiency (WUE) and nitrogen use efficiency (NUE) in four commercial potato cultivars (Canela Russet, Mesa Russet, Russet Norkotah 3, and Yukon Gold) over two seasons (2016 and 2017) at Colorado State University’s San Luis Valley Research Center. Three irrigation levels (100%, ~80%, and ~70% evapotranspiration replacement) and two N application rates (165 and 131 kg N ha⁻¹) were evaluated using four replications. Moderate deficit irrigation (up to ~18% ET reduction) improved or maintained SG, SC, and TDM in all four cultivars, while severe deficit irrigation (~30–40% reduction) reduced tuber quality. Reduced N application improved NUE in all cultivars without compromising tuber quality or yield. While WUE responded variably to deficit irrigation, NUE was highest under moderate to full irrigation and low N rate. Although effects on WUE were variable, integrating moderate deficit irrigation (18%) with reduced N application (20%) enhanced NUE while maintaining tuber quality. Full article