Search Results (276)

This study investigated alternative pathways involving adaptive traits associated with drought tolerance in popcorn cultivated under soil water restriction through path analysis. Direct and indirect effects were estimated for morpho-agronomic variables, including ear height (EH), grain number per ear (GNE), grain number per row (GNR), 100-grain weight, grain yield (GY), and popping expansion (PE); physiological variables, such as relative chlorophyll content, anthocyanin and flavonoid indices, and maximum quantum efficiency of photosystem II; and root-related traits, including brace- and crown-root number and root angle. Fifty popcorn inbred lines were assessed under contrasting water conditions (WC), namely well-watered and water-stressed environments, during two crop seasons (CS). Water restriction was imposed before male anthesis, and the permanent wilting point was reached at 63 days after sowing in CS-2020 and at 100 days in CS-2021. Significant genotype × WC × CS interactions were identified for all evaluated traits. The effects of drought varied according to the developmental stage at which stress occurred. Under both water regimes, indirect selection through EH and GNR favored gains in GY, whereas EH and GNE showed the strongest indirect contributions to PE. Among the evaluated variables, EH emerged as a promising trait for indirect selection in popcorn breeding under water-limited conditions. Full article

Adventitious rooting remains a major constraint for the clonal propagation of Coffea arabica, limiting the large-scale multiplication of elite genotypes. This study evaluated the effects of genotype, auxin treatment, and their interaction on adventitious rooting and basal callus formation in coffee cuttings under controlled nursery conditions, while morphophysiological traits were assessed as complementary indicators of cutting performance. A completely randomized 3 × 3 factorial design was used, including three hybrids (H3, Excelencia, and Milenio) and three plant growth regulator (PGR) treatments: control, indole-3-butyric acid (IBA), and a commercial auxin formulation (RH; NAA + IBA). Rooting probability and root number were significantly affected by PGR treatment, whereas the longest root length was influenced by hybrid, PGR treatment, and their interaction. Model-estimated rooting probability increased from 4.76% in the control to 17.05% under IBA and 35.73% under RH. Similarly, the estimated number of roots per cutting increased from 0.14 in the control to 0.99 under IBA and 1.85 under RH. Although the hybrid × PGR interaction was not significant for rooting probability, the highest observed rooting percentage was recorded in H3 under RH (52.38%), followed by Milenio under RH (33.33%). For the longest root length, the strongest responses were observed under RH, particularly in Milenio (71.15 mm) and H3 (70.08 mm). Callus formation varied among treatments, but its association with rooting performance was weak and inconsistent. Morphophysiological traits provided complementary information on cutting status but were not interpreted as direct mechanistic drivers of rooting. These findings indicate that adventitious rooting in C. arabica was more closely associated with genotype-dependent responsiveness to exogenous auxin than with the extent of callus formation. However, anatomical studies are needed to determine the developmental origin of root primordia and their possible relationship with callus tissue. Full article

Polyploidy is increasingly recognized as a mechanism enhancing physiological resilience in woody fruit crops, yet its functional consequences remain poorly understood in mangoes (Mangifera indica L.), a major tropical species expanding into water-limited environments. Because leaf structure underpins plant water relations and gas exchange, this study evaluated how genome duplication alters foliar traits by comparing diploid and autotetraploid individuals of three polyembryonic cultivars (Gomera-1, Gomera-3, and Kensington Pride). Morphological and anatomical analyses revealed consistent ploidy-related modifications. Autotetraploids exhibited enlarged stomatal guard cells, increased leaf thickness, and changes in mesophyll organization, indicating greater structural investment in leaf tissues. These features are commonly associated with structural strategies that may contribute to water retention and hydraulic regulation, although their direct physiological consequences were not evaluated in the present study. Overall, our results indicate that genome duplication substantially modifies leaf structural traits in mangoes, although the magnitude and direction of these responses were cultivar-dependent. This study provides new insights into how polyploidy reshapes leaf morphology and anatomy in mangoes and advances our understanding of polyploid-induced structural variation in perennial fruit crops. Full article

Perfluoroalkyl carboxylic acids (PFCAs) are persistent contaminants increasingly subjected to regulatory restrictions. To date, their effects on terrestrial plants remain poorly investigated. To address these knowledge gaps, a comparative assessment was conducted to identify the most sensitive plant species and the most responsive early-growth endpoints. Five PFCAs were selected according to their carbon-chain length (from 3 to 8 C-atoms). Seven plant species were exposed to a wide range of concentrations (from 0.01 up to 100 µg kg⁻¹). Germination and root elongation were evaluated as developmental endpoints to assess both acute and sublethal effects. Across species, germination exhibited weak responses, whereas root elongation appeared to be the most sensitive screening parameter, displaying divergent species-specific patterns. Notably, Sinapis alba and Cucumis sativus emerged as the most responsive species, although they exhibited opposite responses. While mustard exhibited low-dose root stimulation, cucumber showed root inhibition. Interestingly, species within the same family (Brassicaceae and Cucurbitaceae) showed contrasting sensitivity, suggesting that PFCA phytotoxicity is species-specific rather than driven by taxonomic relatedness. This divergent pattern may be linked to distinct morpho-physiological traits, supporting their use as suitable model organisms for phytotoxicity screening of PFCAs. Full article

The increasing pressure on water resources has stimulated the use of treated wastewater in agricultural irrigation, although its effects on plant development remain uncertain. This study evaluated the effects of wastewater treatments and irrigation depths on the morphophysiological development of lettuce (Lactuca sativa L.). A split-plot experiment was conducted with crop cycles in the main plots and a factorial arrangement in the subplots, consisting of five water sources and five irrigation depths (50% to 150% ETc), with three replications. Seven variables were evaluated, including growth traits and water productivity. Irrigation depth significantly affected all variables (p ≤ 0.01) and was the main driver of vegetative growth, increasing shoot fresh mass, stem diameter, and plant height. In contrast, water sources showed smaller effects. Water productivity decreased with increasing irrigation depth and showed weak correlations with other variables (r ≤ 0.468). Machine learning models achieved moderate accuracy for irrigation depth prediction (≈55%), with confusion among adjacent classes, indicating detection of a gradient rather than precise classification. Prediction of water sources was low (<30%), confirming limited morphological differentiation. Plant height and stem diameter were the most informative variables. These results indicate that irrigation management has a stronger influence on lettuce growth than water source. Full article

Chromium (Cr) is one of the most toxic heavy metals in the environment. The tolerance to metal stress involves sophisticated regulation of gene expression networks, which involve microRNAs (miRNAs). However, the role of miRNAs in Cr stress response in Avicennia marina has not been resolved, and was addressed here. The analysis of response characteristics revealed that morpho-physiological traits such as root length, Cr accumulation level and antioxidant enzyme activity all exhibit significant changes under Cr stress. Via sRNA sequencing, a total of 27 known and 149 novel miRNAs were identified, 63 of which showed differential expression after Cr stress (q-value < 0.001). Further, 571 miRNA-target interaction pairs were identified for differentially expressed miRNAs, corresponding to 355 target genes. GO and KEGG analyses indicated that these target genes could participate in stress-related biological processes such as signal transduction, transcription regulation, protein synthesis and the MAPK signaling pathway. 54 miRNA target genes, corresponding to 37 miRNAs such as Ama-miR160, Ama-nmiR25-5p and Ama-nmiR118-5p, were enriched for “plant signal hormone transduction” (ko04075), “phenylpropanoid biosynthesis” (ko00940) and “MAPK signaling pathway” (ko04016), which indicated an important role of these miRNAs in regulating Cr stress response in A. marina. Based on the findings, a Cr stress-responsive regulatory model was developed, offering new insights into the molecular regulatory mechanisms of Cr response. In conclusion, this study shows the identity and potential role of miRNAs in the heavy metal stress response of A. marina, and provides the foundation for future research. Full article

Plantago lanceolata L. is increasingly incorporated in temperate pasture systems for its agronomic resilience and potential to reduce the environmental footprint of ruminant production through its specific secondary metabolites (SMs). However, how light intensity per se regulates P. lanceolata L. physiology, nutritive value and SM accumulation remains poorly understood due to confounding factors in field studies. This controlled-environment study evaluated the effects of three light intensities (200, 300, and 400 µmol photons m⁻² s⁻¹) on morphophysiological traits, forage quality, and SM concentrations in P. lanceolata L. cv. “Ceres Tonic”. Plants were grown in controlled-environment chambers under similar temperature, humidity and nutrient conditions. Morphological traits, biomass allocation, chlorophyll fluorescence, gas exchange, chemical composition, and root architecture were measured. Additionally, the most important secondary metabolites, aucubin, catalpol and acteoside, were also evaluated. Under the different light intensity treatments plants maintained stable physiological parameters, total biomass production, leaf dimensions or root architecture. However, moderate light intensity (300 µmol photons m⁻² s⁻¹) optimized nutritive value by minimizing fiber concentrations and maximizing metabolizable energy. Acteoside concentration, as well as the iridoid glycosides aucubin and catalpol, were not affected by the different light intensities. These findings demonstrate that P. lanceolata L. maintains morphophysiological stability across the tested light intensity range studied, while selectively modulating forage quality. Full article

Salinity stress impairs maize growth by inducing osmotic stress, pigment degradation, and ionic imbalance, particularly during early seedling development. This study investigated the morpho-physiological and ionic responses of different maize genotypes exposed to increasing salinity levels (control, 3, 6, and 9 dS/m) at the seedling stage. Salinity caused a reduction in biomass accumulation (shoot fresh weight and shoot dry weight), plant height, and K⁺/Na⁺ ratio, with pronounced effects under severe stress. Significant genotypic variability was detected for photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) growth traits, and ionic regulation, indicating diverse physiological adaptation strategies. Stress tolerance indices and multivariate analysis revealed that chlorophyll stability, carotenoid accumulation, and maintenance of ionic homeostasis (K⁺/Na⁺ ratio) were the dominant physiological determinants of salinity tolerance. Additionally, principal component analysis showed a shift from biomass-driven variation under non-stress conditions to pigment- and ion-driven variation under higher salinity. Based on the results, genotypes BML 6 and HKI 163 maintained higher pigment content and improved K⁺/Na⁺ balance, enabling better growth under saline conditions. These findings highlight key physiological traits underlying salinity tolerance and provide insight into early-stage adaptive mechanisms in maize. Full article

Terminalia arjuna (Arjun) is a tropical deciduous tree species significantly valued for its pharmaceutical properties for various heart diseases, as well as its economic role in the sericulture industry. However, the growth performance and physiological responses of T. arjuna under water stress conditions remain largely unexplored, particularly in the context of increasing climate variability and the growing challenges posed by climate change. Therefore, this study aimed to examine the morpho-physio-biochemical alterations, nutrient uptake changes, and adaptive strategies under different degrees of water stress with respect to field capacity ($F_{wc}$), maintained at 100% $F_{wc}$ (control), 75% $F_{wc}$ (mild), 50% $F_{wc}$ (moderate), and 25% $F_{wc}$ (severe). Key growth parameters, including shoot and root length, leaf traits and shoot dry biomass, were significantly (p < 0.05) reduced under the given water stresses. Root dry biomass showed a distinct response, increasing under mild to moderate water stress but failing to sustain its levels under severe stress. Increasing drought severity resulted in a substantial reduction in stomatal density (15–37%), while stomatal size increased (18–49%) under mild to moderate stress but decreased under severe stress. These responses were associated with significant reductions in gas exchange traits (45–75%), whereas water use efficiency increased by 59–99%, reflecting a survival-focused adaptive mechanism. Moderate water stress triggered the stress responses in T. arjuna through high proline accumulation and increased oxidative stress markers. The most critical impact was found under the severe stress with a substantial reduction in leaf relative water content and membrane stability index (MSI), although MSI was sustained above the critical threshold, reflecting cellular protection. Increased stress intensity also altered mineral uptake, decreased major nutrients, and increased potassium and calcium content, indicating an adaptive strategy. These findings suggest a threshold effect, where T. arjuna tolerates mild stress well and activates adaptive morpho-physiological mechanisms under moderate stress but shifts to survival-focused strategies under severe stress. The demonstrated tolerance of Terminalia arjuna to mild–moderate drought suggests that climate-resilient forestry policies and conservation programs should prioritize its cultivation and restoration in drought-prone landscapes while ensuring adequate water management to prevent severe stress and sustain its medicinal and economic benefits. Full article

Silicon-based biostimulants are gaining increasing interest for their ability to enhance plant performance and stress tolerance. In protected cultivation, where environmental conditions are already carefully managed, it remains unclear whether adding biostimulants provides meaningful benefits and how they should be used. This study examines whether silicon (Si) biostimulants can enhance the growth and morpho-physiological traits of sweet basil (Ocimum basilicum L.) in glasshouse production and which application rates are most effective. Two Si-based products with similar silicon content and different formulations were applied as soil drenches at four rates (10 mL, 100 mL, 1 L, and 2 L per hectare). Plant growth, biomass, photosynthetic performance, and physiological traits including membrane stability and electrolyte leakage were measured. Overall, silicon treatments improved most traits compared with untreated plants. Basil receiving Si showed longer shoots and roots, greater fresh and dry weight, and healthier leaves with better photosynthetic activity, as reflected by higher SPAD values and chlorophyll content. The response often depended on the dose: lower rates (10 mL and 100 mL h⁻¹) of the silicic acid tetraethyl ester (21% Si) led to clear improvements in 7 of 12 measured traits, while higher rates (especially 2 L ha⁻¹) reduced leaf size and morphology. However, root length: shoot length ratios were low across all treatments with the second biostimulant product: SiO₂ with chelated iron (T5–T9). Certain results are paradoxical, suggesting a trade-off in growth and defense. In some instances, low doses promote growth but potentially worsen some physiological indicators, while high doses inhibit growth but improve stress resistance indicators. The conclusion indicates that silicon-based biostimulants are valuable to include in single-harvest basil production systems, when applied at a suitable rate. Choosing the correct formulation and dose requires testing and optimization to the crop and growing system. Full article

Phosphorus (P) is an essential macronutrient for plant growth and a major limiting factor for crop productivity, especially in tropical soils characterized by low P availability and high fixation capacity. The strong dependence of modern agriculture on non-renewable phosphate fertilizers, combined with their low use efficiency, raises economic and environmental concerns and reinforces the need to improve phosphorus use efficiency (PUE) in maize. PUE is a complex trait governed by integrated morphophysiological, biochemical, and molecular mechanisms related to phosphorus acquisition, internal remobilization, metabolic reprogramming, and root system plasticity. Recent advances using omics-based approaches have substantially expanded the understanding of these mechanisms, revealing coordinated regulation of carbon and energy metabolism, phosphatase activity, redox balance, and root meristem dynamics under P-limiting conditions. In parallel, increasing evidence demonstrates the important role of phosphate-solubilizing and plant growth-promoting bacteria in enhancing P availability through organic acid secretion, enzymatic mineralization of organic P forms, and modulation of root architecture. However, despite these advances, the genetic basis of plant responsiveness to beneficial bacteria and the interaction between host genotype and microbial activity remain poorly explored. This review integrates current knowledge on phosphorus dynamics in the soil–plant system, the genetic control of PUE in maize, and the contribution of beneficial bacteria, highlighting the importance of combining classical breeding, molecular approaches, and microbial strategies to accelerate the development of maize cultivars with improved phosphorus efficiency and reduced fertilizer dependency. Full article

Chenopodium album L. is a highly problematic weed in agricultural systems, exhibiting resistance or tolerance to multiple herbicides. This weed significantly impacts crop growth and yield, threatening global agricultural production. Since the introduction of genetically modified herbicide-resistant crops, glyphosate has become a primary option for controlling C. album. However, the continuous application of glyphosate has led to shifts in weed community composition, favoring species that are more challenging to manage, and thus complicating weed control efforts. Although glyphosate resistance in C. album has not been confirmed, varying tolerance among populations brings practical problems to weed evolution. This review provides a synthesis of the progress on the mechanisms of glyphosate tolerance in C. album. Key factors influencing plant responses to glyphosate are examined, including target proteins, encoding genes, morphological and physiological traits, transport capacity, and metabolic detoxification processes. The existing evidence indicates that glyphosate tolerance in C. album is driven primarily by non-target-site adaptations or morpho-physiological changes, not target-site mutations. The insights gained from this review will aid in designing precision approaches to manage glyphosate-tolerant weeds in agricultural systems. Full article

Water scarcity, intensified by climate change, limits the growth and survival of threatened tree species, such as Paubrasilia echinata (Lam.) Gagnon, H.C.Lima & G.P.Lewis. This study analyzed the effects of water availability in the soil on the morphophysiology and enzymatic activity of P. echinata seedlings under different irrigation intervals. The experiment consisted of five treatments (irrigation intervals: 0, 3, 6, 9, and 12 days) distributed in four randomized blocks, totaling 20 plots of five plants each. Variables analyzed included stem diameter, number of leaves and leaflets, leaf area, shoot and root length, root volume, dry matter mass, Dickson quality index, relative water content, leaf indices of chlorophyll, peroxidase, polyphenol oxidase, and phenylalanine ammonia-lyase. Water deficit reduced root dry matter mass by up to 27.78% and chlorophyll b by up to 29.56%, and increased peroxidase by up to 244.44%. Principal component analysis revealed correlated changes among biomass, chlorophyll, and Dickson index, with root volume and enzymatic activities varying oppositely, indicating an integrated regulatory response. P. echinata exhibits phenotypic plasticity under water deficit, reflected in stem diameter, root volume, leaf area, physiological traits, and enzymatic regulation, tolerating an irrigation interval of 12 days. P. echinata has establishment potential in areas subjected to water deficit. Full article

The light spectrum and vapor pressure deficit (VPD) are key environmental factors that significantly influence the morphophysiological development and survival of micropropagated woody plants during acclimatization. However, few studies have focused on their interactive effects under ex vitro conditions. This study examined the combined effects of four light spectra (white, blue, red, and red–blue) and two VPD levels (low: 0.2 kPa; high: 1.0 kPa) on growth, photosynthesis pigments, biochemical indices, and leaf temperature of Pistacia spp. ‘UCB1’ plantlets over a 30-day acclimatization period. The results demonstrated that red–blue light under low VPD significantly enhanced plantlet performance across multiple parameters, resulting in the highest leaflet number (79.25 pieces), stem diameter (2.13 mm), leaf dry weight (0.048 g), leaf fresh weight (0.15 g), root length (1.48 cm), and leaf area (103.3 cm²). Furthermore, this treatment markedly increased anthocyanin, total soluble carbohydrate content, and photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids). Principal component and correlation analyses identified that red–blue light under low VPD was strongly associated with traits linked to growth and photosynthetic ability, whereas blue and white light under high VPD showed the weakest responses. Entropy-weighted TOPSIS ranked red–blue light under low VPD as the most effective treatment for balanced morpho-physiological functions during acclimatization. These findings highlight the importance of optimizing spectral quality and VPD to enhance autotrophic transition and ex vitro establishment in pistachio plantlets. These findings are important for improving ex vitro survival and large-scale propagation efficiency of micropropagated pistachio plantlets. Full article

Rootstocks play a central role in modulating grapevine responses to water scarcity, yet their morpho-functional strategies remain highly genotype-dependent. This study compared three functionally contrasting rootstocks, 1103 Paulsen, 420 A, and M2, grafted with Vitis vinifera cv. Merlot, which differ in root system architecture, hydraulic efficiency, canopy development, and stomatal regulation, with the aim of elucidating their hydraulic, morphological, and physiological responses under controlled conditions. Plants were grown in containers and assessed for root system architecture, hydraulic conductance, gas exchange including transpiration rate, chlorophyll fluorescence, and biomass allocation. The results revealed three distinct adaptive strategies: 1103 P exhibited the highest structural root biomass and rootstock hydraulic conductivity, supporting elevated axial water transport, higher transpiration rates, and a larger canopy, consistent with an “active tolerance” strategy; 420 A showed balanced structural and absorptive root development, moderate hydraulic performance, and the highest transpiration rates, reflecting a flexible, opportunistic response to water availability. In contrast, M2 displayed markedly reduced structural root biomass but a high proportion of absorptive roots and the greatest scion hydraulic conductance combined with low stomatal conductance, reduced transpiration, and high intrinsic water use efficiency, which is indicative of a conservative, resource-efficient strategy. These findings demonstrate that the three rootstocks express fundamentally different drought response syndromes driven by coordinated variation in root morphology, hydraulic traits, canopy development, and stomatal behavior. The integration of hydraulic and morphological traits provides a robust framework for selecting rootstocks tailored to specific pedoclimatic and management contexts in water-limited environments. Full article