Search Results (336)

Urochloa brizantha (Brizantha) is cultivated under varying altitudinal and management conditions. Twelve full-sun (monoculture) plots and twelve shaded (silvopastoral) plots were established, proportionally distributed at 170, 503, 661, and 1110 masl. Evaluations were conducted 15, 30, 45, 60, and 75 days after establishment. The conservation and integration of trees in silvopastoral systems reflected a clear anthropogenic influence, evidenced by the preference for species of the Fabaceae family, likely due to their multipurpose nature. Although the altitudinal gradient did not show direct effects on soil properties, intermediate altitudes revealed a significant role of CaCO₃ in enhancing soil fertility. These edaphic conditions at mid-altitudes favored the leaf area development of Brizantha, particularly during the early growth stages, as indicated by significantly larger values (p < 0.05). However, at the harvest stage, no significant differences were observed in physiological or productive traits, nor in foliar chemical components, underscoring the species’ high hardiness and broad adaptation to both soil and altitude conditions. In Brizantha, a significant reduction (p < 0.05) in stomatal size and density was observed under shade in silvopastoral areas, where solar radiation and air temperature decreased, while relative humidity increased. Nonetheless, these microclimatic variations did not lead to significant changes in foliar chemistry, growth variables, or biomass production, suggesting a high degree of adaptive plasticity to microclimatic fluctuations. Foliar ash content exhibited an increasing trend with altitude, indicating greater efficiency of Brizantha in absorbing calcium, phosphorus, and potassium at higher altitudes, possibly linked to more favorable edaphoclimatic conditions for nutrient uptake. Finally, forage quality declined with plant age, as evidenced by reductions in protein, ash, and In Vitro Dry Matter Digestibility (IVDMD), alongside increases in fiber, Neutral Detergent Fiber (NDF), and Acid Detergent Fiber (ADF). These findings support the recommendation of cutting intervals between 30 and 45 days, during which Brizantha displays a more favorable nutritional profile, higher digestibility, and consequently, greater value for animal feeding. Full article

Polyploidy in plants can enhance stress resistance and secondary metabolite production, offering potential benefits for Clausena lansium (L.) Skeel, a medicinally valuable species. However, systematic studies of polyploidy-induced morphological, anatomical, and metabolic changes in this species are lacking. This study aimed to induce and characterize polyploid C. lansium lines, assess ploidy-dependent variations, and evaluate their impact on bioactive metabolite accumulation. Three cultivars were hybridized, treated with colchicine, and bred, yielding 13 stable polyploid lines confirmed by flow cytometry and chromosome counting. The polyploids exhibited distinct traits, including larger pollen grains, altered leaf margins, increased leaflet numbers, enlarged guard cells with reduced stomatal density, and thicker leaf tissues. Metabolomic analysis revealed that tetraploids accumulated significantly higher levels of flavonoids, alkaloids, and phenolic acids compared to diploids, while triploids showed moderate increases. These findings demonstrate that polyploidization, particularly tetraploidy, enhances C. lansium’s medicinal potential by boosting pharmacologically active compounds. The study expands germplasm resources and supports the development of high-quality cultivars for pharmaceutical applications. Full article

Leaves are essential for photosynthesis and transpiration, directly influencing plant growth and development. Leaf morphology, such as length, width, and area, affects photosynthetic efficiency and transpiration rates. In this study, we investigated the role of PtoWOX1 in leaf morphogenesis by generating both overexpression and CRISPR/Cas9 knockout lines in P. tomentosa. The results showed that PtoWOX1A and PtoWOX1B encode nuclear-localized transcription factors highly expressed in young leaves, particularly in palisade and epidermal cells. Knockout of PtoWOX1 resulted in reduced leaf width and area, enlarged upper epidermal cells, and lower stomatal density. Overexpression led to wrinkled leaf surfaces and reduced margin serration. Anatomical analysis revealed altered palisade cell arrangement and increased leaf thickness in knockout lines, accompanied by higher chlorophyll content and enhanced photosynthetic rates. Additionally, PtoWOX1A interacts with PtoYAB3B, suggesting a complex that regulates leaf margin development. These findings clarify the function of PtoWOX1 in regulating mid-lateral axis development and leaf margin morphology and provide new insights for the molecular breeding of poplar. Full article

Globally, rice cultivation consumes large amounts of fresh water, and urgent improvements in water use efficiency (WUE) are needed to ensure sustainable production, given increasing water scarcity. While stomatal traits have been a primary focus for enhancing WUE, complex interactions between stomatal and non-stomatal leaf traits remain poorly understood. In this review, we present an analysis of stomatal and non-stomatal leaf traits influencing WUE in rice. The data suggests that optimising stomatal density and size will be insufficient to maximise WUE because non-stomatal traits such as mesophyll conductance, leaf anatomy, and biochemical composition significantly modulate the relationship between stomatal conductance and the photosynthetic rate. Integrating recent advances in high-throughput phenotyping, multi-omics technologies, and crop modelling, we suggest that combinations of seemingly contradictory traits can enhance WUE without compromising yield potential. We propose a multi-trait breeding framework that leverages both stomatal and non-stomatal adaptations to develop rice varieties with superior WUE and climate resilience. This integrated approach provides a roadmap for accelerating the development of water-efficient rice cultivars, with broad implications for improving WUE in other crops. Full article

[Background] Brasenia schreberi is a perennial floating leaf aquatic plant with high ecological protection value and potential for economic development, and thus, its endangered mechanisms are of great concern. The rapid endangerment of this species in modern times may be primarily attributed to the deterioration of water and soil environmental conditions, as its growth relies on high-quality water and soil. [Objective] Exploring the responses of B. schreberi to water and soil conditions from the perspective of functional traits is of great significance for understanding its endangered mechanisms and implementing effective conservation strategies. [Methods] This study was conducted in the Tengchong Beihai Wetland, which has the largest natural habitat of B. schreberi in China. By measuring the key functional traits of B. schreberi and detecting the water and soil parameters at the collecting sites, the responses of these functional traits to the water and soil conditions have been investigated. [Results] (1) The growth status of B. schreberi affects the expression of its functional traits. Compared with sporadic distribution, B. schreberi in continuous patches have significantly higher stomatal conductance, intercellular CO₂ concentration, transpiration rate, and vein density, while these plants have significantly smaller leaf area and perimeter. (2) Good water quality directly promotes photosynthetic, morphological, and structural traits. However, high soil carbon, nitrogen, and phosphorus contents can inhibit the photosynthetic rate. The net photosynthetic rate is significantly positively correlated with dissolved oxygen content, pH value, ammonia nitrogen, and nitrate nitrogen contents in the water, as well as the magnesium, zinc, and silicon contents in the soil. In contrast, the net photosynthetic rate is significantly negatively correlated with the total phosphorus content in water and the total carbon, total nitrogen, and total phosphorus content in the soil. (3) Leaf area and perimeter show positive correlations with various water parameters, including the depth, temperature, pH value, dissolved oxygen content, ammonium nitrogen, and nitrate nitrogen content, yet they are negatively correlated with total phosphorus content, chemical oxygen demand, biological oxygen demand, and permanganate index of water. [Conclusions] This study supports the idea that B. schreberi thrives in oligotrophic water environments, while the notion that fertile soil is required for its growth still needs to be investigated more thoroughly. Full article

Elevated [CO₂] enhances light interception and carboxylation efficiency in plants. The combined effects of [CO₂] and photosynthetic photon flux density (PPFD) on stomatal morphology, leaf anatomy, and photosynthetic capacity in tomato seedlings remain unclear. This study subjected tomato seedlings (Solanum lycopersicum Mill. cv. Jingpeng No.1) to two [CO₂] (ambient [a[CO₂], 400 µmol·mol⁻¹] and enriched [e[CO₂], 800 µmol·mol⁻¹]) and three PPFD levels (L; low[Ll: 200 µmol·m⁻²·s⁻¹], moderate[Lm: 300 µmol·m⁻²·s⁻¹], and high[Lh: 400 µmol·m⁻²·s⁻¹]) to assess their interactive impacts. Results showed that e[CO₂] and increased PPFD synergistically improved relative growth rate and net assimilation rate while reducing specific leaf area and leaf area ratio. Notably, e[CO₂] decreased stomatal aperture (−13.81%) and density (−27.76%), whereas elevated PPFD promoted stomatal morphological adjustments. Additionally, Leaf thickness increased by 72.98% under e[CO₂], with Lm and Lh enhancing this by 10.79% and 41.50% compared to Ll. Furthermore, photosynthetic performance under e[CO₂] was further evidenced by improved chlorophyll fluorescence parameters (excluding non-photochemical quenching). While both e[CO₂] and increased PPFD Photosynthetic performance under e[CO₂] was further evidenced by improved chlorophyll fluorescence parameters (excluding non-photochemical quenching). Moreover, e[CO₂]-Lh treatment maximized total dry mass and seedling health index. Correlation analysis indicated that synergistic optimization of stomatal traits and leaf structure under a combination of e[CO₂] and increased PPFD enhanced light harvesting and CO₂ diffusion, thereby promoting carbon assimilation. These findings highlight e[CO₂]-Lh as an optimal strategy for tomato seedling growth, providing empirical guidance for precision CO₂ fertilization and light management in controlled cultivation. Full article

Longshan Lilium lancifolium is a well-known medicinal and edible lily and has been registered as a geographical indicator in China. Polyploidization confers many advantages in lily production; however, characteristics of Longshan L. lancifolium improved by polyploidization have not been reported. Here, polyploidization was induced in regenerated Longshan L. lancifolium shoots using colchicine, and the mutant plantlets were characterized by morphological observation, flow cytometry, and inter simple sequence repeat (ISSR) marker technology. The optimal medium for inducing shoot regeneration was Murashige and Skoog (MS) media supplemented with 0.2 mg/L of naphthaleneacetic acid (NAA) and 0.4 mg/L of thidiazuron (TDZ). The greatest mutation induction effect was obtained after soaking the regenerated shoots in 0.10% colchicine for 48 h, for an 80.00% frequency of morphological variants. Forty-one mutant plantlets were subjected to flow cytometry, identifying one homozygous polyploid, ‘JD-12’, and one chimeric polyploid, ‘JD-37’. Additionally, 68 chromosomes were found in the ‘JD-12’ root tip cells. Compared with the control, both the tissue-cultured and field-generated ‘JD-12’ plantlets presented a slight decrease in plant height, a darker green leaf color, a rougher leaf surface, and a larger bulblet diameter; furthermore, the upper epidermal and guard cells of ‘JD-12’ were much larger with a significantly lower stomatal density. The ISSR marker detection indicated a genetic variation rate of 6.10% in ‘JD-12’. These results provide a basis for lily polyploidization breeding and the cultivation of superior Longshan L. lancifolium via shoot regeneration. Full article

This study investigated the effects of Trichoderma harzianum inoculation on the growth, physiological responses, and soil nutrient uptake of three turfgrass species cultivated on eco-concrete—Axonopus compressus (Sw.) Beauv., Cynodon dactylon (L.) Pers., and Zoysia sinica Hance. A 2 × 2 factorial design was used to evaluate plant growth, physiological responses, and soil metrics under cement stress, incorporating T. harzianum inoculation (inoculated vs. control) and substrate composition (eco-concrete vs. pastoral soil). Our results indicate that inoculation with Trichoderma harzianum significantly enhanced the growth potential of the three turfgrass species compared to uninoculated controls. Furthermore, under cement stress conditions in vegetated concrete, inoculation with T. harzianum significantly alleviated the inhibition of growth and development. More specifically, in the vegetated concrete habitat, inoculated plants exhibited significantly increased root length and surface area. This enhancement promoted the uptake of available nitrogen (AN), available phosphorus (AP), and available potassium (AK) from the soil. Concurrently, inoculated plants showed higher leaf epidermal cell density, stomatal width, soluble sugar content, and antioxidant enzyme activity (SOD, POD, CAT, and APX). Additionally, significant reductions were observed in root activity, relative conductivity, and malondialdehyde (MDA) and proline contents. In conclusion, T. harzianum inoculation promotes the growth of the three turfgrass species under cement stress, likely by enhancing root development, increasing osmoregulatory substance accumulation, and elevating antioxidant enzyme activities. Full article

As a critical ecologicalbarrier in the semi-arid to semi-humid transition zone of northern China, the interaction between afforestation and climatic stressors in the Yellow River Basin constitutes a pivotal scientific challenge for regional sustainable development. However, the synthesis effects of afforestation and climate on primary productivity require further investigation. Integrating multi-source remote sensing data (2000–2020), meteorological observations with the Standardized Precipitation Evapotranspiration Index (SPEI) and an improved CASA model, this study systematically investigates spatiotemporal patterns of vegetation net primary productivity (NPP) responses to extreme drought events while quantifying vegetation coverage’s regulatory effects on ecosystem drought sensitivity. Among drought events identified using a three-dimensional clustering algorithm, high-intensity droughts caused an average NPP loss of 23.2 gC·m⁻² across the basin. Notably, artificial irrigation practices in the Hetao irrigation district significantly mitigated NPP reduction to −9.03 gC·m⁻². Large-scale afforestation projects increased the NDVI at a rate of 3.45 × 10⁻⁴ month⁻¹, with a contribution rate of 78%, but soil moisture competition from high-density vegetation reduced carbon-sink benefits. However, mixed forest structural optimization in the Three-North Shelterbelt Forest Program core area achieved local carbon-sink gains, demonstrating that vegetation configuration alleviates water competition pressure. Drought amplified the suppressive effect of afforestation through stomatal conductance-photosynthesis coupling mechanisms, causing additional NPP losses of 7.45–31.00 gC·m⁻², yet the April–July 2008 event exhibited reversed suppression effects due to immature artificial communities during the 2000–2004 baseline period. Our work elucidates nonlinear vegetation-climate interactions affecting carbon sequestration in semi-arid ecosystems, providing critical insights for optimizing ecological restoration strategies and climate-adaptive management in the Yellow River Basin. Full article

To understand the mechanisms underlying species assemblage along salt gradients in intertidal zones, we measured the xylem hydraulic vulnerability curves (HVCs), leaf water potential (ψ), stomatal conductance (g_s), specific leaf area (SLA), and wood density (WD) for six mangrove species of Avicennia marina, Bruguiera gymnorrhiza, Aegiceras corniculatum, Kandelia obovata, Sonneratia apetala, and Sonneratia caseolaris. We found the following: (1) A. marina and B. gymnorhiza had the most negative P₅₀ (water potential at which 50% of hydraulic conductivity was lost), while S. caseolaris and S. apetala had the least negative P₅₀, indicating different resistance to embolism in xylem; (2) P₅₀ and P₈₈ (water potential at which 88% of hydraulic conductivity was lost) declined with increasing salinity from the onshore to offshore species, as their water regulation strategy meanwhile transitioned from isohydry to anisohydry; (3) B. gymnorhiza had smaller SLA but larger hydraulic safety margin (HSM), implying potentially higher capacity of water retention in leaves and lower risk of hydraulic failure in xylem. These results suggest that hydraulic traits play an important role in shaping the salt-driven niche segregation of mangroves along intertidal zones. Our research contributes to a more comprehensive understanding of the hydraulic physiology of mangroves in salt adaption and may facilitate a general modeling framework for examining and predicting mangrove resilience to a changing climate. Full article

This study investigated the effects of oryzalin treatments on the induction of polyploids and variants, as well as their subsequent morphological and physiological characteristics, in Lysimachia xiangxiensis, a perennial herbaceous plant belonging to the Primulaceae family that is known for its ornamental value. A total of 52 of the 162 treated stem segments survived after treatments and further developed into plantlets, and significant morphological changes in leaf color and growth status were observed. Using flow cytometry and chromosome counting, plants are categorized into the three variant types (VT1, VT2, and VT3), that is, VT1 and VT2 were diploid aneuploids, while VT3 was triploid. The optimized polyploid induction scheme involved treatment with 0.001% oryzalin for 4 days, resulting in an induction rate of up to 100%. Higher concentrations and longer exposure durations resulted in lower survival and polyploid induction rates of all stem segments during the above-mentioned processing. Observation of morphological features indicated that triploid VT3 vines were longer, with larger and thicker leaves and more guard cells, but lower stomatal density, compared with diploid aneuploids or the wild type. Polyploids outperformed other types in terms of chlorophyll content, net photosynthesis rate, stomatal conductance, and intercellular CO₂ concentration, but had a lower flavonoid content. The results demonstrate that oryzalin can effectively induce polyploidy and variants in L. xiangxiensis, resulting in beneficial changes in morphology and physiological characteristics; this should provide valuable insight into the improvement of excellent varieties in plants. Full article

Coal gangue is a fine-grained mineral with nutrient content, which can be used as a potential soil amendment. Nevertheless, current research on using coal gangue to improve soil water and support plant growth is still insufficient. In this study, coal gangue powder (CGP) was added to aeolian sandy soil. We compared the soil hydraulic properties and plant growth of original aeolian sandy soil (CK) and different CGP application rates (10% and 20%). The results indicated that the application of CGP transformed the soil texture from sandy to loamy, significantly reduced soil bulk density and saturated hydraulic conductivity (Ks) values, altered the soil water characteristic curve, enhanced soil water-holding capacity, and increased plant-available water. Compared with the CK group, the emergence rate of alfalfa seeds increased from approximately 50% to over 70% after CGP application. During the growth process, CGP application significantly elevated the net photosynthetic rate, transpiration rate, and stomatal conductance of alfalfa leaves. Rapid fluorescence kinetics monitoring of leaves demonstrated that alfalfa treated with CGP had a higher efficiency in light energy utilization. However, the photosynthetic capacity of leaves did not improve as the CGP application rate increased from 10% to 20%, suggesting that excessive CGP addition did not continuously benefit plant gas exchange. In conclusion, CGP application can improve the soil hydraulic properties of aeolian sandy soil and support plant growth and development, which is conducive to reducing the accumulated amount of coal gangue, alleviating plant water stress, and promoting ecological restoration in arid mining areas. We recommend a 10% addition of coal gangue powder as the optimal amount for similar soils. Full article

Elevated temperatures and extended drought periods are driving significant changes in the structure and function of forest ecosystems. High-elevation alpine ash forests (Eucalyptus delegatensis R.T. Baker) in Australia are an example of forests that are already impacted by climate change. These obligate seeder forests can shift to non-forest ecosystems following extreme drought and altered fire regimes, raising concern about their adaptation to a rapidly changing environment and long-term forest persistence. Plant functional traits play a major role in determining adaptive mechanisms to environmental conditions. While alpine ash forests are vulnerable to climate change, it is unclear if different provenances have adapted to the climatic conditions in which they grow. We therefore studied the variation in expression of functional traits related to drought tolerance in 21 provenances of alpine ash distributed across an environmental gradient. We investigated if functional traits varied between the provenances and were related to climate of origin in order to identify provenances that may be better adapted to drought. We measured the following traits in a common garden experiment under well-watered conditions: stomatal density, specific leaf area, minimum stomatal conductance and osmotic potential at full turgor. There was very little variation in trait expression between the 21 provenances for all functional traits related to drought tolerance. All provenances had medium-range stomatal density (170–300 stomata mm²) and specific leaf area (SLA, 50–70 cm² g⁻¹), a very low minimum stomatal conductance (2–4 mmol m² s⁻¹) and a high osmotic potential at full turgor (−0.6–0.7 MPa). There was no statistically significant correlation of trait expression with the climate of origin. Thus, there is very little evidence for genetically controlled differences in trait expression of drought tolerance traits in this species. It is likely that the high elevation and high rainfall environment of the species’ ecological niche has not been subjected to frequent and extensive drought periods that would elicit an evolutionary pressure selecting for drought-tolerant traits. We could not identify provenances that would have different drought-tolerant functional trait responses than others, potentially conferring an adaptive advantage under climate change. This has implications for using climate-adjusted provenancing to improve resilience in alpine ash forests predicted to experience more frequent and severe droughts in the future. Full article

The use of chemical stimulants in resin tapping is essential for prolonging the resin flow and enhancing production. Traditional stimulants, primarily composed of sulfuric acid, pose concerns related to workplace safety, environmental impact, and tree health. In this study, we compared alternative stimulant pastes containing ethrel, salicylic acid, and citric acid with the traditional Spanish and Brazilian stimulant pastes with higher contents of sulfuric acid. We tapped Pinus pinaster seedlings with five different stimulants, using untreated and mechanically wounded plants as controls. The resin yield, tree growth, and physiological parameters were compared. The pines stimulated with citric acid released ca. 50% more resin, while ethrel and salicylic acid yielded similar amounts to the traditional paste, suggesting their potential as viable alternatives. Although all stimulants reduced the seedling growth, no significant differences were observed in the midday water potential or stomatal conductance. The internal resin accumulation and resin canal density were strongly correlated with the total resin production, and more-acidic pastes tended to cause xylem damage and resin retention. Our findings suggest that moderate acidity is sufficient to trigger resin biosynthesis and release, and that safer, less corrosive formulations, like citric acid, may provide viable, safer, and more sustainable alternatives to conventional stimulants. While the results from the seedlings provide a rapid and cost-effective screening tool, anatomical and physiological differences from mature trees should be considered when extrapolating findings to operational settings. Full article

Grewia tembensis and Grewia trichocarpa inhabit dry tropical zones and arid environments, adapting to extreme climatic conditions and limited moisture supplies. Overall, Grewia L. possesses a significant variety of bioactive chemical constituents of great therapeutic importance. Indeed, for these species, precise morphological analyses are poor, and their detailed characterization is almost non-existent. This research attempts to investigate and compare the micromorphological traits of G. tembensis and G. trichocarpa species through scanning electron microscopy (SEM). Micromorphological characteristics of the leaf and fructiferous structures turned out to be highly effective in separating the two species, G. tembensis and G. trichocarpa, especially regarding the type, density, and distribution of trichomes on the lower and upper surfaces of the leaves, along with the stomatal and trichome types on the surfaces of the fruits. Statistical analyses using principal component analysis, t-tests, and hierarchical clustering conducted on micromorphological data of the leaves, flowers, and fruits showed considerable variation within samples of G. tembensis and samples of G. trichocarpa. On the basis of their morphological assessment characteristics, the samples of both species were distinct and clustered into separate groups. This study emphasizes the necessity of performing detailed morphological studies of species by means of an electron microscope and proves that the leaf features are important for separating species. Such morphological traits of trichomes would offer an efficient tool to distinguish the species. Within the findings, this suggests that such diagnostics are likely to be highly useful for species identification in Grewia, especially in cases where there are no fruits available. Full article