Search Results (1,007)

A field experiment was conducted in three ecological zones to evaluate the effects of broadcast sowing (BS), drill sowing (DS), and ridge–furrow precision sowing (RFS) on winter rapeseed (Brassica rapa L.) grown in lightly saline–alkaline soils, using two cultivars (L6 and L7). RFS improved soil temperature and soil moisture conditions across the zones. Its warming effect was most pronounced in the JT zone, where soil temperatures at seedling and flowering stages were 9.7% and 10.3% higher than under BS, respectively. RFS also showed a moisture-conservation advantage at regreening, with soil moisture 13.8% and 6.6% higher than under BS and DS, respectively. In addition, RFS reduced soil salinity and increased soil total carbon, available potassium, and ammonium nitrogen contents. Plants under RFS showed higher SPAD values, net photosynthetic rates, and transpiration rates at seedling and regreening stages, along with higher antioxidant enzyme activities and lower MDA accumulation. RFS advanced key phenological stages, improved overwintering survival, and produced the highest yield. Compared with BS and DS, respectively, RFS increased the mean yield of L6 by 11.46% and 6.97%, and that of L7 by 16.02% and 10.52%. Overall, RFS promoted yield formation by improving soil conditions, photosynthetic activity, and stress resistance. Full article

Agroecosystems are perpetually subjected to environmental factors. Driven by a shifting global climate, soil moisture deficits represent an increasingly frequent threat to crop productivity. In farming, however, these abiotic stressors seldom occur in isolation, as fields are invariably compounded by biotic weed pressure. Consequently, investigating plant responses to such combinatorial, multi-faceted stress is paramount to evaluating the realistic efficacy of modern agrotechnical interventions. A 2-year, three-factor pot experiment was conducted at the Research and Education Station in Swojczyce, belonging to the Wrocław University of Environmental and Life Sciences. The aim of the study was to examine the response of winter wheat (Triticum aestivum L., cv. Agil) to drought stress during the period when cereal plants were at the 51–65 BBCH developmental stages. Additionally, in some pots with winter wheat, Apera spica-venti (L.) Beauv. was sown as a weed to evaluate the effects of biotic stress. To observe the mitigation of stressors, three different types of biostimulants were used—a silicon-based preparation and two seaweed-based preparations derived from Ecklonia maxima (Osbeck) Papenfuss and Ascophyllum nodosum (L.) Le Jolis, respectively, representing structural, morphological, and biochemical defense strategies. Drought stress significantly and negatively affected the length of the wheat main stem, lateral tillers, and lateral spikes, as well as the weight of the main wheat spike. The simultaneous occurrence of drought stress and A. spica-venti competition resulted in the greatest cumulative reduction in main spike weight. Furthermore, drought stress was associated with an increase in nitrogen/protein content and potassium content in wheat straw. The presence of A. spica-venti significantly reduced both the weight of the main wheat spike and the number of non-productive tillers. The limited effectiveness of biostimulants may be associated with the severity and timing of stress exposure during reproductive development. Full article

Low temperature constitutes a critical abiotic stress that significantly impairs plant growth and development, particularly for species in cold regions. In Northeast China, the persistently low winter temperatures over an extended period pose significant challenges to the survival of chrysanthemums. This study employed the ground cover plant ‘Yingjie’ as the experimental material and cloned CmMYBS3. The CmMYBS3 protein lacks transcriptional activity and is localized exclusively in the nucleus. Under low-temperature treatment, the activities of SOD, CAT, and POD were significantly lower in chrysanthemums overexpressing CmMYBS3 than in the wild-type line. Additionally, the MDA content in the CmMYBS3 overexpression lines was higher than in the wild-type lines. To elucidate the mechanism by which CmMYBS3 regulates the response to low temperature, we conducted transcriptome sequencing analysis and identified a total of 5425 differentially expressed genes, comprising 2646 upregulated genes and 2779 downregulated genes. The GO analysis reveals that the primary enrichment occurs in the “biological process”, “cellular component”, and “molecular function”. The KEGG enrichment analysis identified significant alterations in several pathways associated with plant growth and development, as well as stress responses. Through yeast single-hybrid analysis, it was demonstrated that CmMYBS3 specifically binds to the promoter region of CmDREB1 and inhibiting the expression of the CmDREB1. This study demonstrates that CmMYBS3 reduces the cold tolerance of ground cover chrysanthemums by suppressing the expression of the CmDREB1 gene, providing an important theoretical basis for the breeding of cold-tolerant ground cover chrysanthemum varieties. Full article

Global warming is reshaping the climatic suitability of invasive ectotherms. In this study, we used an optimized Maximum Entropy (MaxEnt) model combined with GIS-based centroid tracking to quantify the spatiotemporal changes in the potential climatic suitability of Zeugodacus tau, a major polyphagous quarantine pest, in China. Projections were conducted under the historical baseline climate (1970–2000) and future climate scenarios, including SSP1–2.6, SSP2–4.5, and SSP5–8.5 for the 2050s and 2070s. Here, we projected potential climatic suitability rather than future occurrence or abundance. The model showed high predictive performance (AUC = 0.921). Annual mean temperature (Bio1) and mean diurnal range (Bio2) were identified as the primary environmental variables shaping the species’ climatic suitability. Future projections suggested contrasting spatial changes in climatic suitability, with expansion mainly in northern marginal regions and contraction of the southern highly suitable core area. As winter temperatures increased, the low- and moderate-suitability areas were projected to expand northward into temperate agricultural regions. However, under the extreme warming scenario (SSP5–8.5), the highly suitable core area in southern China was projected to decline by 31.61%, while the centroid of the highly suitable area shifted inland and northwestward by approximately 168 km toward the Wuling Mountains. These spatial patterns may be associated with increasing summer heat stress in low-altitude southern regions, although this mechanism requires further physiological validation. Overall, these findings provide a scientific basis for risk-oriented early warning, quarantine planning, and region-specific pest management under future climate change. Full article

Heat stress is a physiological challenge for dairy cattle, linked to oxidative imbalance and immune dysregulation. This study evaluated seasonal heat stress effects on systemic redox and inflammatory status in healthy dairy cows and tested saliva as an alternative diagnostic fluid to serum. A total of 114 clinically healthy Holstein cows were sampled across summer, autumn, and winter (38 cows per season). Environmental exposure was quantified using the temperature–humidity index (THI). Paired saliva and serum samples were analyzed for total oxidant status (TOS), total antioxidant capacity (TAC) and adenosine deaminase (ADA); the oxidative stress index (OSI = TOS/TAC) was calculated. In saliva, TOS, TAC and ADA were significantly lower in summer than in autumn and winter, while salivary OSI remained stable across seasons. In serum, summer was characterized by increased TOS and OSI together with reduced ADA activity, indicating systemic oxidative stress accompanied by diminished ADA-linked immune activation under heat stress. Although salivary markers correlated with THI, saliva did not mirror the systemic oxidative imbalance detected in serum. Under the conditions and biomarkers evaluated, serum provided a more reliable assessment of heat-stress-related redox and immune disturbances in dairy cattle, whereas saliva showed limited utility as a substitute for monitoring. Full article

The genus Ilex L., the sole member of the family Aquifoliaceae, is valued for its high ornamental value. However, low winter temperatures restrict the distribution of its evergreen species in colder regions. In this study, detached leaves of seven evergreen Ilex cultivars were subjected to acute low-temperature stress, and key physiological parameters (cell membrane permeability, osmoregulatory substances, and chloroplast pigments) were measured. The results showed that under low-temperature stress, relative electrical conductivity (REC) and malondialdehyde (MDA) content increased with decreasing temperature, while soluble protein (SP), soluble sugar, and free proline (Pro) contents first increased and then decreased. A positive association was observed between REC and MDA, as well as between REC and SP, while REC showed a negative association with Pro. Furthermore, random forest analysis indicated that MDA, proline, and chlorophyll a together accounted for 72.6% of the variance in REC. These findings demonstrate the physiological responses of detached leaves of evergreen Ilex species to acute low-temperature stress and offer an initial assessment of their cold tolerance. Full article

The biosynthesis and accumulation of plant secondary metabolites are tightly regulated by environmental fluctuations, serving as a crucial interface mediating plant–environment interactions. Nevertheless, the phenotypic instability of secondary metabolism-related traits induced by environmental variability has hampered the precise breeding of stress-resistant cultivars. Pinus taeda is an key timber tree species in southern China, and its foliar catechins exhibit substantial stress-resistant potential. However, phenotypic variation driven by seasonal changes has limited the germplasm innovation and genetic selection of this species. In this study, 54 half-sib families of P. taeda were used as experimental materials. Combined with near-infrared spectroscopy (NIRS) and the BLUP model, we systematically analyzed the seasonal variation characteristics, genetic parameters of catechin content (CC), and genetic gains under different breeding strategies across four seasons. Our results demonstrated that family and season had extremely significant effects on CC (p < 0.001), whereas the season × family interaction effect was not significant, indicating that the genetic expression of CC is stable across seasons. CC was higher in spring and winter but lower in summer and autumn; specifically, the mean CC in summer was 47% lower than the peak value in spring (26.95 ± 0.46 μg·g⁻¹), reflecting a resource trade-off between growth and defense metabolism. Genetic parameter analysis revealed that family-mean heritability (0.373–0.714) was higher than individual heritability and within-family heritability, with August identified as the optimal selection season. The maximum genetic gain across the three breeding strategies (individual selection, family selection, and combined selection) reached 7.86%, among which individual selection exhibited the smallest fluctuation in genetic gain. Finally, three superior families and 14 superior individuals were screened out. This study elucidates the seasonal genetic pattern of foliar CC in P. taeda, clarifies the optimal selection stage and efficient breeding strategies, and provides theoretical guidance and material support for the genetic improvement, germplasm innovation, and resource utilization of secondary metabolic traits in this ecologically and economically important tree species. Full article

Banana fruits are susceptible to chilling injury (CI) under field conditions, which significantly impairs fruit quality. Cold tolerance varies among genotypes; however, only a limited number of cultivars have been identified as tolerant and are commercially cultivated. This study aimed to investigate the physiological responses and quality attributes of banana cultivars exposed to natural cold fronts during development, compared with fruits developed under summer conditions. Furthermore, it evaluated whether the B genome confers greater cold tolerance, driven by a more efficient antioxidant mechanism, thereby supporting its recommendation for cultivation in regions prone to low temperatures. Bunches were harvested in winter following five natural cold fronts, during which air temperatures fell below 12 °C (137 h). The experimental design followed a completely randomized design in a factorial arrangement. Consecutive cold fronts intensified CI symptoms up to the fourth exposure event. CI severity was highest in ‘Grande Naine’ (AAA), which exhibited lower L*, a*, and b* values at the ripe stage compared to ‘BRS Princesa’ (AAAB) and ‘Prata Catarina’ (AAB), along with greater deviations relative to summer-harvested fruits. Malondialdehyde (MDA), total phenolic content, and antioxidant enzyme activities (SOD, CAT, APX, and POD) in the peel of unripe fruits were significantly higher during winter, particularly in ‘BRS Princesa’ and ‘Prata Catarina’, compared to ‘Grande Naine’. Proline accumulation followed a similar pattern, with the highest levels observed in ‘BRS Princesa’, followed by ‘Prata Catarina’ and ‘Grande Naine’. The findings indicate that ‘BRS Princesa’ exhibits greater tolerance to cold stress and highlights of the contribution of the B genome. Phenolic content was identified as a consistent marker of seasonal variation across cultivars. Full article

Wheat yellow (stripe) rust (Puccinia striiformis f. sp. tritici) remains a major constraint to wheat production, yet relationships between infection level, yield, and quality-related traits are often inconsistent. This study evaluated how contrasting yellow rust races and infection intensities influence yield, test weight (TW), thousand kernel weight (TKW), and crude protein content in commercial winter wheat varieties. Field trials were conducted in 2016, 2021, and 2023, representing seasons that differed in yellow rust incidence and severity. The yellow rust race was changed in 2023 compared to the yellow rust race that was the same in 2016 and 2021. Associations between qualitative variables (variety and year) and quantitative variables (yield, TKW, TW, disease index (DI), and protein content) were analyzed using principal component analysis for mixed data and regression modeling. At low to moderate infection levels, TW showed a stronger negative linear association with yellow rust DI than TKW, suggesting that TW acts as an early indicator of source limitation. In contrast, TKW declined only when genotypes could no longer compensate for reduced assimilate supply, after which both traits responded similarly under severe physiological stress. Protein concentration increased under high infection levels, but its association with yield loss and DI was weak. Under high disease pressure, yield and quality-related responses were highly variable and genotype-specific at comparable DI levels, demonstrating that equivalent symptom expression does not necessarily translate into equivalent physiological disruption. These results show that yield and quality responses to yellow rust cannot be inferred from DI alone, highlighting the importance of physiological tolerance and source–sink efficiency in breeding and disease management strategies. Full article

Salt stress is one of the major abiotic stresses limiting the yield of agriculture production worldwide. Rice is an aquatic summer crop, while barley represents a drought winter crop. Both are classified as diploid sequenced crops within the Poaceae family, and are vital staples in the world. As a plant-specific transcriptional regulator, suppressor of gamma response (SOG) plays crucial roles in plant adaptation under abiotic stresses by repairing DNA damage pathway. However, little research has reported the function of SOGs in barley and rice. This study presents the first genome-wide identification and comparative analysis of the SOG gene family in barley and rice, two cereal crops with contrasting salt tolerance. A total of 97 HvSOGs and 74 OsSOGs were identified in the genome of barley and rice, which were divided into three subfamilies. There was significant variation between barley and rice in terms of gene structures, motif compositions, gene duplication, and cis-elements. Notably, rice may have suffered stronger purifying selection pressure than barley, whereas the proportion of SOGs with stress-related cis-elements was significantly higher in barley than in rice. The expression patterns of SOGs in barley and rice tissues under salt stress indicated that barley’s stronger salt tolerance was largely due to an energy-saving strategy in shoots. Moreover, homologous gene similarity comparison with sea barleygrass suggested that gene loss and possible functional divergence during evolution may contribute to salt sensitivity in rice. Functional validation of a differentially expressed OsSOG17 gene confirmed its positive regulatory role in salt tolerance. Our findings uncover an energy-saving strategy as a potential mechanism underlying differential salt tolerance, and functionally link a SOG gene to salt stress responses in rice. Full article

The expansion of floriculture into climatic transition regions requires precise tools to mitigate thermo-hydric risks. Gladiolus (Gladiolus × grandiflorus Hort.) is sensitive to temperature extremes, requiring strategic planning of planting schedules and heat stress mitigation. The objective in this study was to evaluate the PhenoGlad model for its ability to simulate developmental stages and heat stress damage in eight gladiolus cultivars across multiple environments and planting dates in the state of Mato Grosso do Sul, Midwest Brazil. Field experiments were conducted in five municipalities during the autumn, winter, and spring growing seasons. Model performance was evaluated by starting the simulation at planting or at emergence, using the statistics root mean square error (RMSE), bias index (BIAS), Willmott’s index of agreement (d), and the correlation coefficient (r). Simulations starting at emergence reduced the error in predicting the timing of developmental stages (from 5.34 to 3.16 days). For leaf development, the model was highly accurate, with an RMSE lower than one leaf for different planting dates, sites, and cultivars. Furthermore, the model accurately predicted extreme heat stress events (daily maximum temperatures > 34 °C associated with low relative humidity), which resulted in severe damage and inhibition of reproductive development in the field. In conclusion, the PhenoGlad model is a robust decision-support system and agricultural engineering tool for production scheduling and climate loss mitigation in tropical floriculture. Full article

Seasonal body mass fluctuations in mammals reflect fundamental trade-offs between ecological constraints and reproductive effort, yet few studies have simultaneously linked these dynamic changes with activity budgets in high-altitude primates inhabiting extreme-temperature environments. We examined the effects of environmental stress and mating effort on body mass dynamics in black-and-white snub-nosed monkeys (Rhinopithecus bieti). Using monthly non-invasive monitoring over a full annual cycle, we obtained 464 body mass records from free-ranging adults (127 male records, 337 female records). Both sexes showed marked seasonal variation: body mass peaked in spring and autumn, declined moderately in winter (males: −7.4%, females: −2.9%), and dropped more sharply during the mating season (males: −11.1%, females: −12.9%). Male mass loss was positively correlated with the number of mates. Seasonal shifts in activity budgets accompanied these patterns: in summer, males increased movement and females increased both movement and social interaction, while both sexes reduced resting; in winter, both sexes increased feeding time, with females additionally reducing social activities. These findings reveal two distinct phases of body mass loss. Body mass decline was more pronounced during the mating season than in winter, a pattern that may be associated with higher energetic costs related to reproductive activity. Our study demonstrates how high-altitude primates balance survival and reproduction through flexible energy allocation, offering key insights into their seasonal energy allocation resilience in provisioned high-altitude habitats. Full article

Low temperature and low irradiance (LTLI) stress severely limits strawberry growth and productivity during winter protected cultivation. This study investigated the physiological responses of the short-day strawberry cultivar ‘Benihoppe’ to individual and combined LTLI stress and developed a quantitative damage evaluation index. Seedlings were exposed to four treatments for 20 d: control (25/15 °C, 600 μmol m⁻² s⁻¹), single low temperature (LT: 15/5 °C), single low irradiance (LI: 100 μmol m⁻² s⁻¹), and combined stress (LTLI: 15/5 °C, 100 μmol m⁻² s⁻¹). Compared to isolated stress factors, combined LTLI treatment exhibited a statistically verified synergistic damaging effect (two-factor ANOVA, LT × LI p < 0.01) on leaf structure and function. LTLI-treated plants showed severe reductions in leaf area, palisade tissue thickness, chlorophyll content, and net photosynthetic rate (Pn), alongside elevated malondialdehyde (MDA) accumulation. Chlorophyll a fluorescence (OJIP) analysis revealed that LTLI stress strongly blocked the electron transport chain at the PSII acceptor side, increasing the J-step relative variable fluorescence (Vj) and suppressing the performance index (PI). To quantify these impacts, a Low Temperature and Low Irradiance Damage Index (LTLDI) was derived from 12 core physiological and morphological variables. The LTLDI scores demonstrated that LTLI induced severe damage by day 10 (score: 0.69) and extremely severe damage by day 20 (0.87), which were substantially higher than the damage caused by LT (0.58 at 20 d) and LI (0.63 at 20 d) alone. The index reliability was confirmed by its strong correlation (r > 0.9) with key stress markers (Fv/Fm, Pn, and MDA). Overall, combined LTLI stress exacerbates structural degradation and PSII photoinhibition in strawberry leaves. The proposed LTLDI offers a practical, standardized tool for evaluating stress severity, facilitating timely environmental management in greenhouse strawberry production. Full article

Winter wheat (Triticum aestivum L.) production in the Yellow River Delta is limited by saline–alkali soils and freshwater scarcity, while the responses of different straw-returning modes under contrasting irrigation regimes remain unclear. A field experiment was conducted with two irrigation regimes, normal irrigation (W1) and deficit irrigation (W2), and four straw-returning modes, direct straw return (RS), straw-derived cattle manure return (RM), straw biochar return (RB), and straw pellet return (RG). The experiment followed a split-plot randomized block design with three replicates. Soil properties, leaf physiology, photosynthetic performance, grain yield, and irrigation water use efficiency (IWUE) were evaluated. Compared with W2, W1 increased mean grain yield by 9.4%, whereas W2 increased mean IWUE by 36.7%. Among the straw-returning modes, RS showed the most consistent performance. Under W1, W1RS produced the highest grain yield (3509.72 kg ha⁻¹). The stable performance of RS was characterized by relatively favorable soil moisture status, lower MDA content, higher antioxidant enzyme activity, and better maintenance of Pn. Pearson correlation analysis showed that grain yield was positively correlated with Pn and CAT activity, whereas MDA was negatively correlated with Pn. These results suggest that RS may be a feasible straw-returning mode for winter wheat production in saline–alkali soil. Full article

Climate change and rising global temperature values lead to a cascade of effects on human health and well-being. Methodologies for assessing thermal conditions and identifying areas with increased thermal stress are important for enhancing the quality of life in urban environments. This study is aimed at developing a methodology that combines high-resolution simulation data with surface meteorological observations for application in urban thermal stress assessment. Eleven urban public sites within the metropolitan area of Athens, Greece (i.e., squares and parks) were simulated using the three-dimensional microclimate model ENVI-met. The model was validated using micrometeorological data from field campaigns conducted in summer, autumn and winter. The validation results confirmed that ENVI-met showed satisfactory performance for further research analysis. Subsequently, Physiologically Equivalent Temperature (PET) and Universal Thermal Climate Index (UTCI) were calculated using data from weather stations operated by the National Observatory of Athens and the Hellenic National Meteorological Service. PET and UTCI were then spatially interpolated using a mixed modeling and kriging method, with parameters optimized based on statistical validation metrics derived from the ENVI-met simulations. Finally, seasonal bioclimatic maps were produced to identify areas experiencing unfavorable thermal conditions. The spatial analysis revealed distinct seasonal patterns in the distribution of unfavorable thermal conditions across the Athens metropolitan area. Full article