Search Results (1,278)

Diploid Vaccinium fuscatum is a wild blueberry species with a low chilling requirement, an evergreen growth habit, and soil adaptability to southeast US growing regions. Regardless of its potential to improve the abiotic and biotic resilience of cultivated blueberries, this species has rarely been used for blueberry breeding. One hurdle is the ploidy barrier between diploid V. fuscatum and tetraploid cultivated highbush blueberries. To overcome the ploidy barrier, vegetative shoots micro-propagated from one genotype of V. fuscatum, selected because it grew vigorously in vitro and two southern highbush cultivars, ‘Emerald’ and ‘Rebel,’ were treated with colchicine. While shoot regeneration was severely repressed in ‘Emerald’ and ‘Rebel,’ shoot production from the V. fuscatum clone was not compromised at either 500 µM or 5000 µM colchicine concentrations. Due to the high number of shoots produced in vitro via the V. fuscatum clone shoots of this clone that had an enlarged stem diameter in vitro were subjected to flow cytometer analysis to screen for induced polyploidy. Sixteen synthetic tetraploid V. fuscatum, one synthetic octoploid ‘Emerald,’ and three synthetic octoploid ‘Rebel’ were identified. Growth rates of the polyploid-induced mutants were reduced compared to their respective wildtype controls. The leaf width and length of synthetic tetraploid V. fuscatum and synthetic octoploid ‘Emerald’ was increased compared to the wildtypes, whereas the leaf width and length of synthetic octoploid ‘Rebel’ were reduced compared to the wildtype controls. Significant increases in stem thickness and stomata guard cell length were found in the polyploidy-induced mutant lines compared to the wildtypes. In the meantime, stomata density was reduced in the mutant lines. These morphological changes may improve drought tolerance and photosynthesis in these mutant lines. Synthetic tetraploid V. fuscatum can be used for interspecific hybridization with highbush blueberries to expand the genetic base of cultivated blueberries. Full article

With the increasing awareness of energy consumption issues, there has been a growing emphasis on energy-saving retrofits for central air-conditioning systems that constitute a significant proportion of energy consumption in buildings. Efficient energy utilization can be achieved by optimizing the modeling of the equipment within the chiller plants of central air-conditioning systems. Traditional modeling approaches have been static and have focused on modeling within narrow time frames when a certain amount of equipment operating data has accumulated, thus prioritizing the precision of the model itself while overlooking the fact that energy-saving retrofits are a long-term process. This study proposes a modeling scheme for the equipment within chiller plants throughout the energy-saving retrofit process. Based on the differences in the amount of available operating data for the equipment and the progress of retrofit implementation, the retrofit process was divided into three stages, each employing different modeling techniques and ensuring smooth transitions between the stages. The equipment within the chiller plants is categorized into two types based on the clarity of their operating characteristics, and two modeling schemes are proposed accordingly. Based on the proposed modeling scheme, chillers and chilled-water pumps were selected to represent the two types of equipment. Real operating data from actual retrofit projects was used to model the equipment and evaluate the accuracy of the model predictions. The results indicate that the models established by the proposed modeling scheme exhibit good accuracy at each stage of the retrofit, with the coefficients of variation (CV) remaining below 6.88%. Furthermore, the prediction accuracy improved as the retrofitting process progressed. The modeling scheme performs better on equipment with simpler and clearer operating characteristics, with a CV as low as 0.67% during normal operation stages. This underscores the potential application of the proposed modeling scheme throughout the energy-saving retrofit process and provides a model foundation for the subsequent optimization of the refrigeration system. Full article

Late-spring frost events severely damage low-chill peach blossoms, causing significant yield losses. Although 5-aminolevulinic acid (ALA) enhances cold tolerance through the PpC3H37-PpWRKY18 module, the regulatory mechanism of ALA on PpC3H37 remains to be elucidated. Using yeast one-hybrid screening with the PpC3H37 promoter as bait, we identified PpDof9 as a key interacting transcription factor. A genome-wide analysis revealed 25 PpDof genes in peaches (Prunus persica). These genes exhibited variable physicochemical properties, with most proteins predicted as nuclear-localized. Subcellular localization experiments in tobacco revealed that PpDof9 was localized to the nucleus, consistent with predictions. A synteny analysis indicated nine segmental duplication pairs and tandem duplications on chromosomes 5 and 6, suggesting duplication events drove family expansion. A conserved motif analysis confirmed universal presence of the Dof domain (Motif 1). Promoter cis-element screening identified low-temperature responsive (LTR) elements in 12 PpDofs, including PpDof1, PpDof8, PpDof9, and PpDof25. The quantitative real-time PCR (qRT-PCR) results showed that PpDof1, PpDof8, PpDof9, PpDof15, PpDof16, and PpDof25 were significantly upregulated under low-temperature stress, and this upregulation was further enhanced by ALA pretreatment. Our findings demonstrate ALA-mediated modulation of specific PpDof TFs in cold response and provide candidates (PpDof1, PpDof9, PpDof8, PpDof25) for enhancing floral frost tolerance in peaches. Full article

The current study explores the changes in beef quality following partial freezing and during superchilled storage, alongside chilled storage comparisons. Kinetic models were developed to predict changes in colour difference (∆E), thiobarbituric acid−reactive substances (TBARS), total volatile basic nitrogen (TVB−N), drip loss and firmness. Beef samples were partially frozen in an air blast freezer at −30 °C for 9 min prior to storage at −5 °C, −4 °C, −2.8 °C, −1.8 °C. Chilled beef samples were directly stored at 2 °C and 6 °C without partial freezing. All samples were stored for 21 days. The lightness (L*), redness (a*), yellowness (b*) and colour difference (∆E) were significantly lower in superchilled storage samples compared to chilled storage samples. The pH of beef samples increased gradually over time (p < 0.05). TBARS, TVB−N and drip loss increased while firmness decreased with the increase in storage time in both storage conditions (p < 0.05). Overall, beef quality was affected by both storage duration and temperature. Firmness followed the first order kinetic model; drip loss, TVB−N, TBARS and colour difference (∆E) fitted the zero−order kinetic model. Temperature dependence was adequately modelled using Arrhenius−type equation with the activation energy values of 110.111, 52.870, 68.553, 119.480, 47.301 kJ/mol for drip loss, firmness, TBARS, TVB−N and colour difference (∆E), respectively. The models demonstrated strong predictive performance, with RMSE and MAPE values within ±10%. The developed kinetic models successfully predicted quality changes within the −5 °C to 6 °C temperature range. Full article

Chilling injury (CI) frequently occurs in postharvest flat peach fruit during cold storage, leading to quality deterioration and a reduced shelf life. Therefore, investigating the key factors involved in alleviating CI and developing effective preservatives are vital scientific issues for the industry. 2,4-Epibrassinolide (EBR) is a crucial endogenous hormone involved in plant response to both biological and environmental stressors. At present, most studies focus on the mechanisms of mitigating CI using a single concentration of EBR treatment, while few studies focus on the effects varying EBR concentrations have on CI. The purpose of this research is to explore the effects of varying concentrations of EBR on the postharvest quality and cold resistance of peach fruit, thereby establishing a basis for refining a technical framework of environmentally sustainable strategies to mitigate postharvest CI. The results show that EBR treatment effectively inhibits the generation of reactive oxygen species (ROS) and malondialdehyde (MDA) by maintaining the activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), thereby delaying the internal browning process of postharvest peaches. In addition, EBR treatment reduced the consumption of total phenolics by inhibiting the activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL). Experimental results identify that 5 μmol L⁻¹ EBR treatment emerged as the most effective concentration for maintaining core postharvest quality attributes. It significantly delayed the decrease in firmness, reduced weight loss, effectively inhibited the production of H₂O₂ and O₂⁻·, particularly during the early storage period, strongly restrained the activity of PAL, and maintained lower rot rates and internal browning indexes. While the 15 μmol L⁻¹ EBR treatment enhanced antioxidant activity, increased total phenolic content at certain stages, and maintained higher soluble solids and acid content, its effects on key physical quality parameters, like firmness and weight loss, were less pronounced compared to the 5 μmol L⁻¹ treatment. Full article

Cordyceps sinensis (C. sinensis) is widely recognized for its bioactive compounds and associated health benefits. However, due to its delicate nature, conventional chilled storage often results in the rapid degradation of valuable compounds, leading to loss of nutritional value and overall quality. This study integrated and evaluated comprehensive strategies: three gas-conditioning and two light-based preservation methods for maintaining both quality and nutritional integrity during 12-day chilled storage at 4 °C. The results revealed that vacuum packaging significantly inhibited weight loss (3.49%) compared to in the control group (10.77%) and preserved sensory quality (p < 0.05). UV-based interventions notably suppressed polyphenol oxidase and tyrosinase activities by 36.4% and 29.7%, respectively (p < 0.05). Modified atmosphere packaging (MAP) with 80% N₂ and 20% CO₂ (MAP-N₂CO₂) maintained higher levels of cordycepin (1.77 µg/g) and preserved energy charge above 0.7 throughout storage. The results suggest that MAP-based treatments are superior methods for the chilled storage of C. sinensis, with diverse advantages and their corresponding shelf lives associated with different gas compositions. Full article

In recent years, early olive fruit drop has been observed in the northern Mediterranean regions, causing significant economic losses, although the exact cause remains unknown. Recent studies have identified several possible causes; however, our understanding of how olive trees respond to these environmental stresses remains limited. This study includes an analysis of selected meteorological and flowering data for Olea europaea L. “Istrska belica” to evaluate the use of a chilling and forcing model for a better understanding of flowering time dynamics under a changing climate. The flowering process is influenced by high diurnal temperature ranges (DTRs) during the pre-flowering period, resulting in earlier flowering. Despite annual fluctuations due to various climatic factors, an increase in DTRs has been observed in recent decades, although the mechanisms by which olive trees respond to high DTRs remain unclear. The chilling requirements are still well met in the region (1500 ± 250 chilling units), although their total has declined over the years. According to the Chilling Hours Model, chilling units—referred to as chilling hours—represent the number of hours with temperatures between 0 and 7.2 °C, accumulated throughout the winter season. Growing degree hours (GDHs) are strongly correlated with the onset of flowering. These results suggest that global warming is already affecting the synchrony between olive tree phenology and environmental conditions in the northern Mediterranean and may be one of the reason for the green drop. Full article

In the swine industry, artificial insemination (AI) primarily uses chill-stored semen, making sperm preservation crucial for reproductive success. However, sperm quality declines at varying rates during chilled storage at 17 °C, distinguishing high-survival semen from low-survival semen. This study investigates the metabolomic profiles of boar sperm with different abilities to survive liquid storage. We analyzed sperm motility, kinematics, and morphology in freshly extended (Day 0) and 7-day stored AI semen doses. The AI semen doses were classified as high-motile (HM) or low-motile (LM) based on sperm motility after 7 days of storage (Day 7). Metabolomic data were collected in positive (ESI+) and negative (ESI−) ion modes using a Vanquish Flex UPLC coupled with a Q Extractive Plus. We consistently detected 442 metabolites (251 in ESI+, 167 in ESI−, and 24 in both) across samples and storage durations. In freshly extended and 7-day stored AI doses, we identified 42 and 56 differentially expressed metabolites (DEMs), respectively. A clustering analysis showed significant changes in DEMs between the HM and LM samples. These DEMs were mainly enriched in amino acid metabolism, the pentose phosphate pathway, glycerolipid metabolism, glyoxylate and dicarboxylate metabolism, terpenoid backbone biosynthesis, etc. In summary, this study highlights the metabolomic differences between semen doses with varying abilities to survive liquid storage. Glyceric acid and lysoPC(20:3) emerged as potential markers for sperm preservation. Full article

Cold storage is widely used for the postharvest preservation of fruits and vegetables; however, okra, as a tropical vegetable, is susceptible to chilling injury under low-temperature storage conditions, leading to quality deterioration, reduced nutritional value, and significant economic losses. Nitric oxide (NO), as an important signaling molecule, plays a crucial role in the postharvest preservation of fruits and vegetables. To investigate the effects of different concentrations of nitric oxide on the postharvest quality of okra under cold storage, fresh okra pods were treated with sodium nitroprusside (SNP), a commonly used NO donor, at concentrations of 0 (control), 0.5 (T1), 1.0 (T2), 1.5 (T3), and 2.0 mmol·L⁻¹ (T4). The results showed that low-concentration NO treatment (T1) significantly reduced weight loss, improved texture attributes including hardness, springiness, chewiness, resilience, and cohesiveness, and suppressed the increase in adhesiveness. T1 treatment also effectively inhibited excessive accumulation of cellulose and lignin, thereby maintaining tissue palatability and structural integrity. Additionally, T1 significantly delayed chlorophyll degradation, preserved higher levels of soluble sugars and proteins, and enhanced the activities of key antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), contributing to improved oxidative stress resistance and membrane stability. In contrast, high-concentration NO treatments (T3 and T4) led to pronounced quality deterioration, characterized by accelerated membrane lipid peroxidation as evidenced by increased malondialdehyde (MDA) content and relative conductivity, and impaired antioxidant defense, resulting in rapid texture degradation, chlorophyll loss, nutrient depletion, and oxidative damage. These findings provide theoretical insights and practical guidance for the precise application of NO in extending shelf life and maintaining the postharvest quality of okra fruits. Full article

The formation of hot tearing during direct chill casting of aluminum alloys, specifically AA6111, is a significant challenge in the production of ingots for industrial applications. This study investigates the role of hydrostatic pressure and tensile stress in the formation of hot tearing during direct chill casting of rectangular ingots. Combining experimental results and finite element modeling with ABAQUS/CAE 2022, the mechanical behavior of the semi-solid AA6111 alloy was analyzed under different cooling conditions. “Hot” (low water flow) and “Cold” (high water flow) conditions were the two types of cooling conditions that produced cracked and sound ingots, respectively. The outcomes indicate that high tensile stress and localized negative hydrostatic pressure in the hot condition are the main factors promoting the initiation and propagation of cracks in the mushy zone, whereas the improvement of the cooling conditions reduces these defects. Full article

Climate change has contributed to a decline in winter chilling accumulation, a critical requirement for budbreak in temperate fruit crops. Its consequence has been a reduction in fruit production. To compensate for insufficient chilling, hydrogen cyanamide (HC) is widely applied, though its effectiveness remains limited. This study investigated the effect of HC application on budbreak in low-chill kiwifruit under warm conditions by correlating phenological responses with changes in carbohydrate and nitrogen concentrations in bark tissues across bud positions. Phenological observations revealed the highest budbreak percentage and total flower buds at the apical position. HC significantly increased budbreak by 58.82% at the apical position and by 375% at the middle position, with corresponding increases in total flower buds by 148.78% and 1066.67%, respectively. Additionally, shoot lengths were uniform among bud positions in HC-treated canes, whereas non-treated canes showed shoot length heterogeneity. Moreover, HC treatment triggered an earlier and more pronounced reduction in soluble sugars (sucrose and hexoses) concentrations along the gradient from apical to basal bud positions, where the response was strongest at the apical position, which was strongly associated with enhanced budbreak percentages and total flower bud formation. While total nitrogen content was highest in the apical position, it was unaffected by HC application. These findings indicate that HC may promote budbreak by enhancing the mobilization and consumption of soluble sugars for bud growth, thereby improving budbreak performance, flower bud production, and uniform shoot development in low-chill kiwifruit under warm conditions. Full article

Fossil fuels, including coal, are a basis of energy systems in many countries worldwide. However, coal mining is associated with several difficulties, which include high temperatures within the coal mining area. It causes a need for cooling for safety reasons and also for the comfort of miners’ work. Typical cooling systems in mines are based on central systems, in which chilled water is generated in the compressor or absorption coolers on the ground and transported via pipelines to the air coolers in the areas of mining. The progressive mining operation causes a gradual increase in the distance between chilled water generators and air coolers, causing a decrease in the efficiency of the entire system and insufficient cooling capacity. As a result, it is necessary to increase the diameter of the chilled water pipelines and increase the cooling capacity of the chillers, which is associated with additional investment and technical problems. One solution to this problem may be the use of so-called ice slurry instead of chilled water in the existing mine cooling system. This article presents the cooling system, located in the mine LW Bogdanka S.A., based on ice slurry. The structure of the system and its key parameters are presented. The results show that switching from cooling water to ice slurry allowed the cooling capacity of the entire system to increase by 50% while maintaining the existing piping. This demonstrates the very high potential for the use of ice slurry, not only in mines, but wherever further increases in piping diameters to maintain the required cooling capacity are not possible or cost-effective. Full article

Betula platyphylla Sukaczev (white birch) is a cold-tolerant tree species native to northeastern Asia, valued for its ecological adaptability and economic utility. While its responses to various abiotic stresses have been studied, the physiological and biochemical mechanisms underlying its cold stress tolerance remain insufficiently explored. In this study, we investigated the effects of prolonged cold exposure (6 °C for up to 27 days) on key physiological and biochemical traits of B. platyphylla seedlings, including plant height, chlorophyll content, electrolyte leakage (EL), malondialdehyde (MDA), proline levels, and antioxidant enzyme activities (SOD, CAT, POD). Cold stress resulted in visible phenotypic changes, reduced growth, and significant declines in chlorophyll content, suggesting inhibited photosynthesis. EL and MDA levels increased with exposure duration, indicating progressive membrane damage and oxidative stress. In response, antioxidant enzyme activities and proline accumulation were significantly enhanced, reflecting a coordinated defense strategy. Correlation analyses further revealed strong associations among antioxidant enzymes, MDA, proline, and EL under cold stress. These findings advance our understanding of the adaptive responses of B. platyphylla to low-temperature stress and provide a physiological and biochemical basis for future breeding programs aimed at improving cold tolerance. Full article

Ensuring the safety and extending the shelf life of chilled poultry meat is vital in modern poultry meat production, particularly given the recent increase in demand in this area. Chilled meat has a short shelf life, so producers have limited time to sell their products and must rely on various methods of extending shelf life. Compared with other non-thermal methods, electron beam irradiation is a new non-thermal meat preservation technique with low cost, avoidance of contamination, and antibacterial effects. In this study, we investigate the effect of electron beam irradiation on the microbiological and physicochemical quality of chilled poultry meat produced in Kazakhstan to assess its suitability for use in local food processing systems. The samples were electron-beam-treated at doses of 2, 4, 6, and 8 kGy and stored in a refrigerator. Microbiological and physicochemical property evaluations were carried out for a period of 14 days. Our results demonstrated a significant decrease in total aerobic and facultative anaerobic microorganisms, and no detectable levels of Salmonella spp. and Listeria monocytogenes in the irradiated samples. The pH measurements remained stable at low doses; in comparison, higher doses resulted in a slight decrease. Moisture, protein, fat, and ash content were also evaluated and showed minimal changes as functions of irradiation dose. Our results indicate that electron beam irradiation, particularly at a dose of 2–4 kGy, effectively improves microbiological safety and extends the shelf life of chilled poultry meat up to 5–6 days, making it a promising solution for the modern poultry meat industry. Full article

Pear (Pyrus pyrifolia) is an important deciduous fruit tree that requires a specific period of low-temperature accumulation to trigger spring flowering. The warmer winter caused by global warming has led to insufficient winter chilling, disrupting floral initiation and significantly reducing pear yields in Southern China. In this study, we integrated targeted phytohormone metabolomics, full-length transcriptomics, and proteomics to explore the regulatory mechanisms of dormancy in ‘Mixue’, a pear cultivar with an extremely low chilling requirement. Comparative analyses across the multi-omics datasets revealed 30 differentially abundant phytohormone metabolites (DPMs), 2597 differentially expressed proteins (DEPs), and 7722 differentially expressed genes (DEGs). Integrated proteomic and transcriptomic expression clustering analysis identified five members of the dormancy-associated MADS-box (DAM) gene family among dormancy-specific differentially expressed proteins (DEPs) and differentially expressed genes (DEGs). Phytohormone correlation analysis and cis-regulatory element analysis suggest that DAM genes may mediate dormancy progression by responding to abscisic acid (ABA), gibberellin (GA), and salicylic acid (SA). A dormancy-associated transcriptional regulatory network centered on DAM genes and phytohormone signaling revealed 35 transcription factors (TFs): 19 TFs appear to directly regulate the expression of DAM genes, 18 TFs are transcriptionally regulated by DAM genes, and two TFs exhibit bidirectional regulatory interactions with DAM. Within this regulatory network, we identified a novel pathway involving REVEILLE 6 (RVE6), DAM, and CONSTANS-LIKE 8 (COL8), which might play a critical role in regulating bud dormancy in the ‘Mixue’ low-chilling pear cultivar. Furthermore, lncRNAs ONT.19912.1 and ONT.20662.7 exhibit potential cis-regulatory interactions with DAM1/2/3. This study expands the DAM-mediated transcriptional regulatory network associated with bud dormancy, providing new insights into its molecular regulatory mechanisms in pear and establishing a theoretical framework for future investigations into bud dormancy control. Full article