The rapid advancement of jujube industry has produced a large amount of jujube biomass waste, requiring the development of new methods for utilization of jujube resources. Herein, medium-temperature pyrolysis is employed to produce carbon materials from jujube waste in an oxygen-free environment. Ten types of jujube biochar (JB) are prepared by modifying different pyrolysis parameters, followed by physical activation. The physicochemical properties of JB are systematically characterized, and the adsorption characteristics of JB for NO₃⁻ and NH₄⁺ are evaluated via batch adsorption experiments. Furthermore, the pyrolysis and adsorption mechanisms are discussed. The results indicate that the C content, pH, and specific surface area of JB increase with an increase in the pyrolysis temperature from 300 °C to 700 °C, whereas the O and N contents, yield, zeta potential, and total functional groups of JB decrease gradually. The pyrolysis temperature more significantly effects the biochar properties than pyrolysis time. JB affords the highest adsorption capacity for NO₃⁻ (21.17 mg·g⁻¹) and NH₄⁺ (30.57 mg·g⁻¹) at 600 °C in 2 h. The Langmuir and pseudo-second-order models suitably describe the isothermal and kinetic adsorption processes, respectively. The NO₃⁻ and NH₄⁺ adsorption mechanisms of JB may include surface adsorption, intraparticle diffusion, electrostatic interaction, and ion exchange. In addition, π–π interaction and surface complexation may also be involved in NH₄⁺ adsorption. The pyrolysis mechanism comprises the combination of hemicellulose, cellulose, and lignin decomposition involving three stages. This study is expected to provide a theoretical and practical basis for the efficient utilization of jujube biomass to develop eco-friendly biochar and nitrogenous wastewater pollution prevention.

Korla fragrant pear (Pyrus sinkiangensis Yü) fruits have a unique flavor and are rich in phenolic acids, flavonoids, amino acids, and other nutrients. At present, the molecular basis of the quality differences among Korla fragrant pear fruits with a convex calyx and rough skin (RS), calyx shedding (SD), and a convex calyx (CV) remains unknown. To analyze the main metabolic components of Korla fragrant pear fruits and compare the antioxidant activities of these three fruits with different qualities, we used nutrient composition analysis and ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS)-based widely targeted metabolomics approaches to analyze the changes in the quality characteristics of the pulp of these three Korla fragrant pear fruits with different appearances. The nutrient composition analysis showed that the fructose and glucose contents were not significantly different, and sucrose and vitamin C contents were significantly higher in SD fruits compared with CV and RS fruits. However, the levels of flavor substances such as titratable acids, total phenols, and total flavonoids were high in the pulp of RS fruits. The metabolomics results identified 1976 metabolites that were clustered into 12 categories, and phenolic acid and flavonoid metabolites were the most abundant. The differentially accumulated metabolites (DAMs) in the fruits with different appearances were screened by multivariate statistical methods, and a total of 595 DAMs were detected. The analysis identified 300 DAMs between the CV and SD fruits, 246 DAMs between the RS and CV fruits, and 405 DAMs between the RS and SD groups. SD fruits contained the most metabolites with a high relative content, especially phenolic acids, lipids, amino acids and derivatives, alkaloids, and organic acids. Compared with CV fruits, flavonoid metabolism was more active in RS fruits, which also had a higher content of flavonoids, whereas the fewest metabolites were found in CV fruits, which also displayed less flavonoid accumulation. KEGG pathway enrichment analysis revealed that the DAMs were mainly enriched in the metabolic pathways of flavone and flavonol biosynthesis, confirming that CV fruits have decreased flavone and flavonol biosynthesis and accumulate fewer flavonoids than RS fruits, which may explain the less bitter and astringent flavor of CV fruits. However, the flavonoid content in RS fruits was very high, which may be one of the reasons why RS fruits have a harder pulp and are less juicy, more slaggy, and less flavorful. Moreover, the analysis of the antioxidant activity showed that during fruit development and maturation, RS fruits had stronger antioxidant activity than SD and CV fruits. These results provide a theoretical basis for improving the fruit quality of Korla fragrant pears and the processing of pear pulp.

Korla fragrant pear (Pyrus sinkiangensis Yü) fruit development involves complex physiological and biochemical processes; however, few data are available at the proteomic and metabolomic levels, which would be helpful for understanding the molecular mechanisms of fruit and quality development. Here, Korla fragrant pear was investigated across three stages, namely, early development (5 weeks after flower blooming, WAF), middle development (10WAF), and near ripening (15WAF), via tandem mass tag (TMT) labeling technology and ultra-performance liquid chromatography‒tandem mass spectrometry (UPLC‒MS/MS). Through proteomic and metabolomic analyses, we identified a total of 8487 proteins expressed during pear fruit development, and 3762 differentially expressed proteins (DEPs) were characterized at three fruit development stages. Moreover, 27 soluble sugars and 43 organic acids were found to accumulate differentially in the fruit at different developmental stages. The expression of proteins related to sugar metabolism and accumulation increased with increasing fruit development stage, which was consistent with the trend in soluble sugar content during fruit development. All 6 disaccharides, including cellobiose (Cel), lactose (Lac), maltose (Mal), trehalose (Tre), phenylglucoside (Phe) and sucrose (Suc), detected in this study were present at low levels in the early stages of fruit development but accumulated in large amounts from 15 WAF to 20 WAF, which may explain the high sweetness of the ripe Korla fragrant pear. In addition, The low organic acid levels during fruit development may explain the low organic acid content of Korla fragrant pear. Thus, our proteomic and metabolomic analyses reveal the molecular basis for the high sweetness and the low organic acidity of Korla fragrant pears.

Objective: This study aims to elucidate the relationship between canopy structure and fruit spatial distribution, establish a model linking canopy light distribution with fruit positioning, and identify optimal training strategies for consistently high yield. The findings provide a theoretical foundation for optimizing modern cultivation practices in Korla fragrant pear orchards.Methods: Four training treatments were established: precision pruning, reduction, falling head, and thinning. Canopy structural parameters and light distribution were measured, along with canopy light interception (ALI). Fruit number and individual fruit weight were recorded at different canopy positions. Correlation analysis was used to revealing the relationship between canopy structure, light distribution, and spatial distribution of fruits.Results: (1) Canopy Structure: Reduction and falling head effectively controlled canopy spread, significantly reduced the proportion of long branches while increased the proportion of middle branches. Thinning, however, increased the proportion of long branches, total branch length and average branch length, led to significant expansion in canopy diameter, surface area, and volume. (2) Light Distribution: Reduction increased average light interception (ALI) by 15%, while thinning improved ALI by 11% significantly, enhanced light availability across different canopy aspects, falling head notably improved light penetration in the middle and lower canopy layers. Persistent low-light zones (ALI < 300 μmol·m^-²·s^-¹) were identified in the lower canopy, inner canopy, and inter-tree spaces, highlighted key areas for light optimization. (3) Fruit Spatial Distribution: Smaller canopies had fewer but more uniformly distributed fruits. As canopy size increased, light interception and photosynthesis improved, total fruit yield improved, however, spatial heterogeneity intensified, with fruit-bearing zones shifted outward and upward, reduced carbon allocation uniformity. (4) Yield Correlations: Two canopy structural parameters showed significant negative correlations with consistently high yield traits, while ten exhibited positive correlations. Tree height, canopy surface area, and total branch length had the strongest positive associations with total yield. (5) Key Relationship: The correlation between light distribution and fruit spatial distribution strengthened significantly with canopy expansion.Conclusion: The influence of canopy structure and light distribution on fruit spatial distributions depends on canopy size. For small canopies, canopy structure serves as the dominant factor affecting fruit distribution, while in large canopies, light distribution becomes the primary driver. Accordingly, distinct canopy management strategies should be adopted, small canopies should focus on increasing canopy surface area and total branch length, to increase fruiting sites and enhance yield, large canopies require optimizing light distribution to improve fruit spatial uniformity. Thinning promoted flower bud formation significantly by increased the proportion of long branches and lateral branch number, thereby optimized consistently high yield traits.

Background/Objectives: The ‘Xinli No. 7’ pear is a new pear variety with the advantages of early ripening, high quality, high storage resistance, and a long shelf life. Peel color is an important appearance-related trait and an important indicator of fruit quality and commercial value. Methods: In this study, we investigated the polyphenol compound biosynthesis metabolic pathway in the fruit pericarp of ‘Xinli No. 7’ pear using metabolomic and transcriptomic approaches, and qRT–PCR was used for the relative expression analysis of 21 DEGs associated with flavonoid biosynthesis. Results: A total of 128 phenolic compounds were identified, along with 1850 differently expressed genes (DEGs) in peels of different colors. Caftaric acid, apigenin, astragalin, phlorizin, prunin, taxifolin, rutin, naringenin, and their derivatives were abundant in the peel of ‘Xinli No. 7’ pear. An integrated analysis of transcriptomic and metabolomic data revealed that one PGT1, one LAR, two ANS, three 4CL, one CHS, one DFR, and one CHI gene involved in flavonoid biosynthesis exhibited markedly different expression levels in the fruit pericarp of ‘Xinli No. 7’ pear. Metabolic profiling of pear skin led to the identification of polyphenol substances involved in the flavonoid biosynthetic process and revealed 16 flavonoid compounds with high accumulation in pear fruit with red skin (PR). Notably, MYBs (25), bHLHs (18), WRKYs (15), NACs (15), ERFs (15), and MADs (2) may also contribute to the accumulation of flavonoid metabolites and the biosynthesis of anthocyanins in the peel of ‘Xinli No. 7’. Conclusions: Therefore, our results demonstrate the key role of phenolic compounds and candidate transcription factors involved in the peel color formation of ‘Xinli No. 7’ pear fruit.

Soil quality is fundamental to agricultural ecosystems sustainability, influencing crop productivity, nutrient cycling, and environmental health. However, soil quality dynamics in perennial orchard systems and their long-term evolution remain insufficiently understood. This study examined the soil physicochemical properties and microbial community structure of Korla fragrant pear orchards of different planting ages (0, 5, 10, and 25 years) through integrated field surveys and laboratory analyses. Soil organic carbon (SOC) significantly increased in the 0-100 cm soil layer, with average annual rates of 0.18-1.06 g C kg^-1. The total nitrogen (TN) and alkali-hydrolyzable nitrogen significantly increased in the 0-60 cm soil layer, with average annual rates of 0.01-0.03 g N kg^-1 and 0.09-1.45 mg N kg^-1, respectively. Nitrate accumulation in the 0-100 cm soil layer increased from 427 kg N ha^-1 before planting to 707 kg N ha^-1 after 25 years. The Olsen-P significantly increased in the 0-40 cm soil layer, with average annual rates of 0.42-0.84 mg P kg^-1. In contrast, the soil pH, electrical conductivity (EC), and total soluble salts decreased significantly with orchard age. Both bacterial and fungal alpha diversity increased, with bacterial communities stabilizing after 5 years and fungal communities continuing to succeed. Redundancy analysis revealed that the soil water content, SOC, TN, pH, and EC were the key environmental factors shaping microbial community assembly. These findings demonstrated that long-term pear orchard cultivation enhanced soil fertility and shaped microbial communities, while simultaneously revealing associated risks such as soil acidification and nitrate accumulation, thus providing a critical foundation for developing sustainable soil management strategies.