Lin Wu

Aiming to solve the problems of excessive chemical fertilizer application and reduced soil fertility in Lonicera caerulea cultivation, this study investigated soil carbon and nitrogen nutrients, enzyme activities, and rhizosphere microbial characteristics using potted seedlings. Seven treatments, including control, single straw application, single nitrogen fertilization, and four C/N ratios (10, 15, 20, 25), were established. The results showed that a soil C/N ratio of 15–25 achieved the optimal soil fertilization effect. The 20:1 C/N ratio produced the highest soil total nitrogen and active organic carbon contents, as well as the maximum nutrient-converting enzyme activity. C/N ratio significantly regulated rhizosphere microbial communities: increasing nitrogen improved bacterial diversity but slightly reduced fungal diversity, and C/N imbalance altered dominant fungal phyla. Soil nitrogen and active organic carbon were positively correlated with bacterial diversity and negatively correlated with fungal diversity. Based on a comprehensive analysis of various indicators, a C/N ratio range of 15:1 to 25:1 improves soil fertility, while a ratio of 20:1 yields the most balanced overall results, enhancing soil carbon and nitrogen reserves, optimizing the microbial community, and reducing nutrient loss. This study provides a reference for fertilizer reduction and efficiency improvement in Lonicera caerulea cultivation.

Blueberries (Vaccinium spp.) are highly sensitive to winter chilling fulfillment, growing degree days above 7 °C (GDD7), and water balance (WB). By integrating a climate-based natural suitability index (CNSI), three-dimensional kernel density estimation, traditional and spatial Markov chains, and optimal geographic detector analysis, this study examines the spatiotemporal evolution and driving mechanisms of blueberry climatic suitability realization in 19 major producing provinces in China during 2008–2023. Results show that CNSI exhibits a stable and moderately right-skewed distribution, with partial convergence and a narrowing interprovincial gap. Suitability realization is highest in the middle and lower Yangtze River rice-growing belt, whereas the northern dryland belt and the southern subtropical mountainous belt show persistent mismatches between climatic potential and production advantages. Markov results reveal path dependence and moderate mobility, with “low–low lock-in” and “high–high club” phenomena reinforced under neighborhood effects. GeoDetector results indicate that effective facility irrigation and fertilizer input are dominant factors explaining spatial variation in CNSI, while comprehensive transportation accessibility and agricultural labor act as stable complements. Interaction analysis suggests that multi-factor synergies, particularly irrigation-centered combinations, yield strong dual-factor enhancement and near-nonlinear enhancement. These findings highlight the importance of aligning climatic suitability with adaptive infrastructure investment and region-specific management to promote sustainable production-share advantages in China’s blueberry industry.

The method of pollination significantly affects the growth and development of blueberry fruit. However, there remains a deficiency in systematic research regarding the impact of various pollination treatments on the cellular structure of blueberries. In the present study, a cross-pollination experiment was conducted on the blueberry varieties ‘Reka’, with the objective of comparing the characteristics of blueberry fruit cells under different pollination treatments. The results showed that different pollen sources had certain effects on the pedicel marks, calyx width and seed number of blueberry fruit. Simultaneously, various pollination treatments significantly affected both the transverse and longitudinal diameters as well as the individual fruit weight of the fruits. However, no significant differences were noted in the fruit shape index across the various pollination treatments. Within the internal cellular tissue of each treated fruit, certain indicators exhibited distinct variances. In the cell height of the inner region of the mesocarp, all cross-pollination treatments were significantly higher than self-pollination. The fruit of ‘Northland’ and ‘Blomidon’ were significantly lower than self-pollination in the number of cells in the outer area of the mesocarp. These effects lead to differences in cell arrangement and spatial distribution, resulting in differences in the correlation between cell indexes and fruit morphological indexes among different treatments. In the ‘Reka’ self-pollination treatment, the endocarp width was significantly negatively correlated with the fruit weight (p < 0.05), while the correlation in the other four treatments showed an upward trend, showing a positive correlation. This study comprehensively examined the formation of fruit cells under cross-pollination at the cellular level, thereby providing a cytological basis for understanding the development of blueberry fruit.

These days, one of the main issues preventing agricultural development is salinized soils. Potassium fulvic acid (PFA) not only regulates plant growth, but also improves the soil nutrient content and physical structure, which makes it a soil conditioner worth promoting. Nevertheless, the research conducted thus far on the subject of PFA with regard to plant growth and inter-root microbial communities remains somewhat limited in scope. In this study, a pot experiment was conducted to simulate both the normal environment and salt stress environment. The objective of this experiment was to verify the effect of PFA on the growth of blueberry (Vaccinium corymbosum L.) as well as its effect on the soil physical and chemical indices and the soil microbial community structure. The findings demonstrated that the implementation of potassium fulvic acids exhibited a minimal impact on the growth of blueberry plants under standard environmental conditions. However, it was observed to exert a substantial effect on enhancing various physiological parameters, including plant height, root activity, and chlorophyll synthesis, particularly in response to salt stress. PFA led to a substantial augmentation in the soil organic matter content, alongside a notable rise in the alkali-hydrolyzable nitrogen (AN) and available potassium (AK) content. Concurrently, PFA caused a notable escalation in the activities of soil urease, sucrase, acid phosphatase, and catalase (p < 0.05) in the salt-stressed environment. PFA increased the abundance of Acidobacteria, Myxococcota, Ascomycota, and Fungi_phy_Incertae_sedis under salt stress, which was mainly related to the decrease in electrical conductivity (EC) values and increase in soil acid phosphatase (S-ACP) activity. It is evident that the implementation of PFA is advantageous in enhancing the saline environment, mitigating the impact of salt damage on blueberries and establishing a foundation for the expansion of cultivated areas and the sustainable cultivation of blueberries.

Drought stress is a significant environmental factor that can impede plant growth and ornamental quality. Hemerocallis middendorffii, a drought-tolerant garden plant, has attracted attention for its ornamental value and application prospects. To investigate the molecular mechanism of drought stress resistance of H. middendorffii, this study employed 20% polyethylene glycol (PEG) 6000 to simulate drought stress. Leaves and roots of H. middendorfii were subjected to 24 h treatment and followed by transcriptome sequencing. Analysis revealed 8796 and 3401 differentially expressed genes (DEGs) in leaves and roots. The major biological processes and key molecular pathways activated under drought stress in H. middendorffii were revealed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The focus of this analysis was on the gene expression changes within plant hormone signal transduction pathway. Additionally, drought-associated transcription factor families such as AP2/ERF, WRKY, MYB, bHLH, NAC, and bZIP were identified among DEGs. Furthermore, potential regulatory relationships of the above transcription factors (TFs) with functional genes in the abscisic acid (ABA) and jasmonic acid (JA) signalling pathways were analysed using correlation network prediction. This research establishes the groundwork for subsequent exploration of drought-responsive gene expression and regulatory patterns in H. middendorfii and provides an importance for the systematic study of its drought-resistant molecular mechanism.

The degree of soil salinization is still on the rise. In saline environments, NaCl is the main substance that causes plant salt damage, with the toxicity of ions under salt stress primarily involving sodium (Na⁺) or chloride (Cl⁻). However, fewer studies have focused on Cl⁻ stress. This study investigated the differences in the growth and physiology of five blueberry varieties under Cl⁻ stress, aiming to understand the mechanisms of Cl⁻ tolerance and the physiological responses to Cl⁻ stress in these varieties. Five blueberry varieties (‘Northland’, ‘PL19’, ‘Duke’, ‘Reka’, and ‘Bonnie’) were used as test materials. This study examined the changes in growth and physiological indices of blueberry plants under different concentrations of Cl⁻ (A1–A6: 50, 100, 150, 200, 250, and 300 mmol/L) treatments. A control treatment (CK) was included to serve as a baseline for comparison. We comprehensively evaluated the Cl⁻ tolerance of these five varieties to screen for chlorine-tolerant varieties. This study examined the concentration-dependent changes in growth and physiological indices of blueberry plants, including plant height, leaf area, chlorophyll content, electrical conductivity, levels of soluble sugar (SS), malondialdehyde (MDA), proline (Pro), and soluble protein (SP), as well as the activities of superoxide dismutase (SOD) and catalase (CAT). The results revealed that as the Cl⁻ concentration increased, the growth of all blueberry varieties was inhibited; plant height, leaf area, and chlorophyll content consistently declined, whereas electrical conductivity showed a steady increase. SS and MDA content exhibited a biphasic response, with an increase at lower Cl⁻ concentrations followed by a decrease at higher concentrations. The activities of SOD and CAT in ‘Duke’ consistently increased with rising Cl⁻ levels. In ‘PL19’ and ‘Reka’, chlorophyll content decreased with increasing Cl⁻, while their proline content rose initially and then declined. In contrast, the other varieties generally showed an increasing trend in proline content. Similarly, the soluble protein content of ‘Northland’ and ‘PL19’ increased at lower Cl⁻ levels and decreased at higher concentrations, whereas ‘Bonnie’, ‘Duke’, and ‘Reka’ displayed an overall declining trend. Principal component analysis indicated that the Cl⁻ tolerance of the blueberry varieties ranked as follows: ‘Duke’ > ‘Bonnie’ > ‘Reka’ > ‘PL19’ > ‘Northland’. These findings lay a foundation for blueberry cultivation in saline–alkaline soils and support the selection and development of new, chlorine-tolerant varieties.

Blueberries are highly prone to postharvest decay, resulting in significant nutrient loss and economic damage. Current research on the postharvest storage of blueberries primarily focuses on storage techniques, while the underlying mechanisms remain insufficiently explored. To further explore the role of exogenous melatonin (MT) in delaying the senescence of blueberry fruit, this study treated fruits with sterile water (control) and 300 μmol·L⁻¹ MT during the pink fruit stage. After maturation, the fruits were stored at 4 °C for 30 days, and we investigated the effects of exogenous MT on postharvest blueberry quality, reactive oxygen species (ROS) metabolism, antioxidant enzyme activities, and the expression of related genes. The results showed that, compared to the control, 300 μmol·L⁻¹ MT effectively delayed the increase in fruit decay rate and the decline in firmness, while enhancing the total soluble solids (TSS) content and ascorbic acid (AsA) levels. It also reduced the accumulation of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and the production rate of superoxide anion (O₂⁻), while maintaining higher activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), and catalase (CAT). Furthermore, MT treatment upregulated the expression of antioxidant enzyme-related genes VcSOD1, VcSOD2, and VcAPX3. These findings indicate that treating blueberries with 300 μmol·L⁻¹ MT at the pink fruit stage improves postharvest quality, alleviates oxidative damage, and delays senescence. This study provides a theoretical foundation and practical reference for blueberry storage and preservation, laying the groundwork for further understanding the regulatory mechanisms of exogenous MT in postharvest fruit senescence.

In order to clarify the relationship between mineral nutrients and rhizosphere microorganisms at different growth and development stages of blueberry (Vaccinium spp.), this work studied the dynamic changes in element content and microbial quantity in different parts of blueberry plants. The test material was a 12-year-old half-highbush blueberry variety (‘Beilu’). The changes in the mineral nutrient elements in leaves, branches and the soil of blueberry plants were studied at the full bloom stage (T1), green fruit stage (T2), mature stage (T3) and late mature stage (T4), and the correlations of the average contents of mineral elements in the four periods were studied. The bacterial community in the rhizosphere soil was determined and analyzed using 16S rRNA high-throughput sequencing technology. The results showed that the changes in other mineral elements in various parts of blueberry plants varied in different periods. Nitrogen (N) showed a downward trend in branches, leaves and soil, especially in leaves (p < 0.05). The N contents in T2, T3 and T4 decreased by 9.9%, 26.4% and 29.9%, respectively. The N contents in the leaves and branches showed a downward trend at different growth stages, especially in leaves. The phosphorus (P) content in leaves showed a trend of increasing first and then decreasing, while it continued to increase in branches. The content of potassium (K) in leaves changed significantly, where it increased first and then decreased. The content of calcium (Ca) in leaves decreased first and then increased, while the content of magnesium (Mg) in branches and leaves decreased first and then increased, and the relative change was significant. The contents of iron (Fe) and zinc (Zn) in leaves decreased first and then increased, while the contents of manganese (Mn) and copper (Cu) were relatively stable. Cu decreased first and then increased in leaves and soil, and it increased first and then decreased in branches. The mineral nutrients in different growth stages of blueberry showed significant correlation in leaves, branches and soil. Mn in leaves was significantly positively correlated with P, Ca, Mg, Mn, Cu and Zn in soil (p < 0.01). Nitrogen and calcium in leaves were significantly correlated with manganese and phosphorus in soil, respectively. Ca in branches was significantly positively correlated with N and K in soil and was significantly positively correlated with Zn in soil (p < 0.01). Magnesium was significantly negatively correlated with iron in soil. The bacterial community structure of the blueberry rhizosphere soil changed significantly over time (p < 0.05), and the relative abundance showed the following trend: T4 > T2 > T3 > T1. At the phylum level, Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi and Verrucomicrobia were the dominant bacteria in different periods. Candidatus solibacter and Bryobacter were significantly higher in T1 and T3 than in T1 and T4. Bradyrhizobium flora increased significantly at T3. Sphingomonas increased significantly at T1 (p < 0.05).

The swelling agent is a plant growth regulator that alters the composition and content of nutrients and volatile gases in the fruit. To identify whether grape fruit had been treated with swelling agent, the odor information and quality indexes of grape berries treated with different concentrations of swelling agent were examined by using electronic nose technology and traditional methods. The contents of soluble sugars, soluble solids, soluble proteins and vitamin C were significantly increased in N-(2-chloro-4-pyridyl)-N’-phenylurea (CPPU) treated fruit. The contents of hexanal, (E)-2-hexenal, and nonanal aldehydes decreased significantly. Similarly, the levels of phenyl ethanol, 1-octanol, ethanol, and ethyl acetate alcohols and esters also decreased noticeably. Additionally, the levels of damascenone, linalool, and geraniol ketones and terpenoids decreased. However, the contents of benzaldehyde, D-limonene, acetic acid and hexanoic acid increased. In addition, the electrical signals generated by the electronic nose (e-nose) were analyzed by linear discriminant analysis (LDA), support vector machine (SVM) and random forest (RF). The average recognition rate of SVM was 94.4%. The results showed that electronic nose technology can be used to detect whether grapes have been treated with swelling agent, and it is an economical and efficient detection method.

Soil improvement methods can result in changes in the microbial community in blueberry soil. Bacterial communities play an important role in soil fertilizer and plant nutrient acquisition. In this study, the response of microbial community composition, microbial function, and the nitrogen (N) cycle to different improvement methods was analyzed using high-throughput sequencing to investigate the best soil improvement method from a microbial perspective. The results showed that the highest microbial diversity was observed in the treatment involving peat combined with mushroom bran (T2), followed by the peat combined with acidified rice husk (T2) both in the rhizosphere and roots. The dominant phyla were Proteobacteria and Actinobacteria both in the blueberry rhizosphere soil and roots. Interestingly, Acidobacterium and Paludibaculum, belonging to the Acidobacteria phylum, exhibited the most significant influence and were most predominant in the T2 treatment rhizosphere soil. The T2 treatment promoted the growth of N fixation functional bacteria both in the rhizosphere soil and roots. At the module level, the T2 treatment enhanced N fixation and suppressed the assimilatory and dissimilatory nitrate reduction reactions, denitrification, and nitrification in the blueberry rhizosphere. Additionally, the T2 treatment increased the abundance of root endophytic microbes involved in N fixation. Overall, our findings suggest that the addition of peat combined with acidified rice husk is the optimal soil improvement method for blueberry cultivation.