Brassinosteroids (BRs) play pivotal roles in improving plant stress tolerance. To investigate the mechanism of BR regulation of salt tolerance in kiwifruit, we used ‘Hongyang’ kiwifruit as the test material. We exposed the plants to 150 mmol/L NaCl stress and irrigated them with exogenous BR (2,4-epibrassinolide). The phenotypic analysis showed that salt stress significantly inhibited photosynthesis in kiwifruit, leading to a significant increase in the H₂O₂ content of leaves and roots and a significant increase in Na⁺/K⁺, resulting in oxidative damage and an ion imbalance. BR treatment resulted in enhanced photosynthesis, reduced H₂O₂ content, and reduced Na⁺/K⁺ in leaves, alleviating the salt stress injury. Furthermore, transcriptome enrichment analysis showed that the differentially expressed genes (DEGs) related to BR treatment are involved in pathways such as starch and sucrose metabolism, pentose and glucuronate interconversions, and plant hormone signal transduction, among others. Among the DEGs involved in plant hormone signal transduction, those with the highest expression were involved in abscisic acid signal transduction. Moreover, there was a significant increase in the expression of the AcHKT1 gene, which regulates ion transduction, and the antioxidant enzyme AcFSD2 gene, which is a key gene for improving salt tolerance. The data suggest that BRs can improve salt tolerance by regulating ion homeostasis and reducing oxidative stress.

Excessive shoot vigor in grapevines negatively impacts plant growth and fruit quality, necessitating the use of plant growth regulators (PGRs) for canopy management. This study investigated the effects of mepiquat chloride (MC) and chlormequat chloride (CCC) on shoot growth (including new shoot length, relative chlorophyll content, leaf area, etc.) and fruit quality in Vitis vinifera cv. ‘Shine Muscat’. Different concentrations of MC (100, 300, 500, 700 mg/L) and CCC (100, 300, 500, 700 mg/L) were applied via foliar spraying at multiple stages before flowering. The results demonstrated that both PGRs effectively suppressed shoot elongation, with CCC exhibiting superior inhibitory efficacy compared to MC. However, high concentration of either compound also restricted leaf and cluster development. Optimal treatments MC (500 mg/L) and CCC (100 mg/L) significantly enhanced berry size, soluble solids content (SSC), and solid–acid ratio while maintaining effective shoot control. For practical application, we recommend spraying MC (500 mg/L) or CCC (100 mg/L) during the new shoot growth, flower-cluster separation, and flowering stages of ‘Shine Muscat’ grapevines to improve the new shoot control effect and fruit quality.

To investigate the effects of different seedless treatments on grape coloring and fruit quality, Vitis vinifera × Vitis labrusca cv. ‘Jumeigui’ were treated with different concentrations of forchlorfenuron (CPPU) (0.5, 1 and 1.5 mg/L), thidiazuron (TDZ) (0.5, 1 and 1.5 mg/L), and 6-benzyladenine (6-BA) (10, 20 and 30 mg/L) in combination with 18 mg/L gibberellic acid (GA₃) during the seedless-fruit-setting period. After the grapes ripened, multiple quality indicators were measured to analyze and evaluate the effects of different treatments on the fruit coloration and quality of ‘Jumeigui’ grapes. The results showed that increasing concentrations of CPPU and TDZ gradually reduced the comprehensive fruit quality of ‘Jumeigui’ grapes. The treatments with 18 mg/L GA₃ + 0.5 mg/L CPPU/TDZ were relatively effective in improving the comprehensive quality of ‘Jumeigui’ grapes. With increasing concentrations of 6-BA, the comprehensive effect initially increased and then decreased. The treatment with 18 mg/L GA₃ + 20 mg/L 6-BA resulted in a soluble solids content of 20.03% and a coloring index of 4.10, demonstrating the best overall improvement in the comprehensive quality of ‘Jumeigui’ grapes. Based on practical production considerations, it is recommended to apply 18 mg/L GA₃ + 20 mg/L 6-BA during the seedless-fruit-setting period of ‘Jumeigui’ grapes to enhance coloring effects and improve fruit quality.

This study investigated the physiological responses of Actinidia eriantha Benth. cv. ‘Zaoxu’ to water-soluble fertilizer (OWS) and microbial fertilizer (MF) under field conditions from 2022 to 2023. Utilizing a randomized block design, four sequential applications of OWS (T1, T2, and T3) and MF (T4 and T5) were applied at distinct dilution ratios during the shoot elongation phase. A multivariate analytical framework was employed to assess treatment effects on growth dynamics and fruit quality. Experimental data revealed that OWS applied at 1000× dilution significantly enhanced the growth of mother-bearing shoots and the bearing branch group. During the fruit development stage, both the longitudinal and transverse diameters exhibited differential expansion patterns, with the maximal dimensional increases observed under the 1000× and 1500× dilution OWS treatments. The 1000× dilution OWS treatment demonstrated a superior single-fruit weight, achieving a mean single-fruit weight of 57.07 g—a 32.23% increase relative to the control. Fruit quality analyses further indicated elevated concentrations of sugar components, ascorbic acid, and total phenols in the 1000× dilution OWS treatment group. Principal component analysis (PCA) generated a composite quality index (Z-value) yielding the following treatment ranking: T2 > T3 > T5 > T1 > T4 > control. These findings collectively indicate that the 1000× dilution OWS application demonstrated superior efficiency in enhancing both plant growth and fruit quality in ‘Zaoxu’, providing empirical support for optimized fertilization protocols in commercial cultivation systems.

The vigorous growth of new shoots can significantly reduce grape yield and compromise fruit quality. In order to explore the effects of prohexadione calcium (Pro-Ca) and mepiquat chloride (MC) on the control effect of new shoot growth and fruit quality of grape, ‘Shine Muscat’ grapevine (Vitis labruscana × V. vinifera) was used as the test material, and different concentrations of Pro-Ca and a combination of Pro-Ca and MC were sprayed four times before flowering of ‘Shine Muscat’ grapevines, and the effects of the different treatments on the new shoot growth and fruit quality of ‘Shine Muscat’ grape were analyzed and evaluated. The results demonstrated that low concentrations of Pro-Ca had limited efficacy in controlling shoot growth. However, the combined treatment of Pro-Ca 300 mg/L + MC 300 mg/L not only effectively inhibited shoot elongation but also significantly enhanced the chlorophyll content of the leaves opposite to the clusters and increased branch density. Additionally, this treatment improved berry size (single berry weight, vertical and horizontal diameter) and elevated the soluble solids content (SSC). These findings suggest that the combined application of Pro-Ca (300 mg/L) and MC (300 mg/L) is the most effective strategy for balancing vegetative growth and enhancing fruit quality in ‘Shine Muscat’ grapevines.