Xujiao Li

Ethylene is commonly used in agricultural production for fruit ripening and degreening. However, further exploration is needed on how to apply it in its gaseous form in practical production. This study compared the effects of ethylene gas (E1: 100 ppm, E2: 120 ppm, E3: 150 ppm) application via subsurface drip irrigation (SDI) and fruit surface spraying of ethephon solution (ETH) on the quality and coloration of ‘Flame Seedless’ grape fruit during veraison. The effects of applying ethylene gas via SDI were most pronounced at 3, 6, and 9 days post-treatment. At day 6 post-treatment, E2 had a higher soluble solid content (SSC), solid–acid ratio, and anthocyanin content than ETH, although by day 15 most differences among the ethylene gas treatments, ETH, and CK had diminished. E2 also increased the abundance of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) and ACC synthase (ACS) and the expression of VvCHI, VvCHS, VvGST, and VvF3H at day 3 post-treatment, and all of these were also higher than in the ETH treatment. The gaseous nature of ethylene allows it to contact the fruit effectively and to be taken up by the plant through multiple pathways, so that the grapes respond faster to ethylene gas than to ETH treatment.

In response to the challenges posed by soil degradation in the arid regions of Xinjiang, China, green and organic management practices have emerged as effective alternatives to conventional agricultural management methods, helping to mitigate soil degradation by promoting natural soil recovery and ecological balance. However, most of the existing studies focus on a single management practice or indicator and lack a systematic assessment of the effects of integrated orchard management in arid zones. This study aims to investigate how different agricultural management practices influence soil physicochemical properties and inter-root microbial communities in apple orchards in Xinjiang and to identify the main physicochemical factors affecting the composition of inter-root microbial communities. Inter-root soil samples were collected from apple orchards under green management (GM), organic management (OM), and conventional management (CM) in major apple-producing regions of Xinjiang. Microbial diversity and community composition of the samples were analyzed using high-throughput amplicon sequencing. The results revealed significant differences (p < 0.05) in soil physicochemical properties across different management practices. Specifically, GM significantly reduced soil pH and C:N compared with OM. Both OM and GM significantly decreased soil available nutrient content compared with CM. Moreover, GM and OM significantly increased bacterial diversity and changed the community composition of bacteria and fungi. Proteobacteria and Ascomycota were identified as the dominant bacteria and fungi, respectively, in all management practices. Linear discriminant analysis (LEfSe) showed that biomarkers were more abundant under OM, suggesting that OM may contribute to ecological functions through specific microbial taxa. Co-occurrence network analysis (building a network of microbial interactions) demonstrated that the topologies of bacteria and fungi varied across different management practices and that OM increased the complexity of microbial co-occurrence networks. Mantel test analysis (analyzing soil factors and microbial community correlations) showed that C:N and available potassium (AK) were significantly and positively correlated with the community composition of bacteria and fungi, and that C:N, soil organic carbon (SOC), and alkaline hydrolyzable nitrogen (AN) were significantly and positively correlated with the diversity of fungi. Redundancy analysis (RDA) further indicated that SOC, C:N, and AK were the primary soil physicochemical factors influencing the composition of microbial communities. This study provides theoretical guidance for the sustainable management of orchards in arid zones.