Cucumber (Cucumis sativus L.) is an annual climbing herb that belongs to the Cucurbitaceae family and is one of the most important economic crops in the world. The breeding of cucumber varieties with excellent agronomic characteristics has gained more attention in recent years. The size and shape of the leaves or fruit and the plant architecture are important agronomic traits that influence crop management and productivity, thus determining the crop yields and consumer preferences. The growth of the plant is precisely regulated by both environmental stimuli and internal signals. Although significant progress has been made in understanding the plant morphological regulation of Arabidopsis, rice, and maize, our understanding of the control mechanisms of the growth and development of cucumber is still limited. This paper reviews the regulation of phytohormones in plant growth and expounds the latest progress in research regarding the genetic regulation pathways in leaf development, fruit size and shape, branching, and plant type in cucumber, so as to provide a theoretical basis for improving cucumber productivity and cultivation efficiency.

Light quality optimization is a cost-effective method for increasing leafy vegetable quality in plant factories. Light-emitting diodes (LEDs) that enable the precise modulation of light quality were used in this study to examine the effects of red-blue (RB), red-blue-green (RBG), red-blue-purple (RBP), and red-blue-far-red (RBF) lights on the growth, antioxidant capacity, and nitrogen metabolism of Chinese cabbage leaves, while white light served as the control (CK). Results showed that the chlorophyll, carotenoid, vitamin C, amino acid, total flavonoid, and antioxidant levels of Chinese cabbage were all significantly increased under RBP combined light treatment. Meanwhile, RBG combined light treatment significantly increased the levels of amino acids but decreased the nitrite content of Chinese cabbage. In addition, RBF combined light treatment remarkably increased the amino acid levels but decreased the antioxidant capacity of Chinese cabbage. In conclusion, the addition of purple light to red-blue light was effective in improving the nutritional value and antioxidant capacity of Chinese cabbage. This light condition can be used as a model for a supplemental lighting strategy for leafy vegetables in plant factory production.

Peppers (Capsicum annuum L.) are among the most widely consumed vegetable globally and cultivated in large areas in China (Zhou and Zhou 2021). In December 2023, pepper pith necrosis was discovered in a field located in Haiwan Town, Haitang District, Sanya City, Hainan, China (109.69°N, 18.35°E), with an incidence of 15%. The lower leaves of diseased plants exhibited yellowing, and the stem epidermis degenerated, revealing aberrantly thickened and browning vascular tissue. Additionally, a small number of adventitious roots were observed on the stem. When main stems were longitudinally cut, a brown and disintegrated, partially hollow pith was observed. To isolate and identify the causal agent of pith necrosis in peppers, the border tissue between diseased and healthy areas was excised, sterilized by immersion in 70% ethanol for 1 minute, and then washed three times with sterile water. After drying, the treated tissues were cut into small pieces measuring 5 x 5 mm and cultured on Luria-Bertani agar (LB) medium. Following incubation at 28°C for 48 hours, isolation and purification of the bacteria obtained from the cultures were continued. After several purification, the colonies appeared yellow, circular, and smooth-margined. The cells obtained from colonies were negative for Gram staining and rod-shaped under the optical microscope. They were positive for catalase and urease but negative for oxidase and amylase, and were able to utilize L-arabinose, D-glucose and D-mannitol. Morphological, physiological and biochemical characteristics of the isolates resembled that of Pseudomonas sp.. To verify the species identity of the bacteria, genomic DNA from the isolated strain HN6 was extracted, and the universal primers 27F/1492R (Lane 1991) were used to amplify the 16S rRNA gene, while specific primers LAPS27/VIC4 (Mulet et al. 2010) and gyrBPF/gyrBPR (Yamamoto et al. 2000) were used to amplify the rpoB and gyrB genes. The BLASTn analysis of 16S rDNA, rpoB, and gyrB sequences showed strain HN6 (PQ374171, PQ393140, and PQ393141) had 100.00, 98.94% and 98.97% identity with P. oryzihabitans(CP044074). The phylogenetic analysis ( Mega 11 ) indicates that strain HN6 is clustered with P. oryzihabitans into one branch with Bootstrap supported 100 using the neighbor-joining method with 5,000 bootstrap replicates, further confirms that strain HN6 is most closely related to P. oryzihabitans. Therefore, strain HN6 was identified as P. oryzihabitans based on morphology, metabolic profile, and sequence analysis. Peppers were planted in non-porous pots containing sterilized substrates for the pathogenicity test. Sterile syringes were used to prick the stems near the roots of the peppers. The wounds were wrapped with sterile defatted cotton dipped in bacterial suspension ( 108 CFU / mL ). As a control, sterile defatted cotton soaked in sterile water was applied. Subsequently, the pots were covered with a plastic film to prevent contamination and moisturize. The temperature was maintained above 28°C, and moisture levels were kept consistent to support plant growth. Each treatment had 6 replicates. The 10-15 days post-treatment group showed symptoms at the inoculation site, including epidermal degeneration, thickened and browned vascular tissue and a disintegrated, hollow pith in the stems, while no symptoms were observed in the controls. Koch's postulates were fulfilled through the reisolation of the pathogen from infected tissues and subsequently identified as the same pathogenic bacterium using the aforementioned methods. While Pseudomonas syringae pv. syringae has been reported as the causative agent of leaf spot disease in peppers (Miller et al. 2010), this study presents the first report of P. oryzihabitans causing pith necrosis on pepper worldwide. P. oryzihabitans can cause rice panicle blight and grain discoloration (Hou et al. 2020), and has also found to caused center blackening disease (Choi et al. 2019) as well as stem and leaf rot (Li et al. 2021 ) on muskmelon. Pseudomonas sp. can causing leaf spot disease in peppers (Miller et al. 2010). As far as we know, this is the first Report of P. oryzihabitans causing pith necrosis on Pepper in China.

Background and Aims Chinese cabbage (Brassica rapa ssp. pekinensis) is a crucial leafy vegetable crop in China and globally. It ranks first in terms of planting area and output among all vegetables and is an important economic and livelihood-supporting crop. Methods This study investigated the effects of five concentrations (15, 24, 36, 60, and 72 L/hectare) of a Si-containing water-soluble fertilizer applied via root irrigation on cabbage cultivar 'Jingcui 60' under greenhouse conditions. Reselts Results showed that moderate Si application (T3 and T4) significantly promoted plant growth, with T3 increasing shoot fresh weight by 47.8%. Si fertilization also enhanced cabbage quality, with T4 increasing leaf amino acid content by 99% and T2 boosting soluble sugar content by 42.25%. Soil analysis revealed that Si increased soil EC, organic matter, and alkali-hydrolyzable nitrogen and enhancing soil enzyme activities. Microbial profiling showed that Si reshaped bacterial and fungal communities, in creasing bacterial richness, promoting beneficial genera like Bacillus, and suppressing pathogenic fungi such as Fusarium. Conclutions The 60 L/hectare application rate (T4) provided the most benefits. This study clarifies the soil-microbe-plant interactions in Si-mediated quality regulation and provides a basis for precise Si fertilizer application in sustainable leafy vegetable production.

To address the current mismatch between processing pepper cultivars and the requirements of mechanized production, this study aims to construct a comprehensive evaluation model for the suitability of mechanized transplanting and harvesting, thereby screening highly adaptable varieties. An evaluation system comprising eight indicators for the transplanting stage and thirteen indicators for the harvesting stage was established using 105 processing pepper varieties (including 56 erect-fruit and 49 pendent-fruit peppers). Variation analysis, hierarchical clustering, principal component analysis (PCA), and Pearson correlation analysis were integrated to reveal the clustering effects of the cultivars and the synergistic and antagonistic relationships among the indicators. Furthermore, a combined CRITIC–VIKOR model was applied to conduct a multi-criteria comprehensive ranking of mechanization suitability. The results indicated that the biomechanical properties of processing peppers exhibited a significantly higher degree of variation than conventional morphological indicators (e.g., the coefficient of variation for lodging resistance reached 93.60%). Significant differences were observed in the mechanization adaptation mechanisms between the two pepper types: erect-fruit peppers were primarily limited by fruiting branch toughness (weight: 5.907%), whereas pendent-fruit peppers were mainly constrained by fruit morphological uniformity. Compared with the traditional PCA model, the CRITIC–VIKOR model effectively identified varieties with critical biomechanical defects by constraining the “individual regret value”, which highly aligns with Liebig’s Law of the Minimum in mechanized operations. Based on this model, varieties with superior comprehensive mechanization adaptability were successfully identified, notably C21, C55, and C23 (erect-fruit peppers), and D20, D11, and D19 (pendent-fruit peppers). This study provides a theoretical foundation and mathematical modeling support for the directional breeding of mechanization-suitable cultivars, the integration of agronomy and agricultural machinery, and the quantitative evaluation of multi-trait pyramiding in processing peppers.

Cadmium (Cd) contamination in agricultural soils poses a severe threat to food safety and human health through the food chain. This study investigated the efficacy of tobacco straw-derived biochar, applied at varying rates (0%, 1%, 2%, and 5% w/w), in mitigating Cd accumulation and modulating the growth and nutritional quality of two amaranth (Amaranthus tricolor L.) cultivars (red and green) grown in Cd-contaminated soil (initial total Cd of 2.18 mg/kg). The pot experiment revealed that biochar significantly reduced Cd uptake in both cultivars. Mechanistically, biochar elevated soil pH and drove the in-situ transformation of highly bioavailable exchangeable Cd into the more stable Fe-Mn oxide-bound fraction. Consequently, shoot Cd concentrations were notably suppressed, with the red cultivar exhibiting a superior response; the 2% biochar treatment optimally reduced its shoot Cd concentration by 37.6% compared to the control. Crucially, the amendments induced highly cultivar-specific growth responses. While biochar application simultaneously mitigated Cd toxicity and promoted biomass accumulation in red amaranth (yielding a 58.6% increase in shoot dry weight at the 2% rate), it exerted antagonistic, inhibitory effects on the growth of green amaranth. In conclusion, the incorporation of 2% tobacco straw biochar serves as a highly effective, dual-purpose strategy for significantly reduced health risks and enhancing the yield of red amaranth in Cd-contaminated fields. However, in green amaranth, biochar application induced a physiological trade-off, inhibiting growth despite successful Cd reduction. Furthermore, while Cd concentrations were significantly reduced on a dry-weight basis, future evaluations based on fresh-weight regulatory limits are required to fully confirm food safety.