Allium vegetables attract attention for their flavor and aroma in Asia, especially in China and Japan. The aim of this experiment was to uncover the differences in the unique flavor compounds of two Welsh onions that are typical cultivars in China and Japan (‘Zhangqiu’ and ‘Tenko’). Chemical methods and solid-phase microextraction–gas chromatography-mass spectrometry were performed to determine the nutritional quality and quantity of volatile compounds of various organs of Welsh onions. The results show that a total of 30, 37, and 28 compounds were detected in the roots, pseudostem, and leaves of ‘Zhangqiu’, respectively, while 21, 27, and 20 compounds were detected in the corresponding organs of ‘Tenko’. The distribution of sulfur compounds in the roots, pseudostem, and leaves of ‘Zhangqiu’ accounted for 72%, 83%, and 26% of the total content, while those of ‘Tenko’ accounted for 55%, 84%, and 57%, respectively. Aldehydes are the second largest class of volatiles in Welsh onions. The distribution of aldehydes in the leaves was notably different: 52% and 27% in ‘Zhangqiu’ and ‘Tenko’, respectively. The contribution of S to the volatile substances was outstanding, and through forward selection, it was found that P, Ca, and Mg contribute to the volatile substances of Welsh onions. The above results indicate that the different genotypes of Welsh onions have various flavors, and mineral elements contribute variously to these flavors. Calcium could be a new topic of interest for our subsequent research on elements and volatiles.

Grafting is an effective horticultural technique that significantly enhances disease resistance and stress tolerance in watermelon. This review systematically summarizes the types of rootstocks used in watermelon grafting and analyzes the effects of grafting on plant responses to biotic stresses, such as viral and fungal pathogens, root-knot nematodes infections, and abiotic stresses, including drought, temperature extremes, and salinity. Furthermore, it discusses the changes in fruit quality and explores the underlying mechanisms associated with graft-induced resistance. By synthesizing recent research advances, this review aims to offer valuable insights and practical references for improving resistance and promoting sustainable production in cucurbit and other vegetable crops through grafting. As a sustainable cultivation strategy, grafting demonstrates considerable potential for enhancing watermelon resilience and yield; however, optimizing fruit quality remains a critical focus for future research.

Grafting is an effective horticultural technique that can significantly enhance the disease resistance and stress resistance of watermelon. This review summarizes the types of rootstocks used in watermelon grafting and investigates the responses of graft-cucurbits to viral/fungal pathogens, root-knot nematodes, and stresses (such as drought, temperature, and salinity). The reviews also summarize the changes in fruit quality and underlying mechanisms induced by graft resistance. With recent research advances summarizing and analyzing, this review will provide valuable insight and reference for promoting resistance improvement and sustainable production in cucurbit and other vegetable crops by grafting. In summary, grafting can effectively improve the stress resistance and yield of watermelon, but optimizing fruit quality is still the focus of future research.

Welsh onion (Allium fistulosum L.) is a globally significant culinary vegetable with extensive cultivation and high application value. In China, Welsh onion is vulnerable to drought and strong-light stress in summer production, resulting in growth inhibition and quality decline. This study utilized LED-intelligent spectral-customized lamps to simulate high-light stress and a 10% PEG-6000 Hoagland solution to simulate drought stress. The effects of different stress treatments on the nutritional quality, volatile compounds, and mineral element composition of the edible portions were systematically analyzed. The results demonstrated that drought stress significantly promoted the accumulation of alcoholic compounds in leaf tissues while reducing the content of sulfur-containing compounds. High-light stress markedly increased the levels of hydrocarbon compounds in leaves. Sulfur-containing compounds in leaf tissues were predominantly disulfides, but under combined drought and high-light stress, their content decreased, while the proportion of trisulfides significantly increased. Volatile compounds in pseudostems were primarily composed of sulfur-containing and aldehyde compounds, yet their levels markedly declined under combined stress. Additionally, combined stress led to reductions in pyruvic acid, soluble sugars, and soluble protein content in the edible portions, while the crude fiber content increased, thereby significantly impairing nutritional quality. This study provides a scientific basis for understanding the abiotic stress response mechanisms of Welsh onion and offers valuable insights for cultivation management and quality regulation.

To investigate the effects of regulated deficit irrigation (RDI) on tomato fruit quality and flavor, a study was conducted using the tomato cultivar 'Gaotang No. 1' under three irrigation treatments: CK (conventional irrigation, 16 m³/mu per session), T1 (50% reduction, 8 m³/mu), and T2 (25% reduction, 12 m³/mu). The impact on plant growth, yield, fruit quality, and volatile organic compounds (VOCs) was evaluated. Results showed that the T2 treatment significantly reduced yield (−26.55%) but enhanced fruit firmness (35.57% increase in shoulder hardness), soluble solids (14.56%), vitamin C content (44.19%), and the sugar-to-acid ratio (2.25%). Volatile analysis revealed that T2 markedly increased the concentration of key aroma compounds with odor activity values (OAV) >10, including 2-pentyl furan (24.71%), (Z)-3,7-dimethyl-1,3,6-octadecatriene (128.49%) contributing to floral aroma, 2-ethyl-5-methylpyrazine (204.10%) associated with fruity aroma, and 4- isopropyltoluene (125.79%) contributing to citrus aroma. These compounds significantly shaped the overall aroma profile, resulting in a richer flavor. The findings confirm that moderate RDI (25% reduction) effectively balances yield and fruit quality by improving texture, nutritional value, and aroma complexity, offering a promising strategy for water-efficient, quality-focused tomato production.