Search Results (143)

Excessive fertilization is a widespread issue in onion (Allium cepa L.) production in Southwest China. This practice not only leads to environmental pollution but also decreases the marketable yield and fertilizer productivity of onions. Identifying an optimal fertilization rate is crucial for promoting high-yield and highly efficient onion cultivation. The objective of this research is to determine the appropriate amount of fertilizer by investigating the effects of different fertilization rates on the growth characteristics and bulb yield of onion. The study was conducted over two consecutive growing seasons utilizing a randomized complete block design, which included six treatments: local routine fertilizer application (F1), a 20% reduction from F1 (F2), a 40% reduction from F1 (F3), a 60% reduction from F1 (F4), an 80% reduction from F1 (F5), and no fertilizer application (F0). The results show that, at the mature stage, aboveground dry matter quantity and its accumulation rate of onion under treatment F2 were found to be the highest among all other treatments across both growing seasons. Following the onset of bulbing, dry matter accumulation initially increased but subsequently decreased with reduced fertilizer supply; notably, it was greater under treatment F2 compared to other treatments. Compared with F1, the PFPN (partial factor productivity of nitrogen fertilizer) under treatment F2 increased by 35.2% and 32.0%, and the marketable bulb yield under treatment F2 increased by 8.4% and 5.8% during the 2022–2023 and 2023–2024 growing seasons, respectively. The marketable bulb yield demonstrated extremely significant positive correlations with aboveground dry matter and the dry matter accumulation rate throughout all growth periods in both growing seasons. Furthermore, marketable bulb yield exhibited extremely significant positive correlations with dry matter translocation before the onset of bulbing and dry matter accumulation following bulbing initiation. It was concluded that the appropriate fertilizer application (F2), characterized by a fertilization rate of 339-216-318 kg ha⁻¹ for N-P₂O₅-K₂O, enhanced onion bulb yield and nitrogen fertilizer productivity by promoting post-bulbing dry matter accumulation. This study emphasizes the significance of optimizing the fertilization rate as a crucial factor in achieving high-yield and highly efficient onion cultivation by enhancing dry matter accumulation. Full article

The purpose of this study was to determine the impact of blanching various onion (Allium cepa L.) varieties on the process of lactic fermentation by probiotic strain Levilactobacillus brevis ŁOCK 0944. The materials for the research were twelve varieties of yellow onion: Venecia, Moondance, Sedona, Alonso, Hysky, Centro, Dormo, Hypark, Hybelle, Armstrong, EXP 2236, and Hysinger. We also studied the resulting changes in bioactive compound content. Acidic bacterial metabolites, the lactic acid bacteria count, and the polyphenol and carbohydrate contents were assessed in both raw onions and onions blanched at 60 °C, before and after fermentation. Onion varieties that showed morphological changes after blanching (Hysky, Centro, Dormo) demonstrated better growth of L. brevis and higher lactic acid production. Blanching loosened the tissue structure, reducing the carbohydrate content in the blanched and fermented onions, particularly Alonso, Centro, Dormo, and Hypark varieties. Although the combined process reduced the polyphenol content, four varieties showed no statistically significant differences, indicating variety-specific responses. The varying susceptibility of onion varieties to thermal treatment highlights the importance of selecting the appropriate variety for further processing. Full article

Salinity poses a significant challenge in modern agriculture, often inhibiting growth and yield, especially in sensitive crops like onions (Allium cepa L.). This study evaluated the effectiveness of a freshwater-algae-based biostimulant on two onion cultivars, Franciscana IPA-10 and Vale Ouro IPA-11, to mitigate saline irrigation’s adverse effects. Five biostimulant concentrations (0, 1, 2, 3, and 4 mL L⁻¹, applied to the soil) were tested, along with two foliar treatments at 2 mL L⁻¹ as controls. Our findings showed that applying 4 mL L⁻¹ to the soil boosted growth rates to 1.0 cm per day (1), increased the potassium-to-sodium ratio in bulbs, and improved both average bulb weight by 25.11% and overall productivity by 24.28%, relative to untreated conditions. These results suggest that the biostimulant at 4 mL L⁻¹ is an effective method to enhance resilience to saline stress and increase productivity in the IPA-10 and IPA-11 cultivars. However, while the biostimulant improved plant performance, it did not counteract the accumulation of salts in the soil. Therefore, additional management practices such as leaching and drainage are recommended to ensure sustainable onion production under saline water irrigation. Full article

Onions (Allium cepa L.) are widely consumed worldwide and are recognized for their high content of bioactive compounds with potential health benefits. This study investigates the nutritional and phytochemical properties of three onion varieties—Tropea red onion, red onion, and yellow onion—analyzed in their whole form as well as in their peel and pulp. An innovative drying system was employed to assess its impact on the retention of bioactive compounds. The results highlight significant differences in nutrient composition among varieties and onion parts. The peel exhibited the highest concentrations of proteins, phenolic compounds, flavonoids, and antioxidants, followed by the whole onion and pulp. Tropea red onion stood out for its superior antioxidant capacity, vitamin C content, and phenolic acid levels, reinforcing its potential for functional food applications. This study also revealed that mineral content, particularly calcium, potassium, and sulfates, varied across onion varieties, influencing their nutritional and health-promoting properties. These findings support the valorization of onion byproducts for their bioactive potential and sustainability in the food industry. The data emphasize the need for further research on innovative processing techniques that enhance the bioavailability and effectiveness of onion-derived health-promoting compounds. Full article

Considering the resistance of weeds to different herbicides with different mechanisms of action, the search for new, more selective compounds with low toxicity to other species in nature has been very important for the development of agriculture. Because of that, considering the biological activity of allelochemicals and natural epoxides, four new epoxy compounds derived from dehydrocostus lactone were synthetized and evaluated for their potential herbicide activity against three species of seeds, Allium cepa (onion), Lepidium sativum (garden cress), and Lactuca sativa (lettuce). In assays with A. cepa, compound 4 inhibited radicle length by 80% at 100 μM. Notably, for L. sativum, compound 4 showed significant inhibition, reducing stalk and radicle lengths by 80% at 100 μM, surpassing the performance of the commercial herbicide Logran. However, diol 5 notably inhibited radicle growth by 28% at 100 μM, making the most significant observed effect. One of the noteworthy lactones studied is epoxide 4. This highlights the importance of the epoxide functional group in affecting both radicle and shoot lengths of seeds. Therefore, the synthesis of these compounds has proven advantageous and holds great potential for the development of new herbicides. Full article

The efficiency and consistency of biologicals in the field remain a drawback of current conventional products. The development of systemic biological products has opened a new avenue for microbiological and agricultural research. In this study, we evaluated over a two-year period (2022 and 2023) the functioning of two systemic products, a biofertilizer and biofungicide, on the performance of the onion. The first indicator of proper functioning of these products in onions was reflected in increased chlorophyll accumulation. At the end of both years, the inoculated plants were taller, heavier, and developed more leaves than their control counterparts (p < 0.5). Inoculated onion bulbs collected at harvest time were significantly heavier (45.1% in 2022 and 56.2% in 2023) than their non-inoculated counterparts (p < 0.5). Onion quality, expressed in terms of total soluble solids and pyruvic acid content, was also significantly improved in plants inoculated with the biological products; the two-year average values for these quality variables were 10.2 vs. 14.4°Brix and 2.3 vs. 4.0 µmol∙g⁻¹ for control and biologically treated plants, respectively. The two-year average fungal incidence was 1.9 times greater in the control group than in the inoculated plants, while the average onion yield for this period was 44.7% higher (p < 0.5) in the biologically treated plot (54.7 t∙ha⁻¹) than in the control one (37.8 t∙ha⁻¹). Based on comparisons with previous studies employing conventional biologicals, our results demonstrate the superior effectiveness of the systemic biologicas in improving onion performance. Full article

The plant cell wall (CW) is a physical barrier that plays a dual role in plant physiology, providing structural support for growth and development. Understanding the dynamics of CW growth is crucial for optimizing crop yields. In this study, we employed onion (Allium cepa L.) epidermis as a model system, leveraging its layered organization to investigate growth stages. Microscopic analysis revealed proportional variations in cell size in different epidermal layers, offering insights into growth dynamics and CW structural adaptations. Fourier transform infrared spectroscopy (FTIR) identified 11 distinct spectral intervals associated with CW components, highlighting structural modifications that influence wall elasticity and rigidity. Biochemical assays across developmental layers demonstrated variations in cellulose, soluble sugars, and antioxidant content, reflecting biochemical shifts during growth. The differential expression of ten cell wall enzyme (CWE) genes, analyzed via RT-qPCR, revealed significant correlations between gene expression patterns and CW composition changes across developmental layers. Notably, the gene expression levels of the pectin methylesterase and fucosidase enzymes were associated with the contents in cellulose, soluble sugar, and antioxidants. To complement these findings, machine learning models, including Support Vector Machines (SVM), k-Nearest Neighbors (kNN), and Neural Networks, were employed to integrate FTIR data, biochemical parameters, and CWE gene expression profiles. Our models achieved high accuracy in predicting growth stages. This underscores the intricate interplay among CW composition, CW enzymatic activity, and growth dynamics, providing a predictive framework with applications in enhancing crop productivity and sustainability. Full article

Onion (Allium cepa L.) plants produce umbellate inflorescences that bear dozens of hermaphrodite flowers. Outcrossing is encouraged by a strong protandrous dichogamy. Honeybees are reported as the most suitable pollinator for this crop due to their efficiency in pollen transfer. However, bee activity does not always guarantee pollination success and an adequate seed set. This work aimed to analyze the developmental changes of the pistil along the flower lifespan to determine the reasons for common failures in the onion seed set. Studies were carried out in two productive seasons, in a male sterile line and a fertile line, using two different pollination procedures. The results showed that the stigma papillae did not fully develop until 4 days after anthesis (DAA), reducing the stigma receptivity to only 4 days. The style did not reach its maximum length until 8 DAA, when ovule fertility was achieved. Eight days were needed for the pollen tube to grow, reach, and fertilize the ovules. The results were consistent over two consecutive years. The short period of stigmatic receptivity and strong protandrous dichogamy limit the duration of the effective pollination period and could explain the poor cropping performance in obtaining seeds from some onion hybrid lines. Full article

In this study, polyphenols in the crude extract (CE) from red onion peel were recovered by macroporous resin, and their antioxidant and anti-inflammatory activities were evaluated. Among the four resins screened (SP850, XAD2, XAD7HP, and XAD16N), XAD7HP showed the highest desorption and recovery ratios, and it was used to optimize polyphenol recovery through single-factor experiments. The optimal conditions were established as 1 g resin, pH 4, 25 °C, 7 h for adsorption, followed by desorption with 70% ethanol for 1 h at 25 °C. These conditions achieved 85.00% adsorption ratio, 87.10% desorption ratio, and 20.9% yield of the macroporous resin-recovered extract (MRE) from the CE. HPLC analysis revealed that rosmarinic acid, quercetin, and myricetin were major compounds in the MRE, with the content of these compounds higher (about 7-fold) compared to the CE, confirming enhanced recovery of polyphenols by macroporous resin. Moreover, FT-IR and ¹H-NMR analysis confirmed the successful recovery of these polyphenol compounds in the MRE. Furthermore, the MRE displayed significantly improved antioxidant activities (DPPH, ABTS, and FRAP) and anti-inflammatory activities (inhibition of nitric oxide synthesis and reactive oxygen species production) compared to the CE. In summary, our findings suggest that macroporous resin can effectively recover polyphenol compounds from red onion peel extract and enhance their biological activities. Full article

The yield of flowering crops depends on multiple factors, with pollination and the availability of nutrients being particularly crucial. However, fewer studies have explored the combined effects of nutrients and insect-mediated pollination on onions (Allium cepa L.). Here, we studied how different levels of insect pollination (0%, 25%, 50%, and 100%) and nitrophos fertilizer application (188, 375, and 750 kg/hectare) affect onion seed yield. We found that pollination benefits to yield were maximum at intermediate levels of nitrophos availability. A higher pollinator abundance was recorded at a high nitrophos level, followed by intermediate and low levels. Syrphid flies and honey bees were the most abundant insect pollinators. The abundance of honey bees was higher at a low nitrophos level, while syrphid flies were more abundant at a higher nitrophos level. Moreover, the umbel weight and seed number were higher at the intermediate fertilizer level. Also, single visits by insect pollinators were observed, and the highest umbel weight was found at the intermediate fertilizer level with a single visit from A. florea. This finding provides evidence that resource and pollination availability have interactive, nonlinear effects on seed production. Our results also support ecological intensification as a reliable strategy for sustainable agro-ecosystem management. Full article

Onions (Allium cepa L.) are a globally significant horticultural crop, ranking second only to tomatoes in terms of cultivation and consumption. However, due to the crop’s complex genome structure, lengthy growth cycle, self-incompatibility, and susceptibility to disease, onion breeding is challenging. To address these issues, we implemented digital breeding techniques utilizing genomic data from 98 elite onion lines. We identified 51,499 high-quality variants and employed these data to construct a genomic estimated breeding value (GEBV) model and apply machine learning methods for bulb weight prediction. Validation with 260 new individuals revealed that the machine learning model achieved an accuracy of 83.2% and required only thirty-nine SNPs. Subsequent in silico crossbreeding simulations indicated that offspring from the top 5% of elite lines exhibited the highest bulb weights, aligning with traditional phenotypic selection methods. This approach demonstrates that early-stage selection based on genotypic information followed by crossbreeding can achieve economically viable breeding results. This methodology is not restricted to bulb weight and can be applied to various horticultural traits, significantly improving the efficiency of onion breeding through advanced digital technologies. The integration of genomic data, machine learning, and computer simulations provides a powerful framework for data-driven breeding strategies, accelerating the development of superior onion varieties to meet global demand. Full article

Onions (Allium cepa L.) are nutritious vegetables; however, variations in processing methods can influence their chemical composition and functional properties. Raw processing and cooking are the two main food-processing methods for onions, but it is not clear what kind of changes these two methods cause. In the present study, ultrahigh-resolution liquid chromatography–mass spectrometry (UHPLC–MS) was utilized to observe the changes in onion composition during cooking and to investigate the protective effects of raw and cooked onion extracts against lead damage in vitro and at the cellular level. Many compounds were identified, including amino acids, nucleosides, flavonoids, and organosulfur compounds. Cooking causes changes in the content of numerous amino acids (e.g., DL-glutamine) in onions and increases nucleoside content (e.g., 5’-S-methyl-5’-thioadenosine, adenine). Both raw and cooked onion extracts can reduce neuronal cell damage caused by lead exposure, but cooking increased the free radical scavenging (e.g., DPPH, ABTS, hydroxyl radicals) and chelating of lead ions (up to about 25%) of the onion extracts. In conclusion, cooking can cause changes in the chemical composition of onions and increase their antioxidant and lead chelating capacity. Full article

Background/Objectives: Skin injuries are common in the equine clinical practice, requiring effective treatment to support natural healing. Bacuri butter is gaining attention for its potential in wound healing and its anti-inflammatory, antimicrobial, and antioxidant properties. Natural polymers such as onion (Allium cepa) bioplastics have been investigated for their potential as occlusive dressings and for tissue regeneration. Methods: This study evaluated the healing process of experimentally induced skin wounds on horses treated with bacuri butter, washed onion film, and unwashed onion film. Clinical and histopathological analyses of the wounds were conducted in six clinically healthy horses over 28 days, with a control group receiving Ringer’s lactate solution. The onion films were produced and characterized for their chemical structure and properties, while the bacuri butter was sourced and prepared for application. Results: All treatments, including the control group, promoted wound healing without relevant differences in wound contraction rates, gross aspect, or histopathological parameters. Conclusions: Therefore, despite minor variations observed in the clinical evaluations between the treatment groups, the bacuri butter or onion biopolymer showed no significant healing effect on skin wounds in horses. Additionally, this study showed the potential of equine models in testing novel therapeutic approaches for wound healing, benefiting both veterinary and human medicine. Full article

This study optimized the extraction conditions to maximize the recovery yields of quercetin and total flavonoids from red onion skin waste using sequential microwave/ultrasound-assisted extraction. Five effective factors of quercetin extraction yield were investigated using response surface methodology. The method was successfully performed under optimal 60 s microwave irradiation conditions followed by 15 min sonication at 70 °C with 70% (v/v, water) ethanol with a solvent-to-solid ratio of 30 mL/g. The variance analysis of the model for both quercetin (Y₁) and total flavonoid (Y₂) recovery from DOS demonstrated that ultrasound temperature (X₂) was the most highly significant and influential factor, with a p-value of <0.0001 for both responses. Additionally, three key interaction terms—X₁X₂, X₂X₄, and X₂X₅—were identified as highly significant, further underscoring the critical role of ultrasound temperature in optimizing the extraction process for both quercetin and total flavonoids. The maximum recovery yields of quercetin and total flavonoids from red onion skin were 10.32% and 12.52%, respectively. The predicted values for quercetin (10.05%) and total flavonoids (12.72%) were very close to the experimental results. The recovery yields obtained from different extraction methods under the identical experimental conditions mentioned earlier were ultrasound/microwave-assisted extraction (7.66% quercetin and 10.18% total flavonoids), ultrasound-assisted extraction (5.36% quercetin and 8.34% total flavonoids), and microwave-assisted extraction (5.03% quercetin and 7.91% total flavonoids). The ANOVA confirmed highly significant regression models (p-values < 0.0001), with an insignificant lack of fit (p = 0.0515 for quercetin, p = 0.1276 for total flavonoids), demonstrating the robustness and reliability of the optimization. This study provides valuable insights for improving the extraction of bioactive compounds, which is critical for developing effective cancer treatments and advancing medical research. Additionally, the model shows potential for scaling up food processing applications to recover valuable products from red onion skin waste. Full article

Early sprouting is a main cause of onion spoilage during storage. However, limited knowledge is available on which factors trigger sprouting. Here, this was studied in the Hyfive and Exhibition cultivars, which largely differ in sprouting time. Sprouting progress was compared to the fructan and abscisic acid (ABA) profiles in the bulb scales and basal plates. Fructan concentrations decreased in the scales from harvest time onwards in the late-sprouting cultivar Hyfive, while remaining constant in the cultivar Exhibition until internal sprouting. In the basal plates, fructan concentrations increased in both cultivars from approximately one month after harvest, but reached maximum concentrations at moments that could not be related to the difference in internal sprouting. ABA levels generally decreased in the scales of both cultivars, while increasing in their basal plates. Nevertheless, for fructans, the measured variation in ABA concentrations was not consistently associated with differences in internal sprouting. A subsequent perturbation of internal sprouting by Maleic Hydrazide treatment in the cultivar Hyfive confirmed a lack of correlation. Altogether, this indicates that fructan and ABA levels in the scales and basal plate tissue change independent of internal sprouting and cannot be regarded as predictive markers for sprouting and storability. Full article