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16 pages, 2481 KB  
Review
Quercetin as a Potential Therapeutic Agent for Malignant Melanoma—A Review of Current Evidence and Future Directions
by Teodora Hoinoiu, Victor Dumitrascu, Daniel Pit, David-Alexandru Schipor, Madalina Jabri-Tabrizi, Bogdan Hoinoiu, David Emanuel Petreuș and Corina Seiman
Medicina 2025, 61(4), 656; https://doi.org/10.3390/medicina61040656 - 2 Apr 2025
Cited by 7 | Viewed by 3162
Abstract
Neoplastic disorders, particularly malignant carcinomas, are complex systemic diseases characterized by unregulated cellular proliferation, the invasion of adjacent tissues, and potential metastasis to distant bodily sites. Among the diverse spectrum of cancer subtypes, malignant melanoma is a highly aggressive form of cutaneous cancer [...] Read more.
Neoplastic disorders, particularly malignant carcinomas, are complex systemic diseases characterized by unregulated cellular proliferation, the invasion of adjacent tissues, and potential metastasis to distant bodily sites. Among the diverse spectrum of cancer subtypes, malignant melanoma is a highly aggressive form of cutaneous cancer originating in melanocytes, the pigment-producing cells resident in the skin. This malignancy is distinguished by its rapid and uncontrolled growth, as well as its propensity for metastasis to vital organs, thereby posing significant challenges to therapeutic intervention and prognostication. Early detection of melanoma is crucial for optimizing patient outcomes, as diagnosis at an advanced stage often yields a poor prognosis and limited treatment options. Diagnostic modalities for melanoma encompass comprehensive clinical evaluations by dermatologists; radiological imaging techniques such as ultrasonography, magnetic resonance imaging (MRI), computed tomography (CT) scans; and excisional biopsies for accurate histopathological assessment. Malignant melanoma is typically treated with surgery to remove the tumor, followed by immunotherapy to enhance the immune response, targeted therapy for tumors with specific genetic mutations, chemotherapy for advanced stages, radiation therapy to manage metastasis, and other adjunct therapies. This review presents the properties and possible adjunct therapeutic effects against malignant melanoma of quercetin found in the literature and explores, based on the observed physicochemical properties and biological activity, its potential development as a topical formulation for cutaneous application. Quercetin is a naturally occurring flavonoid compound abundant in various plant-based food sources, including apples, onions, berries, and citrus fruits, and has exhibited promising antiproliferative, antioxidant, and anticancer properties. Its distinctive biochemical structure enables quercetin to effectively neutralize reactive oxygen species and modulate key carcinogenic pathways, thereby rendering it a potential candidate for therapeutic intervention in managing malignant tumors, including melanoma. Full article
(This article belongs to the Special Issue Advances in the Diagnosis, Prevention and Treatment of Skin Tumors)
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22 pages, 3134 KB  
Article
Cell Wall–Based Machine Learning Models to Predict Plant Growth Using Onion Epidermis
by Celia Khoulali, Juan Manuel Pastor, Javier Galeano, Kris Vissenberg and Eva Miedes
Int. J. Mol. Sci. 2025, 26(7), 2946; https://doi.org/10.3390/ijms26072946 - 24 Mar 2025
Viewed by 3301
Abstract
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 ( [...] Read more.
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
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16 pages, 2124 KB  
Article
Genotype-Driven Phenotype Prediction in Onion Breeding: Machine Learning Models for Enhanced Bulb Weight Selection
by Junhwa Choi, Sunghyun Cho, Subin Choi, Myunghee Jung, Yu-jin Lim, Eunchae Lee, Jaewon Lim, Han Yong Park and Younhee Shin
Agriculture 2024, 14(12), 2239; https://doi.org/10.3390/agriculture14122239 - 6 Dec 2024
Cited by 2 | Viewed by 2867
Abstract
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 [...] Read more.
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
(This article belongs to the Topic Vegetable Breeding, Genetics and Genomics, 2nd Volume)
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32 pages, 1226 KB  
Review
Spontaneous and Chemically Induced Genome Doubling and Polyploidization in Vegetable Crops
by Maria Fomicheva, Yuri Kulakov, Ksenia Alyokhina and Elena Domblides
Horticulturae 2024, 10(6), 551; https://doi.org/10.3390/horticulturae10060551 - 24 May 2024
Cited by 10 | Viewed by 5448
Abstract
Plant ploidy manipulation is often required for breeding purposes. However, there is no comprehensive review covering genome doubling in vegetable crops despite the abundance of data for a large number of vegetable species. Similar to other species, genome doubling is required in vegetable [...] Read more.
Plant ploidy manipulation is often required for breeding purposes. However, there is no comprehensive review covering genome doubling in vegetable crops despite the abundance of data for a large number of vegetable species. Similar to other species, genome doubling is required in vegetable crops to obtain doubled haploids (DHs). It is also utilized for the production of polyploids to overcome interspecific hybrid sterility and improve agricultural traits. Spontaneous haploid genome duplication (SHGD) occurs in many Apiaceae, Brassicaceae, Cucurbitaceae, and Solanaceae crops, allowing for the laborious treatment with antimitotic agents to be bypassed. SHGD mechanisms are not fully understood, but existing data suggest that SHGD can occur via nuclear fusion, endoreduplication, or other mechanisms during microspore or ovule early embryogenic development. Other studies show that SHGD can occur at later developmental stages during extended plant growth in vitro or ex vitro, possibly due to the presence of phytohormones in the medium and/or diploid cell competitive advantage. For unresponsive accessions and species with rare SHGD, such as onion (Allium cepa L.) and beet cultivars (Beta vulgaris subsp. vulgaris L.), antimitotic agent treatment has to be applied. Antimitotic agent application efficiency depends on the treatment conditions, especially the agent concentration and exposure time. Also, plant developmental stage is critical for agent accessibility and plant survival. The existing methods can be used to further improve genome doubling methodology for major vegetable crops and other species. Full article
(This article belongs to the Special Issue Vegetable Genomics and Breeding Research)
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20 pages, 3991 KB  
Article
Prediction of Live Bulb Weight for Field Vegetables Using Functional Regression Models and Machine Learning Methods
by Dahyun Kim, Wanhyun Cho, Inseop Na and Myung Hwan Na
Agriculture 2024, 14(5), 754; https://doi.org/10.3390/agriculture14050754 - 12 May 2024
Cited by 3 | Viewed by 2755
Abstract
(1) Background: This challenge is exacerbated by the aging of the rural population, leading to a scarcity of available manpower. To address this issue, the automation and mechanization of outdoor vegetable cultivation are imperative. Therefore, developing an automated cultivation platform that reduces labor [...] Read more.
(1) Background: This challenge is exacerbated by the aging of the rural population, leading to a scarcity of available manpower. To address this issue, the automation and mechanization of outdoor vegetable cultivation are imperative. Therefore, developing an automated cultivation platform that reduces labor requirements and improves yield by efficiently performing all the cultivation activities related to field vegetables, particularly onions and garlic, is essential. In this study, we propose methods to identify onion and garlic plants with the best growth status and accurately predict their live bulb weight by regularly photographing their growth status using a multispectral camera mounted on a drone. (2) Methods: This study was conducted in four stages. First, two pilot blocks with a total of 16 experimental units, four horizontals, and four verticals were installed for both onions and garlic. Overall, a total of 32 experimental units were prepared for both onion and garlic. Second, multispectral image data were collected using a multispectral camera repeating a total of seven times for each area in 32 experimental units prepared for both onions and garlic. Simultaneously, growth data and live bulb weight at the corresponding points were recorded manually. Third, correlation analysis was conducted to determine the relationship between various vegetation indexes extracted from multispectral images and the manually measured growth data and live bulb weights. Fourth, based on the vegetation indexes extracted from multispectral images and previously collected growth data, a method to predict the live bulb weight of onions and garlic in real time during the cultivation period, using functional regression models and machine learning methods, was examined. (3) Results: The experimental results revealed that the Functional Concurrence Regression (FCR) model exhibited the most robust prediction performance both when using growth factors and when using vegetation indexes. Following closely, with a slight distinction, Gaussian Process Functional Data Analysis (GPFDA), Random Forest Regression (RFR), and AdaBoost demonstrated the next-best predictive power. However, a Support Vector Machine (SVM) and Deep Neural Network (DNN) displayed comparatively poorer predictive power. Notably, when employing growth factors as explanatory variables, all prediction models exhibited a slightly improved performance compared to that when using vegetation indexes. (4) Discussion: This study explores predicting onion and garlic bulb weights in real-time using multispectral imaging and machine learning, filling a gap in research where previous studies primarily focused on utilizing artificial intelligence and machine learning for productivity enhancement, disease management, and crop monitoring. (5) Conclusions: In this study, we developed an automated method to predict the growth trajectory of onion and garlic bulb weights throughout the growing season by utilizing multispectral images, growth factors, and live bulb weight data, revealing that the FCR model demonstrated the most robust predictive performance among six artificial intelligence models tested. Full article
(This article belongs to the Special Issue Applications of Data Analysis in Agriculture—2nd Edition)
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16 pages, 1159 KB  
Article
Bactericera tremblayi (Wagner, 1961) (Hemiptera: Triozidae): The Prevalent Psyllid Species in Leek Fields of Northwestern Spain
by Yolanda Santiago-Calvo, Laura Baños-Picón, Diego Flores-Pérez and M. Carmen Asensio-S.-Manzanera
Insects 2024, 15(1), 4; https://doi.org/10.3390/insects15010004 - 21 Dec 2023
Viewed by 1957
Abstract
Bactericera tremblayi (Wagner, 1961) (Hemiptera: Triozidae), the onion and leek psyllid, belongs to the Bactericera nigricornis Förster complex, along with B. trigonica and B. nigricornis. In contrast to the other two species, there has been a notable absence of studies examining the [...] Read more.
Bactericera tremblayi (Wagner, 1961) (Hemiptera: Triozidae), the onion and leek psyllid, belongs to the Bactericera nigricornis Förster complex, along with B. trigonica and B. nigricornis. In contrast to the other two species, there has been a notable absence of studies examining the distribution and seasonal occurrence of B. tremblayi, despite its association with significant issues in leek crops. Surveys were conducted between 2017 and 2020 in the main leek-growing area of Castile and Leon (Spain). An extensive survey encompassing 29 distinct plots was monitored with sweep nets and visual inspection, counting plants with immature forms at three times in the crop cycle. Additionally, a total of seven seasonal monitoring surveys were conducted in the same area of study. Plots were monitored every ten days, employing three distinct sampling methods including horizontal green tile water traps, sweep nets, and visual inspection, counting the juvenile stages by plant. The results revealed that B. tremblayi predominated as the primary species of jumping plant-lice in leek crops throughout the entire crop cycle. To date, there exists no documented incidence of pathogenic agents within symptomatic leeks. Consequently, the manifestation of severe symptoms is highly likely to be a direct consequence of the feeding activity of the onion psyllid. Populations of B. tremblayi were present in leek crops from May–July to harvest (September–November). Adults were captured in horizontal green water traps several days before they were found in sweep net samples, making the former effective in capturing early immigrant individuals. The maximum peaks of B. tremblayi were observed at the end of the crop cycle, particularly during late-season cycles characterized by lower mean temperatures. During observations made in a controlled environment, temperature exerted a significant influence on the developmental time of all stages of B. tremblayi. The complete development from egg to adult occurred within a temperature range of 15 to 25 °C. At 30 °C, the survival of eggs and N1 nymphs was limited and B. tremblayi did not complete its developmental cycle. The optimum temperature for the development of B. tremblayi provided by the models used was close to 24 °C with the application of Briere, Taylor, and Lactin models and around 21 °C with the SSI model. These results provided a good adjustment in predicting the survival patterns of B. tremblayi under the studied environmental conditions. Full article
(This article belongs to the Section Insect Physiology, Reproduction and Development)
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10 pages, 621 KB  
Article
Estimating Fertilizer Nitrogen-Use Efficiency in Transplanted Short-Day Onion
by Hanna Ibiapina de Jesus, Andre Luiz Biscaia Ribeiro da Silva, Kate Cassity-Duffey and Timothy Coolong
Nitrogen 2023, 4(3), 286-295; https://doi.org/10.3390/nitrogen4030021 - 15 Aug 2023
Cited by 7 | Viewed by 3744
Abstract
Efficient nitrogen (N) fertilizer applications in onion (Allium cepa L.) can reduce input costs and improve fertilizer-use efficiency, while maintaining high yields and quality. Understanding the N requirements of onion at different growth stages is necessary to enhance fertilizer N-use efficiency (FNUE). [...] Read more.
Efficient nitrogen (N) fertilizer applications in onion (Allium cepa L.) can reduce input costs and improve fertilizer-use efficiency, while maintaining high yields and quality. Understanding the N requirements of onion at different growth stages is necessary to enhance fertilizer N-use efficiency (FNUE). In a two-year study (2021 and 2022), the FNUE of onions was determined at five stages of development (at transplant, vegetative growth, bulb initiation, bulb swelling and bulb maturation). The FNUE was estimated by substituting a conventional N fertilizer (ammonium nitrate) with a 5% enriched 15N ammonium nitrate at a rate of 22.4 kg·ha−1 N, at one of five application times corresponding to a stage of development. All onions received a season total of 112 kg·ha−1 N. Marketable yield of onions was significantly greater in 2022 compared to 2021 and FNUE was affected by application timing in both years. In 2021, the FNUE at transplant was 8.9%, increasing to 26.4% and 35.28% at vegetative growth and bulb initiation stages, respectively. At bulb swelling and bulb maturation stages, FNUE was greater than 95%. In 2022, the FNUE at transplant was 25.2%. This increased to 75.7% and 103% at vegetative growth and bulb initiation stages, respectively. Results suggest that the application of fertilizer N at transplant is inefficient due to limited plant uptake ability, while N applications during bulb initiation and swelling were the most efficient. Full article
(This article belongs to the Special Issue Optimizing Fertilizer Nitrogen Use on Crops)
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16 pages, 3228 KB  
Communication
Molecular Real-Time PCR Monitoring of Onion Fusarium Basal Rot Chemical Control
by Elhanan Dimant and Ofir Degani
J. Fungi 2023, 9(8), 809; https://doi.org/10.3390/jof9080809 - 30 Jul 2023
Cited by 12 | Viewed by 3370
Abstract
Fusarium basal rot disease (FBR) is a destructive threat to onion crops around the globe. It causes seedlings’ death, development disruption, and pre- and post-harvest bulb infection and rotting, with a concern for toxin infestation. It is an emerging disease in Israel, with [...] Read more.
Fusarium basal rot disease (FBR) is a destructive threat to onion crops around the globe. It causes seedlings’ death, development disruption, and pre- and post-harvest bulb infection and rotting, with a concern for toxin infestation. It is an emerging disease in Israel, with new reports from farms nationwide. Recently, we reported on a full-season pot experiment to protect two leading commercial cultivars against FBR chemically. Here, we present new real-time qPCR molecular tracking of the pathogens inside the host plant and compare the infection levels to a deep analysis of the impacts of this experiment’s treatments on plant growth and health indexes. The new findings reveal variations within each treatment’s effectiveness regarding sprout development and bulb ripening stages. For instance, in the yellow Orlando cv., high protection was obtained with Azoxystrobin + Tebuconazole (Az-Te) in sprouts against F. oxysporum f. sp. cepae and with Fludioxonil + Sedaxen in mature plants against Fusarium acutatum. Thus, combining these fungicides may protect plants throughout their lifecycle. Also, Prochloraz at low dose was highly efficient in the Orlando cv. Still, to shield red Noam cv. plants from both pathogens, increasing this fungicide concentration towards the season-ending should be preferred. The qPCR tracking showed that all chemical treatments tested could reduce infection from pathogens by 80–90%, even with compounds such as Az-Te that were less effective. This implies that the pesticide was effective but probably phytotoxic to the plants, and thus, lower dosages must be considered. The molecular-based analysis discloses the high infection ability of F. oxysporum f. sp. cepae compared to F. acutatum in both cultivars. It also indicates an antagonism between those species in the Orlando cv. and synergism in the Noam cv. The current work reveals weak and strong points in chemical FBR protection and offers new ways to improve its application. The qPCR-based method enables us to closely monitor the pathogenesis and efficacy of chemical-preventing treatments and optimize crop-protection protocols. Full article
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30 pages, 1674 KB  
Review
Phytochemicals and Vitamin D for a Healthy Life and Prevention of Diseases
by Kazuki Santa, Kenji Watanabe, Yoshio Kumazawa and Isao Nagaoka
Int. J. Mol. Sci. 2023, 24(15), 12167; https://doi.org/10.3390/ijms241512167 - 29 Jul 2023
Cited by 17 | Viewed by 7196
Abstract
A variety of phytocompounds contained in medical plants have been used as medication, including Kampo (traditional Japanese) medicine. Phytochemicals are one category of the chemical compounds mainly known as antioxidants, and recently, their anti-inflammatory effects in preventing chronic inflammation have received much attention. [...] Read more.
A variety of phytocompounds contained in medical plants have been used as medication, including Kampo (traditional Japanese) medicine. Phytochemicals are one category of the chemical compounds mainly known as antioxidants, and recently, their anti-inflammatory effects in preventing chronic inflammation have received much attention. Here, we present a narrative review of the health-promotion and disease-prevention effects of phytochemicals, including polyphenols, the latter of which are abundant in onions, oranges, tea, soybeans, turmeric, cacao, and grapes, along with the synergetic effects of vitamin D. A phenomenon currently gaining popularity in Japan is finding non-disease conditions, so-called ME-BYO (mibyou) and treating them before they develop into illnesses. In addition to lifestyle-related diseases such as metabolic syndrome and obesity, dementia and frailty, commonly found in the elderly, are included as underlying conditions. These conditions are typically induced by chronic inflammation and might result in multiple organ failure or cancer if left untreated. Maintaining gut microbiota is important for suppressing (recently increasing) intestinal disorders and for upregulating immunity. During the COVID-19 pandemic, the interest in phytochemicals and vitamin D for disease prevention increased, as viral and bacterial infection to the lung causes fatal inflammation, and chronic inflammation induces pulmonary fibrosis. Furthermore, sepsis is a disorder inducing severe organ failure by the infection of microbes, with a high mortality ratio in non-coronary ICUs. However, antimicrobial peptides (AMPs) working using natural immunity suppress sepsis at the early stage. The intake of phytochemicals and vitamin D enhances anti-inflammatory effects, upregulates immunity, and reduces the risk of chronic disorders by means of keeping healthy gut microbiota. Evidence acquired during the COVID-19 pandemic revealed that daily improvement and prevention of underlying conditions, in terms of lifestyle-related diseases, is very important because they increase the risk of infectious diseases. This narrative review discusses the importance of the intake of phytochemicals and vitamin D for a healthy lifestyle and the prevention of ME-BYO, non-disease conditions. Full article
(This article belongs to the Section Molecular Pharmacology)
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21 pages, 4815 KB  
Article
Prevention and Control of Fusarium spp., the Causal Agents of Onion (Allium cepa) Basal Rot
by Ofir Degani, Elhanan Dimant, Asaf Gordani, Shaul Graph and Eliyahu Margalit
Horticulturae 2022, 8(11), 1071; https://doi.org/10.3390/horticulturae8111071 - 14 Nov 2022
Cited by 18 | Viewed by 10898
Abstract
Fusarium basal rot disease (FBR) is considered a serious threat to commercial onion production in Israel and worldwide. Today, coping means applied in Israel against the disease have limited efficiency and include a four-year crop cycle and disinfecting the soil with metam sodium. [...] Read more.
Fusarium basal rot disease (FBR) is considered a serious threat to commercial onion production in Israel and worldwide. Today, coping means applied in Israel against the disease have limited efficiency and include a four-year crop cycle and disinfecting the soil with metam sodium. At the same time, agricultural tools (harrows, plows, etc.), contaminated equipment and workers facilitate spread of the disease to new growth areas, and the field disease incidence in Israel now reaches 8% of yields in heavily infected areas. Infected onions do not always show disease symptoms and the problem worsens if they arrive at storage facilities, especially since this pathogen genus produces known toxins. The current study aims at examining the potential of chemical control to reduce the damage caused by this disease. To this end, nine commercial fungicides were scanned in plate sensitivity assay against the main pathogens involved, Fusarium oxysporum f. sp. cepae and Fusarium acutatum. Several fungicides were found to be highly effective against the two pathogens, especially the mixtures Azoxystrobin + Difenoconazole, Fluopyram + Trifloxystrobin, or the Fluazinam compounds. Three selected preparations previously tested in seedlings were evaluated here in a full growing season. Prochloraz successfully protected the Orlando variety (white onion, Riverside cv.) and the Noam variety (red onion) at all growth stages against F. oxysporum f. sp. cepae. At the same time, this treatment was ineffective against F. acutatum in Noam cv. Another anti-fungal preparation, Fludioxonil + Sedaxen mixture, showed a wider range of effectiveness at the season’s end against the two Fusarium species tested in both onion cultivars. These results are an important step towards developing FBR control in commercial onion fields. Follow-up work is needed to optimize the pesticides’ concentrations and their application methods and to test them on a field scale. Interestingly, these pathogens were more aggressive towards the cultivar from which they were isolated: F. oxysporum f. sp. cepae to the red onion Noam cv. and F. acutatum to the white Orlando cv. Infecting the plants with both pathogens reduced disease symptoms in the white Orlando cv, suggesting antagonistic interactions in this onion genotype. Full article
(This article belongs to the Special Issue Vegetable and Fruit Postharvest Physiology and Diseases)
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21 pages, 8100 KB  
Article
Clarification of Temperature Field Evolution in Large-Scale Electric Upsetting Process of Ni80A Superalloy through Finite Element Method
by Jiang Zhao, Guo-Zheng Quan, Yu-Qing Zhang and Jian-Sheng Zhang
Materials 2022, 15(18), 6358; https://doi.org/10.3390/ma15186358 - 13 Sep 2022
Cited by 2 | Viewed by 2444
Abstract
Electric upsetting has been widely employed to manufacture the preformed workpiece of large-scale exhaust valves. The temperature field in the electric upsetting process plays an important role in microstructure evolution and defect formation. In order to uncover the temperature evolution in a larger-scale [...] Read more.
Electric upsetting has been widely employed to manufacture the preformed workpiece of large-scale exhaust valves. The temperature field in the electric upsetting process plays an important role in microstructure evolution and defect formation. In order to uncover the temperature evolution in a larger-scale electric upsetting process, the electric-thermal-mechanical multi-field coupling finite element model was developed to simulate the electric upsetting forming process of Ni80A superalloy. The temperature distribution characteristics and their formation mechanisms under different stages were analyzed systematically. Results indicate that at the preheating stage, the billet temperature increases from 20 °C to 516.7 °C, and the higher temperature region firstly appears at the contact surface between billet and anvil due to the combined effects of contact resistance and volume resistance. With increasing preheating time, the higher temperature region is transferred to the interior of the billet because the contact resistance is reduced with increasing temperature. As for the forming process, the billet is gradually deformed into an onion shape. The highest billet temperature increases to 1150 °C and keeps relatively constant. The high temperature region always appears at the neck of the onion due to the relatively higher current density at this place. It enlarges continuously in the primary stage and intermediate stage, and then decreases at the stable deformation stage. The low temperature regions lie in the contact surface and the outer surface of the onion because a lot of heat is lost to the anvil and surroundings through thermal conduction and radiation. Finally, the established finite element model was verified by an actual electric upsetting experiment. The average relative error between simulated temperatures and experimental ones was estimated as 7.54%. The longitudinal and radial errors between simulated onion shape and the experimental one were calculated as 1.38% and 2.70%, respectively. Full article
(This article belongs to the Special Issue Commemorating the Launch of the Section 'Metals and Alloys')
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15 pages, 1141 KB  
Article
The Influence of Non-Optimal Rearing Conditions and Substrates on the Performance of the Black Soldier Fly (Hermetia illucens)
by Nuno Ribeiro, Rui Costa and Olga M. C. C. Ameixa
Insects 2022, 13(7), 639; https://doi.org/10.3390/insects13070639 - 16 Jul 2022
Cited by 39 | Viewed by 8612
Abstract
Among the insect species reared as alternative protein sources, Hermetia illucens (black soldier Fly, BSF) has shown a huge potential mostly due to its high protein content, its bioconversion rates, and versatility in using different feeding substrates. Insect rearing may use continuous or [...] Read more.
Among the insect species reared as alternative protein sources, Hermetia illucens (black soldier Fly, BSF) has shown a huge potential mostly due to its high protein content, its bioconversion rates, and versatility in using different feeding substrates. Insect rearing may use continuous or batch feeding regimes and, among the used substrates, supermarket feedstock waste has gained recent interest under a circular economy perspective, but several uncertainties remain regarding the heterogeneity and the potential effects of the quantity and quality of these substrates on BSF larvae (BSFL) development. In this experimental work, five replicates of a hundred BSFL were fed in a continuous feeding regime, using seven different isolated vegetables as substrates (wheat bran, pumpkin, apple, grape pomace, red onion, red cabbage, and spinach), at three different temperatures (20, 25, and 30 °C) and two substrate moisture conditions (natural and 70% substrate moisture), until 50% of the larvae achieved the prepupal stage. BSFL performance and bioconversion parameters were evaluated. Our results show that some substrates should be avoided when rearing Hermetia illucens on feedstocks. Among these, apple feed led to poorer and slower development performances with more than 100 days of larval stage, while grape pomace and spinach showed higher mortality rates, which may be due to some anti-nutritional compounds. Larvae fed on pumpkin, red cabbage, and red onion presented good bioconversion results with higher values of efficiency of conversion of digested feed between 14.4 and 25. This work delivers relevant results for black soldier fly reared on a continuous feeding system using vegetable feedstock substrates and their potential trade-offs. Full article
(This article belongs to the Special Issue Recent Advances in Black Soldier Fly Research)
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24 pages, 5000 KB  
Article
Characteristics of Meteorological Conditions during a Severe Outbreak of Onion Downy Mildew and Metalaxyl Sensitivity of Peronospora destructor in Saga, Japan, in 2016
by Shin-ichirou Syobu and Sachiko Watanabe
Horticulturae 2022, 8(7), 578; https://doi.org/10.3390/horticulturae8070578 - 26 Jun 2022
Cited by 4 | Viewed by 4091
Abstract
In 2016, an onion downy mildew epidemic caused by Peronospora destructor severely damaged the commercial onion fields in Saga Prefecture, western Japan. To identify the factors underlying the outbreak, we investigated the symptoms of downy mildew caused by secondary infections and examined P. [...] Read more.
In 2016, an onion downy mildew epidemic caused by Peronospora destructor severely damaged the commercial onion fields in Saga Prefecture, western Japan. To identify the factors underlying the outbreak, we investigated the symptoms of downy mildew caused by secondary infections and examined P. destructor’s sensitivity to metalaxyl, the most effective traditional fungicide used against this onion pathogen, in 2016–2018. Disease symptoms developed in late March 2016, which was earlier than symptom development in 2017 and 2018. Furthermore, there were synchronous repeated disease development and favourable meteorological conditions for infection in early and late April resulting in the development of polycyclic epidemics. In field trials from 2016 to 2018, the efficacy of chlorothalonil + metalaxyl-M application ranged 18–45%, as calculated by comparing disease severity at the final stage of each treatment to that in the untreated plots. On the basis of the metalaxyl sensitivity observed in 2016, the effective concentration, which reduced germ-tube elongation in P. destructor by 50%, exceeded 200 µg ai/mL for certain strains. Our observations indicate that these characteristic meteorological conditions were major factors contributing to the severe disease outbreak in 2016. The emergence of less-metalaxyl-sensitive P. destructor strains may be an additional predisposing factor. Full article
(This article belongs to the Special Issue Horticultural Plants Pathology and Advances in Disease Management)
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20 pages, 4500 KB  
Article
WRKY Gene Family Drives Dormancy Release in Onion Bulbs
by Guglielmo Puccio, Antonino Crucitti, Antonio Tiberini, Antonio Mauceri, Anna Taglienti, Antonio Palumbo Piccionello, Francesco Carimi, Martijn van Kaauwen, Olga Scholten, Francesco Sunseri, Ben Vosman and Francesco Mercati
Cells 2022, 11(7), 1100; https://doi.org/10.3390/cells11071100 - 24 Mar 2022
Cited by 18 | Viewed by 4535
Abstract
Onion (Allium cepa L.) is an important bulb crop grown worldwide. Dormancy in bulbous plants is an important physiological state mainly regulated by a complex gene network that determines a stop of vegetative growth during unfavorable seasons. Limited knowledge on the molecular [...] Read more.
Onion (Allium cepa L.) is an important bulb crop grown worldwide. Dormancy in bulbous plants is an important physiological state mainly regulated by a complex gene network that determines a stop of vegetative growth during unfavorable seasons. Limited knowledge on the molecular mechanisms that regulate dormancy in onion were available until now. Here, a comparison between uninfected and onion yellow dwarf virus (OYDV)-infected onion bulbs highlighted an altered dormancy in the virus-infected plants, causing several symptoms, such as leaf striping, growth reduction, early bulb sprouting and rooting, as well as a lower abscisic acid (ABA) level at the start of dormancy. Furthermore, by comparing three dormancy stages, almost five thousand four hundred (5390) differentially expressed genes (DEGs) were found in uninfected bulbs, while the number of DEGs was significantly reduced (1322) in OYDV-infected bulbs. Genes involved in cell wall modification, proteolysis, and hormone signaling, such as ABA, gibberellins (GAs), indole-3-acetic acid (IAA), and brassinosteroids (BRs), that have already been reported as key dormancy-related pathways, were the most enriched ones in the healthy plants. Interestingly, several transcription factors (TFs) were up-regulated in the uninfected bulbs, among them three genes belonging to the WRKY family, for the first time characterized in onion, were identified during dormancy release. The involvement of specific WRKY genes in breaking dormancy in onion was confirmed by GO enrichment and network analysis, highlighting a correlation between AcWRKY32 and genes driving plant development, cell wall modification, and division via gibberellin and auxin homeostasis, two key processes in dormancy release. Overall, we present, for the first time, a detailed molecular analysis of the dormancy process, a description of the WRKY-TF family in onion, providing a better understanding of the role played by AcWRKY32 in the bulb dormancy release. The TF co-expressed genes may represent targets for controlling the early sprouting in onion, laying the foundations for novel breeding programs to improve shelf life and reduce postharvest. Full article
(This article belongs to the Special Issue Omics in Plant Genetics and Breeding)
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Article
Improvement of the Soil Moisture Retrieval Procedure Based on the Integration of UAV Photogrammetry and Satellite Remote Sensing Information
by Amal Chakhar, David Hernández-López, Rocío Ballesteros and Miguel A. Moreno
Remote Sens. 2021, 13(24), 4968; https://doi.org/10.3390/rs13244968 - 7 Dec 2021
Cited by 8 | Viewed by 5393
Abstract
In countries characterized by arid and semi-arid climates, a precise determination of soil moisture conditions on the field scale is critically important, especially in the first crop growth stages, to schedule irrigation and to avoid wasting water. The objective of this study was [...] Read more.
In countries characterized by arid and semi-arid climates, a precise determination of soil moisture conditions on the field scale is critically important, especially in the first crop growth stages, to schedule irrigation and to avoid wasting water. The objective of this study was to apply the operative methodology that allowed surface soil moisture (SSM) content in a semi-arid environment to be estimated. SSM retrieval was carried out by combining two scattering models (IEM and WCM), supplied by backscattering coefficients at the VV polarization obtained from the C-band Synthetic Aperture Radar (SAR), a vegetation descriptor NDVI obtained from the optical sensor, among other essential parameters. The inversion of these models was performed by Neural Networks (NN). The combined models were calibrated by the Sentinel 1 and Sentinel 2 data collected on bare soil, and in cereal, pea and onion crop fields. To retrieve SSM, these scattering models need accurate measurements of the roughness surface parameters, standard deviation of the surface height (hrms) and correlation length (L). This work used a photogrammetric acquisition system carried on Unmanned Aerial Vehicles (UAV) to reconstruct digital surface models (DSM), which allowed these soil roughness parameters to be acquired in a large portion of the studied fields. The obtained results showed that the applied improved methodology effectively estimated SSM on bare and cultivated soils in the principal early growth stages. The bare soil experimentation yielded an R2 = 0.74 between the estimated and observed SSMs. For the cereal field, the relation between the estimated and measured SSMs yielded R2 = 0.71. In the experimental pea fields, the relation between the estimated and measured SSMs revealed R2 = 0.72 and 0.78, respectively, for peas 1 and peas 2. For the onion experimentation, the highest R2 equaled 0.5 in the principal growth stage (leaf development), but the crop R2 drastically decreased to 0.08 in the completed growth phase. The acquired results showed that the applied improved methodology proves to be an effective tool for estimating the SSM on bare and cultivated soils in the principal early growth stages. Full article
(This article belongs to the Special Issue Satellite Soil Moisture Validation and Applications)
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