Search Results (29)

Carotenoids are essential nutritional compounds in tomato (Solanum lycopersicum), and mutations in carotenoid biosynthesis genes can alter both fruit color and other quality traits. Carotenoid isomerase (CRTISO) converts prolycopene to all-trans-lycopene; its mutation results in the orange-fruited tangerine mutant characterized by prolycopene accumulation. However, the broader impacts of distinct SlCRTISO mutations on fruit quality traits and agronomic performance remain largely unexplored. Here, we evaluated agronomic traits and nutritional quality in two tangerine mutants carrying distinct SlCRTISO alleles. The yellow/orange-fruited tomato 5 (yft5) mutant, which harbors a single point mutation in SlCRTISO, exhibited lower flavonoids, chlorogenic acid, and prolycopene than the CRISPR/Cas9-mediated knockout mutants, but maintained fruit size and weight comparable to wild type, whereas knockout lines showed severely reduced fruit size, highlighting the potential agronomic advantage of yft5. Pearson correlation analysis revealed negative associations between abscisic acid (ABA) levels and rutin, chlorogenic acid, as well as the prolycopene-to-lycopene ratio during fruit ripening. Transcriptome analysis demonstrated that knockout mutations more profoundly affected primary metabolism than the yft5 point mutation. Notably, 9-cis-epoxycarotenoid dioxygenase 2 (NCED2), a gene involved in ABA biosynthesis, was specifically upregulated in yft5 fruits at the mature green stage (38 days post-anthesis (dpa)), consistent with ABA levels. Quality-related genes including chalcone synthase (CHS), citrate synthase (CS), and invertase (INV) were significantly upregulated in knockout lines during ripening. These findings reveal a trade-off between phenolic content and fruit size in tangerine tomatoes carrying distinct SlCRTISO alleles, positioning yft5 as a valuable genetic resource for breeding high-quality varieties. Full article

In response to the challenges of drastic illumination variations, large differences in fruit scale, and severe occlusion in real-field environments, this paper proposes a lightweight end-to-end detection model, termed EMBS-DETR, for tomato maturity detection. The proposed method is built upon the RT-DETR-R18 baseline framework, retaining the advantages of global modeling and end-to-end detection enabled by the Transformer architecture, while introducing targeted improvements in feature extraction and multi-scale feature fusion. In the feature extraction stage, a C2f-FDConv module is incorporated to enhance the modeling capability of high-frequency fine-grained features, such as the surface texture and color gradients of tomatoes, while reducing redundant parameter overhead. For high-level semantic representation, an improved parameter-free attention mechanism, SimAM-TF, is designed. By jointly modeling neuron energy functions and color-aware modulation, it effectively enhances feature representation under complex lighting and occlusion conditions. For multi-scale feature fusion, a novel EMBS-FPN structure is proposed. Based on bidirectional feature flow and a multi-scale weighted fusion mechanism, this structure integrates multi-branch receptive field modeling with an efficient upsampling strategy, enabling adaptive fusion of P3–P5 feature layers. This design significantly improves representation stability for objects of varying scales while maintaining model lightweight characteristics. To evaluate the proposed method, a real-field tomato maturity dataset was constructed, consisting of 2327 images collected from facility-grown pink large-fruit tomato varieties widely cultivated in North China. According to agricultural industry standards and physicochemical properties, the dataset is categorized into three classes: immature (796 images), turning stage (718 images), and mature (813 images). Experiments were conducted on an Ubuntu 20.04 platform with an NVIDIA GeForce RTX 3080 Ti GPU. The input resolution was set to 640 × 640. Standard evaluation metrics, including Precision, Recall, mAP@0.5, mAP@0.5:0.95, as well as Params, GFLOPs, and Model Size, were used for comprehensive assessment. The experimental results demonstrate that EMBS-DETR achieves 90.9% Precision, 85.7% Recall, 89.9% mAP@0.5, and 79.8% mAP@0.5:0.95. Meanwhile, with only 37.03 M parameters, 25.2 GFLOPs computational cost, and a model size of 46.3 MB, the proposed model maintains low computational and storage overhead, achieving a favorable balance between accuracy and efficiency. Compared with mainstream YOLO-based models, the proposed method demonstrates superior overall performance in complex field environments, providing effective technical support for automated tomato maturity perception and intelligent visual understanding in precision agriculture. Full article

Tomato (Solanum lycopersicum) is a globally important vegetable crop, with fruit quality being a major focus of research. Starch serves as the primary carbohydrate reserve during early fruit development and functions as a key carbon precursor for flavor compound biosynthesis in later stages. To elucidate the role of starch accumulation in determining ripe fruit quality, we analyzed the relationship between starch content in mature green fruits and flavor-related traits across eight tomato cultivars. The results demonstrated that starch content at the mature green stage showed a significantly positive correlation with total soluble solids (TSS) content (r = 0.922) and a significantly positive correlation with total acidity content (r = 0.783) in red-ripe fruits. Furthermore, the expression levels of starch synthesis gene AGPS1 and degradation gene PWD at the mature green stage were both significantly positively correlated with the final fruit TSS levels. These findings highlight the important role of starch accumulation during the mature green stage in shaping final fruit quality, providing a theoretical basis for breeding high-quality tomato varieties. Full article

Tomato landraces possess distinct flavors, colors, textures and aromas, making them suitable for traditional cuisine. Tomato landraces contain a wide range of genes, including those involved in fruit quality, that can be isolated and used in local breeding programs. In regions recognized as centers of origin, domestication and diversification, traditional farmers play an important role in the preservation of tomato landraces adapted to local conditions and agricultural practices, on the whole maintaining high genetic diversity. This work aimed to evaluate the effects of the crop cycle (C), genotype (G) and C × G interactions on the contents of soluble solids, reducing sugars, lycopene, total polyphenols, flavonoids, and vitamin C, as well as the pH and antioxidant activity, in fifteen tomato landraces (genotypes) undergoing phenotypic selection and a commercial tomato variety (control). All the varieties were grown in two crop cycles under uniform greenhouse management using a randomized block design with four repetitions. Fruit composition was analyzed with AOAC and spectrophotometric methods. Significant differences (p ≤ 0.01) were detected in the soluble solid content, pH, flavor and maturity indices, polyphenol and flavonoid contents, and antioxidant activity between C, G and C × G interactions. In contrast, titratable acidity, reducing sugars, lycopene and vitamin C did not differ between cycles. Coefficients of phenotypic and genotypic variation and broad-sense heritability (H²) ranged from 4.3 to 33.7, 2.0 to 19.0, and 3.2 to 63.5%, respectively. H² for bioactive compounds ranged from moderate to slightly high (16.3–38.8%). These findings, supported by laboratory analyses, suggest that genotypes under agronomic selection have potential as parents to enhance fruit quality in current and future breeding programs. Full article

In order to screen high-quality processed tomato germplasm resources, the present research measured the content of quality indicators—lycopene, soluble solids, total acidity, total sugar, and vitamin C—in mature fruits of 113 processed tomato high-generation inbred lines. Comprehensive evaluations of germplasm quality were conducted through genetic diversity analysis, correlation analysis, principal component analysis, and cluster analysis. The results indicated that the variability of the five quality traits in the materials under test was relatively high, with a range of variation from 12.21% to 39.04%. Total sugar exhibited the greatest variation, while soluble solids content showed the least variation. The genetic diversity index ranged from 1.899 to 2.064, with total sugar, vitamin C, and lycopene showing high genetic variation. Soluble solids content was significantly positively correlated with lycopene, total sugar, and total acidity, while lycopene content was significantly positively correlated with total sugar. Vitamin C showed weaker correlations with other traits, but exhibited a significant negative correlation with total sugar. Total acidity had relatively simple correlations with other traits, being significantly correlated only with soluble solids. The three principal components extracted from the principal component analysis all had eigenvalues above 0.8%, contributing to a cumulative contribution rate of 77.435%. Through cluster analysis, the tested materials were divided into six major groups at an Euclidean distance of 15. Group I serves as candidate materials for breeding varieties with good basic quality and high vitamin C content. Group II stood out in terms of high sugar and lycopene content, suitable for developing tomato sauce or juice products with high vibrancy and sweetness. Group III had a high nutritional value and vibrant color, serving as core germplasm resources for breeding high-end processing-specific varieties. Group IV had high soluble solids content, making it a parent source for improving the viscosity and flavor of sauce tomatoes. Group V was suitable for specific formulations requiring high acidity or as breeding materials for high-acidity characteristics. Group VI had limited processing potential and should be used cautiously in breeding. The comprehensive evaluation results showed that the top five germplasm resources in terms of score were W119, 61, 82, 83, and W144. This study enriched the high-quality processed tomato germplasm resources and provided parental resources for quality breeding of processed tomatoes. Full article

Varieties show their unique characteristics in morphology, growth, and fruits. Tomato maturity is related to multiple dimensional characteristics including color, texture, smell, etc. An effective classification method of tomato variety and maturity is crucial for evaluating its growth and yield. However, due to the complex growth environment, some problems such as leaf occlusion and fruit shaded by each other make it difficult to accurately and efficiently identify them. To solve these problems, this study innovatively proposes a simultaneous detection model on tomato variety and maturity based on improved YOLOv8n, with the combination of frequency-adaptive dilated convolution (FADC) feature extraction module and the high-level screening-feature path aggregation network (HSPAN) with the aim of local and global feature fusion by the channel attention module and feature selection fusion mechanism. In addition, we use the Powerful-IoU (PIoU) loss function to replace the original Complete IoU (CIoU) to enhance the accuracy of bounding boxes. We also introduce a dynamic detection head as the final output of the model, which can adaptively adjust the focus of feature extraction according to the color and size of tomato fruits, thereby improving the recognition accuracy. Experimental results show that our model with better global perception capability achieves the highest detection accuracy and lower computation complexity among the comparative models. Full article

This study investigates the impact of dynamically adjusting the potassium-to-calcium ratio (molar ratio) in nutrient solutions used on cherry tomatoes at different growth stages (seedling, flowering and fruit setting, and maturity) to enhance fruit appearance, nutritional quality, and mineral content. By focusing on the ‘Saopolo’ variety, 17 treatments were implemented, each involving a specific potassium-to-calcium ratio in the nutrient solutions applied during the seedling, flowering and fruit setting, and fruiting stages. The aim was to optimize the nutrient solution formula and enhance fruit quality. Fruit quality parameters were assessed at the initial maturity stage across various treatments, encompassing commodity quality (fruit stalk length, fruit shape index, and fruit hardness), taste quality (total soluble sugar, titratable acid content, and sugar-acid ratio), nutritional quality (vitamin C (Vc), soluble protein, and lycopene content), antioxidant quality (total phenol and flavonoid content), as well as comprehensive quality (soluble solids content). Principal component analysis was conducted on these parameters. Additionally, mineral element levels in fruits were analyzed at different developmental stages (white ripe, color transition, and mature stages). When tomato plants were treated with nutrient solutions containing varying potassium-to-calcium ratios at different growth stages, observations revealed distinct outcomes in the first fruit cluster. T15 (seedling stage (A): 0.5 times standard nutrient solution; flowering and fruit-setting stage (B): potassium-to-calcium = 1.6:1; fruiting stage (C): potassium-to-calcium = 2.1:1) exhibited the highest fruit firmness (1.54 kg·cm⁻²), while T14 (A; B (K:Ca = 1.6:1); C (K:Ca = 2.0:1)) elevated levels of total soluble sugars (6.59%), titratable acidity (0.74%), soluble proteins (2.79 mg·g⁻¹), and total phenolics (2.56 mg·g⁻¹). T13 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.9:1)) demonstrated superior soluble solids (5.9%), lycopene (32.09 µg·g⁻¹), and flavonoid contents (0.77 mg·g⁻¹), whereas T12 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.8:1)) showcased the highest sugar–acid ratio (12.63) and soluble solids content (5.9%). Notably, T8 (A; B (K:Ca = 1.5: 1); C (K:Ca = 1.9:1)) exhibited the highest Vc content (10.03 mg·100 g⁻¹). Mineral element analysis indicated that an increased potassium-to-calcium ratio in the nutrient solution during various growth stages enhanced phosphorus and potassium uptake by the fruits but hindered the absorption of nitrogen, calcium, magnesium, and iron. In summary, employing half the standard nutrient solution dosage during the seedling stage, utilizing a potassium-to-calcium ratio of 1.6:1 in the nutrient solution at the flowering and fruit setting stage, and applying nutrient solution T13 with a potassium-to-calcium ratio of 1.9:1 during the fruit-bearing phase, optimally coordinates fruit nutrient accrual and enhances flavor quality. These findings support the use of stage-specific nutrient modulation to improve cherry tomato quality in controlled-environment agriculture. Full article

Anthocyanins, which accumulate in fruits, flowers, and vegetative organs, play a critical role in plant reproduction, disease resistance, stress tolerance, and promoting human health. Although light significantly influences the development of various fruit pigments, the specific mechanisms through which it regulates anthocyanin accumulation during fruit ripening are not yet fully understood. This study aimed to investigate the role of light in anthocyanin biosynthesis using Aft tomato fruits, which accumulate pigments in the epidermis. To explore the effects of light on anthocyanin biosynthesis, half of each fruit was covered with aluminum foil to establish light-exposed and bagged conditions for comparative analysis. The results showed that the bagged treatment led to a significant decrease in the total anthocyanin content of the fruits. Transcriptome analysis revealed a notable upregulation of several structural genes involved in the anthocyanin biosynthetic pathway, specifically Sl4CL, SlCHS, SlCHI, SlF3H, SlDFR, and Sl3GT in the light-exposed fruits. Additionally, the expression levels of light-responsive genes and transcription factors, such as SlCRY1, SlSPA, SlUVR3, SlHY5, SlBBX24, SlMYB11, MADS-box transcription factor 23, SlHD-ZIP I/II, SlAN2-like, SlbHLH and SlWD40 proteins, were significantly higher in the light-exposed samples compared to those subjected to the bagged treatment. Weighted Gene Co-Expression Network Analysis (WGCNA) demonstrated a strong association between light-induced gene expression such as SlPAL, SlCHS1, SlDFR, SlF3H, SlF3′5′H, SlANS, SlHY5, and SlAN2-like quantified by qRT-PCR analysis and anthocyanin biosynthesis. Moreover, as the fruit matured, both anthocyanin accumulation and the expression of genes related to its biosynthetic pathway increased. These findings contribute to a foundational understanding of the regulatory network that influences light-induced processes and fruit development impacting anthocyanin accumulation, which will facilitate in-depth study of the functions of these identified genes and provide a foundation for breeding anthocyanin-rich tomato varieties. Full article

In North China, the overwintering production of the tomato (Solanum lycopersicum L.) encounters difficulties posed by extreme weather conditions and the high costs of traditional greenhouses. Soft-shell solar greenhouses present a viable alternative because of their low cost and excellent heat-retaining properties. This study establishes a technical framework for high-yield and high-quality winter tomato production in soft-shell greenhouses through analyzing dynamic light, temperature, and humidity parameters, cultivar responses, and optimized production–marketing models. Field experiments monitored microclimate data in soft-shell solar greenhouses during different growth stages of six cherry tomato and three large tomato varieties, combined with yield, quality, and economic return analysis. The results showed that (1) soft-shell greenhouses increased average daily temperatures by 10–15 °C, reduced low-temperature stress duration by 25%, achieved 82% light saturation compliance, and decreased humidity fluctuations by 23%; (2) the yield per cluster of cherry tomatoes increased first and then decreased for early maturing varieties, and decreased for middle and late maturing varieties, while the yield of large tomatoes decreased first and then increased; (3) light intensity was positively correlated with Brix accumulation, and humidity was negatively correlated with yield; (4) cherry tomato yields were more temperature-sensitive, whereas large-fruited tomatoes were more influenced by light intensity; (5) a “variety optimization + scenario-based sales” model integrating multi-cultivar layouts and gift-box marketing strategies improved economic returns. This research provides an integrated environmental regulation and market adaptation solution for North China’s protected agriculture, offering a reference value for greenhouse agriculture development in global cold regions. Full article

Raspberry is a berry whose fruit is not tolerant to storage; breeding varieties with extended storage time and high comprehensive quality are significant for raspberries in cold regions. 1-Aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) is a limiting enzyme in the ethylene synthesis process, which plays essential roles in fruit ripening and softening in plants. In this study, the RiACS1 gene in raspberry (Rubus idaeus L.) variety ‘Polka’ was cloned. The RiACS1 gene overexpression vector was constructed and transformed into tomato plants using the Agrobacterium tumefaciens infection method to verify its function in their reproductive development. The RiACS1 gene, with a total length of 1476 bp, encoded a protein with 491 amino acids. The subcellular localization analysis of the RiACS1 protein in the tobacco transient expression system revealed that the RiACS1-GFP fusion protein was mainly located in the nucleus. Compared with the control, the flowering time and fruit color turning time of transgenic strains were advanced, and the fruit hardness was reduced. Overexpression of RiACS1 increased the activity of ACC synthase, ethylene release rate, and respiration rate during the transchromic phase. It changed the substance content, increased the content of vitamin C and anthocyanin in the fruit ripening process, and decreased the content of chlorophyll and titrable acid at the maturity stage. In addition, RiACS1 increased the relative expression levels of ethylene synthesis-related genes such as SlACS4, SlACO3, and SlACO1 in the fruit ripening process, while it decreased the expression levels of SlACS2 at the maturity stage. These results suggested that the RiACS1 gene could promote early flowering and fruit ripening in tomato plants. This study provided a basis for further modifying raspberry varieties using molecular biology techniques. Full article

Citric acid is an important organic acid with wide applications and diverse biological functionality. As the predominant organic acid in lemons, citric acid plays a crucial role in determining the flavor of citrus, especially in lemons. ATP citrate lyase (ACL, EC4.1.3.8) is the keg gene in citric acid metabolism. Several research studies on ACL only focused on high-sugar- and low-acid-content citrus varieties; however, the ACL mechanism in lemons with high acid and low sugar levels remains undetermined. In this study, a key candidate gene, ClACLB-1, for citrate cleavage was identified from the genome data of ‘Xiangshui’ lemon [Citrus limon (L.) Burm f.]. The putative protein coded by the gene ClACLB-1 is localized in the nuclear and cell membranes. The ClACLB-1 gene was expressed in all tissues, with the highest expression in male flowers and the lowest expression in mature fruits; the expression decreased during lemon fruit development. The overexpression of ClACLB-1 in transgenic tomatoes significantly increases the activity of citrate lyase, which subsequently reduces citric acid content. This study clarified the function of the ClACLB-1 gene in cleaving citric acid, provided new insights into the citric acid metabolism of citrus, and offered a theoretical reference for reducing acid and increasing sugar in citrus to improve fruit quality. It also helped to enhance the understanding of the metabolism and role of citrate in plants. Full article

In order to solve the problems that existing tomato maturity detection methods struggle to take into account both common tomato and cherry tomato varieties in complex field environments (such as light change, occlusion, and fruit overlap) and the model size being too large, this paper proposes a lightweight tomato maturity detection model based on improved YOLO11, named GFS-YOLO11. In order to achieve a lightweight network, we propose the C3k2_Ghost module to replace the C3K2 module in the original network, which can ensure a feature extraction capability and reduce model computation. In order to compensate for the potential feature loss caused by the light weight, this paper proposes a feature-refining module (FRM). After embedding each feature extraction module in the trunk network, it improves the feature expression ability of common tomato and cherry tomato in complex field environments by means of depth-separable convolution, multi-scale pooling, and channel attention and spatial attention mechanisms. In addition, in order to further improve the detection ability of the model for tomatoes of different sizes, the SPPFELAN module is also proposed in this paper. In combining the advantages of SPPF and ELAN, multiple parallel SPPF branches are used to extract features of different levels and perform splicing and fusion. To verify the validity of the method, this study constructed a dataset of 1061 images of common and cherry tomatoes, covering tomatoes in six ripened categories. The experimental results show that the performance of the GFS-YOLO11 model is significantly improved compared with the original model; the P, R, mAP50, and MAP50-95 increased by 5.8%, 4.9%, 6.2%, and 5.5%, respectively, and the number of parameters and calculation amount were reduced by 35.9% and 22.5%, respectively. The GFS-YOLO11 model is lightweight while maintaining high precision, can effectively cope with complex field environments, and more conveniently meet the needs of real-time maturity detection of common tomatoes and cherry tomatoes. Full article

Melon (Cucumis melo) includes more than ten botanical groups, many of which feature netting ornamentation on the surface of mature fruit. Ripe melons display a netted skin that signifies their ripeness and readiness for consumption. Previously, we identified SKIN NETTING (CmSN), which encodes an EamA-like transporter family protein, as the candidate gene controlling fruit skin netting formation in melon, while its biological functions remain unclear. In this study, we demonstrated that the expression of the CmSN gene was considerably lower in netted melons compared to smooth-skinned melons, indicating a negative correlation between CmSN expression and netting formation. Subsequently, we employed transient overexpression and virus-induced gene silencing (VIGS) experiments to explore the role of CmSN gene during fruit development. Overexpression of the CmSN gene inhibited netting development, whereas silencing it promoted netting formation. Using heterologous transformation in tomato, we further confirmed the effect of the CmSN gene on rind texture and toughness, as these tomatoes exhibited rougher and tougher skins. Analysis with near-isogenic lines (NILs) revealed that CmSN gene-bearing fruits (NIL_CmSN) possessed significantly harder rinds than the control smooth-skinned variety HB42, underscoring the role of CmSN in enhancing rind protection. Together, our research offers essential insights into the netting formation and genetic improvement of melon fruits. Full article

Tomato (Solanum lycopersicum L.) is a widely cultivated horticultural crop. It belongs to the Solanaceae family and is known for its high concentration of essential nutrients, including vitamins, minerals, and bioactive compounds with antioxidant properties. The Mediterranean countries, including Italy, Spain, and Greece, have a diverse range of tomato landraces. Assessing the nutritional and bioactive composition of different tomato varieties and their ripening stages is crucial to determine their suitability for the market. Therefore, the aim of this study was to investigate the effect of ripening on nutritional composition (including carotenoids and polyphenols content) and antioxidant activities of fruits of three specific tomato varieties grown in Spain: Josefina and Karelya, which are cherry-like tomatoes, and Muchamiel, a type of salad tomato. In addition to evaluating their characteristics and composition (including carotenoids and polyphenol content), the antioxidant activities of these varieties at three different ripening stages were quantified. As expected, the results reveal that, as the tomatoes matured, their antioxidant capacity increased along with higher levels of carotenoids and polyphenols. Interestingly, cherry-like tomatoes showed a higher antioxidant activity than the salad tomatoes. This investigation emphasizes the role of fruit ripening in increasing carotenoid levels, which contribute to the antioxidant activity of three tomato varieties. Full article

Black soldier fly larvae (BSFL) can convert various organic substrates into high added-value biomass. In addition, the residue can be used as a soil conditioner. Several studies have been conducted on a laboratory scale that may not represent what happens on a prototype scale. Using fruit and vegetable waste as a basic substrate, mixing them with agro-industry by-products (called co-substrates), the Hermes project set up a process on medium (2 kg) and large (10 kg) scales with two different feeding regimes (1.25 g/BSFL and 2 g/BSFL). At the mature stage, larval biomass was separated from frass (the by-product of the larval rearing). The production of larval proteins and fats and the use of frass as soil conditioning were evaluated. The lowest feeding regime (1.25 g/BSFL) provided the best waste valorization. The shift towards higher production scales is not completely linear. The addition of co-substrates to fruit and vegetable waste, as they are provided by the large-scale retail trade, can help to standardize a process as part of an insect farm. The frass recovered from the residue of rearing (on the diet or on the agrifood leftovers) was composted and used in field to grow a processing tomato variety. The addition of composted frass assured a slightly lower yield than synthetic fertilizer but there was no statistically significant difference (p > 0.10). This suggests that partial replacement of synthetic fertilizer with composted frass has potential. Overall, the work demonstrated that, using a multidisciplinary approach, the interest and the value in building a supply chain based on bioconversion mediated by Hermetia illucens can be emphasized. Full article