Nutrient Analysis of Soil and Soilless Strawberries and Raspberries Grown in a Greenhouse

Soilless (hydroponic) vegetables and fruits grown in greenhouses are gaining popularity and potentially represent a compliment toward sustainable food sources. Only a few studies have looked at the nutrient quality of strawberries (Fragaria × ananassa) and raspberries (Rubus idaeus) grown in soilless systems. Dry weights, content of ascorbic acid, tocopherol, total polyphenolic compounds, glucose, fructose, and soluble solids (BRIX) of strawberries and raspberries grown in soilless systems were compared to their counterpart grown in soil. There was no change in dry weights but BRIX values (28% - 31%), glucose (158% - 175%), and fructose (75% - 102%) content for strawberries and raspberries respectively were significantly higher for the soil grown berries compared to soilless grown berries. Contents of ascorbic acid, tocopherol and total polyphenolic compounds were significantly higher in soilless grown strawberries compared to soil grown strawberries by 74%, 53%, and 22% respectively, and contents of ascorbic acid and total polyphenolic compounds were significantly higher in soil grown raspberries by 83% and 67% respectively compared to soilless grown raspberries. Soilless grown produce warrants future research to strive toward the potential to provide nutrient dense crops and opportunities toward optimized sustainable production.

Edible Coatings Based on Apple Pectin,Cellulose Nanocrystals,and Essential Oil of Lemongrass:Improving the Quality and Shelf Life of Strawberries(Fragaria Ananassa)

In this work,nine different types of edible coating based on pectin,cellulose nanocrystals,glycerol,and essential oil of lemongrass were prepared and used to coat strawberries with a film formed directly on the surface of the coated fruit.The effects of the different edible coatings on refrigerated fruits in terms of weight loss,titratable acidity,total soluble solids,pH,and anthocyanin content was evaluated after 2 days,4 days,6 days,and 8 days of storage.Application of the edible coatings reduced the weight loss of the coated strawberries and the anthocyanin content.The total soluble solids content of or uncoated fruit increase more markedly than that of coated fruit.In contrast,pH was maintained for both coated and uncoated strawberries.The edible coatings were effective in minimizing of the weight loss,without worsening the physical chemistry attributes.The treatments T5 and T9 presented the best results.

Effect of Different Processing Methods on Storage Quality of Strawberries

[Objectives]This study aimed to explore the effect of different processing methods on the storage quality of strawberries.[Methods]Strawberries purchased from Xintongtian Supermarket in Cangzhou City were used as the experimental material,and they were subjected to different processing methods:45℃hot air for 30 min,45℃hot water for 10 min and 3%calcium chloride for 1 min.[Results]The processing effect of 45℃hot water for 10 min was better than that of 45℃hot air for 30 min.The processing effect of 3%calcium chloride for 1 min was good.Hot water processing could prolong the time to begin to rot,obviously alleviate the increase in weight loss rate,and obviously alleviate the decrease of soluble solids and Vc contents of strawberry fruit.However,the ability of hot water to delay the decrease of strawberry fruit hardness was not as good as that of calcium chloride.[Conclusions]The strawberries processed with 45℃hot water for 10 min showed the best storage quality.

Cytological Studies on Unreduced Gamete Formation of Strawberries (Fragaria)

A diploid strawberry (Fragaria vesca L.) which can naturally produce unreduced gametes (2n pollen) and doubled-unreduced gametes (4n pollen) was used to study the cytological mechanism of 2n and 4n gamete formation. The result showed that the formation of 2n gamete was mainly due to the abnormal orientation of spindles at metaphase II. The normal orientation of two spindles at metaphase I was perpendicular to each other, which led to tetrad formation at the end of meiosis. Two kinds of abnormal orientation of metaphase II spindles, i. e. parallel spindles and triangle spindles, were observed. Of the parallel spindles, the 4 group chromosomes were distributed to 2 poles and formed a dyad which formed two 2n pollen grains further-ly. Of the triangle spindles, the 4 group chromosomes were distributed to 3 poles and formed a triad which formed one 2n pollen grain and two n pollen grains. In addition, a few very big pollen grains (4n pollen) which probably due to the fusion of the tetrad were found.

Comparison between Hydroponic and Soil-Grown Strawberries: Sensory Attributes and Correlations with Nutrient Content

Hydroponic growing methods are growing in popularity and seem to have numerous benefits (i.e., environmental, increased product yields, year round growing) compared to soil grown crops. Although these advantages are attractive, they do not guarantee a high quality product. Taste is a driver of consumer acceptance;therefore, sensory analysis of the hydroponic product will be an important indicator in its success. In this study, we evaluated the sensory differences and preferences in hydroponically grown and soil-grown strawberries (Fragaria x ananassa) using unspecified discriminatory and preference analyses, and descriptive testing correlated with nutrition content data. Most (87%) of participants could identify differences between hydroponically and soil grown strawberries and 70% preferred the hydroponically grown strawberry (p = 0.06). The nutrient composition of the strawberries significantly influenced several sensory analysis categories (sweetness, overall flavor and overall taste (p < 0.05)). The use of sensory studies in relation to consumer acceptance and nutrient quality will be an important factor to consider for exploring growing methods and techniques in hydroponic technology.

Changes in Physicochemical and Sensory Qualities of “Goha” Strawberries Treated with Different Conditions of Carbon Dioxide

Harvested strawberry fruit is highly perishable because of its soft texture and microbial infestation during postharvest handling. The applications of carbon dioxide (CO2) gas on the quality parameters of strawberry harvested in winter season have shown better effects in several studies. However, very little information is available for the same in summer harvested strawberry. This study was aimed at finding an optimum concentration and duration of CO2 treatment in strawberry fruit var. “Goha” harvested in summer season to increase or maintain postharvest qualities. Fresh strawberries were treated with 15%, 30% and 50% CO2 for 1 or 3 h and then stored at 4?C for up to 13 days along with untreated control. Strawberry samples treated with 50% CO2 for 1 or 3 h and both 15% and 30% for 3 h had higher firmness than samples treated with both 15% and 30% for 1 h and control. In general, total soluble solids (TSS) slightly increased or maintained during storage in all samples except control. The values of pH slightly declined whereas titratable acidity showed opposite trends. However, there was no significant difference found among CO2 treated samples. Lightness (L*) of “Goha” samples with no CO2 treatment decreased gradually while it was almost maintained in CO2 treated strawberries. Strawberry samples treated with 15% CO2 for 3 h maintained better quality with higher scores of overall quality and visual texture until 9 days of storage. Samples treated with 15% CO2 for 3 h also received lower softening scores until 9 days of storage compared to other CO2 treated samples. These results showed that 15% CO2 for 3 h condition could be an effective postharvest treatment for maintaining quality of “Goha” strawberry.

Resistance status of the carmine spider mite, Tetranychus cinnabarinus and the twospotted spider mite, Tetranychus urticae to selected acaricides on strawberries

The carmine spider mite, Tetranychus cinnabarinus （Boisduval） and the twospotted spider mite, Tetranychus urticae Koch, are serious pests of strawberries and many other horticultural crops. Control of these pests has been heavily dependent upon chemical acaricides. Objectives of this study were to determine the resistance status of these two pest species to commonly used acaricides on strawberries in a year-round inten- sive horticultural production region. LC90 of abamectin for adult carmine spider mites was 4% whereas that for adult twospotted spider mites was 24% of the top label rate. LC90s of spiromesifen, etoxazole, hexythiazox and bifenazate were 0.5%, 0.5%, 1.4% and 83% of their respective highest label rates for carmine spider mite eggs, 0.7%, 2.7%, 12.1% and 347% of their respective highest label rates for the nymphs. LC90s of spiromesifen, etoxazole, hexythiazox and bifenazate were 4.6%, 11.1%, 310% and 62% of their respec- tive highest label rates for twospotted spider mite eggs, 3%, 13%, 432,214% and 15% of their respective highest label rates for the nymphs. Our results suggest that T. cinnabarinus have developed resistance to bifenazate and that the T. urticae have developed resistance to hexythiazox. These results strongly emphasize the need to develop resistance management strategies in the region.

Real-Time Detection and Instance Segmentation of Strawberry in Unstructured Environment

The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-ronment is a challenging task.Current instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low accuracy.To this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT framework.The key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature extraction.Additionally,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s performance.Furthermore,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum suppression.The experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom dataset.Moreover,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 FPS.The method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.

FaSnRK1a mediates salicylic acid pathways to enhance strawberry resistance to Botrytis cinerea

Strawberry is a major fruit crop worldwide because its nutritional and health benefits to human health,but its productivity is limited by Botrytis cinerea.Sucrose nonfermentation 1-related protein kinase 1(SnRK1)has a defense function against pathogens,but the function of SnRK1 in the defense response to B.cinerea in plants is still unclear.In this study,FaSnRK1a-OE and RNAi fruits were constructed and then inoculated with B.cinerea.The result reveals a positive role of Fa SnRK1a in the regulation of resistance to gray mold.FaSnRK1a affects SA content by regulating FaPAL1 and FaPAL2 expressions.The genes related to the SA signaling pathway(FaTGA1 and FaTGA2.1)were significantly increased/decreased in FaSnRK1a-OE or FaSnRK1a-RNAi fruit,respectively.FaSnRK1a interacted with the FaWRKY33.2 protein and negatively regulated FaWRKY33.2 expression,and FaWRKY33.2 acts as a repressor of disease resistance to B.cinerea.Finally,FaSnRK1a regulates the expression of six PR genes and the activities of antioxidant enzymes to boost defense response after B.cinerea inoculation.Our findings showed that FaSnRK1a increases the resistance of strawberry fruit to B.cinerea via SA signaling pathway and interaction with the FaWRKY33.2 transcription factor.

Ellagic Acid Enhances Antioxidant System Activity and Maintains the Quality of Strawberry Fruit during Storage

Ellagic acid(EA)is a natural antioxidant,widely present in a lot of forms’soft fruits,nuts,and other plant tissues,and helpful for promoting human health;however,its protective effect on postharvest fruit and improving the quality index of postharvest fruit have rarely been studied.In this experiment,the strawberries were soaked in 0,100,200,300,400,and 500 mg L^(−1) EA,respectively,and the influential EA on fruit quality and the antioxidant system of strawberries were studied.Compared with the control,EA treatment can reduce the browning degree and rotting rate of strawberry fruit during storage and augment the soluble solid content(SSC).EA treatment can also increase the content of related stuff and enzyme activity in antioxidant systems;the gene expression level of polyphenol oxidase(PPO)in strawberries treated with EA was always down-regulated,correspondingly,the expression of other antioxidant enzyme genes was enhanced.Among the strawberry fruits treated with EA of different concentrations,300 mg L^(−1) EA had the best effect in the process of strawberry preservation.The results suggested that the proper concentration of exogenous EA at 300 mg L−1 could maintain strawberries’quality and enhance the antioxidant system by improving the activities of antioxidative enzymes and the ascorbateglutathione(AsA-GSH)cycle during storage.

Genome-Wide Discovery and Expression Profiling of the SWEET Sugar Transporter Gene Family in Woodland Strawberry (Fragaria vesca) under Developmental and Stress Conditions: Structural and Evolutionary Analysis

The SWEET(sugar will eventually be exported transporter)family proteins are a recently identified class of sugar transporters that are essential for various physiological processes.Although the functions of the SWEET proteins have been identified in a number of species,to date,there have been no reports of the functions of the SWEET genes in woodland strawberries(Fragaria vesca).In this study,we identified 15 genes that were highly homolo-gous to the A.thaliana AtSWEET genes and designated them as FvSWEET1–FvSWEET15.We then conducted a structural and evolutionary analysis of these 15 FvSWEET genes.The phylogenetic analysis enabled us to categor-ize the predicted 15 SWEET proteins into four distinct groups.We observed slight variations in the exon‒intron structures of these genes,while the motifs and domain structures remained highly conserved.Additionally,the developmental and biological stress expression profiles of the 15 FvSWEET genes were extracted and analyzed.Finally,WGCNA coexpression network analysis was run to search for possible interacting genes of FvSWEET genes.The results showed that the FvSWEET10 genes interacted with 20 other genes,playing roles in response to bacterial and fungal infections.The outcomes of this study provide insights into the further study of FvSWEET genes and may also aid in the functional characterization of the FvSWEET genes in woodland strawberries.

Management of Strawberry Grey Mold Disease Using Biocontrol Agents and Plant Extracts

Strawberry (Fragaria × ananassa Duch.) is a significant global soft fruit crop, prized for its nutrient content and pleasant flavor. However, diseases, particularly grey mold caused by Botrytis cinerea Pers. Fr. poses major constraints to strawberry production and productivity. Grey mold severely impacts fruit quality and quantity, diminishing market value. This study evaluated five B. cinerea isolates from various locations in the Ri-Bhoi district of Meghalaya. All isolates were pathogenic, with isolate SGM 2 identified as highly virulent. Host range studies showed the pathogen-producing symptoms in the fava bean pods, marigold, gerbera, and chrysanthemum flowers and in the fava bean, gerbera, and lettuce leaves. In vitro tests revealed that neem extract (15% w/v) achieved the highest mycelial growth inhibition at 76.66%, while black turmeric extract (5% w/v) had the lowest inhibition at 9.62%. Dual culture methods with bio-control agents indicated that Bacillus subtilis recorded the highest mean inhibition at 77.03%, while Pseudomonas fluorescens had the lowest at 20.36% against the two virulent isolates. Pot evaluations demonstrated that B. subtilis resulted in the lowest percent disease index at 20.59%, followed by neem extract at 23.31%, with the highest disease index in the control group at 42.51%. Additionally, B. subtilis significantly improved plant growth, yielding an average of 0.32 kg compared to 0.14 kg in the control. The promising results of B. subtilis and neem leaf extract from this study suggest their potential for eco-friendly managing grey mold in strawberries under field conditions.

Effect of K Fertilizer on Absorption of Mineral Elements in Greenhouse-grown Strawberry Fruits

[Objectives]The paper was to explore the effect of K fertilizer on the absorption of mineral elements in greenhouse-grown strawberry fruits.[Methods]A systematic investigation was conducted on the effects of K fertilizer dosage levels on the absorption of mineral elements in Fengxiang strawberries,an excellent variety suitable for cultivation in Anhui Province.The investigation was carried out under medium N and P conditions in a greenhouse.[Results]The N content of strawberry fruits increased as the K_(2)O dosage increased within the range of 0-250 kg/hm^(2).Similarly,the P content of strawberry fruits increased gradually with the increase of K_(2)O dosage within the range of 0-125 kg/hm^(2).[Conclusions]This study presents a basis for enhancing the absorption of mineral elements in strawberry fruit by applying K appropriately.

Recognition and localization of strawberries from 3D binocular cameras for a strawberry picking robot using coupled YOLO/Mask R-CNN

To solve the problem of high labour costs in the strawberry picking process,the approach of a strawberry picking robot to identify and find strawberries is suggested in this study.First,1000 images including mature,immature,single,multiple,and occluded strawberries were collected,and a two-stage detection Mask R-CNN instance segmentation network and a one-stage detection YOLOv3 target detection network were used to train a strawberry identification model which classified strawberries into two categories:mature and immature.The accuracy ratings for YOLOv3 and Mask R-CNN were 93.4%and 94.5%,respectively.Second,the ZED stereo camera,triangulation,and a neural network were used to locate the strawberry in three dimensions.YOLOv3 identification accuracy was 3.1 mm,compared to Mask R-CNN of 3.9 mm.The strawberry detection and positioning method proposed in this study may effectively be used to supply the picking robot with a precise location of the ripe strawberry.

Application of electronic nose and GC-MS for detection of strawberries with vibrational damage

Objectives: This study evaluated the potential of using electronic nose (e-nose) technology to non- destructively detect strawberry fruits with vibrational damage based on their volatile substances (VOCs). Materials and methods: Four groups of strawberries with different durations of vibrations (0, 0.5, 1, and 2 h) were prepared, and their e-nose signals were collected at 0, 1, 2, and 3 days after vibration treatment. Results: The results showed that when the samples from all four sampling days during storage were used for modelling, both the levels of vibrational damage and the day after the damage happened were accurately predicted. The best models had residual prediction deviation values of 2.984 and 5.478. The discrimination models for damaged strawberries also obtained good classification results, with an average correct answer rate of calibration and prediction of 99.24%. When the samples from each sampling day or vibration time were used for modelling, better results were obtained, but these models were not suitable for an actual situation. The gas chromatography-mass spectrophotometry results showed that the VOCs of the strawberries varied after experiencing vibrations, which was the basis for e-nose detection. Limitations: The changes in VOCs released by other forces should be studied in the future. Conclusions: The above results showed the potential use of e-nose technology to detect strawberries that have suffered vibrational damage.

Metabolomic and transcriptomic analysis reveals the molecular mechanism by which blue light promotes lutein synthesis in strawberry

Carotenoids are an important component of the human diet, and fruit is a primary source of carotenoids. The synthesis and regulation of carotenoids in fruit are important contributors to the formation of fruit quality. In China, strawberry is one of the main seasonal fruits grown in the winter. Previous studies have shown that light has a significant effect on the metabolism of anthocyanins, sugars, and polyphenols in strawberry. However, the understanding of the role of light in regulating the metabolism of carotenoids in strawberry remains limited. This study investigated the effects of blue, red, yellow-green, and white light on carotenoid metabolism in strawberry.Blue light treatment promoted the synthesis of multiple carotenoids, including lutein, compared with the other three treatment groups. The RNA sequencing data revealed that blue light treatment promoted the expression of lycopene ε-cyclase(LCYE), and the transient overexpression of LCYE in strawberry fruit promoted lutein accumulation in strawberry. Overall, the results suggest that blue light can promote the synthesis of lutein in strawberry by inducing the expression of LCYE.

Nutritional, Textural, Sensory Properties and Storage Stability Evaluation of Newly Formulated Strawberry Bar

An analytical study was conducted to develop a strawberry bar and analysis of the nutritional quality and storage stability of a newly formulated strawberry bar. In proximate analysis moisture, ash, pH, acidity, vitamin C, total phenolic content, and antioxidant of strawberry pulp were found 82%, 0.5%, 2.57, 1.38%, 49 mg/100g, 0.33%, 75.17% whereas, in the strawberry bar, it was found 18%, 0.71%, 2.10, 1.10%, 22 mg/100g, 0.14%, 56.13% respectively. For textural properties analysis, the textural profile of the strawberry bar such as hardness, factorability, viscosity, cohesiveness, adhesiveness, springiness, gumminess, chewiness, probe diameter, threshold, filtering range of strawberry bar was found 5.538 × 104 N/m, 0.000 N/m2, 1.687 × 104 N/m2, 0.6636, 2.908 × 103 J/m3, 0.8664, 3.675 × 104 N/m2, 3.184 × 104 N/m2, 20.000 mm, 5 N, 0.4 N respectively whereas the maximum level was 17.4 N at 29.628 seconds and the minimum level was -5.3 N at 30.166 seconds. The sensory evaluation of the strawberry bar was conducted based on nine-point hedonic scales. The sensory evaluation results indicated that the appearance of the strawberry bar was liked very much and the taste, texture, color, aroma, and overall acceptability of the strawberry bar were liked moderately by panelists. In microbiological analysis, the Total Viable Count (TVC) and Total Coliform Count (TCC) of the strawberry bar were found safe levels for up to third days. But on the sixth day, the TCC of the strawberry bar was not found and the TVC of the strawberry bar was found 17 × 104 cfu/g respectively which is higher than the permitted value (Gulf Standard: 105 cfu/g). From the microbial point of view, the newly formulated strawberry bar was safe to consume for up to 3 days but not for 6 days.

Rapid Screening of Pesticide Residues in Strawberry Based on HPLC-QTOF/MS SWATH Acquisition Mode

[Objectives]The paper was to establish a rapid screening method of pesticide residues in strawberry based on HPLC-QTOF/MS SWATH acquisition mode.[Methods]The strawberry sample was extracted with acetonitrile,purified with anhydrous magnesium sulfate,sodium chloride and primary secondary amine(PSA)powder,and then loaded on the machine.The full information spectrum was collected by positive ion mode and screened by comparing with the spectrum library,and 20 kinds of pesticide residues were quantitatively analyzed.[Results]The detection limits of 20 pesticide residues were 0.0002-0.0100 mg/kg,and they showed good linearity in the range of 0.0005-0.1000μg/mL(R 2≥0.995).The recoveries ranged from 62.8%to 106.3%.[Conclusions]This method is rapid,simple,sensitive and non-targeted,and can be used for rapid screening of multiple pesticide residues in strawberry.

Study on a Bowl-based Mechanism for Transplanting Potted Strawberry Seedlings

To improve the efficiency of fetching and transplanting seedlings for the mechanization of strawberry planting,an integrated transplanting mechanism was designed with protruding,fetching and planting performance to achieve rapid fetching and pushing bowl movements.According to the working principle of the slewing mechanism,a kinematics model and the optimization goal were established,respectively.Based on visual auxiliary analysis software,optimal parameters were obtained.A three-dimensional model was established to obtain a simulation trajectory by means of a virtual simulation design analysis.Three-dimensional printing technology was used to manufacture the test prototype,and the actual working trajectories of the test prototype were extracted using high-speed photography technology,which verified the consistency of the actual trajectory with the theoretical and simulated trajectories.A prototype transplanting experiment was performed with the success rate of seedling extraction of 91.2%and excellent planting rate of 82.8%,which met the requirements for integrated strawberry harvesting,planting and transplanting.The experimental results verified the correctness and feasibility of the design of integrated transplanting mechanism.