Fruit Acidity Research Articles

Sensor-Based Fertigation Management Enhances Resource Utilization and Crop Performance in Soilless Strawberry Cultivation

The use of wireless sensors for real-time sensing of substrate water status and electrical conductivity could be an effective tool for precision irrigation management in soilless cultivation. In this research, the effects of timer-based (TB) compared to smart sensor-based irrigation (SB) were investigated. The highest consumption of fertilizers and water were recorded in TB, with nutrient solution and total applied water savings of 38% and 26%, respectively, in SB. The highest yield was obtained in SB treatment, with a total and marketable yield decrease of 7% in TB, with no differences in terms of the total soluble solids content, dry matter, firmness, juice pH and titratable acidity of the strawberry fruits. The higher yield, combined with water and nutrient saving in SB, allowed water use efficiency (fresh weight of marketable fruits per liter of total water applied) to be increased by 46% and nutrient productivity (fresh weight of marketable product per gram of nutrient supplied via nutrient solution) by 74%. The study confirms that sensor-based, compared to empiric fertigation management, ameliorates the sustainability of open, free-drain, soilless cultivation of strawberry, leading to better resource use without compromising crop performance and fruit quality.

β-Aminobutyric Acid Effectively Postpones Senescence of Strawberry Fruit by Regulating Metabolism of NO, H2S, Ascorbic Acid, and ABA

Current researchis focused on the influence of β-aminobutyric acid (BABA) on the metabolism of nitric oxide (NO), hydrogen sulfide (H2S), ascorbic acid, and abscisic acid (ABA) in strawberry fruit. The increases in ion leakage and malondialdehyde (MDA) concentration in strawberry fruit and the degradation of chlorophyll in the sepals of the fruit were markedly inhibited by BABA at 20 mM. BABA-immersed fruit exhibited lower activities and expressions of polygalacturonase (PG), pectinmethylesterase (PME), and ethylene biosynthetic enzymes compared to the control. Furthermore, BABA immersion evidently upgraded the metabolic levels of NO and H2S, including the enzymatic activities and intermediary contents of metabolites, which collectively enhanced the levels of endogenous NO and H2S contents in strawberry fruit. The high enzymatic activities and gene expressions of the AsA biosynthesis pathway jointly maintained AsA accumulation in the BABA-treated sample. The application of BABA led to a decrease in ABA concentration, which was associated with reduced activities and gene expression levels of key enzymes participating in ABA metabolism. Our experimental observations showed that immersion with BABA may be a highly promising means to delay senescence and reduce natural decay in strawberry fruit, and the alleviation in senescence using BABA may be attributed to the modulation of NO, H2S, AsA, and ABA metabolism.

Identifying candidate host plants for trap cropping against Drosophila suzukii in vineyards

AbstractThe spotted wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is a serious pest in vineyards where it is difficult to control. Trap cropping, which involves manipulating the host plant composition in the crop vicinity to lure the pest away from grapes and towards more attractive host plant fruits, might be an interesting but so far neglected control approach to limit SWD egg-laying in grapes. An ideal trap crop should be more attractive to the pest than the actual crop and should ideally restrict pest development. We determined the attractiveness of fruits of 60 plant species for SWD egg-laying and their suitability for larval development in laboratory assays. Compared to grapes, 16 of the 60 fruits were strongly preferred by SWD females for egg-laying and additionally inhibited the development of SWD larvae into adults. Host preference was strongly influenced by the hardness of the fruit skin, and larval development was marginally affected by the acidity of fruits. However, none of the measured fruit traits had a significant effect on the emergence success of SWD. All 16 candidate trap crop plants should be further tested for their potential to reduce SWD infestation of grapes. We provide practical advice on the next steps to be taken for implementing a successful trap cropping strategy against SWD in commercial vineyards.

Exploring the impact of cold plasma treatment on the antioxidant capacity, ascorbic acid, phenolic profile, and bioaccessibility of fruits and fruit juices

AbstractIn recent years, cold plasma (CP) has emerged as a promising preservation technology for fruit products. Several CP sources include dielectric barrier discharge, plasma jets, corona discharges, micro‐discharges, glow discharges, and gliding arc discharges. However, the effects of these different types of CP on the chemical compounds of fruits and juices are not fully understood. In this review, we summarize (I) the current knowledge on the use of CP for the preservation and processing of fruits and juices; (II) the diverse types of CP sources and explore their applications within a scientific context; (III) the physicochemical transformations that take place in fruits and juices following CP treatment; and (IV) the changes observed in antioxidant activity, vitamin C content, phenolic compounds, and their bioaccessibility. Numerous studies have explored CP's influence on microbial contamination, shelf life, enzymes, and various physicochemical changes. This review uniquely centers its attention on the impact of CP on bioactive phenolic compounds, their bioaccessibility, vitamin C content, and antioxidant activity in different types of fruits and fruit juices. Additionally, this review delves into the assessment of selected sensory properties, notably color, which is an important parameter for consumer acceptance. By focusing on these particular aspects, we aim to provide a targeted and comprehensive analysis of CP's effects on essential nutritional and quality attributes of fruits and fruit juices, distinct from the broader spectrum covered in the existing literature.

Prohexadione-calcium improves grape quality by regulating endogenous hormones, sugar and acid metabolism and related enzyme activities in grape berries.

Prohexadione-Calcium (Pro-Ca) plays key roles in improving fruit quality and yield by regulating various aspects of plant growth. However, the effects of how Pro-Ca regulates the regulation of sugar and acid balance and its impact on the production of volatile aroma substances during fruit growth and development are poorly understood. In this study, the Pro-Ca solutions developed at concentrations of 200, 400, 600 and 800 mg·L-1 were sprayed on the entire "Chardonnay" grape tree 22, 42, 62 and 82 days after initial flowering. The values of endogenous hormones, sugar and acid content, enzyme activities and flavor content were then measured in grapes 45, 65, 85 and 105 days (ripeness stage) after the initial flowering. The results showed that Pro-Ca had significant effects on fruits during development, including reducing ABA content, increasing ZT, GA3 and IAA levels, promoting fruit ripening and enhancing enzymes, which are involved in sugar and acid synthesis. Consequently, these effects led to an increase in sugar and acid content in the berries. Particularly during the ripening phase, the application of 600 mg L-1 Pro-Ca resulted in an increase in soluble sugar content of 11.28% and a significant increase in citric acid and malic acid content of 97.80% and 68.86%, respectively. Additionally, Pro-Ca treatment enhanced both the variety and quantity of aroma compounds present in the berries, with the 600 mg·L-1 Pro-Ca treatment showcasing the most favorable impact on volatile aroma compounds in 'Chardonnay' grapes. The levels of aldehydes, esters, alcohols, phenols, acids, ketones, and terpenes were significantly higher under the 600 mg·L-1 Pro-Ca treatment compared to those of control with 51.46 - 423.85% increase. In conclusion, Pro-Ca can regulate the content of endogenous hormones and the activities of enzymes related to sugar and acid metabolism in fruit, thereby increasing the content of soluble sugar and organic acid in fruit and the diversity and concentration of fruit aroma substances. Among them, foliar spraying 600mg · L-1 Pro-Ca has the best effect. In the future, we need to further understand the molecular mechanism of Pro-Ca in grape fruit to lay a solid foundation for quality improvement breeding.

Effect of Foliar Feeding with Nutrients and Bioregulators on Yield and Quality Attributes of Litchi cv. Bombai

Litchi (Litchi chinensis Sonn.) is considered one of the most important sub-tropical fruits of the world. In the western part of Odisha, India, litchi growers are facing problems of unstable and lower marketable yield and inferior quality due to a higher incidence of fruit cracking, fruit drop, low sugar content, and higher fruit acidity. Keeping in mind the positive effects of nutrients and bioregulators, the current study was conducted to elucidate their impact on fruit yield and quality in the farmers’ field of Jamankira block in Sambalpur district of Odisha, which is under the care of Odisha University of Agriculture and Technology, India. For this study, eight-year-old litchi trees were selected. With 12 treatments, the experiment was set up in a Randomized Block Design replicated thrice, as follows: T1: spray treatment with Borax—0.5%; T2: spray treatment with Borax—0.3%; T3: spray treatment with ZnSO4—0.75%; T4: spray treatment with ZnSO4—0.5%; T5: spray treatment with CaCl2—0.5%; T6: spray treatment with CaCl2—0.1%; T7: spray treatment with humic acid—1.5%; T8: spray treatment with humic acid—1%; T9: spray treatment with seaweed extract—0.5%; T10: spray treatment with seaweed extract—0.1%; T11: foliar spray with NAA—20 ppm; and T12: control (Water Spray). The current study compared foliar feeding treatments comprising different nutrient and bioregulators, which were applied during the first week of December, just after the completed formation of new leaves and the untreated control. The highest total number of fruits per plant was recorded in plants sprayed with 0.5% ZnSO4 (T4) followed by those treated with 1% humic acid (T8). The highest total fruit yield was recorded in plants subjected to foliar feeding with 0.3% Borax (T2) which was found to be statistically similar to plants treated with 0.1% seaweed extract (T10) and 0.5% seaweed extract (T9). Among the treatments, a better response, i.e., a higher number of marketable fruits and marketable yield, was recorded in litchi plants treated with 0.3% Borax (T2) followed by 0.5% zinc sulphate (T4), 1% humic acid (T8), and 0.1% CaCl2 (T6). The application of 1% humic acid (T8) followed by 1.5% humic acid (T9) enhanced fruit setting (%) and fruit retention rates (%) and reduced the fruit drop rate (%). The enhanced fruit size (fruit length and fruit width) and higher fruit weight was obtained in litchi plants treated with 0.3% Borax. The foliar application of 0.3% Borax (T2) also resulted in a higher TSS, total sugars, reducing sugar content, lower acidity, the highest aril weight, and lower seed weight in litchi cv. Bombai. In this research, among the five principal components, only PC1 demonstrated approximately 45.14% variability within the influential axes. PC1 contributed the highest proportion (48.9%) to the overall variability, followed by PC2 with 29.1%, PC3 with 11.9%, PC4 with 0.59%, and PC5 with 0.20%. Consequently, the outcomes of the principal component analysis indicate the presence of extensive variability among treatments.

Synergistic Influence of Arbuscular mycorrhizal Fungi Inoculation with Nanoparticle Foliar Application Enhances Chili (Capsicum annuum L.) Antioxidant Enzymes, Anatomical Characteristics, and Productivity under Cold-Stress Conditions.

In this study, we aimed to evaluate the effects of Arbuscular mycorrhiza fungus (AMF) inoculation, foliar application of zinc oxide and selenium nanoparticles (ZnO-NPs and Se-NPs), and their combined interactions on the growth and productivity of chili pepper under cold-stress conditions. Two field experiments were successfully conducted during the winter seasons of 2021 and 2022 in an experimental field at the Faculty of Agriculture, Cairo University, Giza, Egypt. The results showed that, under cold stress, the combination of AMF inoculation and ZnO-NPs + Se-NPs as a foliar spray increased the average fruit weight by 92.4% and 98.7%, and the number of fruits by 34.6% and 54.8 compared to control treatment in the 2021 and 2022 seasons, respectively. Additionally, the combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) significantly increased the total marketable yield by 95.8% and 94.7% compared to the control, which recorded values of 2.4 and 1.9 kg m-2 in the 2021 and 2022 seasons, respectively. Furthermore, the combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) showed the highest total content of ascorbic acid and capsaicin in chili fruits compared to the other treatments. The combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) stimulated the accumulation of peroxidase (POD) and nitrogen glutamate dehydrogenase (GDH) while decreasing hydrogen peroxide (H2O2) and lipid peroxidation (MDA) contents. SDS analysis revealed that the application of ZnO-NPs, Se-NPs, AMF + ZnO-NPs, and AMF + ZnO-NPs + Se-NPs induced the emergence of new protein bands and reconstitution of those damaged by cold stress. Regarding histological structure, the combination of AMF inoculation and ZnO-NPs + Se-NPs as a foliar spray showed an enhancement in the thickness of grana thylakoids and increased the number of chloroplasts. Intriguingly, the findings showed that AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) could offer guidance for increasing plant development and productivity under cold-stress conditions.

Effects of Naphthalene Acetic Acid and Zinc Sulphate on Fruiting Behavior and Quality of Litchi (Litchi chinensis Sonn.) cv. Rose Scented

The current study evaluated the effect of NAA and zinc sulphate to maintain fruiting behaviour and qualitative attributes of fruit in litchi cv. Rose scented. This experiment was done in 2022 and 2023 at the Horticulture Garden, Department of Fruit Science, C.S. Azad University of Agriculture and Technology, Kanpur (U.P.). There were sixteen treatments including four levels of zinc sulphate (0, 0.2, 0.4 and 0.6 %), NAA (0, 25, 50 and 75 ppm) and their combinations imitated in Factorial- CRD. The foliar application of treatments was done on January 28 and March 16 of each year, prior to flowering and fruit setting at pea stage, respectively. This experiment showed that the treatment with NAA 50ppm and 0.4% zinc sulphate improved fruit set (63.40 and 62.73 %), fruit retention (30.76 and 31.36 %) and reduced fruit drop (69.23 and 68.63 %). The same treatment blend increased juice content of litchi fruit (63.63 and 64.22 %) and also improved nutritional qualities of fruit like total soluble solids (22.75 and 22.62 0Brix), total sugar (14.48 and 14.54 %), ascorbic acid (41.22 and 41.64 mg/ 100g of pulp), organoleptic test (85.36 and 86.82) and minimum titratable acidity (0.473 and 0.421 percent) in litchi fruits. The treatment combination of NAA 50ppm and 0.4% zinc sulphate was found to be the best in this experiment.

Morfološka i kemijska analiza introduciranih sorti nektarine u Hercegovini

A 2-year study was done to compare fruit morphological and chemical composition of three nectarine cultivars grown in south Hercegovinia conditions. A high variability among and within cultivars was found and significant differences were observed among them in all properties analyzed. On the basis of evaluated data, the best fruit performance was registered in ‘Caldesi 2000’ and ‘Venus’ grown in the condition of this part of the Mediteran. This evaluation may help to select a set of nectarine cultivars with better fruit quality attributes, which in our growing conditions might be indicated in ‘Caldesi 2000’ and somewhat in ‘Venus’. The highest average of fruit width (61.18 mm) and fruit weight (148.24 g) was found in cultivar Caldesi 2000. As for friut thickness, also cultivar Caldesi 2000 had the highest value (55.39 mm). The results for the highest fruit length (60.48 mm) had Venus cultivar also fruit stone weight length, width and thickness. The contents sugars (glucose, fructose) total soluble dry matter, and total acids in fruits were found in cultivar Venus, but pH and sucrose were found in cultivar Sun Grand.

Identification and expression analysis of citrate synthase 3 gene family members in apple

As one of the key enzymes in cell metabolism, the activity of citrate synthase 3 (CS3) regulates the substance and energy metabolism of organisms. The protein members of CS3 family were identified from the whole genome of apple, and bioinformatics analysis was performed and expression patterns were analyzed to provide a theoretical basis for studying the potential function of CS3 gene in apple. BLASTp was used to identify members of the apple CS3 family based on the GDR database, and the basic information of CS3 protein sequence, subcellular localization, domain composition, phylogenetic relationship and chromosome localization were analyzed by Pfam, SMART, MEGA5.0, clustalx.exe, ExPASy Proteomics Server, MEGAX, SOPMA, MEME, WoLF PSORT and other software. The tissue expression and inducible expression characteristics of 6 CS3 genes in apple were determined by acid content and real-time fluorescence quantitative polymerase chain reaction (qRT-PCR). Apple CS3 gene family contains 6 members, and these CS3 proteins contain 473-608 amino acid residues, with isoelectric point distribution between 7.21 and 8.82. Subcellular localization results showed that CS3 protein was located in mitochondria and chloroplasts, respectively. Phylogenetic analysis divided them into 3 categories, and the number of genes in each subfamily was 2. Chromosome localization analysis showed that CS3 gene was distributed on different chromosomes of apple. The secondary structure of protein is mainly α-helix, followed by random curling, and the proportion of β-angle is the smallest. The 6 members were all expressed in different apple tissues. The overall expression trend from high to low was the highest relative expression content of MdCS3.4, followed by MdCS3.6, and the relative expression level of other members was in the order of MdCS3.3 > MdCS3.2 > MdCS3.1 > MdCS3.5. qRT-PCR results showed that MdCS3.1 and MdCS3.3 genes had the highest relative expression in the pulp of 'Chengji No. 1' with low acid content, and MdCS3.2 and MdCS3.3 genes in the pulp of 'Asda' with higher acid content had the highest relative expression. Therefore, in this study, the relative expression of CS3 gene in apple cultivars with different acid content in different apple varieties was detected, and its role in apple fruit acid synthesis was analyzed. The experimental results showed that the relative expression of CS3 gene in different apple varieties was different, which provided a reference for the subsequent study of the quality formation mechanism of apple.

Responses of growth, yield and chemical composition of tomato to phosphorus nutrition under different saline environments

Growing crops on marginal and salt-affected soils with saline water will be more important for agricultural production in the future. The most prevalent anions in saline soils, chloride (Cl-) and sulfate (SO4 2-) have distinct effects on plant growth, metabolism, nutrient composition, productivity, and nutrient requirements. In order to ascertain the role of phosphorus in mitigating salinity stress in tomato plants, a pot experiment was conducted in a screen house under two types of saline environments chloride-dominated (Cl-: SO4 2- = 7:3) and sulfate-dominated (Cl-: SO4 2- = 3:7), with two comparable ECe levels (non-saline and 6 dS m−1) and four graded phosphorus levels (0, 12.5, 25, 50 mg kg−1soil). The significant increase in yield up to 50 ppm added P indicated that plants require more P under chloride salinity than sulfate salinity. In non-saline, chloride, and sulfate-dominated conditions, increased P from 0 to 50 ppm increased chlorophyll 'a‘ and 'b‘ values by 21.4, 19.8 and 23.8% and 10, 20 and 14%, respectively. The reduced photochemical efficiency due to salinity, was increased 32%, 30% and 13% as P level increased from 0 to 50 ppm in non-saline, Cl--6 and SO4 2—6 conditions, respectively. The TSS, ascorbic acid content and titrable acidity of tomato fruits was improved with mild salinity stress but reduced with added P. The plant N, P and K content increased significantly with each added P level irrespective of types of salinity. The plant composition indicated an antagonism between phosphorus and chloride ions and synergism between phosphorus and sulfate ions.

Effects of Glomus fasciculatum, Azotobacter chroococcum and Vermicompost Leachate on the Production and Quality of Tomato Fruit

Arbuscular mycorrhizal fungi, plant-growth-promoting bacteria (PGPB) and vermicompost constitute important environmental and economic resources for improving the production and quality of tomato fruits. The present research aims to determine the single and combined effect of Glomus fasciculatum (Gf) fungus, Azotobacter chroococcum (Azot), PGPB and vermicompost leachate (VL) organic fertilizer on the yield and quality of tomato fruit. Thus, an open-field experiment was established with seven treatments, a control and three replicates. Total soluble solids, vitamin C, acidity, fruit mass and fruit diameter were evaluated as fruit quality variables; the yield was recorded and estimated in tons per hectare−1. The results showed that Gf, Azot and VL were effective in promoting tomato yield and fruit quality. As a trend, the triple combination (Gf + Azot + VL) evidently obtained the highest values of total soluble solids, vitamin C and fruit acidity. The range of improvement concerning the fruit size was 66.6% (single treatment) compared to 78.5% (triple combination). The maximum yield of 54.5 t/ha−1 was recorded for the Gf + Azot + VL combination. Therefore, G. fasciculatum, A. chroococcum and VL are considered useful as organic alternatives for open-field tomato biofertilization programs in tropical countries.

Differences in primary metabolism related to quality of raspberry (Rubus idaeus L.) fruit under open field and protected soilless culture growing conditions.

The raspberry (Rubus idaeus) fruit is characterized by good taste and high acceptability by consumers. Thus, the impact on the quality attributes and metabolites related to raspberry taste should be evaluated in crop alternatives such as the protected soilless culture. This study aimed to evaluate the metabolic changes during fruit development and postharvest of raspberry grown in open field and protected soilless culture and their relationship with quality parameters and sensory perception. In this study, the quality parameters and polar metabolites -sugar and amino acids- content were evaluated during raspberry ripening. In addition, ripe fruit was stored at 1 °C for five days, followed by one day of shelf life at 20 °C. The physiological and quality parameters showed typical changes during ripening in both growing conditions: a constant production of CO2, a drastic loss of firmness, an increase in weight and soluble solids content, loss of acidity, and a turning to red color from the green to fully ripe fruit stages in both growing conditions. Fruit from the protected soilless culture had significantly higher weight but a lower soluble solids content. The metabolic analysis showed differences in primary metabolites content during ripening and storage at 1 °C between both growing conditions. The raspberries grown in the open field showed higher contents of sugars such as D-glucose and D-fructose. On the contrary, the fruit from the protected soilless culture showed higher contents of some amino acids such as L-alanine, L-serine and L-valine, among others. The sensorial panel showed significant differences in the perception of the sweetness, acidity, color and firmness of ripe fruit from both growing conditions. The present study provides interesting and useful results with direct commercial application for this alternative growing system, mainly in areas where soil and water scarcity are a reality.

Salicylic acid mitigates 'Hayward' kiwifruit chilling injury by regulating hormone and proline metabolism, as well as maintaining cellular structure

The 'Hayward' kiwifruit is extremely susceptible to chilling injury (CI) during the late stages of cold storage, thus limiting its storage quality and life. Therefore, mitigating the losses caused by CI is imperative. Salicylic acid (SA) has been demonstrated to mitigate CI in fruit and vegetables. In this study, we conducted a comparative analysis of proline metabolism, key endogenous hormone levels, as well as the effects on cell structure and membrane lipid oxidation in kiwifruit treated with 1 mM SA during low-temperature storage. The results showed that SA could attenuate lipoxygenase (LOX) activity, enhance catalase (CAT) activity, suppress the elevation of malondialdehyde (MDA) content, mitigate starch granule degradation in cells, and preserve cell structure integrity. Moreover, SA was found to enhance proline biosynthesis by activating ornithine transaminase (OAT) and pyrroline-5-carboxylate synthase (P5CS) while concurrently suppressing proline dehydrogenase (PDH) activity. Additionally, exogenous SA increased endogenous levels of both SA and abscisic acid (ABA), while simultaneously decreasing the concentration of gibberellic acid (GA) in fruit. In conclusion, exogenous SA treatment could alleviate the development of CI in kiwifruit by maintaining cell structure, promoting proline synthesis, and balancing endogenous hormone content. Our study offers a theoretical foundation for understanding the mechanism by which SA mitigates cold damage in kiwifruit, and provides novel insights into the low-temperature preservation of kiwifruit.

Isolation and determination of phenolic acids in rowanberry fruits (Sorbus L.) by gas chromatography

Species of the genus Sorbus L. (rowan) are woody plants growing in the Northern Hemisphere; they are of interest as decorative, food and medicinal plants. Rowan fruits contain a unique complex of macro- and microelements, as well as biologically active substances, including phenolic compounds. Complexity of the composition of plant samples requires the development of highly selective and sensitive methods for determining the content of organic components of different classes. A method for determining phenolic acids in rowan fruits is proposed. The method is based on two-stage chemical modification of the acids, and involves preparing methyl esters under acidic methanolysis conditions, liquid extraction with toluene, intermediate re-extraction into an aqueous alkaline solution, subsequent silylation with N, O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) and gas chromatographic determination of the obtained derivatives using a flame ionization or mass spectrometric detector. Conditions for extraction of phenolic acids from rowan fruits were studied according to the following parameters: type of extractant, sample to the extractant mass ratio, and duration of extraction (mechanical stirring). The stage of gas chromatographic determination of obtained phenolic acid derivatives was optimized, and their chromatographic characteristics established. The possibility of achieving practically complete separation of aliphatic acids and other accompanying components of a non-acidic nature from phenolic compounds in the course of sample preparation was demonstrated; which significantly increased both the selectivity and sensitivity of the determination of analytes. The range of determined content of phenolic acids (4-hydroxybenzoic acid, 2-hydroxybenzoic acid, 4-hydroxy-3-methoxy-benzoic acid, 4-hydroxycinnamic acid, 4-hydroxy-3-methoxy-cinnamic acid) in rowan fruits was 0.005–0.5 mg/g, the limit of detection was 0.001–0.002 mg/g, the relative error was 10–15%, the sample weight was 0.5 g, the total duration of the analysis was 4 hours.

Transcriptional co-regulation of anthocyanin accumulation and acidity in fruits

Transcriptional co-regulation of anthocyanin accumulation and acidity in fruits

The impacts of factors existed in surrounding environment on the synthesis of nutritional substances abundant in citrus

Carotenoids, vitamin C and flavonoids are mainly enriched in citrus fruits, and the effects of different environmental factors such as light, temperature, pH and humidity on the synthesis of these three nutrients are discussed. Because of its rich nutrients and delicious taste, citrus has become the first choice of fruit in People’s Daily life. Carotenoids are important nutrients and natural pigments in citrus, and their synthesis is affected by light, temperature and pH value. However, this paper does not delve into the effects of different environmental factors on the synthesis of common nutrients in plants, such as water, fructose, and fruit acids, which require further discussion. Through these discussions, this review aims to provide a scientific basis for the cultivation of citrus and other fruits, promote sustainable agricultural production, and provide consumers with more healthy and nutritious fruit choices.

Production and postharvest quality of <i>Passiflora edulis</i> Sims under brackish water and potassium doses

<abstract> <p>The aim of this research was to assess the yield and postharvest characteristics of 'BRS Sol do Cerrado' sour passion fruits based on irrigation with varying levels of saline water and potassium fertilization. The study was conducted under field conditions at an experimental farm in São Domingos, Paraíba, Brazil. A randomized block design was implemented in a 5 × 4 factorial arrangement, with five levels of electrical conductivity of water (ECw): 0.3, 1.1, 1.9, 2.7, and 3.5 dS m<sup>−1</sup>, and four potassium doses (KD): 60, 80,100, and 120% of the recommended amount, with 3 replications. The potassium dose equivalent to 120% of the recommended dose in combination with low-salinity water resulted in the highest fresh mass accumulation in the sour passion fruit. Water electrical conductivity up to 2.7 dS m<sup>−1</sup>, along with the lowest recommended KD, led to increased levels of soluble solids and ascorbic acid in the sour passion fruit. Irrigation with water of 3.5 dS m<sup>−1</sup> and using 80 to 100% of the recommended KD enhanced the total sugar content in the sour passion fruit. On the other hand, irrigation with water of 3.5 dS m<sup>−1</sup> combined with 60% of the recommended KD resulted in a higher pulp yield in the 'BRS Sol do Cerrado' sour passion fruit 160 days post-transplantation. Adjustments in potassium fertilization management at different irrigation water salinity levels played a crucial role in maintaining both the production and quality of the sour passion fruit.</p> </abstract>

The metabolism of amino acids, AsA and abscisic acid induced by strigolactone participates in chilling tolerance in postharvest zucchini fruit.

Zucchini fruit are notably susceptible to chilling injury when stored at low temperatures. The purpose of this experimental investigation was to assess the influence of strigolactone (ST) (5 μmol L-1) on mitigating chilling injury and the metabolic changes in amino acids, ascorbic acid, and abscisic acid in zucchini fruit stored at 4°C. Research findings demonstrated that ST-treated zucchini fruit displayed a significantly higher tolerance to chilling stress compared to the control group. Postharvest ST treatment led to a decrease in weight loss, accompanied by reduced levels of malondialdehyde and relative ion leakage compared to the untreated group. ST immersion significantly boosted the metabolic pathways associated with proline and arginine, affecting both the enzymatic reactions and gene expressions, thus cumulatively increasing the internal concentrations of these amino acids in zucchini fruit. Zucchini treated with ST exhibited an increased concentration of γ-aminobutyric acid (GABA) as a result of augmented activities and elevated transcriptional levels of glutamate decarboxylase (GAD), GABA transaminase (GAT), and succinate semialdehyde dehydrogenase (SSD). In the ST-treated sample, the elevated enzymatic activities and enhanced gene expressions within the ascorbic acid (AsA) biosynthesis pathway worked together to sustain AsA accumulation. The application of ST resulted in a rise in abscisic acid (ABA) concentration, which correspondingly correlated with the induction of both activities and gene expression levels of crucial enzymes involved in ABA metabolism. Our findings revealed that submerging zucchini fruit in ST could be a highly effective strategy for boosting their chilling tolerance. The alleviation in chilling injury induced by ST may be attributed to the modulation of proline, arginine, GABA, AsA and ABA metabolism.

Effects of meliponiculture Tetragonula laeviceps on productivity, physical and chemical characteristics of tomatoes (Solanum lycopersicum)

Tomato plants are widely grown in Indonesia using the open agriculture system. However, the widespread application of pesticides in horticultural farming, such as tomato, has prevented pollinators from visiting flowers, contributing to decreased diversity and population due to climate change and pollen and nectar availability in agroecosystems. This study aimed to determine the effects of pollination by stingless bee (Tetragonula laeviceps) on pollination success, fruit yield, and estimated productivity on tomato (Solanum lycopersicum). Furthermore, the effects of T. laeviceps as a pollinator was investigated on the physical and chemical characteristics of tomato fruit. This study used two treatments: with and without meliponiculture T. laeviceps. Pollination success and fruit yield increased on with meliponiculture (30.91% and 68.68%, respectively) compared without meliponiculture. The physical (fruit weight, diameter, and mesocarp) and chemical characteristics (moisture content, titratable acidity, total soluble solids, ascorbic acid, and lycopene) of tomato fruit were not affected by T. laeviceps pollination. Meliponiculture T. laeviceps increased pollination success, fruit yield, and estimated productivity but had no effects on the physical and chemical characteristics of tomato fruit. The application of meliponiculture T. laeviceps in tomato plantations proved to be a valuable strategy for increasing productivity.