Horticulturae, Volume 10, Issue 5 (May 2024) – 77 articles

Enzymatic browning, occurring on the cut surfaces of many popular fresh-cut fruit and vegetables due to wounding and the activity of endogenous polyphenyloxidase enzymes, is considered as the main reason for their rejection by consumers. In this study, water extracts were obtained from seeds of cabbage, sinapis, and wild rocket at 10 and 20% w/w seed:water ratios (SWE) and analyzed for total phenolic compounds (TPC) and antioxidant capacity (AC). The extract was then applied on cut surfaces of mid rib segments of lettuce leaves for 1 or 3 min. The segments were stored at 7 °C for 14 days. The SWE’s inhibitory capacity on enzymatic browning were measured by CIELAB color coordinates L* a* and b* and expressed as second derivatives, their % inhibition and different indices. An additional visual acceptance measurement and calculation of shelf life was also performed. The seed extracts of cabbage at 10–20% and wild rocket at 20% showed the highest anti-browning efficacy (comparable to 25 mM potassium metabisulfite control) along with TPC and AC. A high % of seed:water extract and increased exposure time led to a considerable increase in shelf life, visual score, % inhibition of browning or whitening index of the extracts of all seed sources. Chromatometric outcome data clearly showed that the visual data were more accurate than the chromatometric procedure (L*, a*, b* values, their derives ΔE, h°, C, Δh° and ΔC or calculated indices), although the latter could detect the differing degrees of browning development or its inhibition in treated and control segments during storage. Full article

To explore the effects of different preservation methods on the quality of loquat after fresh-keeping treatment, various preservation techniques were employed. These included natural preservation (NP), vacuum freezing preservation (VFP), vacuum at room temperature preservation (VP) and freezing preservation (FP). The quality assessment involved analyzing the effects of these preservation methods using physicochemical indexes, a colorimeter, an electronic nose (E-nose), an electronic tongue (E-tongue) and gas chromatography–mass spectrometry (GC–MS). The results showed minor differences in loquat quality under different preservation methods, with sensory scores ranging from 55 to 78 and ΔE values ranging from 11.92 to 18.59. Significant variations were observed in moisture content (ranging from 53.20 g/100 g to 87.20 g/100 g), calorie content (ranging from 42.55 Kcal/100 g to 87.30 Kcal/100 g), adhesion (ranging from 0.92 to 1.84 mJ) and hardness (ranging from 2.97 to 4.19 N) (p < 0.05). Additionally, the free amino acid content varied from 22.47 mg/g to 65.42 mg/g. GC–MS analysis identified a total of 47 volatile flavor substances in varieties of loquats, including 13 aldehydes, 9 esters, 6 ketones, 2 acids, 3 alcohols, 2 phenols, 3 pyrazines, 1 furan and 8 other substances. The relative content of aldehydes was significantly higher than that of other chemicals. The VFP and FP samples exhibited higher aldehyde content compared to the NP and VP samples. Moreover, Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) revealed 18 marked compounds that could differentiate between 5 loquat species. Analysis using E-nose and E-tongue indicated significant changes in the olfactory and gustatory senses of loquats following preservation. The VFP samples demonstrated the most effective preservation of loquat quality with minimal impact. This study provides some theoretical guidance for the home preservation of loquats. Full article

Citrus is a subtropical fruit tree with high water requirements. This study aimed to determine the effects of water deficit on an orange orchard subjected to different water-saving strategies. The study was realised in an orange orchard in a semiarid area by adopting four different water management techniques: 100% crop evapotranspiration (control); SSDI—subsurface sustained deficit irrigation; RDI—regulated deficit irrigation; PRD—partial rootzone drying treatment during five growing seasons. The experimental design foresaw a randomised block design with six replicates per treatment (24 index plants). The results of the study showed that the water-saving strategies reduced irrigation water consumption by 25% (SSDI), 33% (RDI), and 49% (PRD) compared to the fully irrigated treatment without yield reduction, thus increasing water use efficiency. Mineral nutrition of the trees was slightly affected by irrigation treatments; element concentration in leaves was generally in the optimal range; only potassium showed values below the recommended leaf concentrations. Regarding fruit quality parameters, the vitamin C concentration in RDI showed significant differences with a value of 62.7 mg 100 mL⁻¹ compared to 58.5 mg 100 mL⁻¹ in the control. Plants subjected to SSDI and PRD strategies showed increased levels of pulp colour index with significant values of 10 and 9.90, respectively, compared to the control (8.44). By implementing targeted water management, citrus growers could save water and increase the ascorbic acid and sugar concentration in the fruits; anthocyanins also increased but not significantly. These findings open new market opportunities for citrus growers in marginal areas, where they cannot rely solely on producing citrus fruits to remain competitive. Full article

Sedimentable solids generated in aquaponic systems are mainly composed of organic waste, presenting molecules such as phytate, which can be a potential source of inorganic nutrients through mineralization. This work aimed to isolate and identify phytase-producing bacteria and evaluate the inoculation effects of pure strains on mineralization and nutrient release from solid waste generated in aquaponic systems at different oxygen and temperature conditions. The bacteria were isolated from the settleable solids of a commercial aquaponic system and molecularly identified by amplifying the 16S rRNA gene. Subsequently, two tests were carried out: 1. Test for the biochemical identification of phytase-producing bacteria; 2. In vitro mineralization test, where the ability to mineralize phytate and release nutrients under different oxygen conditions [0 rpm (2.1 mg L⁻¹) and 200 rpm (7.8 mg L⁻¹)] and temperatures (24 and 37 °C) were evaluated. Our findings show that two pure strains of Lysinibacillus mangiferihumi can mineralize phytate under conditions of 200 rpm and 24 °C, mainly increasing the mineralization of PO4- and Ca, a property that has not yet been reported for this species. On the other hand, at 0 rpm and 24 °C, an increase in K was observed (control conditions), while the conditions of 200 rpm and 24 °C, regardless of bacterial inoculation, favored a rise in S, Mg, and Fe. The Lysinibacillus strains obtained in this investigation are of great importance due to their application in agriculture and the optimization of mineralization in aquaponic systems. A proper combination of oxygen and temperature will lead to a greater availability of nutrients for the growth and development of vegetables. Full article

The PlantEye multispectral scanner is an optoelectrical sensor automatically applied to a mechatronic platform that allows the non-destructive, accurate, and high-throughput detection of morphological and physiological plant parameters. In this study, we describe how the advanced phenotyping platform precisely assesses changes in plant architecture and growth parameters of wild rocket salad (Diplotaxis tenuifolia L. [DC.]) under drought stress conditions. Four different irrigation supply levels from moderate to severe, required to keep 100, 70, 50, and 30% of the water-holding capacity, were adopted. Growth rate and plant architecture were recorded through the digital measure of biomass, leaf area, Canopy Light Penetration Depth, five convex hull traits, plant height, Surface Angle Average, and Voxel Volume Total. Vegetation color assessments included hue, lightness, and saturation. Vegetation and senescence indices were calculated from canopy reflectance in the red (620–645 nm), green (530–540 nm), blue (peak wavelength 460–485 nm), near-infrared (820–850 nm), and 3D laser (940 nm) ranges. The temperature, relative humidity, and solar radiation of the environment were also recorded. Overall, morphological parameters, color, multispectral data, and vegetation indices provided over 7200 data points through daily scans over three weeks of cultivation. Although a general decrease in growth parameters with increasing stress severity was observed, plants were able to maintain the same morpho-physiological performances as the control during the early growth stages, keeping both 70% and 50% of the total water-holding capacity. Among indices, the Normalized Differential Vegetation Index (NDVI) contributed the most to the differentiation between different stress levels during the cultivation cycle. Across the 3 weeks of growth, statistically significant differences were observed for all traits except for the Saturation Average. Comparisons with respect to the control highlighted the strong impact of drought stress on morphological plant traits. This study provided meaningful insights into the health status of wild rocket salad under increasing drought stress. Full article

The objective of this study was to investigate the response of the grapevine variety ‘Tribidrag’ to virus infection over two vegetation seasons. Virus-free plants were greenhouse cultivated and green grafted with five different virus inocula composed of grapevine leafroll-associated virus 3 (GLRaV-3) singly or in coinfection with other most economically important grapevine viruses. Changes in nutrient status and photosynthesis-related parameters, along with symptom development, were measured. Using the quantitative PCR method, the relative concentration of five selected Vitis genes was determined. Cluster analysis and ANOVA revealed the reduction in phosphorus concentration (P) and photosynthesis-related parameters in infected plants in both seasons, even in the absence of symptom expression, indicating P and assimilation rate (Photo (A)) as stable markers of virus infection. Plants infected with inoculum Y composed of five different viruses provoked major significant changes in the first season while, in the second, fewer changes were measured. The sucrose synthase 3 gene was upregulated in infected plants confirming disturbed sugar metabolism related to virus-induced stress. This study showed that virus-induced changes in ‘Tribidrag’ plants even in the absence of symptoms are dependent on plant age, as well as on the composition of virus inocula. Full article

Cordyceps militaris is one of the commercially cultivated mushrooms, valued for its medicinal and nutritional benefits. However, the fruiting body development mechanism has remained elusive. Chitin synthases (CHSs) are ubiquitous enzymes involved in the regulation of fungal growth, development and virulence. In this study, a total of eight CmChs genes were identified. Chromosomal localization analysis revealed an uneven distribution of CmCHSs across the C. militaris genome. Based on the phylogenetic analysis, 100 CHSs from Cordyceps sensu lato, encompassing C. militaris, were categorized into three divisions and seven classes, shedding light on their evolutionary relationships. There was no significant difference in the number of CHSs between ascomycetes and basidiomycetes in general (p = 0.067), as well as between pathogenic and saprotrophic fungi in general (p = 0.151 and 0.971 in Ascomycota and Basidiomycota fungi, respectively). This underscored the essential and conserved nature of these CHSs across various fungal lifestyles and ecological niches. The different transcript patterns of the eight CmChss during key life cycle stages, such as conidia germination, infection, and fruiting body development, indicated that each CHS gene may have a distinct role during specific stages of the life cycle. In conclusion, these findings indeed lay the groundwork for a further exploration of the functional roles of CHSs in the regulatory mechanism of fruiting body development in C. militaris. Full article

Yellow pitahaya (Selenicereus megalanthus Haw.) is an exotic fruit with great potential for exportation in Ecuador. The research was carried out with the objective of evaluating the fruit growth and ripening as affected by four elicitors: salicylic acid (SA), methyl salicylate (MeSa), methyl jasmonate (MeJa), and oxalic acid (OA), all of them at 1, 5, and 10 mM concentration, compared with untreated plants (control). For each elicitor, nine plants were selected, and on each plant, three fruits were marked to follow up the growth by measuring polar and equatorial diameters. At harvest, yield (kg plant⁻¹ and number of fruits plant⁻¹), fruit weight, percentage of pulp and skin, total soluble solids (TSS), titratable acidity (TA), and firmness were determined. Treated plants enhanced fruit size, crop yield, and fruit weight compared with control fruits, although results depended on the elicitor tested and applied doses. The highest and lowest TSS were found in 10 mM MeSa and 5 mM MeJa-treated fruit, respectively, while the highest TA content was shown in 5 mM SA. Firmness was only enhanced in MeJa-treated fruits. Overall, results suggest that preharvest use of elicitors could modulate the pitahaya ripening and could improve quality attributes at harvest. Full article

This study investigates codon usage bias within the chloroplast genomes of 18 Taraxacum species, focusing on the base composition and various metrics including GC content, Relative Synonymous Codon Usage (RSCU), Effective Number of Codons (ENc), and GC3s. Our analysis revealed a pronounced preference for A/T-ending codons across Taraxacum species, with GC content across the first, second, and third positions of the codons (GC1, GC2, GC3) and the average GC content consistently below 50%. A detailed examination using the RSCU metric identified 29 commonly preferred A/T-ending codons, indicating a strong codon usage bias towards these endings. Specifically, the codon for leucine (UUA) emerged as highly preferred, while the codon for serine (AGC) was least favored. Through the ENc–GC3s plot analysis, we explored the forces shaping this bias, finding evidence that both mutation pressure and natural selection significantly influence codon preference, with most coding sequences showing weak bias. The PR2 plot analysis further confirmed the role of these factors by demonstrating a higher frequency of T over A and C over G at the third codon position, pointing towards a mutation bias complemented by natural selection. Collectively, our findings highlight a consistent pattern of codon usage bias in the chloroplast genomes of Taraxacum species, influenced by a combination of mutation pressure, natural selection, and possibly other unidentified factors. Full article

Bell peppers (Capsicum annuum) were grown in a greenhouse to evaluate organic fertilizer and foliar seaweed application effects on plant architecture, yield, and fruit quality. Many organic fertilizers contain phytohormones intrinsically. Hydrolyzed and non-hydrolyzed fish fertilizer and cyano-fertilizer treatments were applied in split applications every 7 days over a 135-day growing period. Control plants received no supplemental N. Each fertilizer treatment received applications of one of two different foliar seaweeds or no foliar seaweed in a 4 × 3 factorial design with three replications. Both hydrolyzed and non-hydrolyzed fish fertilizers and cyano-fertilizer increased the number of branches per plant compared to the N-deficient control. The plants receiving cyano-fertilizer or non-hydrolyzed fish fertilizer yielded more than the N-deficient control, and those treatments received 2–3 times the auxin application as the hydrolyzed fish fertilizer. In addition, the leaves from the plants treated with non-hydrolyzed fish fertilizer contained substantially higher levels of abscisic acid, although no abscisic acid was detected in the fertilizers. Both seaweed products decreased the number of fruits that were “bell”-shaped and increased the number of “long”-shaped fruits. Organic fertilizers are complex matrices of nutrients, phytohormones, and other metabolites, making it very challenging to determine the mechanisms behind the observations. Full article

Rootstocks serve as a strategic tool for grapevine adaptation to specific biotic and abiotic conditions and for managing vine growth, grape yield, and berry composition in commercial vineyards. This study investigates the influences of four different rootstock varieties (101-14 MGt, 3309 C, 110 R, and 140 Ru) on the viticultural performance of ‘Xinomavro’ vines, a prominent Greek red winegrape varietal. By conducting a two-year field experiment using various rootstocks, we assessed parameters related to water status, vegetative growth, yield, and berry composition. Our results revealed that rootstock selection has a significant impact on vine development, especially in terms of berry size and the concentrations of secondary metabolites. Principal component analysis confirmed the complex interaction between rootstock vigor and vine productivity. This study underscores the importance of rootstock variety in manipulating grapevine characteristics, particularly for the ‘Xinomavro’ variety, in response to regional climatic conditions. Full article

The management and improvement of yam productivity are associated with a good supply of essential nutrients for the growth and development of the crop that has economic viability. This research aimed to evaluate the economic feasibility of foliar fertilization with Zintrac^® in two yam agricultural seasons (2022/2023 and 2023/2024). Therefore, two experiments were conducted at the Rafael Fernandes Experimental Farm, Mossoró, RN, Brazil. The experimental design was in a Latin square design with five treatments of doses of Zintrac^® (0, 1, 2, 3, and 4 L ha⁻¹) and five replications. Among the production costs of yams, labor and seed acquisition were the most significant. The highest profitability index was achieved with the dose of 1L Zintrac^® ha⁻¹ in the first season and second season, which corresponded to 78.97 and 57.86%. For the first season, increments were observed in all treatments that received zinc doses with increases of 48.70, 31.22, 14.30, and 15.93% for 1, 2, 3, and 4 L of Zintrac^® ha⁻¹ compared to the dose of 0 L ha⁻¹. On the other hand, in the second season, there was an increase only in the dose of 1 L ha⁻¹ of Zintrac^®, which corresponded to 51.3% in the net yield (ha⁻¹) of the dose of 0 L ha⁻¹. Therefore, foliar zinc oxide fertilization was economically viable for the yam crop, obtaining higher economic indices at the dose of 1 L ha⁻¹. The highest cost for growing yams is using a dose of 4 L ha⁻¹ of Zintrac^®, totaling USD 6977.59 (first season) and USD 6868.33 (second season) Full article

To accurately evaluate the role of storage temperature in improving the quality of fresh-cut fruits and vegetables, the effects of two storage temperatures (5 °C and 15 °C) on the phenylpropanoid pathway and sucrose metabolism in fresh-cut melon (cv. Yugu) cubes were determined. A higher temperature (15 °C) expedited sucrose decomposition in the melon cubes at the early stage of storage, resulting in higher levels of glucose and fructose. This effect was corroborated by increased activities of acid invertase (AI), neutral invertase (NI), and sucrose synthase cleavage (SS-c), along with higher expressions of CmAI1/2, CmNI1/2, and CmSS1/2 in the melon cubes at 15 °C. Additionally, the higher activity and gene expression of hexokinase in melon cubes at 15 °C led to an increase in the utilization rate of sugars toward downstream metabolic pathways. Moreover, the melon cube storage at 15 °C elevated the activities and gene expressions of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), and 4-coumaric acid: CoA ligase (4CL), thereby increasing the synthesis of phenolics. Sucrose showed a significant negative correlation with PAL, C4H, and 4CL, as well as with CmPAL5/7 and CmC4H1/3. However, hexokinase displayed a significant positive correlation with PAL, C4H, and 4CL, as well as with CmPAL1, CmPAL3-9, CmC4Hs, and Cm4CLs. These findings demonstrate that a higher-temperature storage of melon cubes can accelerate the phenylpropanoid pathway and sucrose metabolism by regulating the activity and gene expression of related enzymes, thereby inducing phenolic accumulation. These results also indicate that lower-temperature storage is not conducive to the conversion of sugars into phenolics in fresh-cut melon. Therefore, the temperature can be appropriately and briefly raised in the production and preservation process of fresh-cut melon to obtain higher levels of phenolics. Full article

This study focused on the “Xinlu” walnut and explored the molecular regulatory mechanism of lignin synthesis in the endocarp, aiming to explain the formation of bared-nut walnuts through morphological, metabolomic, and transcriptomic techniques. It was found that the synthesis of lignin, cellulose, p-coumaryl alcohol, and sinapyl alcohol was severely inhibited in the pulpy-hue (PUH) of the endocarp. We obtained 14 modules (gene sets) significantly correlated with the lignification factor (LIG) and 1548 hub genes. Additionally, we identified a MEplum3 module involved in endocarp lignin synthesis, primarily participating in phenylalanine biosynthesis and the lignin biosynthetic process. Meanwhile, we constructed a gene co-expression network for the MEplum3 module and identified a key hub gene for lignin synthesis—JrCAD10. Among the different tissues of “Xinlu”, the expression level of JrCAD10 in the scleritic-hue (SCH) was significantly higher than in other tissues, with a relative copy number (RCN) of 3.2. However, JrCAD10 expression was severely suppressed in the PUH. The suppression of JrCAD10 expression led to the inhibition of lignin monomer synthesis, which further resulted in inhibited lignin synthesis, thus forming the bared-nut walnut. Our findings provide new insights into understanding the regulation of lignin synthesis and offer a possible explanation for the formation of bared-nut walnuts. Full article

The Asteraceae family in Siberian Asia exhibits remarkable biodiversity and has long served as a valuable resource for domesticating various beneficial plants with medicinal, therapeutic, and industrial significance to humanity. In this work, we studied for the first time the chemical composition of six understudied or previously unexplored plant species, Artemisia jacutica (AJ), Carduus nutans subsp. leiophyllus (CL), Cirsium heterophyllum (CH), Echinops davuricus (ED), Ixeris chinensis subsp. versicolor (IV), and Lactuca sibirica (LS), which were successfully cultivated under open-field conditions as biennial or perennial crops. We profiled these species, employing a liquid chromatography–mass spectrometry approach, identifying over 100 phenolic compounds. Among these compounds were hydroxybenzoic acid glucosides, hydroxybenzoyl/p-coumaroyl/feruloyl quinic acids, hydroxycoumarin O-glucosides, caffeoyl/p-coumaroyl/feruloyl glucaric/tartaric acids, O- and C-glucosides of apigenin, acacetin, luteolin, chrysoeriol, 6-hydroxyluteolin, pectolinarigenin, kaempferol, quercetin, isorhamnetin, and tri-/tetra-O-p-coumaroyl spermines and spermidines. All examined species exhibited a significant accumulation of phenolic compounds throughout the experimental period, reaching levels comparable to or exceeding those found in wild samples (WSs), with the best total phenolic content for AJ at 26.68 mg/g (vs. 26.68 mg/g in WS; second year), CL at 50.23 mg/g (vs. 38.32 mg/g in WS; second year), CH at 51.14 mg/g (vs. 40.86 mg/g in WS; sixth year), ED at 86.12 mg/g (vs. 78.08 mg/g in WS; seventh year), IV at 102.49 mg/g (vs. 88.58 mg/g in WS; fourth year), and LS at 127.34 mg/g (vs. 110.64 mg/g in WS; fifth year). Notably, in the first year of cultivation, approximately 40–60% of the wild-level target compounds accumulated in the plants, with even higher levels detected in subsequent years, particularly in the second and third years. This study highlights the potential of cultivation to produce new Asteraceae plants rich in bioactive phenolics. Full article

The levels of different nutraceutical metabolites present in the jicama root were measured when subjecting the plant to induced biotic stress via infestation with Phyllophaga spp. (white grubs). The change in secondary metabolites on the stressed jicama roots (SJ), mostly antioxidants, was followed over 100, 140, and 180 days and compared against the non-infested control jicama (CJ). Our results show that infested (SJ) samples contained higher concentrations of tannins, flavonoids, and total phenols, measured using spectrophotometric methods, peaking at 140 days, and higher overall concentration of saponins. SJ samples showed higher DPPH inhibition, peaking at 100 days. Chlorogenic acid had the highest concentration among the phenolic compounds (7.47 mg g⁻¹), followed by protocatechuic acid, both in SJ, which was possibly related to the lower observed concentrations of caffeic and ferulic acids. As for flavonoids, we observed a high concentration of rutin in CJ and a low concentration of pelargonidin and myricetin in SJ, possibly promoted via the dihydrokaempferol pathway. Taken together, these results show that Phyllophaga spp.-mediated biotic stress affects the concentrations of secondary metabolites in the different maturity stages in jicama, having an effect on its metabolic pathways, which presents an opportunity for the use of material such as agro-industrial waste. Full article

Humulus lupulus (hop) is a necessary material in beer brewing because its female inflorescences (called hop cones) give a floral aroma, bitterness and foam stability to beer. Various aspects of growth conditions in the cultivation area, especially temperature, strongly affect the yield and quality of hop cones. Recent estimates suggest that climate change accompanied by global warming is negatively impacting hop production, with high temperatures reducing the expression of genes that regulate beneficial secondary metabolites in hops. This underscores the need for techniques to enhance hop tolerance to high temperatures. This study explores the potential of N-acectylglutamic acid (NAG), a non-proteinogenic amino acid, to confer hops with tolerance against oxidative and heat stress by suppressing ROS accumulation. Exogenous NAG treatment activated the expression of HlZAT10/12 and HlHSFA2, which are putative homologues considered master regulators in response to oxidative and heat stress in Arabidopsis thaliana (Arabidopsis). Additionally, histone acetylation, a histone modification associated with transcriptional activation, was increased at these stress-responsive genes in the NAG-treated hops. These findings reveal NAG as a potential chemical compound to mitigate hop production reduction caused by high temperatures and suggest the conservation of epigenetic modification-mediated regulation of gene expression in response to environmental stresses in hops. Full article

Arugula (Eruca sativa Mill.) is a nutritious vegetable, commonly used in salads, known for its high glucosinolate content and various health benefits and flavors. However, arugulas may contain -excessive nitrate levels, potentially harmful to human health. We aimed to examine the effect of substrate moisture levels on the growth and quality of arugula under controlled irrigation conditions to investigate a proper irrigation practice for the quality production of arugula. The plants were cultivated using a sensor-based automated irrigation system to maintain the substrate volumetric water content (VWC) levels at 0.20, 0.30, 0.40, and 0.50 m³·m⁻³ over three weeks (vegetative stage). The treatment with VWC of 0.20 m³·m⁻³ resulted in reduced shoot growth, primarily attributed to drought-induced constraints on leaf expansion. Despite the initial reductions in stomatal conductance in arugulas subjected to lower VWC treatments, they eventually recovered and exhibited similar stomatal conductance levels across all VWC treatments 15 days after treatment, indicating acclimation to drought stress. The VWC treatment did not affect the nitrate and total glucosinolate contents of arugula, except for a decrease in glucoerucin content observed in the lowest VWC treatment. Maintaining a VWC level at 0.20 m³·m⁻³ could impair both the growth and quality of arugula due to severe drought conditions. Alternatively, maintaining the VWC at 0.30 m³·m⁻³ would ensure a high water use efficiency while securing the growth and quality of arugula. Full article

Fig is a widespread crop in southern Italy, highly valued for its sweet flavor. However, its consumption as a fresh product is limited to three to four days after harvest because of its high susceptibility to quality loss and microbial contamination. The combined use of low temperature and a modified atmosphere is the traditional preservation method. However, several studies have shown that the use of Aloe arborescens or vera and O. ficus-indica (OFI) mucilage as an edible coating could reduce the microbial load and water loss, respectively. Therefore, our study aimed to evaluate the synergistic effects of Aloe gel (AG) and O. ficus-indica mucilage (OM) on the quality and safety of two fig cultivars, ‘San Giovanni’ and ‘Melanzana’, during cold storage at 4 °C. The main results showed the effectiveness of edible coatings on both fig cultivars. An AG coating significantly reduced the microbial load, while the OM treatment showed the ability to preserve firmness and reduce weight loss. In addition, the combined OM + AG treatment showed the same effects as the individual coating formulations, also improving visual appearance. Thus, the use of the synergetic coating formulation could be a natural way to reduce the microbial load, extending fresh fig fruit’s shelf life. Full article

The citrus industry is of great importance in Mexico, with an estimated production value of USD 2.4 billion and the potential to generate up to 28 million employees per year. Approximately 69,000 Mexican families depend on this sector. However, it is under serious threat from the disease known as Huanglongbing (HLB). The rapid spread of this disease has caused significant economic losses, impacted the livelihoods of citrus growers, and led to substantial job losses. Currently, HLB is not under control in Mexico, and as the management strategies applied have proven to be ineffective, yields have not been recovered to pre-HLB levels, and production costs have significantly increased. Therefore, it remains the most destructive citrus disease. This review paper describes the current situation of the disease, its economic and social impact, and the measures adopted for its management in Mexico. Future perspectives highlight advances in research based on new biotechnological tools as an eco-friendly management alternative. Practical suggestions to address HLB are also mentioned in our analysis. Full article

The use of wood distillate (WD) is emerging as a valuable strategy for protecting horticultural crops from the oxidizing effects of ozone (O₃). To fully understand its effectiveness, extensive testing on different plant species is needed. As a viable interim measure, an assessment of WD efficacy in model plants can be made until species-specific results become available. The aim of this study is to evaluate the ability of WD derived from forest wood, including chestnut (Castanea sativa Mill.) wood, to protect the ozone-sensitive tobacco plant (Nicotiana tabacum L.) BelW3 from the oxidizing effects of O₃, using the ozone-resistant tobacco plant BelB as a benchmark. The protective effect was evaluated during treatment applications and three weeks after these were completed. Ten BelW3 and five BelB plants were grown just outside Parma from June to October 2023, a period when average maximum O₃ concentrations were at least 120 ppb. Starting from July, five BelW3 plants were sprayed weekly with WD at 0.2% for two months. Morphometric and photosynthetic measurements were then taken after six and 11 weeks from the beginning of treatments and three weeks after the end to assess protection persistence (if any). BelW3 showed a significant effect of O₃ compared to BelB plants for both morphometric and photosynthetic measurements, exhibiting increased necrotic areas on the leaf blade, reduced number of viable leaves, reduced average plant height, together with reduced chlorophyll content and impaired photosynthetic system functionality. BelW3 plants also showed a significant decrease in the efficiency of parameters related to PSII and PSI when compared to BelB. Wood distillate application, however, successfully mitigated O₃ effects on BelW3, as revealed by morphometric and photosynthetic values, which were in line with those observed in BelB. Notably, WD protective effect persisted 3 weeks after treatment cessation, highlighting the short-term protective capacity of the distillate against the oxidative action of O₃. Full article

In the current study, the effects of drought stress on the growth and phytochemical profile of Scolymus hispanicus L. (a.k.a. golden thistle) were evaluated. Plants were treated with three irrigation regimes, e.g., plants that received only rainwater (Control; C), deficit irrigation (I1; 50% of field capacity (FC)), and full irrigation (Ι2; 100% of FC). The fresh weight of the rosette of leaves was not negatively impacted by deficit irrigation, whereas root development was severely restrained compared to control and I2 treatments. Drought stress conditions had a positive effect on the nutritional properties of the golden thistle since the treatments of control and deficit irrigation showed the highest content of macronutrients and energy. Oxalic acid was the richest organic acid, especially under the I1 regime. Similarly, α-tocopherol was the only identified vitamin E isoform, whose content was also doubled in I1 treatment. Raffinose, glucose, and sucrose were the most abundant free sugars in amounts that varied among the irrigation treatments, while the total and distinct free sugar content was the highest for the I1 treatment. The most abundant detected fatty acid compounds were α-linolenic acid, followed by palmitic and linoleic acid, with the highest amount being detected in C, I1, and I2 treatments, respectively. Flavonoids were the only class of polyphenols detected in golden thistle leaves, including mostly kaempferol and quercetin derivatives. The greatest antioxidant potency was shown for the control and I1 treatments (for OxHLIA and TBARS methods, respectively). The evaluated leaf samples recorded a varied antimicrobial effect for the different bacterial strains and fungi, whereas no cytotoxic, hepatotoxic, and anti-inflammatory effects against the tested cell lines were recorded. Finally, the mineral content of leaves was significantly affected by the irrigation regime, with Ca, Mg, Cu, and Zn being the highest for the I1 treatment, while the I2 treatment had the highest content of K, Fe, and Mn and the lowest Na content. In conclusion, deficit irrigation showed promising results since it improved the phytochemical content without compromising the fresh weight of leaves, and thus it could be suggested as a sustainable agronomic practice for producing high-added value products without significant constraints in growth development and yield parameters of golden thistle. Full article

Mycorrhizal symbiosis enhances host plant resistance to various unfavorable environmental stresses, but whether and how it also enhances waterlogging tolerance in cucumber plants is not known. The objective of this study was to analyze the effect of Paraglomus occultum inoculation on biomass production, osmolyte levels, and the expression of 12 heat shock protein 70 (Hsp70) genes and 14 plasma membrane intrinsic protein (PIP) genes in the roots of cucumber plants under a short-term waterlogging stress (WS) (5 days) condition. Although the short-term WS treatment significantly inhibited the arbuscular mycorrhizal fungal colonization of roots, the inoculation with arbuscular mycorrhizal fungi (AMFs) significantly increased leaf, stem, and root biomass under WS. AMF inoculation also significantly increased root glucose, sucrose, betaine, and proline contents, along with decreased fructose levels, compared with the uninoculated control. More CsHsp70 and CsPIP genes were up-regulated in AMF-inoculated plants than in AMF-uninoculated plants in response to WS. AMF inoculation showed no significant effect on the expression of any of the examined CsHsp70 genes under no-waterlogging stress, but it did raise the expression of 11 of 12 CsHsp70 genes under WS. AMF colonization also down-regulated or had no effect on CsPIP expression under no-waterlogging stress, whereas it up-regulated the expression of 12 of the 14 CsPIP genes under WS. It is concluded that AMF inoculation enhances waterlogging tolerance in cucumber plants by increasing osmolyte levels and stress-responsive gene (CsPIP and CsHsp70) expression. Full article

Horticultural plant material offers several advantages for isolating exosomes and other natural plant-derived exosome-like nanoparticles (PDENs) due to the accessibility and affordability of plant material for widespread applications. This study aims to explore the impacts of the tomato genotype (‘Admiro’, ‘Roma’, ‘Brooklyn’, ‘Marmande’ and ‘Betalux’) and the main cultivation parameters in controlled environment agriculture on the yield and properties of their PDENs for pharmaceutical and cosmeceutical applications. The PDEN yield, size distribution, and antioxidative properties of young tomato seedlings were evaluated. The ‘Betalux’ tomato was distinguished by a remarkably higher nanoparticle concentration and a uniform size distribution and was selected for further experiments. The impact of cultivation temperature (18, 22, and 26 °C), nitrogen nutrition (0, 250, and 500 mg L⁻¹), and the lighting photosynthetic photon flux density (PPFD; 150, 250, and 450 µmol m⁻² s⁻¹) on nanoparticle properties was investigated. Optimal conditions consisting of a temperature of 22 °C, 250 mg L⁻¹ nitrogen nutrition, and 250 µmol m⁻² s⁻¹ lighting PPFD were used as a reference. Optimal temperature, nitrogen nutrition, and lighting intensity resulted in the highest nanoparticle yield, the most uniform particle distribution, and the highest impact of PDEN preparations on keratinocyte metabolic activity. Deviation from optimal cultivation conditions reduced the tomato biomass and the PDEN protein and yield. Full article

Fresh-cut leafy vegetables are produced in Southern Italy in very intensive crop systems under tunnel greenhouses in which continuous cropping has triggered soil organic carbon (SOC) depletion and the risk of degradation of soil fertility. A two-year trial of soil organic amendment was carried out on a private farm producing baby-leaf crops on a very poor OC soil (<1%). Biowaste compost, two types of olive pomace composts and buffalo manure were compared to evaluate their ability to recover a positive SOC balance and sustain crop growth and yield. The effects on soil health and crop system were studied by measuring different aspects such as SOC stock change and SOC sequestration rate, soil microbial biomass and nine enzyme activities, yields of rocket and concentration of nitrates in leaves. Soil amendments were distributed once a year at doses of 15 and 30 Mg ha⁻¹ as fresh matter without integration of mineral fertilizers. In our study, the SOC stock improved in the amended soils in a range of 4–6 Mg ha⁻¹, except for dose 30 of buffalo manure, with the highest values where biowaste compost was applied. Our data showed an increase in biological parameters in all the amended soils with respect to Control. In soil amended with olive pomace, however, compost mineralization rates likely did not match crops’ nutrient needs so the yields of rocket were lower than with the biowaste compost and buffalo manure. Biowaste compost showed the best results as it balanced the best C conversion efficiency, the higher increment of SOC and yields of rocket. Full article

Watermelons are one of the most important crop species, and they are enjoyed across the globe; however, the cultivation of watermelon commercial varieties in arid regions is challenging, as they are highly susceptible to water deficit. Conversely, their wild relatives and traditional landraces have shown a higher tolerance to water deficit, which makes them important study material. Therefore, this study was undertaken to evaluate the potential roles of two compatible osmolytes (citrulline and arginine) in the tolerance of local watermelon accessions to drought stress. Four commonly cultivated watermelon accessions were used in this study to evaluate their response when exposed to water deficit stress. The accessions were planted in stress boxes in the greenhouse and allowed to grow until the fourth leaf was fully open and then the water deficit stress was initiated by withholding water for a period of nine days, before rewatering for three days. Data and leaf samples were collected at three-day intervals. The common drought indicators that were assessed, like chlorophyll fluorescence, showed that Clm-08 (wild watermelon) had significantly different results when compared to the other accessions; the Fv/Fm values for days 3, 6, and 9 were significantly higher than those of the other accessions, while phiNPQ was higher in the Clm-08 with average values of 0.41 and 0.41 on days 6 and 9 of the drought stress, respectively. This suggests that the wild watermelon responded differently to drought stress when compared with the other accessions. Arginine and citrulline are important osmolytes that play an important role in stress tolerance, and the results of the current study correlate with the common physiological indicators. The expression pattern for both the biochemical and molecular analyses of the two compatible osmolytes was higher in Clm-08 in comparison with that of the other accessions. The gene expressions of the enzymes in the citrulline and arginine pathways were higher in Clm-08; Cla022915 (CPS) recorded a 6-fold increase on day 6 and Cla002611 (ASS) recorded an 11-fold increase. This suggests that citrulline and arginine play an important role in watermelon tolerance to drought stress. Full article

The newly identified Sanghuangporus alpinus species of the Sanghuang mushroom genus has been found to possess significant medical benefits. However, the current artificial cultivation technology has not reached the requisite maturity. The response-surface methodology (RSM) was used to optimize the Sanghuangporus alpinus culture medium formulation and evaluate the functional activity of S. alpinus exopolysaccharides. First, a single-factor experiment was conducted to screen for optimal carbon and nitrogen sources for S. alpinus. Then, using Box–Behnken’s central composite design, a response-surface experiment was conducted to determine optimal culture parameters. Finally, the rationality of those parameters was assessed in a shaking flask experiment. The optimal culture parameters, determined through regression analysis, were 20.20 ± 0.17 g/L fructose (carbon source), 7.29 ± 0.10 g/L yeast extract (nitrogen source), and 0.99 ± 0.01 g/L dandelion. With optimization, the S. alpinus yield increased to 12.79 ± 1.41 g/L, twice that obtained from the initial culture medium. The S. alpinus exopolysaccharide exhibited an excellent antioxidant capacity, with the strongest scavenging effect noted on ABTS free radicals (lowest half-inhibitory concentration: 0.039 mg/mL). Additionally, this exopolysaccharide effectively inhibited various cancer cells, exhibiting the strongest activity against human glioma cells U251 (half-inhibitory concentration: 0.91 mg/mL). The RSM used to optimize the fermentation culture parameters of S. alpinus significantly increased the mycelial biomass. The improvement of Sanghuangporus alpinus yield through liquid fermentation and optimizing the fermentation medium could fill the existing gap in the cultivation of Sanghuangporus alpinus, as well as provide valuable data for the large-scale production of S. alpinus. Full article

The Sebou River Basin is vital for Moroccan agriculture, particularly in terms of producing industrial crops, fruits, vegetables, and olive oil. It is especially significant in viticulture, accounting for 80% and 60% of the national production area for wine and table grapes, respectively. However, the prevalence of diseases and pests requires extensive pesticide application in vineyards. This study aims to assess the impact of pesticides used in vineyards on the environment, human health and their associated sustainability. Agro-environmental indicators were evaluated across 30 vineyards covering 1197 hectares. Results show an average treatment frequency of 24.05 applications per growing cycle, the highest among grape-producing countries, with 77.94% being fungicides. The Quantity of Active Substances Indicator (QASI) reveals a high pesticide application rate of 44.60 Kg a.i./ha. Over 50% of chemicals are classified as “hazardous” based on the Environmental Impact Quotient (EIQ). A Pesticide Environmental Risk Indicator model (PERI) identifies three active ingredients with a high Environmental Risk Score (>5). Life Cycle Assessment (LCA) reveals that copper sulfate has significant environmental impacts compared to Mancozeb and sulfur. These findings highlight the extensive use of pesticides in vineyards, posing challenges to long-term sustainable agriculture due to associated environmental and health risks. Full article

The nematicidal potential of the yeast Papiliotrema terrestris strain PT22AV (YSY) was investigated against the root nematode (RKN) Meloidogyne incognita in in vitro bioassays on infective juveniles (J2) and experiments on tomatoes in pot and greenhouse conditions. The J2 nematodes were exposed to YSY solutions for 19 days, using abamectin (ABA), fosthiazate (FOS) and distilled water as controls. In the experiments on potted and greenhouse tomatoes, 0.5 and 1 kg ha⁻¹ doses of YSY were tested in comparison to ABA, biocontrol agents Purpureocillium lilacinus strain 251 (PUL) and Bacillus firmus strain 1-1582 (BAF), a plant biostimulant/fertilizer (ERG) and the nematicide Fluopyram (FLU). J2’s viability was affected by YSL after 7 days, decreasing to zero on the 15th exposure day, while ABA and FOS resulted in 83 and 100% J2 mortality within 24 h. Only the 1.0 kg ha⁻¹ dose of YSY was able to significantly reduce the final nematode population in soil and gall formation on tomato roots, without significant differences from PUL and BAF. All treatments in comparison also resulted in a significant increase in tomato growth and crop yield, except for 0.5 kg ha⁻¹ of YSY. Data indicated that YSY could represent an additional tool for organic and integrated RKN management. Full article

The rest-breaking agent, hydrogen cyanamide (HC), can substitute insufficient chill unit accumulation in Vitis vinifera and induce uniform bud-break; however, due to its toxicity it is being banned. In South Africa, red seedless grapes, including V. vinifera Crimson Seedless (CS), are the largest table grape export group; therefore, replacing HC in V. vinifera CS is crucial. This study aimed to confirm the molecular triggers induced by HC and assess the bud-break-enhancing abilities of commercial plant biostimulants. Forced bud-break assay experiments using V. vinifera CS single-node cuttings and a small-scale field trial were performed. Results demonstrated that increased chill unit accumulation (CUA) reduced HC efficacy. Bud-break started between 10 and 20 days after treatment, irrespective of final CUA. The small-scale field trial found that HC 3% and biostimulants were similar to the negative control. The treatment of dormant grapevine compound buds with nitric oxide (NO), hydrogen peroxide (H₂O₂), and hypoxia trigger dormancy release to a certain extent, supporting the molecular models proposed for HC action. NO, H₂O₂, and hypoxia, in combination with PBs, may potentially replace HC; however, this needs to be confirmed in future experiments. Full article