Horticulturae, Volume 8, Issue 6 (June 2022) – 93 articles

Developing varieties with diverse features that satisfy varied commercial needs, improving overall fruit quality, and quickly releasing them, are prerequisites in citrus breeding. However, these three goals require trade-offs in conventional breeding, even with the application of the marker-assisted selection technique. Conventional breeding cannot achieve these three goals simultaneously and it has been regarded as a breeding trilemma. Integrating a genomics-assisted breeding (GAB) approach that relies on quantitative trait locus detection by genome-wide association study and genome-wide prediction of a trait by genomic selection using enriched marker genotypes enhances breeding efficiency and contributes to eliminating the trilemma. Besides these efforts, the analysis of the genealogy of indigenous citrus varieties revealed that many high-quality indigenous varieties were selected within a few generations. It suggested that selecting a new premium quality hybrid is possible by integrating it with the GAB technique and helps avoid the trilemma. This review describes how a new approach, “Citrus Breeding 2.0” works for rapidly developing new, premium quality hybrids and introduces three applications of this technique, specifically, rebreeding, complementary breeding, and mimic breeding based on the ongoing citrus breeding program in NARO, Japan. Full article

Zinnia elegans Jacq. is an ornamental plant, widely used in landscaping. Heavy-metal pollution in urban and rural areas is still increasing, which determines the actuality of studying plants’ reactions to pollutants. Zinnia was not sufficiently studied in this regard, so the aim of our research was to identify morphophysiological changes in this species under excess copper concentration in the soil. For this, we treated a growth substrate with 200 µM CuSO₄ solution for 20 days. At the end of the treatment, several morphological, biochemical, and molecular genetic traits were evaluated: the root and the shoot size; the concentration of H₂O₂ and malondialdehyde (MDA), as indicators of stress; the amount of the phenolic compounds and lignin; and the level of the expression of genes, which encoded their biosynthesis. The Cu amount in the substrate and zinnia organs was quantified using atomic-absorption spectroscopy; hydrogen peroxide, MDA, and phenolic compounds were determined spectrophotometrically, while the amount of lignin was determined according to Klason. Real-time PCR was used for estimation of the gene-transcription level. Lignin in tissues was visualized by fluorescent microscopy. In experimental plants, Cu accumulation was higher in the root than in the stem. This caused an increase in stress markers and a decrease in the root and stem lengths. For the first time for zinnia, it was shown that for several genes—4-coumarate-CoA ligase (4CL), cinnamoyl alcohol dehydrogenase (CAD), and class III peroxidase (PRX)—the level of expression increased under copper treatment. The rise of the transcripts’ amount of these genes was accompanied by a thickening and lignification of the cell walls in the metaxylem vessels. Thus, the adaptation of zinnia to the excess Cu in the growth medium was associated with the metabolic changes in the phenylpropanoid pathway. As a result, the lignification increased in the root, which led to the accumulation of Cu in this organ and limited its translocation through the xylem to the stem, which provided plant growth. Full article

Colletotrichum gloeosporioides is the most prevalent phytopathogen, causing anthracnose disease that severely affects the production of various fruit trees, including walnut and jujube. In this study, the volatile organic compounds (VOCs) from Bacillus velezensis CE 100 disrupted the cell membrane integrity of C. gloeosporioides and reduced the spore germination by 36.4% and mycelial growth by 20.0% at a bacterial broth concentration of 10%, while the control group showed no antifungal effect. Based on the headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) analysis, seven VOCs were identified from the headspace of B. velezensis CE 100. Out of the seven VOCs, 5-nonylamine and 3-methylbutanoic acid were only detected in the headspace of B. velezensis CE 100 but not in the control group. Both 5-nonylamine and 3-methylbutanoic acid showed significant antifungal activity against the spore germination and mycelial growth of C. gloeosporioides. Treatment with 100 µL/mL of 5-nonylamine and 3-methylbutanoic acid suppressed the spore germination of C. gloeosporioides by 10.9% and 30.4% and reduced mycelial growth by 14.0% and 22.6%, respectively. Therefore, 5-nonylamine and 3-methylbutanoic acid are the potential antifungal VOCs emitted by B. velezensis CE 100, and this is the first report about the antifungal activity of 5-nonylamine against C. gloeosporioides. Full article

Silymarin, a secondary metabolite found mainly in the Silybum marianum L. fruits, has been associated with the hepatoprotective activity of the plant. Among various elicitors, salicylic acid, a “Generally Regarded As Safe” compound recognized by the Food and Drug Administration, is one of those being used in the induction and enhancement of valuable plant secondary metabolite production in various plant species. In this study, two concentrations (10⁻⁴ and 10⁻³ molar) of salicylic acid have been applied to the S. marianum plants as foliar spray to investigate their effects on plant growth and yield, as well as the production of its bioactive compound, silymarin. Our results indicated that both concentrations of salicylic acid increased the plant height, the number of branches, leaves, and capitula, as well as the dried weight of roots, aerial parts, and fruits. The enhancement effects in plant growth and yield were accompanied by an increase in photosynthetic pigments such as chlorophyll-a, b, and carotenoids as well as element contents such as nitrogen, phosphorus, and potassium. The potential of salicylic acid as an elicitor for the enhancement of secondary metabolites in S. marianum was supported by the increase in silymarin’s major components, silybin (A + B), in the salicylic acid-treated plants. Concomitant expressions of CHS1, 2, and 3 genes that have been associated with the production of silymarin in S. marianum were also observed in the salicylic acid-treated plants. A lower concentration (10⁻⁴ M) of salicylic acid was found to be a better elicitor as compared with the 10⁻³ M salicylic acid. An increase of 3.4 times in capitula number and fruit dried weight as well as 2.6 times in silybin (A + B) contents were observed in plants sprayed with 10⁻⁴ M of salicylic acid as compared with the control. Full article

Mango fruits have a high nutritional value and are beneficial to health. However, losses frequently occur after harvest, because they are perishable. Salicylic acid (SA) can be used to preserve fruit quality and maintain their nutritional contents. Therefore, this study was conducted to investigate the effects of applications of 2 mM SA on the physicochemical properties, bioactive compounds, and antioxidant and anti-inflammatory activities of mango fruit. For this purpose, mango fruits received preharvest (Pre SA) or postharvest applications of SA (Post SA), or their combination (Pre + Post SA); the fruits were stored at 13 °C for 20 days. Weight loss, decay, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity were maintained in SA-treated fruit. The Pre + Post SA treatment was superior in delaying fruit ripening, and maintaining lower soluble solids contents and higher total acidity. In addition, total phenolic compounds, ferric reducing antioxidant power, and free radical scavenging activity of anti-inflammatory substances (such as nitric oxide), as well as hyaluronidase inhibition, were higher in the Pre + Post SA treatment throughout storage. Therefore, both pre- and postharvest SA treatments are recommended for preserving the quality of mango fruit, such as Nam Dok Mai Si Thong, and for maintaining their nutritional properties for human health. Full article

The detection of nutritional compounds is usually performed through laboratory analysis, which requires extensive planning, time, cost, and effort. Alternatively, visible/near-infrared (Vis/NIR) spectroscopy can be used to determine the presence of nutritional compounds in real-time. This study aimed to investigate the potential application of the Vis/NIR spectroscopy in the quantitative detection of nutritional compounds in green ‘Ratuni UNPAD’ cayenne pepper. Prior to the model development, 80 samples were prepared for the calibration set, while another 40 samples were provided for the prediction set. Subsequently, the parameters used to calculate the model accuracy included the coefficient of correlation in calibration set (R_cal), coefficient of correlation in prediction set (R_pred), root mean square error of calibration set (RMSEC), root mean square error of prediction set (RMSEP) and the ratio of prediction to deviation (RPD). The experimental results involving the total carotenoids showed good model indicators with R_cal, R_pred, RMSEC, RMSEP, and RPD at 0.94, 0.89, 1.29, 1.75, and 2.21, respectively. Additionally, the analysis of the water content indicated R_cal, R_pred, RMSEC, RMSEP, and RPD values of 0.86, 0.85, 0.59, 0.61, and 1.90, respectively, while that of capsaicin had R_cal, R_pred, RMSEC, RMSEP, and RPD values of 0.89, 0.90, 117.82, 115.62, and 2.29, respectively. The results showed that Vis/NIR spectroscopy can be used to detect the nutritional compounds in green ‘Ratuni UNPAD’ cayenne pepper based on total carotenoids, water content, and capsaicin parameters. Full article

Table grape (Vitis vinifera L.) is considered to be one of the most popular fruit crops in the world. Italy is the leading table-grape producer in the EU and is the main European exporting country. However, to stay competitive, new solutions and perspectives, including varietal renovation, are now needed in addition to the already well-established Italian table-grape production lines consisting of conventional open-field cultivation and greenhouse cultivation. One of these new perspectives is represented by the development of table-grape soil-less cultivation systems (TGSC) under greenhouse. In fact, TGSC systems are alleged to offer many advantages in terms of the advancement of berry maturity, extreme varietal flexibility, easier manipulation of the vegetative–reproductive cycle, higher yields of high quality extra-seasonal production, higher sustainability for reduced pesticides application, and higher use efficiency of water and fertilizers than conventional (soil-grown) cultivation. They can be also useful for overcoming soil- and rootstock-related problems. In this review, the opportunities offered by the recently developed table-grape soil-less cultivation systems are thoroughly examined and updated to the latest experimental and application findings of the sector’s research activity. A special emphasis is given to the evolution of the applied technical solutions, varietal choice, and environmental conditions for the aims of table-grape soil-less cultivation. Full article

Trunk injection is a targeted delivery of pesticides, insecticides, nutrients, or other plant protection materials into the stem or trunk of woody plants as an alternative to spraying or soil drenching. Trunk injection has historically been used for disease and pest management of high-value forest tree species or ornamental plants when aerial applications are problematic due to spatial problems and health-related concerns. An interest in using the injection technique for protection of agricultural crops in commercial production systems has emerged more recently, where foliar applications and soil drenches have proven ineffective or pose environmental hazards. This review provides an overview of the basic principles of trunk injection and the plant physiological implications, its current use in commercial agriculture and other plant systems, and associated risks. Full article

Physiological responses of different interspecific Pyrus hybrids and an open pollinated Pyrus communis ‘Williams’ (Pcw) grown under in vitro culture conditions simulating lime induced chlorosis were studied. The hybrids were derived from crosses between the ‘Pyriam’ pear rootstock and four Pyrus species of the Mediterranean region, namely P. amygdaliformis Vill. (Pa), P. amygdaliformis persica Bornme. (Pap), P. communis cordata (Desv.) Hook. (Pcc), and P. elaeagrifolia Pall (Pe), all known for their higher field tolerance to iron-chlorosis than P. communis. Twenty hybrids and one open pollinated Pcw were micropropagated, and plantlets were in vitro characterized for their physiological responses to iron-deficiency conditions. Rooted plantlets were transferred to a culture medium with 2 µM Fe³⁺ DTPA and 10 or 20 mM NaHCO₃. These physiological responses were scored at 1, 3, 7, and 28 days from the start of the in vitro assay. Leaf total chlorophyll content, the capacity of roots to acidify the medium, reduced iron, and exudates of phenolic acids and organic acids were analyzed in each media and time sample. Leaf chlorophyll levels for the clones derived from Pcc were the highest, especially under the highest bicarbonate concentration, followed by those derived from Pap and Pa. The higher chlorophyll content of Pcc clones were related with their higher capacity to acidify the media but not with their iron reduction capacity at the root level. On the other hand, hybrid clones derived from Pe showed a higher Fe³⁺ reduction ability than clones from all the other species during the whole assay but only when the bicarbonate concentration was lower. The exudation of phenolic acids by the roots was higher in Pcw than in the other species, and this response might explain why the total chlorophyll levels in Pcw clones are similar to those of Pe and Pa ones. These results with Pyrus spp. bring more evidence in support of the idea that iron reduction capacity at the root level is not directly related with a higher tolerance to iron deficiency caused by the high pH of calcareous soils. Instead, the ability to acidify the rhizosphere is the trait of choice for the selection of the pear hybrid clones better adapted to lime induced chlorosis. In addition, the in vitro assay to select the Pyrus clones for tolerance to iron chlorosis could be shortened to one week of culture in 10 mM NaHCO₃, measuring the leaf chlorophyll level, acidification of the culture medium, and exudation of phenolic acids as the physiological responses to predict tolerance to lime-induced chlorosis. Full article

The plant pomological characteristics and physiological behaviors of genotypes in modern apple cultivation could be different depending on the use of rootstock, changing growth ecology and application of biological control agents. The aim of this research was to determine the effects of rhizobacteria application on leaf and fruit nutrient contents in different apple scion–rootstock combinations. This study was carried out with seven standard cultivars (Scarlet Spur, Red Chief, Fuji, Jeromine, Galaxy Gala, Granny Smith, and Golden Reinders) budded on M.9 and MM.106 rootstocks. In the experiment, trees were sprayed by a nitrogen + phosphorus solvent rhizobacteria three times, with an interval of 15 days in the spring period. The effect of rhizobacteria application on leaf and fruit nutrient contents was statistically significant and provided generally significant positive contributions, except for leaf Mg content. Comparing both rootstocks, the positive effect of bacterial application was higher on the M.9 rootstock for leaf N and B content and fruit N and Fe content, and on the MM.106 rootstock for other nutrient content. While the effects of bacterial application on the basis of cultivars were generally positive, the highest positive contribution was made in leaf P content (10.7%) and fruit Mn content (32.1%) of the Fuji cultivar. Considering the total increase in nutrients in scion–rootstocks combination, rhizobacteria application had a positive effect on the leaf nutrient contents in Golden Reinders/MM.106, but not leaf K content. The highest increases in leaves of scion-rootstock combinations were determined as 4.0% in N content in Granny Smith/M.9, 14.1% in P content in Scarlet Spur/MM.106, 7.1% in K content in Fuji/MM.106, 4.4% in Ca content in Jeromine/M.9, and 14.0% in Mg content in Granny Smith/MM.106. The highest increase in fruit nutrient contents was between 4.9% (N content) and 13.5% (Ca content) for macro elements, and between 9.5% (Cu content) and 41.8% (Mn content) for microelements. The results of the present study may provide significant leads for further studies on this subject. Full article

Combined withering and shaking processes are key steps in the formation of characteristic floral and fruity aromas in black teas. However, the effect of the sequencing of withering and shaking on volatile compounds and aroma formation in black tea has not been evaluated to date. This study used headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry to detect volatile compounds in black teas after withering-shaking and shaking-withering processing. Five main differentially volatile components were screened out by partial least squares discriminant analysis and odor activity value analysis, which were 3-carene, geraniol, β-myrcene, τ-cadinol, and β-ionone. Additionally, sensory evaluation showed black tea produced by withering-shaking was fruitier, while shaking-withering produced a more floral tea. This study provides a theoretical basis for the discrimination of aroma characteristics of black tea processed by shaking, as well as a technical guide for the precise production of black teas with different floral-fruity aroma biases. Full article

Phytohormones play an important role in regulating the maturation process and the quality-related metabolite accumulation of fruits, and their concentration variation has always been concerned during fruit development. However, berry fruits, such as grape berries, are rich in a large number of secondary metabolites, which brings great challenges to the isolation and determination of hormones. In this work, we used grapes as experimental materials and proposed a solid-phase extraction (SPE) protocol to efficiently isolate multiple hormones from phenol-rich matrix using a mixture of dichloromethane, methanol and formic acid as eluent. A highly sensitive method based on ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) was developed to quantify a total of 11 plant growth regulators, including the recognized phytohormones, in grape pericarp and seed. The established method showed satisfactory precision (RSD < 11.3%) and linearity (R² > 0.9980). The limits of detection (LOD) and the limit of quantification (LOQ) were 0.001–0.75 ng/mL and 0.004–2.5 ng/mL, respectively. The recovery for the three levels of analytes spiked ranged from 63% to 118%, and the matrix effect was between 73% and 119%. Finally, the proposed method was applied to investigate the dynamic hormone concentration in Vitis vinifera L. cv. Cabernet Sauvignon berries from different vineyards, and assess the changes in endogenous hormones in grapes after treatment with exogenous growth regulators. We found that the contents of IP, ABA and IAA in pericarp and IP, IAA, IBA and SA in seed were significantly down-regulated after 10 days of treatment with NAA concentrations of 10 mg/L and 40 mg/L. In conclusion, this method helps to elucidate the role played by phytohormones in the maturation process and the accumulation of quality-related metabolites in phenol-rich fruits. Full article

Tomatoes are the most consumed vegetables worldwide and a valuable source of several antioxidants. The consumption of tomato products from appropriate cultivars after suitable processing methods may significantly improve human diet. The purpose of this study was investigating the variations in the contents of the main antioxidants present in tomato fruits, in the new Cuban breeds and yellow varieties, as well as their changes during the processing to tomato puree and ketchup. The quality evaluation comprised the detection of lycopene, ascorbic acid and total phenolics and the analysis of their contribution to antioxidant capacity in selected tomato genotypes. Heating (90–100 °C/15 min) enhanced the content of lycopene and total phenolics in puree, resulting in an increment in antioxidant capacity, despite the reduction in ascorbic acid as a result of concentration processes. The conducted experiments revealed that cultivars ‘Vyta’ and ‘Cima’ are very suitable for industrial purposes due to their high dry-matter content of more than 9% fresh mass and high biological value. With respect to serving size, the best sources of antioxidants are fresh tomatoes, followed closely by tomato puree, irrespective of cultivar. However, the differences are mainly due to the edible portion size (200 g for fresh tomatoes and 60 mL for puree, respectively). Full article

In manufacturing food powders, foam-mat drying provides a cost-effective alternative to traditional drying methods. This study aimed to select the foaming conditions which support the subsequent drying of Magenta leaves extract. In the initial stage, concentrations of egg albumin (5 to 15%) as a foaming agent, xanthan gum as foam stabilizer (0.1 to 0.5%), and whipping time (2 to 8 min) were designed. Multiple regression analysis was applied to analyze the relationship between the dependent variables (Foam expansion volume and foam density) and three independent variables as an indicator of foaming capacity and foam stability. The multiple response optimization was applied to optimize the foam density and foam expansion. The optimum foam density (0.25 g/mL) and foam expansion volume (298.12%) were obtained at the optimum egg albumin and xanthan gum concentrations, and whipping time at 12.21%, 0.24%, and 5.8 min, respectively, indicating a stable foam structure. Experimental moisture loss data are fitted for five selected drying models. The mathematical models were compared according to three statistical parameters, such as coefficient of determination (R²), chi-square (χ²), and root mean square error (RMSE). Among the five mathematical models tested with experimental data, the Page model could be applied to describe the foam-mat drying process of magenta leaves extract. The highest value of R² (99.54%), the lowest value of χ² (0.0007), and RMSE (0.0253) were observed for a air drying temperature of 60 °C. The effect of temperature on diffusion is described by the Arrhenius equation with an activation energy of 100.21 kJ/mol. Effective moisture diffusion values ranged from 2.27 × 10⁻¹⁰ to 6.71 × 10⁻¹⁰ m²/s as the temperature increased. The effect of drying conditions on anthocyanin changes of magenta leaves powder was compared. The results showed that the highest quality of the sample was observed when the sample was dried at 60 °C. Full article

Exposure to surface moisture triggers cuticular microcracking of the fruit skin. In mango fruit cv. apple, microcracking compromises postharvest performance by increasing moisture loss and infections with pathogens. This study reports the effects of exposing the fruit’s skin to surface moisture on the incidence of microcracking and on water vapor permeance. Microcracking was quantified microscopically following infiltration with a fluorescent tracer. Water mass loss was determined gravimetrically. Moisture exposure increased cuticular microcracking and permeance. During moisture exposure, permeance increased over the first 4 d, remained constant up to approximately 8 d, then decreased for longer exposure times. Fruit development followed a sigmoid growth pattern. The growth rate peaked approximately 103 days after full bloom. This coincided with the peak in moisture-induced microcracking. There were no increases in water vapor permeance or in microcracking in control fruit that remained dry. When experimental moisture exposure was terminated, microcracking and water vapor permeance decreased. This suggests a repair process restoring the barrier properties of the fruit skin. Histological analyses reveal a periderm forms in the hypodermis beneath a microcrack. Our study demonstrates that surface moisture induces microcracking in mango cv. apple that increases the skin’s water vapor permeance and induces russeting. Full article

This paper’s aim was to study how the antioxidant activity and the level of certain phenolic complexes and carotenoids vary in the pomace obtained from the fruits of two cultivars of chokeberry at different times of harvest after reaching the stage of maturity. The influence of the cultivar, harvest moment, and the combined effect of these two factors on the antioxidant activity and the dehydrated pomace content in components with antioxidant potentials, such as total phenolics, total tannins, total flavonoids, lycopene, and β-carotene was analyzed. The methanolic extract from the pomace obtained from the ‘Melrom’ cultivar had the highest efficiency (92.14 ± 5.02%). The antiradical activity of the pomace was maximal (93.27 ± 4.32%) after the middle of the harvest season (3 September). The pomace obtained from the ‘Nero’ cultivar displayed superior levels of phenolic content (13,030.16 ± 1414.46 mg/100 g), flavonoids (4627.83 ± 509.63 mg CE/100 g), tannins (7458.56 ± 529.43 mg/100 g), and lycopene (1.171 ± 0.388 mg/100 g). The ‘Melrom’ cultivar presented superior content of β-carotene (0.313 ± 0.07 mg/100 g). On average, a positive significant correlation between radical scavenging activity with total phenolic content and β-carotene was observed. The combined cultivar × harvest moment effect was reflected in the variations in the total tannins content and the total flavonoid content, but also in the antiradical activity of the methanolic extracts. Dehydrated pomace from chokeberry fruit can be an important source of antioxidant biological compounds and can be used to make innovative foods. Full article

Electrostatic devices generating an electric field (EF) are promising tools for greenhouse tomato cultivation. In these devices, an EF is generated in the space surrounding an insulated conductor (IC) that is charged by a voltage generator. Thus, a physical force is exerted on any insect that enters the EF, as a negatively charged IC (NC-IC) pushes a negative charge (free electrons) out of the insect body. The insect is polarized positively to be attracted to the NC-IC, and a grounded metal net (G-MN) repels the insect. This dual function of the apparatus (insect capture and repulsion) is the core of the electrostatic pest-exclusion strategy. In this study, we applied various innovative EF-based devices to evaluate their efficacy in greenhouse tomato cultivation. Our objective was to determine the optimal apparatus for simple, inexpensive construction by greenhouse workers. The results of this study will contribute to the development of sustainable pest-management protocols in greenhouse horticulture. Full article

In this study, we evaluated the effects of edaphic fertilization with N, P, and K (150-50-80, 100-60-60, and without edaphic fertilization (SFE)) and foliar fertilization with nanoparticles (NPs) of Se and Zn (Se: 50 ppm, Zn: 250 ppm, and no nanoparticles (NP0)) on the yield and antioxidant compounds of apple fruits. We conducted this study in a 20-year-old commercial orchard. The experimental design was a randomized complete block design of nine treatments. The treatments with fertilization doses of 150-50-80 and 100-60-60, supplemented with Se and Zn NPs, generally increased the yield, sugar content, and ascorbic acid of the apple fruits. The SFE + NPZn treatment produced the highest increase (+193% compared with the control) in fruit yield. The SFE + NPSe and SFE + NPZn treatments led to higher contents of phenols and flavonoids, with maximum values of 7.6 mg GAE and 15.82 mg QE per gram of dry weight. These compounds presented a direct correlation with the antioxidant activity in the fruits. The foliar application of Se and Zn nanoparticles supplemented the soil fertilization with N, P, and K to improve the yield and bioactive-compound synthesis of the apple fruits. Full article

Greenhouse vegetable production is of great importance in southern Europe. It is a cultivation system characterised by a high planting density and environmental conditions that favour the development of pests and diseases. Although alternatives to chemical pest and disease control have been used over recent years in greenhouse crops, it is still mostly plant protection products that are used to protect crops and prevent crop losses. Hand-held spraying equipment is mainly used to apply plant protection products to this type of crop. This equipment is technologically basic, offering low deposition efficiency in the plant canopy, high losses to the ground, and a high risk of worker exposure. In this context, it is important to utilise technologies that reduce the problems associated with using the conventional hand-held sprayers in greenhouses. This study evaluated the deposition and uniformity in the plant canopy and the losses to the ground when applying plant protection products with an electrostatic hand-held sprayer; the results were then compared with applications carried out using a conventional hand-held sprayer. For this purpose, a colorimetric method has been used based on the application of a tartrazine solution. The tests showed that the electrostatic spraying equipment increased the plant canopy deposition by 1.48 times that of the hand-held spray gun, resulting in a 48% reduction in the application rate. There was also a 1.78-times increase in deposition on the underside of the leaves and a 36.36% reduction in losses to the ground. In general, the electrostatic hand-held sprayer improves the effectiveness of the plant canopy deposition and reduces losses to the ground compared to the hand-held spray gun commonly used in pest and disease control. Full article

Fusarium oxysporum f. sp. conglutinans (FOC) is the dominant pathogen of vascular wilt disease on cabbage and other crucifers. Foc-Nto1 was confirmed to be the homologous protein of Nto1, a subunit of the NuA3 (nucleosomal acetyltransferase of histone H3) complex in Saccharomyces cerevisiae. FOC contains two races, race 1 and race 2. The functions of Nto1 in both races were investigated through functional genetics analyses. The Nto1-deleted mutants were decreased in conidium production and displayed increased sensitivity to hydrogen peroxide. These mutants also had reduced virulence on cabbage. The study provided evidence that Nto1 is a potential metabolic- and pathogenic-related factor in F. oxysporum. Full article

The plateaus of Tibet have a unique climate that poses a great challenge for local agriculture. To promote sustainable development in Tibet, an elite tea variety has been introduced. However, the modifications of tea flavors in response to the climate of the plateaus are unknown. In this study, volatile organic compounds (VOCs) and other taste substances of tea planted in its original location (OOT) and in Tibet (TOT) were systematically analyzed and compared. The volatile components in TOT and OOT showed a slight difference, and principal component analysis revealed that the characteristic aroma compounds distinguishing tea grown in Tibet from tea grown in Guangdong were hotrienol and benzyl alcohol. In terms of taste substances, TOT exhibited higher levels of water extractable compounds, including polyphenols and amino acids, but lower levels of caffeine than OOT, which implies that TOT may taste better than OOT. To our knowledge, this is the first study to describe the changes in aroma and flavor profiles of tea induced by high altitude systematically, which will provide a basis for reference during the introduction and cultivation of tea crops to the plateaus of Tibet. Full article

In common irrigation systems, sprinklers are mounted with circular nozzles, but innovative noncircular nozzles can save water and energy by improving fragmentation in a low–intermediate pressure irrigation system. In order to investigate the effects of nozzle orifice shapes (circular, square, and equilateral triangular) on droplet characteristics, experiments using high-speed photography and water droplet spectrum measurement were performed. Using ImageJ to observe with the overlapped droplets and using the self-compiled programs of MATLAB to observe the morphology of droplets, we extracted the outlines of droplets. In addition, several empirical formulas for the prediction of droplets were obtained by way of a regression analysis of the experimental data. In particular, the shape coefficient of the nozzle orifice and the operating pressure of the nozzle were added to these formulas as variable factors to make them applicable to a variety of nozzles and working conditions. The results show that with the increase in shape coefficient, the jet atomization intensifies, and the droplets breaking from the jet will be dense and uniform. The velocity distribution of the droplets conforms to exponential functions (R² > 0.7). The prediction formulas of diameter and kinetic energy were established with coefficients of determination exceeding 0.95. In low pressure conditions, the specific power multiplies at the end of spraying, and the maximum is proportional to the nozzle orifice coefficient. The impact-driven arm compensates for the disadvantage of the noncircular nozzles with the high irrigation-specific power, by producing a wider diameter gradient of droplets. Therefore, innovative sprinklers based on noncircular nozzles can be applied in a low–intermediate pressure system to increase water use efficiency, reduce energy consumption, and reduce costs. Full article

Cinnamoyl-CoA reductases (CCR) have a possible role in pungency formation of pepper because they can convert feruloyl-CoA, sinapoyl-CoA, and p-coumaroyl-CoA into lignin, which are also competitive precursors of capsaicin biosynthesis in phenylpropanoid metabolism. In this study, genome-wide CCR gene family, exon–intron structures, sequence homology, phylogenetic characterization, and promoters were analyzed in pepper. Two CCR genes were cloned from Capsicum chinense, their enzymic kinetic parameters and regulatory function were identified by heterologous expression, ectopic expression, and VIGS. In total, 38 genes were found as predicted CCRs or CCR-like proteins and were composed of 2–10 exons. The promoters of pepper CCRs contained growth, stress, hormone, and light-response elements. The affinity and catalytic efficiency of CcCCR1/2 to feruolyl-CoA was the highest. The analysis of metabolic substances showed that capsaicin content was negatively correlated with lignin and positively correlated with flavonoids. The highest expression of CcCCR1 was found in stems, the higher expression of CcCCR2 was found in stem and early fruit than other organs. CCR1, 2 had certain effects on capsaicin content by regulating related enzyme activity, CCR2 played a more important role in regulating pungency formation. Our results clarify the competitive mechanism between lignin and capsaicin biosynthesis and provide an explanation for spice regulation. Full article

The water (W; W₅₀, W₇₅, and W₁₀₀)–zeolite (Z; Z₀, Z₃, Z₆ and Z₉) coupling (W-Z) regulation strategy of high-quality and high-yield tomato was explored with alternate drip irrigation under mulch. Greenhouse planting experiments were used in monitoring and analyzing tomato growth, physiology, yield, quality, and water use efficiency (WUE). Suitable amounts of W and Z for tomato growth were determined through the principal component analysis (PCA) method. Results showed that tomato plant height (Ph), stem thickness (St), root indexes, leaf area index (LAI), photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), organic acid (OA), and yield showed a positive response to W, whereas nitrate (NC), vitamin C (VC), soluble solid (SS), intercellular CO₂ concentration (Ci), fruit firmness (Ff), and WUE showed the opposite trend. The responses of Ci and Ff to Z were first negative and then positive, whereas the responses of other indexes to Z showed an opposite trend (except yield under W₅₀). The effects of W, Z, and W-Z on tomato growth, physiological, and quality indexes and yield were as follows: W > Z > W-Z; the effects on WUE were as follows: Z > W > W-Z. The two principal components of growth factor and water usage factor were extracted, and the cumulative variance contribution rate reached 93.831%. Under different treatments for tomato growth, the comprehensive evaluation score F was between −1.529 and 1.295, the highest treated with Z₆W₁₀₀, the lowest treated with Z₀W₅₀. The PCA method showed that under the condition of alternate drip irrigation under mulch, the most suitable W for tomato planting was 100% E (E is the water surface evaporation), and the amount of Z was 6 t·ha⁻¹. Full article

Bull’s-eye rot, produced by Phlyctema vagabunda, is an important postharvest disease in apples. Current measures to control infection include synthetic fungicides, in addition to the application of copper hydroxide and potassium phosphite. However, growing public concern regarding fungicide residues in food has generated interest in developing non-chemical alternative control methods; biological control is one of the most promising alternatives. In this research, native endophytic yeasts were isolated and evaluated for the biocontrol of P. vagabunda in apples. The mechanisms of action involved were also determined. Our research found 2 isolates, Vishniacozyma victoriae EPL4.5 and EPL29.5, which exhibited biocontrol activity against P. vagabunda at 20 °C in apples, the incidence of bull’s-eye rot was reduced by 39% and 61%, respectively, and the severity of the disease was decreased by 67% and 70%, respectively, when apples were inoculated with these yeasts 24 h before applying the pathogen. The main mechanisms that could be involved in the observed biocontrol activity are the ability to form biofilms and the production of volatile organic compounds. Full article

Vermicompost (VC) is a nutrient-rich material that is mixed with soil, and it is used in this study. Four different environments were created such as control (Soil:VC:100–0%), mix one (Soil:VC:70–30% w/w), mix two (Soil:VC:50–50% w/w), and mix three (Soil:VC:40:60% w/w), and three well-developed roses (Vinca rosea valiant, Pelargonium peltatum, Pegasus patio) seedlings were transferred to individual pots. Plant growth parameters, i.e., the number of flowers, plant height, stem diameter, chlorophyll reading value, fresh flower weight, and flower dry weight height, were compared with respect to control seedlings. The improvement in the number of flowers, plant height, stem diameter, chlorophyll reading value, fresh flower weight, and flower dry weight height by 264, 71, 58, 255, and 193% for Vinca rosea valiant rosea, 138, 12, 160, 13, 55 and 112% for P. patio rose, and 50, 14, 23, 8, 61, and 41% for P. peltatum, respectively, grown in soil mixed with VC as compared to control. As a result of the research, the optimum growth parameter values and chlorophyll Meter SPAD values were obtained from the mix-three mediums for all three roses species. These results showed that 40% soil and 60% VC application could be proposed as the most effective medium in ornamental plant production. Full article

Internal flesh breakdown (IFB), a serious physiological disorder of mango fruit, causes significant economic losses in Southwest China. We investigated the extent of IFB in 100 mango orchards and how changes in the mineral nutrients of fruit flesh, leaves and soil affect IFB. We found that 76% of the mango orchards showed IFB symptoms, and the average IFB incidence was 10%. Fruit flesh with IFB showed higher average contents of N, P, K and Mg, lower average Ca content and higher average ratios of N/Ca, K/Ca and Mg/Ca. The leaves from orchards with IFB symptoms exhibited a remarkable increase in the average N and Mg contents. No significant difference was observed in the soil nutrient concentrations between orchards with and without IFB fruit. IFB incidence was significantly positively correlated with the N/Ca, K/Ca and Mg/Ca ratios in the fruit flesh. However, when considering individual orchards with IFB symptoms, fruit flesh that exhibited breakdown symptoms had Ca content higher, lower than or equal to that of the healthy fruit flesh. There was a strong correlation between fruit flesh and leaf in the same mineral elements, but neither of them showed a significant correlation with soil. Considering the mango trees were cultivated on steep slopes, and fertilizer was applied at a fixed position, we hypothesized that long-term fertilization in the partial root zone led to the excess of N, K and Mg in soil, which reduced the total flesh Ca content or resulted in the abnormal cellular distribution of Ca in the flesh, and ultimately triggered IFB development. Full article

Heat shock proteins (HSPs) play important roles in various stress conditions. In this study, CmHSP90.5, whose expression is induced by heat and salt, was cloned from a chrysanthemum (Chrysanthemum morifolium) ‘Jinba’ and expressed in Arabidopsis. We found that CmHSP90.5 localized in the chloroplast. The heterologous expression of CmHSP90.5 weakened the heat tolerance of Arabidopsis and reduced the activity of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), indicating that CmHSP90.5-mediated heat stress sensitivity may be partially due to the regulation of active oxygen cleavage. The levels of expression of AtHSP101, AtHSP15.7, and AtHSP17.6C in CmHSP90.5-overexpressing plants decreased compared with those in wild-type (WT) plants under heat stress, indicating that these HSPs and CmHSP90.5 coregulate a plant’s heat stress tolerance. In addition, the salt stress tolerance of the CmHSP90.5-overexpressing Arabidopsis decreased compared with that of WT plants; CmHSP90.5-overexpressing plants showed increased Na⁺ levels and decreased K⁺ and proline levels compared with those of WT plants. Interestingly, the expression of stress-related genes, such as the Na⁺/H⁺ antiporter encoding gene SOS1, high-affinity K+ transporter encoding gene HKT1;1, and proline synthesis gene AtP5CS1, decreased in CmHSP90.5-overexpressing plants under salt stress compared with those expressions in WT plants. Our findings lay a foundation for understanding the roles of CmHSP90.5 in response to abiotic stresses in chrysanthemum. Full article

Hemp (Cannabis sativa) is a multi-use crop garnering newfound attention from researchers and consumers. While interest has emerged, a lack of substantiated research still exists regarding effects of adverse weather events on physiological health and secondary metabolite production of hemp. The aim of this experiment was to assess cold tolerance of hemp using the cultivars ‘FINOLA’ and ‘AutoCBD’. Effects of cultivar, plant age, cold acclimation, frequency of cold treatments, and intensity of cold treatments were all considered in regard to their influence on physiological stress, biomass, and cannabinoid profile. Few effects of sequential cold treatments were noted, and they were not moderated by cold acclimation, which tended to have negative effects across many responses. This detrimental effect of cold acclimation conditions was further observed in decreased total CBD % and total THC % compared to non-acclimated plants. These findings bear consideration when assessing the unpredictability of a changing climate’s effects on the heath and cannabinoid profile of hemp. Full article

Oleuropein and other phenolic compounds contained in olive leaves give it the potential to be transformed from residue to co-product in an oil mill. However, the moment of the agronomic cycle in which their potential transformation is higher is not known in detail. Therefore, for the first time, a monthly study of the evolution of such compounds throughout an agronomic cycle is made (November 2019 to October 2020). Arbequina olive leaves were collected from three plots and the interactive effects of agronomic conditions were investigated, such as crop management (conventional and ecological), plantation framework (intensive and super-intensive) and location under different climatic conditions. The results showed that the main compound throughout the cycle was oleuropein and the highest levels occurred around the pruning season (February/March). Crop management and location affected the content of verbascoside and hydroxytyrosol, while plantation framework only influenced the flavonoid content. All compounds were affected by relative humidity and differential temperature, although hydroxytyrosol showed the highest correlation with the maximum temperature. The absorbance measurements by ultraviolet-visible spectrophotometry showed trends parallel to the oleuropein concentration measured by high-performance liquid chromatography, which suggests that this method could be useful to easily study the evolution of oleuropein in the oil mill. Full article