Editor’s Choice Articles

Key message. The success of interspecific hybridization in hardy geranium (Geranium sp.) can be predicted by considering the genetic distance between parental genotypes and using the logistic regression model developed in this study. Hardy geranium is a popular ornamental plant known for its architecture, hardiness, prolonged flowering, and diverse colors in leaves and flowers. In ornamental breeding, the pursuit of novel trait combinations is never-ending. Even in Geranium, certain combinations of valuable traits have not yet been achieved. Interspecific hybridization can increase diversity; however, success remains low due to pre- and postzygotic barriers. Crossing success can be predicted by response criteria such as pollen tube growth (tube_length), seed development (seed_dev), and seed setting (seed_set). Within a collection of 42 Geranium genotypes and during two consecutive breeding seasons (years), we evaluated tube_length, seed_dev, and seed_set for 150, 1155, and 349 crosses, respectively. These crosses varied in four parental differences (variables): chromosome number (Chrom), DNA/chromosome (DNA), style length (Style), and genetic distance expressed as the Jaccard distance (cJaccard = 1 − Jaccard). Using logistic regression models has confirmed that most often, the success rate decreased with increasing parental distance. The most consistent association was seen in seed_dev in combination with cJaccard. The model was used to predict the number of crosses necessary to have 10 successful crossing products by taking into account the uncertainty in the model. These findings provide valuable guidance for future planning of interspecific breeding experiments in Geranium. By incorporating the genetic distance between parental genotypes, breeders can enhance the efficiency and success of hybridization efforts. Full article

Recent studies using LED lighting at low to modest intensity have indicated that compared with red light, blue light can promote plant elongation in many crops as a shade avoidance response despite varying sensitivity with light environments, plant species, and growth stages. Currently, there is limited understanding of how temperature affects the blue light-mediated plant response. To clarify this point, two microgreen species (arugula and mustard) were grown indoors under two light quality × two temperature treatments: red LED light (peak at 670 nm) and blue LED light (peak at 450 nm) at 18 °C or 28 °C. A photosynthetic photon flux density of 110 µmol m⁻² s⁻¹ and a photoperiod of 12 h d⁻¹ were used for all treatments. After 6 to 8 days of treatment, at both temperatures, blue vs. red light promoted plant elongation, as demonstrated by a greater plant elongation rate, final plant height, and hypocotyl length, in arugula but not in mustard. Blue vs. red light also promoted some shade-avoidance responses such as decreased cotyledon size in both species and increased petiole length and dry mass partitioning to hypocotyls in arugula only. The elongation promotion in arugula by blue light was greater at 18 °C than at 28 °C, showing interactions between light and temperature on most plant traits. For mustard, plant elongation was promoted at 28 °C compared to 18 °C independent of light treatment, showing no interactions between light and temperature on most plant traits. These results suggest that the blue light-mediated elongation as a shade-avoidance response is not reversed by high temperature, despite the varying sensitivity with temperatures and species. Full article

The tomato brown rugose fruit virus (ToBRFV) causes severe damage to tomato cultivars and has international economic importance. The harmful tobamovirus is easily mechanically transmissible and highly stable. An ongoing cultivation of infected tomato plants may lead to the spread of ToBRFV in and around the production area of the infested tomato farm. We conducted a study in which we collected a representative number of swab samples from various inanimate surfaces in greenhouses, packaging halls, and shared and private accommodations. In addition, numerous fabrics, such as outer clothing, bed linen, and items used by greenhouse workers, were tested. The infectivity of ToBRFV-contaminated surfaces was tested in bioassays using Nicotiana tabacum cv. Xanthi NN and confirmed using DAS-ELISA. The proportion of ToBRFV-contaminated surfaces varied among locations, from 48.7% in greenhouses to 0% in offices with limited access to staff. Samples from shared accommodation and private accommodation were 18.4% and 3.6% ToBRFV positive, respectively. Clothing and protective items were found to be highly contaminated with ToBRFV, and even around the sleeping area, infective ToBRFV was detected in a few apartments. This study provides evidence for the first time on how and where infectious ToBRFV can be spread by humans beyond the production area. To avoid further dissemination, strict hygiene protocols are required to interrupt transmission routes. Full article

Rapid ripeness assessment of fruit after harvest is important to reduce post-harvest losses by sorting fruit according to the duration until they become ready to eat. However, there has been little research on non-destructive estimation of the ripeness and ripening speed of avocado fruit. Unlike previous methods, which classify the ripeness of fruit into a few categories (e.g., unripe and ripe) or indirectly estimate ripeness from its firmness, we developed a method using hyperspectral imaging coupled with deep learning regression to directly estimate the duration until ripeness of Hass avocado fruit. A set of 44,096 sub-images of 551 Hass avocado fruit images was used to train, validate, and test a convolutional neural network (CNN) to predict the number of days until ripeness. Training, validation, and test samples were generated as sub-images of Hass fruit images and were used to train a spectral–spatial residual network to estimate the duration to ripeness. We achieved predictions of duration to ripeness with an average error of 1.17 days per fruit on the test set. A series of experiments demonstrated that our deep learning regression approach outperformed classification approaches that rely on dimensionality reduction techniques such as principal component analysis. Our results show the potential for combining hyperspectral imaging with deep learning to estimate the ripeness stage of fruit, which could help to fine-tune avocado fruit sorting and processing. Full article

Ascorbic acid (AsA) is the most abundant antioxidant in plants and is an important nutritional index for agricultural products. Some plants, such as Rosa roxburghii Tratt., contain exceptionally high levels of AsA, but are relatively unpalatable. In view of its role in human health, as well as plant growth and development, we examined the effects of two important AsA regulatory genes from R. roxburghii in tomato, with the aim of producing a crop of higher nutritional quality. RrGGP2 and RrDHAR were cloned from R. roxburghii fruit. The overexpression vectors were made using 35S promoters and mediated by Agrobacterium tumefaciens to obtain the overexpression lines. A PCR and qRT-PCR verified that the two genes had been inserted and overexpressed in the tomato leaves and fruits. The results showed that the overexpression of RrGGP2 increased tomato leaf and fruit AsA content by 108.5% and 294.3%, respectively, while the overexpression of RrDHAR increased tomato leaf and fruit AsA content by 183.9% and 179.9%. The overexpression of RrGGP2 and RrDHAR further changed the expression of genes related to AsA metabolism, and the upregulation of one such gene, SlGGP, may have contributed greatly to the increase in AsA. Results here indicate that RrGGP2 contributes more towards fruit AsA accumulation in tomato than RrDHAR. Full article

This study analyzed growth patterns, biological compounds, antioxidant properties, ginsenoside contents, metabolites, and the annual net production of ‘Yunpoong’ and ‘K-1’ to find the optimal harvesting time of ginseng sprouts. One-year-old ginseng seedlings were cultivated in a container-type vertical farm under a temperature of 20 °C, a humidity of 60%, and average light intensity of 46.4 µmol m⁻² s⁻¹ (16 h photoperiod). Growth patterns at 2, 3, 4, and 5 weeks after transplanting (WAT) differed between cultivars. Regarding biological compounds and antioxidant properties, ‘Yunpoong’ took 5 WAT (43.59%; 2,2-diphenyl-1-picryl-hydrazine-hydrate radical scavenging activity, 1.47 OD_593nm; ferric reducing antioxidant power assay, 78.01%; 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity), and ‘K-1’ took 4 WAT (0.98 Re mg g⁻¹; total flavonoid contents, 35.93%; DPPH) to show a high content. Two cultivars showed the highest total ginsenoside contents at 5 WAT. Most of the analyzed metabolites had a higher content in ‘Yunpoong’ than in ‘K-1’. In both cultivars, it was confirmed that the longer the growth period (3 − > 5 WAT), the lower the yield and the annual ginsenoside net production. Therefore, ‘Yunpoong’ and ‘K-1’ cultivars should be grown as ginseng sprouts in the vertical farms for approximately 3 WAT and 4 WAT, respectively. Full article

Commercial fruit production in Norway is located at around latitude 60° north, demanding a careful choice of adapted cultivars. The most comprehensive collection of apple genetic resources in Norway is being kept in the Norwegian Apple Collection (NAC) at the Njøs Fruit and Berry Centre (NJØS). The collection contains around 350 accessions and was recently genotyped with a single nucleotide polymorphism (SNP) array. Curated SNP data were used for the assessment of structure and diversity, pedigree confirmation, and core collection development. In the following SNP analysis, we identified several duplicates and parent-child relationships. Across the geographic regions represented, the collection was equally diverse. Different methods for analyzing population structure were applied. K-means clustering and a Bayesian modeling approach with prior assumptions of the data revealed five subpopulations associated with geographic breeding centers. The collection has a distinct genetic structure and low relatedness among the accessions; hence, two core collections with 100 accessions in each were created. These new core collections will allow breeders and researchers to use the NAC efficiently. The results from this study suggest that several of the accessions in the Norwegian Apple Collection could be of high importance for breeding purposes. Full article

Peach trees play an essential role as an economic crop in China. However, the increasing cost of labor has led to a decline in the benefits of peach cultivation. The use of dwarfing rootstock technology can increase planting density, reduce tree height, decrease labor requirements, and reduce production costs. The Cerasus humilis (Bge). Sok. is a promising dwarfing rootstock for peaches owing to its small tree size, abundant resources, strong resistance, and adaptability. In this study, we investigated the effect of Cerasus humilis rootstocks on peach growth and development, and related gene expression. We used Ruipan 4/Cerasus humilis and Ruipan 4/Amygdalus persica L. as experimental materials to measure the growth and fruiting characteristics of two-year-old Cerasus humilis rootstocks. In addition, we used bioinformatic methods to explore the effect of Cerasus humilis rootstock on peach growth gene expression. Our results showed that Cerasus humilis rootstocks can dwarf peach trees, reduce branches, increase pollen count and stigma receptivity, shorten spore development, and promote protein accumulation in the late stage of fruit maturity. The Cerasus humilis rootstock reduced the growth hormone content in peach trees while upregulating the expression of growth-related PpYucca5 and PpYucca2 genes. PpYucca6 expression was downregulated in the early stage of shoot growth and upregulated in the middle stage. By reducing the content of growth hormones, peach trees can be dwarfed, but their impact on fruit quality is minimal. These results indicate that Cerasus humilis is a suitable peach dwarfing rootstock and can provide a theoretical reference for the future breeding of peach dwarfing rootstocks. Full article

The great genetic and phenotypic diversities characterize the mandarin species (Citrus reticulata). The present study aimed to evaluate a part of this diversity with molecular markers and through the composition of leaf (LEO) and fruit peel (PEO) essential oils. Seventy-two cultivars were chosen for this study to represent some wild and cultivated mandarins growing in the same orchards. The essential oils were analyzed via gas chromatography (retention indices) and via gas chromatography coupled with mass spectrometry. The low similarity of ‘Tachibana’ and ‘Korail tachibana’ with mandarins and other species suggested that they were pure mandarins but were not involved in the genesis of the cultivated forms. This distinction was also evident at the aromatic level with specific compounds or unusual proportions, such as δ-3-carene in PEO or β-phellandrene at 24.9% in ‘Korail tachibana’ LEO. ‘Kunembo’ and ‘Ben di gang ju’ were genetically and chemically identical, with a high proportion of myrcene (>20%) in their LEO. In general, the genetic diversity of SSR markers was higher than the chemical diversity. From the 72 accessions, 54 genotypes were identified, with only 8 aromatic profiles in PEO and 9 in LEO. This diversity of essential oils of mandarins offers new perspectives for the research and validation of new aromatic properties for food and cosmetic purposes. Full article

Hibiscus rosa-sinensis is the national flower of Malaysia and is widely cultivated as landscape planting across the nation. In 1995, Hibiscus chlorotic ringspot virus (HCRSV) was reported for the first time in Malaysia. Until today, there have been no follow-up studies on the viral infection in the plant, yet the virus symptom of chlorotic spots has been observed throughout the Hibiscus population. Therefore, this study aimed to report the complete genome sequence of the HCRSV, validate a molecular detection tool for its diagnosis, and measure the impact of the virus symptom and infection in H. rosa-sinensis. This study reported the complete genome of the HCRSV through RNA sequencing. The phylogenetic analysis of the HCRSV isolated from different geographical sources and several other related viruses was performed to confirm its identity and classification. Additionally, primers based on the genome sequence were designed and used for RT-PCR to detect the presence of the virus in symptomatic leaves, further confirming the HCRSV identity and presence. Meanwhile, the impact of the virus was measured by examining the anatomical and morphological changes in the leaf structure of symptomatic samples. Light microscopy and scanning electron microscopy were used to examine potential adaptations and comparisons between the leaf structures of healthy and infected samples, especially in the leaf lamina, petiole, and midrib cells. The results confirmed the complete genome sequence of the HCRSV, its molecular detection strategy, and the impact of the viral infection on Hibiscus leaves in Peninsular Malaysia. This study is beneficial for the management strategy of the virus and for protecting an important plant in the nation. Full article

The high humidity and short, mild winters of the southeastern United States are conducive to many plant diseases including orange cane blotch (OCB), caused by the algal species Cephaleuros virescens (Cv). Since its discovery on blackberry, its presence has been associated with cane cracking, cane girdling, and yield loss. Research detailing the disease cycle on blackberry is limited and is largely inferred from the interactions of Cv with its other hosts. To further detail the disease cycle of OCB, diseased blackberry canes were examined by photography and microscopy. By combining observations made from photography and microscopy, key events in the disease cycle of OCB on blackberry were elucidated as they correspond to blackberry phenology. The alga was observed to be active for a majority of the season, only exhibiting apparent dormancy from December through mid-April, concurrently with blackberry. While it appeared that the presence of algal sexual reproductive structures did not coincide with emerged primocanes, asexual reproductive structures were observed during the period when primocanes emerged. All new infections on newly emerged primocanes appeared around mid-summer, indicating a single infection cycle per year for OCB. These findings provide a foundation for further study and the development of targeted management strategies for OCB. Full article

With the world’s population and pollutants on the rise, it is crucial to find sustainable and environmentally friendly solutions that increase production efficiency. Organic horticulture is an effective strategy for creating a harmless and sustainable crop production system. Arbuscular mycorrhizal fungi (AMF) have been proposed as reliable biofertilizers for sustainable agriculture, and inoculum production is a rapidly expanding market. AMF can enhance plant nutrition and growth, but their efficacy varies depending on the plant species, inoculum type, and available P concentrations. This study evaluates the response of ornamental statice (Limonium sinuatum [L.] Mill.) to mycorrhizal inoculation (first factor) with Glomus mosseae (M1), G. intraradices (M2), or their mixture (M3), plus non-inoculation (M0), and varying available P concentrations (second factor) of 10 (control, P1), 20 (P2), and 40 (P3) mg kg⁻¹ soil in greenhouse conditions in a factorial experiment based on randomized complete block design with three replications. Root colonization, growth parameters, some ornamental traits, and the absorption of P, N, K, Ca, Zn, and Fe were measured. Root colonization was estimated as 30–65% and was reduced approximately by 32.4% with increasing P concentration in the soil. The lowest colonization percentage was recorded in P3 (45.69, 39.31, and 30.18 for M1, M2, and M3, respectively). Statice plants were positively influenced by inoculation, especially with G. mosseae in moderately available P (P2), which was also confirmed by the results of the principal component analysis. Overall, inoculated plants exhibited better nutritional status, growth, and ornamental traits than non-inoculated plants. Furthermore, mycorrhization delayed the time to the flowering of statice by 12, 7, and 9 days in M1, M2, and M3, respectively, compared to non-mycorrhizal (M0) plants. In conclusion, mycorrhizal inoculation can improve the plant nutrition, growth, and ornamental value of statice by selecting appropriate inoculum and optimal P concentrations. The results of this study suggest that mycorrhizal inoculation can be effectively used in the future to increase the quantity and quality of statice production. Full article

Fruit losses and wastage are mainly due to postharvest diseases; their control is reduced with pesticides. The excessive use of synthetic fungicides has caused harmful effects on human health and the environment, so it is therefore necessary to reduce their use. The development of new innocuous strategies has led to the use of compounds of natural or biological origin with the capacity to induce the plant defense system, which improves the fruit’s response against future pathogen attacks in addition to reducing the incidence of postharvest diseases. These compounds are known as “elicitors”. Although the use of molecular tools such as RT-qPCR or the measurement of the enzymatic activity of molecular markers makes it possible to determine the activation of the plant defense system in response to the application of an elicitor compound, in recent years, omics technologies such as the transcriptome, proteome, or metabolome have provided new and interesting information that helps to elucidate the molecular aspects involved in the activation of the plant defense system in response to the application of elicitors. This review summarizes recent advances in molecular aspects, highlighting the contribution of omics technologies to a better understanding of fruit defense mechanisms induced by different elicitors. Full article

Olive oil is one of the basic products in the Mediterranean diet, and, due to its nutritional value, it is becoming more and more widespread in the world. Even though it has traditionally been a rainfed crop, farmers are currently transforming their plantations into super-high-density orchards to increase production. However, the increasingly acute drought in Mediterranean countries forces the establishment of water control mechanisms that allow restriction the contribution of water without undermining the properties of the products obtained. Under this concept, hydroSOS crops and products arose. This study aims to analyze the influence of the application of deficit irrigation on the olive oil obtained from the Arbequina and Arbosana varieties. The sensory parameters descriptive profile and consumers satisfaction degree were measured using trained and consumers’ panels, and the chemical parameters peroxide index, fatty acids, and volatile profile were analyzed using the methods from the International Olive Oil Council and gas chromatography. The experimental results showed that applying this type of irrigation leads to an oil that is more valued by consumers, with a higher concentration of aromatic compounds related with a greener aroma (hexanol, trans-2-hexen-1-ol, hexanal), a higher content of polyunsaturated fatty acids, and greater antioxidant capacity. Deficit irrigation strategies led to environmentally friendly olive oil with high acceptance by Spanish consumers. Full article

Clavibacter michiganensis subsp. michiganensis (Cmm) and Ralstonia solanacearum (Rs) are important bacterial pathogens of tomatoes (Solanum lycopersicum), are included in A2 list in the EPPO (European and Mediterranean Plant Protection Organization) region and are recommended for regulation as quarantine pests. The control of quarantine pathogens requires accurate and rapid detection tools. In this study, a method based on chip digital PCR (cdPCR) was developed to identify and quantify Cmm and Rs. The assays were tested on pure bacteria samples and on tomato samples naturally contaminated or spiked with bacteria DNA. For a better estimation of infection level in host plants, duplex assays that are able to simultaneously amplify plant and bacteria DNA were developed. The two cdPCR assays proposed can be used for the rapid and timely detection of this group of high-risk quarantine bacteria to prevent the spread of pathogens and the occurrence of disease in other areas. Full article

This study aims to expand the artificial lighting potential of controlled environment cultivations systems by introducing UV-A (~315–400 nm) wavelengths into the traditional, visible spectrum lighting, seeking to improve the nutritional and sensory value of cultivated leafy vegetables. The experiment was conducted in a closed climate-controlled chamber, maintaining 21/17 °C day/night temperature, ~55% relative humidity, and a 16 h photo/thermo period. Several genotypes of leafy vegetables, red and green leaf lettuce cultivars, mustard, and kale were cultivated under 250 µmol m⁻²s⁻¹ basal LED lighting, supplemented by 385 nm UV-A or 405 UV-A/violet wavelengths for 1.1 mW cm⁻² for 12 h photoperiod for the whole cultivation cycle. The results show that UV-A/violet light impacts on leafy vegetable growth, free radical scavenging activity, sugar, and phytochemical (α tocopherol, α + β carotenes, epicatechin, rosmarinic and chicoric acid contents) are species-specific, and do not correlate with untrained consumer’s sensory evaluation scores. The 405 nm light is preferable for higher antioxidant and/or sensory properties of kale, mustard, and green leaf lettuces, but both UV-A wavelengths reduce growth parameters in red leaf lettuce. Full article

This study presents a novel hybrid model that combines two different algorithms to increase the accuracy of short-term berry yield prediction using only previous yield data. The model integrates both autoregressive integrated moving average (ARIMA) with Kalman filter refinement and neural network techniques, specifically support vector regression (SVR), and nonlinear autoregressive (NAR) neural networks, to improve prediction accuracy by correcting the errors generated by the system. In order to enhance the prediction performance of the ARIMA model, an innovative method is introduced that reduces randomness and incorporates only observed variables and system errors into the state-space system. The results indicate that the proposed hybrid models exhibit greater accuracy in predicting weekly production, with a goodness-of-fit value above 0.95 and lower root mean square error (RMSE) and mean absolute error (MAE) values compared with non-hybrid models. The study highlights several implications, including the potential for small growers to use digital strategies that offer crop forecasts to increase sales and promote loyalty in relationships with large food retail chains. Additionally, accurate yield forecasting can help berry growers plan their production schedules and optimize resource use, leading to increased efficiency and profitability. The proposed model may serve as a valuable information source for European food retailers, enabling growers to form strategic alliances with their customers. Full article

Target ranging is the premise for manipulators to complete agronomic operations such as picking and field management; however, complex environmental backgrounds and changing crop shapes increase the difficulty of obtaining target distance information based on binocular vision or depth cameras. In this work, a method for ranging large-sized fruit based on monocular vision was proposed to provide a low-cost and low-computation alternative solution for the fruit thinning or picking robot. The regression relationships between the changes in the number of pixels occupied by the target area and the changes in the imaging distance were calculated based on the images of square-shaped checkerboards and circular-shaped checkerboards with 100 cm², 121 cm², 144 cm², 169 cm², 196 cm², 225 cm², 256 cm², 289 cm², and 324 cm² as the area, respectively. The 918 checkerboard images were collected by the camera within the range from 0.25 m to 1.5 m, with 0.025 m as the length of each moving step, and analyzed in MATLAB to establish the ranging models. A total of 2448 images of four oval watermelons, four pyriform pomelos, and four oblate pomelos, as the representatives of large fruit with different shapes, were used to evaluate and optimize the performance of the models. The images of the front were the input, while the imaging distances were the output. The results showed that the absolute error would be less than 0.06 m for both models and would linearly increase with a decrease in the distance. The relative error could be controlled at 5%. The results proved the proposed monocular method could be a solution for the ranging of large fruit targets. Full article

Tomato is considered the most important vegetable crop worldwide. Improving the nutritional value of fruits must be based on sustainable production in terms of varieties and fertilization management. This study aimed to improve the nutritional value (total soluble solids, acidity, lycopene, β-carotene, polyphenols, macro and microelements) of two tomato varieties (‘Cristal’ and ‘Siriana’) under three fertilization types (NPK chemical fertilizer, chicken manure and biological fertilizer with microorganisms) for the greenhouse. Primary metabolism compounds do not vary significantly according to the type of fertilizer used. The results for the antioxidant compounds showed a better effect of biological fertilization compared to chemical fertilizer and control unfertilized. Thus, the antioxidant activity was improved by 28% compared to chemical fertilization, the lycopene content by 36% and β-carotene by 96%, respectively. The tomato fruits from the local cultivar (‘Siriana’) are richer in nutritional compounds such as rutin, regardless of the type of fertilization, which denotes a good ability to adapt to crop conditions. Tomato cultivars reacted positively to microbiological fertilization compared to chemical, thus producing nutritious fruits under sustainable management. Tomato fruits were richer in the quality of microelement contents. Full article

The endangered epiphytic orchid, Dendrobium chrysotoxum, is known for its ornamental and medicinal uses. However, knowledge of this orchid’s symbiotic seed germination, protocorm anatomy, and developmental morphology is completely unknown. In this study, we investigated the process of protocorm development of D. chrysotoxum during symbiotic germination using anatomical technologies and scanning electron microscopy. There are six development stages that were morphologically and anatomically defined during symbiotic seed germination. The embryo transformed into a protocorm at stage two, and a protrusion developed from the top of the protocorm at stage three and elongated to form the cotyledon at stage four. The stem apical meristem (SAM) was initiated at stage three and well developed at stage four. The first leaf and the root appeared at stages five and six, respectively. The hyphae entered through the micropylar end of the seed at stage one and then invaded the protocorm through rhizoids when rhizoids formed. Invading fungal hyphae colonized the inner cortex at the base of protocorms, formed pelotons, and were digested by host cells later. We conclude that protocorm development is programmed by the embryo, which determines the structure and function of the protocorm. The two developmental zones in a polarized D. chrysotoxum embryo include the smaller cells zone, which forms the cotyledon and a shoot apical meristem at the apical end, and the larger cells zone, which forms the mycorrhiza to house the symbiont at the basal end. These results will provide important insights for further research on the mechanisms underlying orchid-fungi symbiosis and enhance the understanding of orchid evolution. Full article

Apple leaf characteristics are the most important vegetative growth and development traits. The apple rhizosphere is also indirectly responsible for apple growth and development. It provides roots with elements and compounds that improve roots’ and shoots’ growth and development. The application of exogenous plant growth regulators such as strigolactones (SLs) has become one of the main trends for improving vegetative growth and enhancing the rhizosphere microbiome. This study aimed to investigate the effect of the exogenous SLs on some leaf characteristics, such as leaf area, angle, nitrogen content, chlorophyll content, and apical area diameter, in addition to the composition of the rhizosphere microbiome of apple M9 rootstock. The apple rootstocks were treated with various concentrations of GR24, an analog of SLs; the concentrations were 0, 1, 5, and 10 µM. The study found that the treatments of 5 µM increased the leaf–stem angles and leaf length while decreasing the apical diameter. The treatments of 1 and 5 µM increased leaf nitrogen content; however, this effect was not observed when using the higher concentration of 10 µM. The lower concentration (1 µM) led to a different abundance and diversity of microorganisms compared to the higher concentration (10 µm). Full article

Apple accessions, currently maintained within the two main ex situ collections in Bosnia and Herzegovina (B&H), have previously been genotyped using microsatellite markers. The obtained molecular data provided insight into mislabeled accessions and redundancies, as well as the overall genetic structure of the germplasm. The available dataset enabled the creation of a core collection consisting of 52 accessions. The reliability and usefulness of microsatellites has made this low-density marker system a norm in studies on apple germplasm. However, the increased access to medium- and high-density SNP arrays, developed specifically for apples, has opened new avenues of research into apple genetic resources. In this study, 45 apple genotypes consisting of 33 diploid core collection accessions from B&H and 12 international reference cultivars were genotyped using an Axiom^® Apple 480 K SNP array in order to examine their genetic relationships, population structure and diversity, as well as to compare the obtained results with those calculated on previously reported SSR profiles. The SNPs displayed a better ability to differentiate apple accessions based on their origin, as well as to cluster them according to their pedigree. Calculating identity by descent revealed 16 pairings with first-degree relationships and uncovered the introgression of ‘Delicious’ and ‘Golden Delicious’ into the core collection. Full article

Maintaining a diverse diet is essential for the preservation of one’s health and may contribute to the fight against significant civilization diseases such as obesity or diabetes. Sweet potato can be fitted into a diverse diet and serve as a functional food with its antioxidant content. Therefore, it is important to know how the production technology alters the content and composition of these antioxidant compounds. The objective of this study was to collect information on how the increased potassium dominant fertilizer levels and also the additional high-dose fertigation can affect the phytonutrient contents and yields in an orange- and a purple-fleshed sweet potato cultivar. Field experiments were conducted in the Hungarian county of Heves in two consecutive growing seasons in 2021–2022. Different doses of potassium-predominant fertilizer were applied to an orange flesh (Beauregard) and a purple flesh (Stokes Purple) varieties of sweet potatoes. Different application techniques were used in the form of base and top dressing at different rates. The effect on yield and polyphenol content of the different fertilizer rates was investigated. Analytical studies were carried out by high-performance liquid chromatography (HPLC). In the case of the Beauregard variety, in addition to identifying the carotenoids, we also performed their quantitative determination. We found that 87% of the carotenoid content was ß-carotene. The total anthocyanin content was investigated for the purple variety—Stokes Purple, for which a new extraction method was developed. In our study, the split dosages, when the pre-planting fertilizer was supplemented with additional liquid fertilization, resulted in 36 and 30.5% higher yields in the Beauregard in Experiment I and Experiment II, respectively, compared to the untreated control plots over the two years. The additional liquid fertilizer increased the yield to a lesser extent when compared to treatments received only pre-planting fertilizer. As for Experiment III, the split dosages resulted in 34.4% higher yields in the Stokes Purple compared to the control plots. However, the additional liquid fertilizer was not effective at all when the plants received a double dose of pre-planting fertilizer in the case of Stokes Purple. Total carotenoid (Experiment I–II) was higher and anthocyanin yield per plant (Experiment III) was significantly higher in the split-dosage treatment than in the untreated control plots. Full article

The diversity of fruit color in sweet cherry (Prunus avium L.) has been attributed to the presence of either anthocyanin or carotenoid. We profiled the anthocyanin and carotenoid metabolites to investigate the different pigments and the underlying regulatory mechanisms of differential expression genes (DEGs) between red and yellow fruits of sweet cherry. We profiled two cultivars, ‘Jiangnanhong’(JNH, red fruits) and ‘Chaoyang’(CY, yellow fruits) to establish their anthocyanin and carotenoid metabolites by LC-MS/MS and transcriptome analysis by RNA-seq to test the difference in gene expression and metabolic substances between the two varieties. Cyanidin-3-O-rutinoside was the most different pigment between two cultivars, the content of which in red fruit was significantly higher than in the yellow one during the whole ripening stage (stage 3 and stage 4). The total carotenoid content in the two color types of fruits was close, but the content in yellow fruit was shown to be more stable after harvest. Based on the transcriptome data, the heatmap of selected structural DEGs showed that all of the anthocyanin genes expressed significantly higher levels in red fruits than that in yellow fruits. Two unigenes encoding chalcone synthase (CHS) and UDP glucose-flavonoid 3-O-glucosyltransferase (UFGT) were expressed 1134.58 and 1151.24 times higher in red than in yellow fruits at stage 4, respectively. Correlation analysis showed that anthocyanin genes in JNH were negatively correlated with those in CY; by contrast, there were some strong correlations observed between the two cultivars in carotenoid genes. Thus, the coloration of sweet cherry was mainly attributed to anthocyanin-related genes. Full article

Modern plant biotechnology often faces the problem of obtaining a stable and powerful vector for gene overexpression. It is known that introns carry different regulatory elements whose effects on transgene expression have been poorly studied. To study the effect of an intron on transgene expression, the stilbene synthase 11 (VaSTS11) gene of grapevine Vitis amurensis Rupr. was selected and overexpressed in grapevine callus cell cultures and several plant generations of Arabidopsis thaliana as two forms, intronless VaSTS11c and intron-containing VaSTS11d. The STS genes play an important role in the biosynthesis of stilbenes, valuable plant secondary metabolites. VaSTS11d contained two exons and one intron, while VaSTS11c contained only two exons, which corresponded to the mature transcript. It has been shown that the intron-containing VaSTS11d was better expressed in several generations of transgenic A. thaliana than VaSTS11c and also exhibited a lower level of cytosine methylation. As a result, the content of stilbenes in the VaSTS11d-transgenic plants was much higher than in the VaSTS11c-transgenic plants. Similarly, the best efficiency in increasing the content of stilbenes was also observed in grapevine cell cultures overexpressing the intron-containing VaSTS11d transcript. Thus, the results indicate that an intron sequence with regulatory elements can have a strong positive effect on both transgene expression level and its biological functions in plants and plant cell cultures. Full article

The aim of this study is to analyze the effect of excess boron (B) on the nutrient uptake, growth, and physiological performance of grapevines. Merlot and Cabernet Franc grapevines, either own-rooted or grafted onto 1103P and 101-14 Mgt rootstocks, were exposed in a hydroponic pot experiment to 0.5 mM boron for sixty days. Twenty-five days following the beginning of B treatment, the first symptoms of boron toxicity appeared, including leaf edge and margin yellowing, subsequent necrosis, and cupping of leaf blades. At harvest, sixty days after the start of the experiment, B concentration of the treated vines increased in all parts of the vine in the following order: Leaves > Roots > Trunks > Shoots. Leaf Boron concentration in treated vines ranged from 980.67 to 1064.37 mg kg⁻¹ d.w. Boron excess significantly reduced the concentrations of all macro and micronutrients studied in this experiment. The total leaf chlorophyll (Chl) concentration decreased from 35.46 to 44.45%, thirty and sixty days, respectively, from the beginning of the boron treatments. In addition, an excess amount of boron resulted in a dramatic decrease in net CO₂ assimilation rate, stem water potential, and PSII maximum quantum yield, irrespective of vine type (own-rooted or grafted). At the end of the experimental period, the total leaf phenolic content increased by 71.73% in Merlot and by 71.16% in Cabernet Franc due to Boron stress. The tressed vines grafted onto 1103P showed increased shoot and root dry weights, leaf chlorophyll content, CO₂ assimilation rates, and F_v/F_m ratio compared to vines grafted onto 101-14 Mgt. It was found that rootstocks play an important role in B toxicity. The results showed that the leaf accumulation of boron was delayed to a greater extent by 1103P rootstock compared to 101-14 Mgt, resulting in the earlier appearance of leaf toxicity symptoms in vines grafted onto 101-14 Mgt rootstock compared to 1103P. Full article

To improve the efficiency of nitrogen (N) fertilization, it is necessary to perform rapid direct measurements in the field rather than time-consuming laboratory-based chemical analysis. Herein, crop and soil data from the early stages of cabbage growth were acquired through two fall cultivations. Chlorophyll meter value, height, and projected leaf area were evaluated as crop indicators. A positive correlation was observed between the projected leaf area or its rate of increase 2–3 weeks after transplantation and head fresh weight (FW). After comparing two water-content reflectometers (WCR) and a nitrate sensor, we selected a WCR with a 12 cm-long rod as the soil indicator. The diagnostic method was verified using varying amounts of N basal fertilizer during spring cultivation. The variable rate of N top dressing (25, 50, and 75% total N) based on the electrical conductivity (EC) 14 days after transplantation reduced the subsequent EC variability. No differences in head FW were observed between the treatments. A 25% reduction in N fertilizer was considered possible for half of the plots. The quantity of inorganic N extracted by potassium chloride from the crop soil after cultivation was unaffected by the amount of N fertilizer. Therefore, the diagnostic method proposed herein is suitable for soil N management. Full article

Herbaceous peony (Paeonia lactiflora Pall.) is a famous ornamental plant, and the study of its flower color is of great significance for cultivating new flower varieties. To explore the factors driving the formation and change of herbaceous peony flower color, we selected five herbaceous peony varieties at four flowering stages to determine the change in flower color, petal area, and microstructure. We also examined the composition and content of petal pigments, soluble sugar and soluble protein content, pH value of cell fluid, and water content. Finally, we analyzed the correlations between each factor. We found that Pn3G5G, Pg3G5G, and Cy3G5G were the main anthocyanin components in red and purple petals. Qu3G, Qu7G, Is3G, and lutein play important roles in yellow petal formation. The change in herbaceous peony flower color during the flowering process is directly caused by changes in the anthocyanin and carotenoid content in petals. In addition, changes in other physiological indices also influence the change in flower color. This study explored the physiological and biochemical factors affecting the color of herbaceous peony petals, which has an important practical significance for studying the physiological mechanism of herbaceous peony flower color formation and color breeding of new flowers. Full article

A relatively new, non-destructive, method for the assessment of optimal blueberry fruit maturity directly on the plant uses a DA-meter (delta absorbance) to measure chlorophyll absorbance (I_AD). Here, ‘Aurora’ fruit quality parameters (peel color, fruit firmness), chemical composition (individual sugars, organic acids and phenolics) and the relative expression of anthocyanidin synthase (ANS) genes were examined at four different maturity stages (immature, light purple, darker purple, fully ripe). All observed parameters changed significantly during ripening and sometimes exhibited high correlation with I_AD values, as R² values ranged between 0.61 and 0.97. Peel lightness (L*), chroma (C*), fruit firmness and organic acids significantly decreased during ripening, while sugars, sugar/organic acid ratio, total phenolics and relative expression of ANS significantly increased. The current study is the first to determine I_AD values during different maturity stages of ‘Aurora’ fruit using a DA-meter and to evaluate their correlation with the most commonly used quality parameters of ripe fruit, fruit chemical composition and relative expression of ANS. Full article

Orchard systems have drastically changed over the last three decades to high-density plantings that prioritize light interception that is evenly distributed throughout the entire canopy. These conditions allow the production of fruit with a high red color that meets consumer demands for uniformly colored fruit without external disorders. However, these systems also expose a higher proportion of fruit to full-sunlight conditions. In many semi-arid apple production regions, summer temperatures often exceed thresholds for the development of fruit sunburn, which can lead to >10% fruit losses in some regions and some years. To combat this, growers and researchers use sunburn mitigation strategies such as shade netting and evaporative cooling, which bring a different set of potential fruit quality impacts. Often, there is a tradeoff between red color development and fruit sunburn, particularly for strategies that affect light intensity reaching the fruit surface. In this paper, we review agronomic and environmental factors leading to reductions in red color and increases in sunburn incidence, along with advancements in management practices that help mitigate these issues. Furthermore, we also identify gaps in knowledge on the influence climate change might have on the viability of some practices that either enhance red color or limit sunburn for apple orchards in semi-arid environments. There is a need for cost-effective management strategies that reduce losses to sunburn but do not inhibit red color development in bicolor apple cultivars. Full article

Microgreens are immature and tender edible vegetables that have become relevant in the market due to their contribution to human health as “functional food”. They can be produced in controlled environments, allowing more efficient use of space and resources and facilitating the management of environmental conditions, such as light, temperature, and relative humidity. The study’s objective was to evaluate the impact of photoperiod and light intensity on red beet microgreens’ yield and the antioxidant compound content. LED growth lamps (spectrum of 75% red, 23% blue, and 2% far-red) under two photoperiods were evaluated: 12 and 16 h, and three intensity levels: 120 (low), 160 (medium), and 220 (high) µmol m⁻² s⁻¹. The largest photoperiod raised 32, 49, and 25% on phenolic compounds, total betalains, and antioxidant capacity, respectively, but a 23% reduction in microgreens yield was obtained compared with the shortest photoperiod. The low and medium intensities promoted the highest yield, reaching 460 g m⁻²; yield decreased significantly by 22.1% at high intensity compared to low and medium intensity. Contrastingly, no effect on antioxidant activity was observed with the evaluated range intensities, except for the betalains concentration, which was reduced by 35% under the highest intensity compared to low intensity. On the other hand, resource use efficiency (energy and water) improved under the shortest photoperiod. Thus, an intensity between 120 and 160 µmol m⁻² s⁻¹ and a photoperiod of 12 h favored the microgreen’s beet growth and saved electricity; meanwhile, a 16 h photoperiod ameliorated the beet microgreens antioxidant activity under a light spectrum composed of blue:red:far-red = 23:75:2. Full article

Managing nutrients in recirculating solutions can be challenging in hydroponic production, and poor management practices can rapidly result in root zone nutrient imbalances in reduced yield. Using mass balance principles to formulate hydroponic replenishment solutions is a proposed strategy to reduce nutrient imbalances and the need to periodically replace the hydroponic solution. Objectives were to (1) formulate species-specific nutrient replenishment solutions for arugula (Eruca sativa L.) and basil (Ocimum basilicum L.) using mass balance principles and (2) evaluate the effects of using these replenishment solutions on plant growth and root zone nutrients over time. In the first experiment, arugula and basil tissues were analyzed over 42 d for macronutrient concentrations which were used to custom formulate species-specific replenishment solutions for both species. In the second experiment, nutrients were resupplied for hydroponic arugula and basil over time using either the species-specific or a standard commercial hydroponic replenishment solution. Species-specific replenishment solutions resulted in decreased solution EC and concentrations of most macronutrients over time for both species. In contrast, replenishment with the standard hydroponic solution resulted in increased solution EC and concentrations of calcium, magnesium, and sulfate and decreased nitrogen, phosphorus, and potassium. Replenishment treatment had no effect on yield for arugula and basil; however, results suggested root zone imbalances may have still occurred eventually for both treatments and species. Species-specific replenishment solutions would be most effective in scenarios where solutions could be formulated for a specific crop, mixed using high-quality irrigation water, and where environmental conditions are controlled and stable, such as indoor farming systems. This study highlighted several practical challenges and considerations regarding the formulation of hydroponic solutions using mass balance. Full article

Knowledge of genetic identity, genetic relationships, ploidy level, and chromosome numbers can enhance the efficiency of ornamental plant breeding programs. In the present study, genome sizes, chromosome numbers, and genetic fingerprints were determined for a collection of 94 Ilex accessions, including 69 I. crenata. The genome size of the entire collection ranged from 1.50 ± 0.03 to 8.01 ± 0.18. Within the species of I. crenata, genome sizes varied (mean ± sd) between 1.98 ± 0.08 and 2.30 ± 0.04, with three outliers: 3.06 ± 0.04, 4.04 ± 0.09, and 4.19 ± 0.08. The chromosome counting results showed 2n = 40 for I. crenata accessions and confirmed the outliers as one triploid and two tetraploids. A high intra-specific genetic diversity in Ilex crenata was found, after genetic fingerprinting using genotyping-by-sequencing (GBS). The species I. crenata was separated into three clades, which coincided with intraspecific differences in genome sizes (mean ± sd) of 2.09 ± 0.006, 2.07 ± 0.05, and 2.19 ± 0.06 pg/2C per clade as mean values for the diploids. Applying a principal coordinate analysis (PCoA) to the genetic fingerprinting data of all species in the collection revealed a wide genetic variation, which has not yet been commercially exploited. These findings could form the basis for selectively breeding parents, in order to create more genetic diversity via intra- and interspecific crosses. Full article

Volatiles are essential substances that determine distinct fruit flavors and user preferences. However, the metabolic dynamic and molecular modulation models that regulate the overall flavor generation during fruit growth and ripening are still largely unclear for most fruit species. To comprehensively analyze the molecular mechanism and regulation mechanism of aroma accumulation and aroma component formation in Pyrus spp. ‘Panguxiang’ (‘Panguxiang’pear), this study compared pear phenotype, sugars, organic acid content, and the expression of related genes and metabolites amid pear growth and development in Pyrus spp. ‘Panguxiang’. A total of 417 VOCs (4 amines, 19 aromatics, 29 aldehydes, 31 alcohols, 38 ketones, 64 heterocyclic compounds, 89 terpenoids, 94 esters, and 49 others) were found. The potential gene expression patterns were explored by combining transcriptomics and metabolomics, and VOC-associated metabolism and transcriptome data from all samples were integrated during the growth and development period. On this basis, we constructed a colorful model depicting changes in the VOCs and genes throughout pear growth and development. Our findings reveal that terpenoid biosynthesis pathways are the main aroma production pathways during pear growth and development. In addition to providing novel insights into the metabolic control of fruit flavor during growth and development, this study also provides a new theoretical basis for studying aroma metabolites in pears. Full article

Cucumber (Cucumis sativus L., cv. “Nina Z”) plants grafted onto squash (Cucurbita maxima, cv. “Yu Yu Ikki”) were grown in a greenhouse using the newly developed nutrient film technique (NFT) hydroponic system “Kappa land” (Mitsubishi aqua solutions Co., Ltd., Tokyo, Japan), from February to June 2022. The growth and development of cucumbers were examined under two different training methods: Lowering training (LT) and Pinching training (PT). Data collected were related to water and nutrient consumption, plant growth and development parameters, and the workload of the main activities. The results showed that plants grown under the LT recorded significantly higher total stem length (10.9 m) and number of nodes (133). In addition, from 21 April to 19 May, the leaf area index was significantly higher in the LT treatment. The highest total yield (15.4 kg m⁻²) and marketable yield per unit area (13.8 kg m⁻²) were recorded in the LT treatment. Regarding fruit growth, the fruits took 14 and 19 days to reach the standard harvest weight in the PT and LT treatments, respectively. In addition, the fruits were more straight in the PT treatment. The water use efficiency was not significantly different between the two treatments. However, the nutrient use efficiency was significantly higher in the PT treatment because plants produced more vegetative organs in the LT treatment instead of fruits. The work for removing old leaves and harvesting fruits was simplified in the LT treatment. The LT method can be effective for the automation of old leaf removal and fruit picking by the robot in the future. Full article

The red color of apple peel is an important phenotypic and economic trait mainly attributed to anthocyanin accumulation. Apples show a deeper red color at higher altitudes than at lower ones; however, the molecular regulatory network underlying color variation along altitudinal gradients has not been investigated. In this study, the effects of environmental conditions associated with low (124 m) and high (1901 m) altitudes on peel color were assessed through physiological, metabolomic, transcriptomic, and qRT-PCR analyses in Huashuo apple and its sister line, Huarui apple. The content of cyanidin-3-O-galactoside, cyanidin-3-O-arabinoside, and cyanidin-3-O-xyloside was abundant in the high-altitude environment and may contribute to the deeper red color. Transcript levels of structural genes in the anthocyanin synthesis pathway, especially MdCHI, MdCHS, MdANS, and MdDFR, in apple peel were significantly higher at high altitude than at low altitude. Based on the protein interaction prediction and correlation analyses, four transcription factors (MDP0000127691, MDP0000284922, MDP0000758053, and MDP0000074681) could interact with anthocyanin synthesis-related proteins, showing high correlation with anthocyanin accumulation. Therefore, the abovementioned four genes and four transcription factors were predicted to account for the color differences between high and low altitudes. These results provide genetic resources and a theoretical basis for color-oriented fruit improvement. Full article

In the cranberry (Vaccinium macrocarpon Ait.) industry, the textural properties and firmness of the fruit are priority traits for producing processed products, such as sweetened dried cranberry (SDC), which have gained popularity in recent years. However, there is currently no reliable methodology for screening these traits in breeding programs. In this study, we examine the key methodologies, textural traits, parameters, and conditions that are necessary to accurately and efficiently measure the texture of cranberry fruit. Double compression, single compression, puncture, shearing and Kramer shear cell methodologies were successfully implemented in cranberry, resulting in a total of 47 textural features. These features allowed the evaluation of the texture of the cranberry fruit based on key factors such as flesh, structure, and skin. This study also examined factors than can affect the performance of texture measurements, including the optimal sample size, storage time, fruit texture-size correlation, fruit temperature and orientation, optimal speed/strain combinations, and the effect of probe diameter. The results of the study suggests that certain texture traits of the compression and puncture methodologies could potentially be used to test varieties and aid in breeding programs. Full article

Fertilization programs in lilium are suggested to start after shoot emergence or when the flower buds become visible because the nutrients stored in the bulb are adequate to meet plant demands at the transplant time. Defining plant nutrient uptake is essential to determine the periods of high demand and the amounts at which they should be provided. The objective of this study was to model the nutrients accumulated in Oriental lilium to provide insight into the design of environmentally sound fertilization programs. The most demanded macronutrient was K (1272.8 mg/plant), followed by N (719.1 mg/plant) and Ca (119.7 mg/plant), while Zn (140.7 mg/plant) and Fe (137.7 mg/plant) were the most demanded micronutrients. At the end of the season, most of the Fe (78.0%), P (55.0%) and N (54.3%) originated from the bulb, whereas most of the Ca (86.5%), Mn (84.8%) and Mg (62.9%) were uptaken by roots. During the first 15 days after transplant, 35.1% of the N in the shoot was absorbed from the substrate, as well as 91.0% Mg, 68.6% S, 49.6% K and 13.0% P, suggesting that fertilization for lilium should start at the transplant time. The results suggest that Ca, Fe, Zn and Cu were remobilized from the bulb. Full article

Healing and acclimatization are critical in vegetable grafting under controlled environments. Here, we investigated the impacts of LED light qualities on the morphological traits and photosynthetic performance of grafted tomato seedlings. Seeds of the tomatoes “DRW 7806 F1” and “Maxifort” (Solanum lycopersicum × Solanum habrochaites) used as scion and rootstock were planted in 104-cell plug trays into a mixture of cocopeat and perlite (volume ratio: 3 to 1). Survival ratio, above- and underground growth, photosynthetic performance, soluble carbohydrate content, pigmentation, and antioxidant enzymes activity were evaluated following 20 days of exposure to different light qualities, including white (35% B, 49% intermediate spectra, 16% R) light as control, blue, red, and a combination of red (68%) and blue with the same light intensity of 75 ± 5 µmol m⁻² s⁻¹. The lowest scion diameter, leaf area, root and shoot dry weight, SPAD value, and the highest scion length and amount of soluble carbohydrate were detected in R-exposed seedlings. Moreover, R-exposed seedlings showed leaf epinasty and reduced photosynthetic performance. On the other hand, RB-exposed seedlings showed the highest leaf area, shoot and root dry weight, plant fresh and dry weight, scion stem diameter and photosystem II efficiency. In addition, superoxide dismutase activity was increased in R-exposed seedlings, while guaiacol peroxidase activity was enhanced in seedlings grown in RB. In conclusion, a combination of R and B is suggested as the suitable light spectrum to promote plant growth and photosynthetic performance in grafted tomato seedlings. Full article

Potassium (K) is the most important element for fruit quality improvement. This study aimed at determining the best K fertilizer type that can promote grape growth and nutrient uptake. Specifically, four types of K fertilizers (complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate) were applied to grapevines grown in plastic pots, and then their effects on grape growth and nutrient uptake were explored. Results showed that the complex fertilizer and potassium nitrate treatments increased the biomass of the grapevine plants, whereas the other fertilizers had no significant effects on the biomass. Only the potassium nitrate treatment increased the contents of photosynthetic pigments in grapevine leaves. The complex fertilizer and potassium nitrate treatments increased the total N content in the grapevine plants to some extent, whereas the other fertilizer treatments decreased the total N content to some extent. It was also evident that all four K fertilizers increased the total P and K contents in the grapevine plants. Compared to the control, the complex fertilizer, potassium nitrate, potassium sulfate, and potassium dihydrogen phosphate treatments increased the scion total P content by 20.18%, 9.77%, 12.52%, and 30.81%, respectively, and increased the scion total K content by 15.37%, 8.41%, 20.15%, and 26.48%, respectively. In addition, correlation and grey relational analyses showed that the rootstock stem total N content, rootstock root biomass, and soil alkali-hydrolyzable N concentration were the top three indicators most closely associated with the scion total N content, whereas the rootstock root total P content, soil available P concentration, and rootstock stem total P content were the top three indicators most closely associated with the scion total P content. Additionally, the rootstock root total K content, soil available K concentration, and rootstock root total P content were the top three indicators most closely associated with the scion total K content. Overall, the different K fertilizers can all promote the uptake of P and K by grapevine plants, and the potassium dihydrogen phosphate fertilizer is the best choice. Full article

Brassica rapa L. ssp. pekinensis (Lour.) Hanelt (kimchi cabbage) is a major vegetable cultivated in Korea, and its hairy roots (HRs) are rich in glucosinolates and phenolic compounds. This study aimed to induce HRs from cotyledon explants via the transformation of the Agroacterium rhizogenes strain R1000 and examine the glucosinolate and phenolic compounds present in the HRs of two kimchi cabbage (green and red) cultivars after exposure to 16 h light/8 h dark conditions (photosynthetic photon flux density of 54.6 µmol m⁻² s⁻¹) and continuous dark conditions. The highest HR production was achieved in the green kimchi cabbage grown under dark conditions (0.37 ± 0.01 DW g/30 mL). The highest glucosinolate and phenolic contents were neoglucobrassicin and catechin hydrate, which were highest in the green kimchi HRs grown under dark (GKHD) conditions (5268.29 ± 292.84 µg/g DW) and green HRs grown under light (GKHL) conditions (203.49 ± 4.70 µg/g DW), respectively. A heat map showed that the red kimchi HRs grown under dark conditions (RKHD) and the GKHL condition accumulated the highest glucosinolate and phenolic contents. Principal component (PCA) and partial least-squares discriminant (PLS-DA) analyses of the 13 identified metabolites showed a clear separation. According to a variable importance in projection (VIP) analysis, quercetin was the most important metabolite, leading to a clear separation. The most suitable conditions for enhancing the glucosinolate and phenolic contents were the GKHD and GKHL conditions, respectively, whereas both compounds were enhanced in the RKHD condition. HRs cultures cultivated under light and dark conditions are a promising method to enhance the production of specific health-promoting bioactive metabolites, which might be helpful in the pharmaceutical and nutraceutical industries. Full article

Germination inhibitors, which inhibit the germination of seeds, spores and other plant reproductive material, are abundant in the plant kingdom and include phenols, cyanides, alkaloids, essential oils, amino acids, etc. These inhibitors can be classified as germination destructors and germination retarders depending on whether they harm the morphology, structure and physiology of the seed. Germination retarders are closely related to seed dormancy, and exogenous retarders can be used to extend the “dormancy” period of non-dormant seeds or perishable seeds by applying the proper dosage. They have significant potential applications as preservatives for seed preservation following harvest or for the storage of long-term germplasm resources. Germination destructors, as a type of relatively high-efficiency, low-specificity “toxic chemicals”, are of significant benefit in the application of effective and environmentally benign herbicides. At present, the main problems related to the research methods of germination inhibitors include difficulty in determining the specific endogenous substances and the minimum inhibitory concentration to induce dormancy, as well as whether the application of exogenous inhibitors will cause physiological damage to seeds. In the future, we should strengthen the tracking of germination inhibitors, explore the mechanisms of action of specific substances and deeper molecular mechanisms and finally explore new developments and new applications of different inhibitors. Full article

Phytopathogenic bacteria represent a risk to global food production by impacting a variety of crops. The aim of this study was to characterize the contents of bioactive constituents in extracts from Ginkgo biloba L. leaves and fruits and test their activity against six phytopathogenic bacteria that affect horticultural crops. Gas chromatography–mass spectrometry (GC−MS) was used for the chemical profiling of the aqueous methanol extracts, and their bacteriostatic activity against Clavibacter michiganensis subsp. michiganensis, Pseudomonas cichorii, Pseudomonas syringae pv. pisi, Pseudomonas syringae pv. syringae, Pseudomonas syringae pv. tomato, and Xanthomonas vesicatoria (formerly Xanthomonas campestris pv. vesicatoria) was determined in vitro through the agar dilution method. The protective effect of the leaf extract was tested in vivo against the most relevant bacterial pathogens based on their economic/scientific importance, i.e., C. michiganensis subsp. michiganensis and P. syringae pv. pisi, in tomato (Solanum lycopersicum L.) and pea (Pisum sativum L.) plants, respectively, under greenhouse conditions. The GC−MS characterization of G. biloba extracts revealed the presence of dihydro-4-hydroxy-2(3H)-furanone, 2,4-dimethyl-3-hexanol, catechol, 3-O-methyl-D-fructose, 4,6-di-O-methyl-α-D-galactose, methyl 2-O-methyl-α-D-xylofuranoside, and 3-methyl mannoside. In vitro growth inhibition tests showed that, while the fruit extract had no activity, the leaf extract exhibited minimum inhibitory concentrations between 500 and 1000 μg mL⁻¹, which may be attributed to the presence of 2,4-dimethyl-3-hexanol and catechol. In vivo tests of the leaf extract demonstrated full protection in tomato and pea plants at 1000 and 1500 μg∙mL⁻¹, respectively. The results indicate that G. biloba leaves may be employed as a biorational source for integrated pest management in horticulture. Full article

Hass avocado quality varies by origin, season, and production practices. However, there is a lack of methodologies to guarantee that fruit reaching the market has consistent quality. The aim of this work was to identify predictive markers for quality management. Fruit samples produced under different nutrient management, elevation, date-to-harvest, and growth cycle conditions were analyzed. Dry matter, oil content, internal disorders, sensory attributes, minerals, and fatty acids were evaluated as quality variables. The results highlighted soil and weather differences among orchards. Nutrient management practices based on index balancing in some samples increased both productivity and fruit size. High variability was observed in the dry matter related to the age of the fruit at harvest. Ripening heterogeneity was very large in low-elevation orchards where the fruit was picked relatively early. High flesh mineral contents delayed fruit ripening. At low growing temperatures, more oleic and linoleic acids were present in fruits. The sensory texture and taste descriptors were affected by the fruit age and related to the flesh composition. Logistic, PLS-DA, and biplot models effectively represented the variabilities in the ripening pattern, composition, and sensory profile of avocado fruits and allowed the samples to be grouped according to the internal fruit quality. Full article

In recent decades, the use of nanocomposites (NCs) in crop production has been actively studied. We have previously shown that chemically synthesized selenium nanocomposites (Se NCs) based on natural polymeric matrices of arabinogalactan (Se/AG NCs), carrageenan (Se/CAR NCs), and starch (Se/ST NCs) stimulated the growth and development of potatoes in vitro and had an antibacterial effect against the phytopathogen Clavibacter sepedonicus. It is important to confirm that the results obtained in the laboratory are also reproducible in the field conditions of crop cultivation. In addition, the applications of NCs can be expanded if a wider range of their biological activity is revealed, and the effect on other types of cultivated plants and phytopathogens is shown. In this regard, the purpose of this research was to study the effect of nanopriming with Se NCs on the productivity of potatoes in a field experiment, the germination of soybeans, and the viability of the phytopathogen Pectobacterium carotovorum under in vitro conditions. The study included the use of traditional methods of conducting a field experiment in natural growing conditions, also using microbiological cultures and studying the bacterial profile from the endosphere of potato tubers by the imprint method, germinating Glycine max L. soybean seeds after nanopriming in Petri dishes, followed by the measurement of morphometric and biochemical parameters such as the activity of antioxidant enzymes and content of diene conjugates. Based on the results of field experiments, it was found that the preplant treatment of tubers with Se/AG and Se/CAR NCs stimulated a significant increase in the number of stems in potato plants and tubers per plant, but for Se/AG NC, the increase was observed only in 2020 and 2022, and the stimulating effect of Se/AG and Se/CAR NCs on the weight of tubers was observed only in 2020. In the yield structure, the proportion of marketable seed tubers was increased under the influence of all Se NCs. Endosphere cultures from tubers showed that bacteria were present in only 56% of the tubers in the control, while 78% of the tubers obtained from plants grown from seed tubers treated with Se/AG NC and 100% of the tubers from plants grown from seed tubers treated with Se/ST and Se/CAR NCs contained bacteria. The bacteria were represented by both spore-forming Gram-positive and Gram-negative bacteria of various sizes. The results presented in this article and previously published data showed that the maximum diversity of bacteria was observed after treatment with Se/ST NC. Experiments on potatoes showed that Se/AG NC had the greatest biological effect. In addition, the growth-stimulating effect of these NCs on the biomass of the roots of soybean seedlings was shown. It activated the antioxidant enzymes and reduced the level of diene conjugates (DCs), the amount of which increased significantly after seed biopriming with the phytopathogen Pectobacterium carotovorum. The antibacterial effect of Se/AG NC in relation to the P. carotovorum was observed as a reduction in the growth of the bacterial culture, biofilm formation, and dehydrogenase activity of cells. Thus, it has been shown that Se/AG NC has a stimulating effect on such agriculturally important crops as potatoes and soybeans, as well as an antibacterial effect against Gram-negative and Gram-positive phytopathogenic bacteria. Full article

In this study, the metabolites in insect tea and hawk tea were analyzed by ultra-high performance liquid chromatography–triple quadrupole mass spectrometry. We found 49 metabolites in insect tea and hawk tea that can be used as key active components in traditional Chinese medicine, as well as 98 metabolites that can be used as active components of pharmaceutical preparations for the treatment of cancers, hypertension, cardiovascular diseases, etc. Comparative analysis found that insect tea and hawk tea had significant differences in their metabolic profiles. Insect tea contains more metabolites beneficial to human health than hawk tea; insect tea also has higher antioxidant activity in vitro than hawk tea. The results of this study will contribute to the development of new health foods using insect tea. Full article

An adequate and balanced diet is fundamental in preserving the health of astronauts from several space-induced diseases. Therefore, the integration of a diet with fresh food, rich in bioactive compounds such as microgreens produced directly onboard, may be useful in space for human nutrition. However, ionizing radiation (IR) in space represents a significant hindrance for organisms, with potential critical outcomes on plant morpho-anatomical, eco-physiological, and biochemical aspects, depending on the plant and IR features (e.g., species, developmental stage, IR dose, and type). In this study, we analyzed the effect of different doses of X-rays (0-control, 0.3, 1, 10, 20, and 30 Gy) on the morpho-anatomical and nutritional traits of microgreens of Brassica rapa L., irradiated at the stage of germinated seeds. After the irradiation, microgreens were cultivated in controlled conditions. At harvest, the morpho-biometric traits were analyzed, along with the leaf functional anatomical traits and the phytochemical content of the aboveground biomass. The results showed that X-ray exposure does not induce detrimental effects on growth, while it stimulates the production of antioxidants, improving plant defense and nutritional value. The overall results support the idea of using this species in space as a supplemental functional food. Full article

One of the major challenges that global society is facing nowadays is finding sustainable and safe methods for crop growth and development. Besides the traditional crops cultivated worldwide (tomatoes, potatoes, lettuce, strawberries, etc.), there is a general trend in the exploitation of polyvalent plants. Mulberry (Morus spp.) faced no exception; with its undeniable proprieties, it became suitable not only to be used in the sericulture industry, but in the food chain, the pharma industry, and environmental safety. Spare parts of the plants can be used in a very wide range, starting from introducing mulberry leaves in supplements to increase the protein content of a meal to extracting biologically active compounds from fruits and roots to be used in phytotherapy. However, the outstanding proprieties of this plant come with some requirements related to space availability and watering; requirements that can be easily surpassed by using vertical farming methods, such as hydroponic, aeroponic, or aquaponic systems. The present paper aims to evaluate vertical farming techniques’ applicability to mulberry propagation in a controlled environment and their prospects for a more sustainable and safer agricultural practice. Full article

Controlled environment agriculture (CEA) optimizes growth parameters for vegetable and aquaculture production and can be used to address growing global food insecurity. Recirculating aquaculture systems (RAS) generate a nutrient-dense effluent that may result in environmental pollution, but with treatment and integration with hydroponic vegetable production may be repurposed as a naturally derived nutrient solution. This work developed a preliminary model using the system feed rate to calculate a plant-essential nutrient discharge rate in RAS effluent. Loading rate equations were created to calculate the daily mass of nutrients entering the system through fish feed, and discharge rate equations were created to calculate the grams of each nutrient discharged in the effluent per kilogram of feed. Data from previous published work were used for validation. The loading-rate percentage discharged for nutrients present in the effluent was between 2.71% and 64.5%, with several nutrients being prominent pollutants and all being required for vegetable growth. This work provides the preliminary framework for calculating nutrient discharge rates, which can be used to mitigate pollution or develop more precise, naturally derived hydroponic nutrient solutions for a circular bioeconomy in CEA. Full article

In a three-year experiment (2019–2021), the roots of 7-year-old apple trees (Malus domestica cv. ‘Red Jonaprince’) grown under drip irrigation were studied. The aim of the study was to determine the effect of irrigation on root density at different depths and distances from the trunk. The working hypothesis assumed that irrigation significantly affects the total length of apple roots. The irrigation treatments corresponding to the calculated water evapotranspiration (ET100), 50% of the calculated ET (ET50), a control (ET0, no irrigation, under rainfed conditions), and a treatment using double-drip lines (2Drops) were monitored. Soil cores were collected in spring and autumn. The total length of the roots (TRLt) and the length of new vital roots (TRLv) to a depth of 80 cm were evaluated. The effects of treatments were mostly insignificant for the TRLt; only in the dry season in 2019 were the TRLt values of the irrigated treatments (ET50 and ET100) significantly higher, 18.67 km·m⁻² and 17.45 km·m⁻², in comparison to 11.16 km·m⁻² for the ET0, at a 10 cm distance from the tree trunk. The irrigation treatments had a statistically significant effect on the TRLv values near the trunk in 2019 and 2020, while in autumn 2020 and 2021, irrigation significantly affected the TRLv at greater distances from the tree trunk. In summary, the irrigation treatments mostly had no significant effect on the total root length. However, an effect of irrigation on the root length of new vital roots was observed at certain sampling dates and distances from the trunk. Full article