Horticulturae, Volume 9, Issue 8 (August 2023) – 102 articles

As a result of increased trade, transportation, and globalization, the phenomenon of growth regarding the entrance of invasive alien species (IAS) represents a serious concern (including flora, fauna, and microbiota). Acanalonia conica (Say, 1830), also known as the green cone-headed planthopper (GCHP), was first identified in the Chrysanthemum collection of the Botanical Garden in Iaşi, Romania. The principal objectives of this article are to update the limited data on the presence of A. conica in Romania, revealing its occurrence in new areas (East Romania, Iași) and on other host plants that were not previously documented in the United States and Europe, as well as to establish the trends of population evolution, with an emphasis on the peak of GCHP population development during the life cycle on East Romania indoor conditions. The evolution of the GCHP population was established using the recorded data on total counts of adults and nymphs observed from a limited area (greenhouse compartment), checked every two days in 115 days of direct observations. The peak of population was established at late-July (25th to 31st day of the month, 30th week of the year) for the conditions of East Romania and it was the appropriate time to monitor the activity of the species, to estimate the damages in specific crops, and to initiate the specific pest control measures. Current findings are significant not only for the general spread of this species in Europe and in Romania but also for the observations regarding new hosts and the population evolution in a greenhouse habitat for the cultivation of ornamental plants. Full article

Tomato (Solanum lycopersicum L.) production in the USA has been severely impacted by the tomato yellow leaf curl virus (TYLCV). Furthermore, a complex association of whitefly-transmitted TYLCV (genus, begomovirus) and tomato chlorosis virus (ToCV, genus, crinivirus) were recently identified in tomato. Several tomato cultivars were developed and commercialized with intermediate resistance (IR) against TYLCV-IL (Israel), the predominant strain of TYLCV found in Georgia, USA. TYLCV-resistant cultivars were tested in open field conditions against multiple whitefly-transmitted viruses in Georgia under natural disease pressure during the fall of 2022. The area under disease progress curve (AUDPC) over time showed a steady increase in disease severity among all cultivars. Further analysis of infected samples using high throughput sequencing (HTS) and quantitative PCR (qPCR) revealed the presence of TYLCV and ToCV in symptomatic upper and lower leaves, respectively. Moreover, the presence of both viruses in upper and lower leaves was determined. A mixed infection of both viruses, TYLCV and ToCV, resulted in severe disease development which may enhance the commercial tomato plants to break resistance and lead to decreased fruit quality and marketable yields. Full article

Low temperature is an abiotic stress factor limiting the distribution of fruit tree cultivation areas. As temperate deciduous fruit trees, apple (Malus domestica) trees go dormant in the winter to adapt to or avoid damage caused by low temperatures. The capacity for cold resistance is closely linked to the physiological, biochemical, and structural characteristics of one-year-old branches. In this study, we investigated such changes in the branches of cold-resistant ‘Hanfu’ (HF) and cold-sensitive ‘Naganofuji 2’ (CF) apple varieties. The relative electrical conductivity, malondialdehyde content, and reactive oxygen species content of HF branches were lower than those of CF branches, while the antioxidant enzyme activity was higher in HF. The proline, soluble protein, and soluble sugar contents in both varieties showed an initial increase, followed by a subsequent decrease. Sucrose and sorbitol were the main sugar components, but sucrose and fructose were higher in HF than in CF. The periderm, phloem, and xylem of HF branches were also found to be thicker than those of CF branches, while the vessel diameter was smaller and the density greater. The results of this study provide a theoretical reference for further research on the low temperature adaptability of apple tree branches during dormancy. Full article

Rosa damascena Mill. is commercially the most important rose species used to produce essential oils. The plants of this species, cultivated in the district of Western Macedonia (Greece) for rose oil production, originated from indigenous genotypes but also nurseries abroad, mainly from Bulgaria. The present study investigated the genetic relationship between nine genotypes of R. damascena from Greece, one genotype from Turkey, three genotypes from Bulgaria and three genotypes from France using the molecular markers ISSR and SCoT. Also, the rooting ability of shoot cuttings from these nine genotypes was investigated by applying 2 g/L of the rooting regulator K-IBA. In addition, petals were chemically analyzed using GC-MS and LC-MS to identify the compounds that are the main components of the rose oil. The nine rose genotypes of R. damascena, cultivated in Greece, one from Turkey and one of the three genotypes from Bulgaria were clustered in one clade in the dendrogram. The other two genotypes from Bulgaria were clustered in a separate clade that demonstrated the existence of genetic diversity among the three Bulgarian genotypes, while the French genotypes were clustered in a third clade. The shoot cuttings rooted relatively easily (55–70%) with the application of K-IBA, without any significant differences among the nine genotypes. Large variation was observed among the nine genotypes in the main volatile compounds of the flower petal extracts, which are related to rose oil components. For these compounds, the concentrations in μg/g of the fresh petal weight were 2-phenylethylalcohol (1148.35–2777.19), nerol (27.45–64.93), citronellol (88.45–206.59), geraniol (69.12–170.99) and nonadecane (209.27–533.15). Of the non-volatile compounds, gallic acid was the most abundant phenolic acid in the petal extracts of the nine genotypes (0.28–0.82 μg/g), while for the flavonoids, quercetin and kaempferol variations of 0.35–1.17 μg/g and 0.26–2.13 μg/g were recorded, respectively. Full article

Nitrogen (N) represents the most important nutrient for plant growth and productivity, but extreme and ineffective usage of N fertilizer results in boosted plant production expenditures and environmental contamination. For the world’s sustainable food production and environmental profits, there has been increased research interest in reducing the use of N fertilization along with improving plant N deficiency (ND) tolerance. Dopamine (DA), a potential antioxidant, mediates several physio-biochemical processes in plants under normal or stressful conditions. However, their roles in increasing ND tolerance in crisphead lettuce are not well-documented. We investigate the role of DA concentration (0.50 and 100 µM) on the growth and yield of crisphead lettuce plants under ND. Under normal conditions (100% recommended N fertilizer dose), DA (50 and 100 μM) application significantly enhanced growth, chlorophyll concentration, N%, antioxidant enzymes activity, as well as yield and its components, decreased nitrate accumulation and oxidative biomarkers compared to untreated plants (0 μM DA). ND significantly decreased plant growth and yield attributes as well as evoked oxidative impairment and nitrate accumulation as compared to 100% recommended N fertilizer dose in the absence of DA. However, within ND conditions, the application of DA concentrations significantly mitigated ND-induced oxidative burst and improved plant growth, chlorophyll concentration, N%, nitrate concentration, peroxidase, catalase, superoxide dismutase, total soluble solid, vitamin C, dry matter %, and total sugars, over 0 μM DA treated plants. Current findings highlighted that exogenous application of 100 μM DA could reinforce the crisphead lettuce plant’s resilience to ND by minimizing reactive oxygen species accumulation and promoting enzymatic antioxidants alongside growth, yield, and quality improvement. The beneficial effects of DA in lessening ND’s drastic impacts on crisphead lettuce resulted from upregulating antioxidant enzyme activity, impairment of oxidative biomarkers, and maintaining chlorophyll levels. The current findings open pioneering prospects to reduce nitrogen fertilization by DA application without any drastic effect on plant productivity. But further research is needed to fully understand DA effects and their mechanisms in inducing ND tolerance in different plant species, including crisphead lettuce. Full article

Internal browning caused by prolonged cold storage poses a significant challenge to the visual appearance and flavor of Asian pears, which are economically valuable and a primary fruit exported from Korea. To address this issue, we established a cost-effective portable non-destructive piece of testing instrument using visible and near-infrared spectroscopy, focusing on the detection and discrimination of internal browning in ‘Greensis’ pears. Our investigation underscores the challenge of visually confirming browning, necessitating alternative methods for accurate assessment. Through comprehensive analysis involving three to four segments of 32 ‘Greensis’ pears, a robust calibration equation was derived. By employing partial least square regression on the absorption spectra within a 650–950 nm range, we developed a predictive model for detecting and quantifying browning. Through principal component analysis, normal pears were distinctly segregated from those exhibiting browning symptoms (discrimination accuracy of 95%). Furthermore, we established that pears with a browning index of 25 ± 2.0 are highly susceptible to browning following extended cold storage. Consequently, our proposed portable non-destructive instrument serves as a pivotal tool for farmers and fruit distributors, enabling efficient and precise selection of high-quality pears in an instance. Overall, our study introduces a practical solution to a pressing issue in the Asian pear industry. Full article

One of the most important crops of the Mediterranean, watermelon (Citrullus lanatus), is almost exclusively established through seedlings. For many years, agronomists, nurseries, and farmers have aimed to produce and use high-quality seedlings for better growth in the field. However, seedling quality has not been examined as to what defines the subsequent plant, flower, and fruit development, and to what extent. Our aim was to test whether different seedling qualities labeled as “Optimum”, “Acceptable”, or “Not Acceptable” for cultivation actually perform variably in terms of vegetative, flowering, and fruit development, as well as fruit quality after a full growing cycle in the field. Vegetative growth (stem diameter, plant area, and leaf number) was evaluated until flowering and was enhanced for Optimum plants. The flowering of Not Acceptable plants started two days later, while Optimum plants retained a greater number of female flowers throughout the two-week blooming evaluation. Most importantly, Optimum plants developed mature fruits four and six days faster than the Acceptable and Not Acceptable ones, respectively, showing considerable yield earliness. The photosynthetic mechanism, as well as fruit morphology and phytochemical content, were not affected by quality categories. Overall, indeed it is important to use high-quality seedlings to achieve yield earliness of watermelon fruits. Full article

Prunus spinosa fruit, commonly known as blackthorn or sloe, possesses a wide range of health-promoting properties, including antioxidant and antibacterial activities. In this study, we investigated the effects of various extraction parameters, such as temperature, time, and solvent composition, on the extraction of bioactive compounds from P. spinosa fruit. Response surface methodology was employed to optimize these parameters and evaluate their impact on the antioxidant properties of the extracts. Furthermore, techniques such as ultrasound (US) and pulsed electric field (PEF) were applied, both individually and in combination, to explore their potential effects on the extraction process. The optimal extraction technique proved to be the combination of PEF and US, followed by stirring. The most suitable solvent was 75% ethanol, whereas the optimum extraction time and temperature were 30 min and 80 °C, respectively. Our findings revealed that under the optimum extraction parameters, a significant improvement in the extraction efficiency of bioactive compounds from P. spinosa fruit was achieved. More specifically, the optimal conditions, according to partial least squares (PLS) analysis, were a combination of all three extraction modes (PEF-US-ST), the shorter extraction time of the present study (30 min), and the corresponding higher temperature (80 °C). As expected, the presence of ethanol was considered necessary, even in an amount of 25%. The total polyphenol content was found to be 30.74 mg gallic acid equivalent (GAE)/g, the total flavonoids content 3.23 mg rutin equivalents (RtE)/g and the total anthocyanins 125.2 μg cyanidin-3-O-glucoside equivalents (CyE)/g. HPLC-DAD analysis showed that neochlorogenic acid was the polyphenol with the highest concentration (4.13 mg GAE/g) in P. spinosa fruit. The antioxidant activity of the optimized, according to PLS analysis, extract was evaluated and found to be 146.09 μmol ascorbic acid equivalent (AAE)/g determined by ferric reducing antioxidant power (FRAP) assay, and by the radical scavenging activity (DPPH) assay was 18.56 μmol AAE/g. Additionally, the ascorbic acid was determined to be 119.4 mg/100 g. Overall, this study contributes valuable insights into the extraction optimization process and the potential applications of P. spinosa fruit in the development of functional foods and pharmaceutical products. Full article

We conducted a survey of the phytosanitary status of the Prunus germplasm collection in the Nikita Botanical Gardens, Yalta, Russia. The virome of plants displaying virus-like symptoms was studied using Illumina MiSeq high-throughput sequencing. Reads related to prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), and ourmia-like virus 1 (OuLV1) were generated in a number of samples. Near complete genomes of two divergent PNRSV isolates, PDV isolate, and a contig partly covered OuLV1 genome were assembled de novo using the metaSPAdes program. The structure of the genomic RNA1, RNA2, and RNA3 of the new ilarvirus isolates was shown to be typical of PNRSV and PDV. This is the first report and characterization of the PNRSV and PDV full-length genomes from Russia, expanding the information on their geographical distribution and genetic diversity. An open reading frames (ORF)-based phylogeny of all full-length PNRSV and PDV genomes available in GenBank divided each ORF into two or three main clusters. A number of isolates migrated from one cluster to another cluster, depending on the analyzed genome segment. The different branching order may indicate reassortment in the evolutionary history of some PDV and PNRSV isolates. Full article

Sweet cherry may develop surface pitting during prolonged cold storage, and susceptibility among varieties is related to metabolites in response to cold and mechanical damage. This study aimed to evaluate the metabolic changes in sweet cherry fruits subjected to melatonin treatment and induced surface pitting. Melatonin (400 µM) was applied to sweet cherries before pitting induction and then stored at 1 °C for 20 d. Melatonin treatment attenuated the severity of pitting damage during cold storage, with an average severity value of 3.1 for cherries with melatonin and 2.6 without melatonin. In addition, melatonin application appeared to modulate metabolic responses due to the regulation of metabolic pathways related to abiotic stress. Upregulation of different secondary metabolites was observed after 16 h of melatonin treatment and cold storage. Moreover, some metabolites of the sphingolipid and sulfur metabolism were upregulated after 10 d. This research is the first to show that melatonin may influence the response of sweet cherries to cold and mechanical damage. Full article

Davallia mariesii T. Moore ex Baker, a member of the section Trogostolon (Copel.) M. Kato and Tsutsumi (Davalliaceae M.R. Schomb.), is a lithophytic or epiphytic herb that grows on rocks and tree trunks in montane forests. This study analyzed the morphological, anatomical, micromorphological, and palynological characteristics of D. mariesii using a digital slide scanner and a field-emission scanning electron microscope and presented an expanded and updated description. A circumendodermal band was observed in the anatomical structure of the stipe, making D. mariesii the second species in the family Davalliaceae with such a band. The frond anatomical studies revealed that the epidermal cells of the indusium were thicker than those of the epidermis on both sides and that hypostomatic fronds with stomata chambers were present. Diacytic, anisocytic, and tetracytic stomatal complexes were observed on abaxial surfaces. The indusia covered numerous sporangia. Leptosporangium consisted of an apical cap, a basal cap, an annulus, and a stalk. The spore had an ellipsoidal outline, a monolete aperture, and verrucae with colliculate ornamentation. The obtained results provide systematic data for the phylogeny of Davalliaceae and establish a basis for future taxonomic delimitation of other taxa. Full article

The pericarp of the Longkong fruit rapidly browns during ambient storage, typically reducing its shelf life to between 3 and 7 days. Recently, n-butanol has demonstrated a promising effect in preventing this deterioration, extending the shelf life of tropical fruits to more than a week. The present study exploited this opportunity to examine the exogenous application of aqueous n-butanol at various concentrations (0.2–0.6%) in controlling pericarp browning and suppressing different oxidoreductase enzymes in the pericarp under prolonged ambient storage conditions (8 days). Every two days, the fruit pericarps were tested for color (lightness (L*), redness (a*), and yellowness (b*)), browning index (BI), membrane permeability loss (MPL), malondialdehyde (MDA) content, total phenolic content (TPC), and reactive oxygen species (ROS). Enzymes including phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), phospholipase D (PLD), lipoxygenase (LOX), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) were also analyzed. All sample test results showed that increased storage significantly impacted color characteristics (decreased L*, b* and increased a*, and BI). MPL, MDA, and ROS also continuously increased. Furthermore, the browning-related enzymes (PAL and PPO), membrane-degrading enzymes (PLD and LOX), and antioxidant enzymes (SOD, CAT, and GPX) continuously increased in all pericarp samples throughout the storage. Among the samples, pericarp color, BI, MPL, MDA, PAL, PPO, PLD, and LOX were significantly high in the control samples, consequently adversely affecting the quality and shelf life of Longkong. On the other hand, the n-butanol-treated samples significantly controlled the loss and all problematic enzymes while improving the activities of SOD, CAT, and GPX in the pericarp. Furthermore, the positive effect of n-butanol application was dose-dependent; higher concentrations (0.4–0.6%) performed well in protecting the fruit from deterioration. Full article

As the second-largest cut flower plant globally and one of the top ten traditional flowers in China, chrysanthemums hold significant economic value, encompassing both ornamental and medicinal applications. However, aphids pose a considerable threat as one of the most critical pests affecting chrysanthemums. These pests not only diminish the ornamental value of chrysanthemums through feeding and reproduction but also transmit numerous plant viruses, causing irreversible damage. This review examines aphids’ feeding and damage patterns as a starting point, highlighting the unique endogenous defense mechanisms that have evolved in chrysanthemums during their continuous struggle against aphids. These mechanisms include constitutive defense and induced defense. In addition, we enumerate aphid-resistance genes that have been reported in chrysanthemums. Furthermore, this paper compares and predicts the aphid-resistance genes of other species based on the published Chrysanthemum nankingense genome, aiming to provide a valuable reference for future research on aphid-resistance genes in chrysanthemums. Full article

Fruit is often bruised during picking, transportation, and packaging, which is an important post-harvest issue especially when dealing with fresh fruit. This paper is aimed at the early, automatic, and non-destructive ternary (three-class) detection and classification of bruises in kiwifruit based on local spatio-spectral near-infrared (NIR) hyperspectral (HSI) imaging. For this purpose, kiwifruit samples were hand-picked under two ripening stages, either one week (7 days) before optimal ripening (unripe) or at the optimal ripening time instant (ripe). A total of 408 kiwi fruit, i.e., 204 kiwifruits for the ripe stage and 204 kiwifruit for the unripe stage, were harvested. For each stage, three classes were considered (68 samples per class). First, 136 HSI images of all undamaged (healthy) fruit samples, under the two different ripening categories (either unripe or ripe) were acquired. Next, bruising was artificially induced on the 272 fruits under the impact of a metal ball to generate the corresponding bruised fruit HSI image samples. Then, the HSI images of all bruised fruit samples were captured either 8 (Bruised-1) or 16 h (Bruised-2) after the damage was produced, generating a grand total of 408 HSI kiwifruit imaging samples. Automatic 3D-convolutional neural network (3D-CNN) and 2D-CNN classifiers based on PreActResNet and GoogLeNet models were used to analyze the HSI input data. The results showed that the detection of bruising conditions in the case of the unripe fruit is a bit easier than that for its ripe counterpart. The correct classification rate (CCR) of 3D-CNN-PreActResNet and 3D-CNN-GoogLeNet for unripe fruit was 98% and 96%, respectively, over the test set. At the same time, the CCRs of 3D-CNN-PreActResNet and 3D-CNN-GoogLeNet for ripe fruit were both 86%, computed over the test set. On the other hand, the CCRs of 2D-CNN-PreActResNet and 2D-CNN-GoogLeNet for unripe fruit were 96 and 95%, while for ripe fruit, the CCRs were 91% and 98%, respectively, computed over the test set, implying that early detection of the bruising area on HSI imaging was consistently more accurate in the unripe fruit case as compared to its ripe counterpart, with an exception made for the 2D-CNN GoogLeNet classifier which showed opposite behavior. Full article

Excessive selenium has gradually become a potential environmentally hazardous element for all organisms. Limited knowledge is available regarding the toxic mechanism of selenium in pepper, so the quantitative proteomics of phosphorylation was studied by Tandem Mass Tag approaches. A total of 4434 phosphorylation sites were identified on 2058 proteins, of which 3749 sites of 1919 proteins contained quantitative information. In the Se/mock (seedlings without Se treatment) comparison group, the number of upregulated phosphoproteins (658) was significantly higher than that of the downregulated ones (61). Systematic bioinformatics analysis, including protein annotation, functional classification, subcellular localization, and cluster analysis was performed. A total of 33 over-represented motifs were found in serine phosphorylation, and the most frequent motif was ‘sP’ (308 occurrences). According to KEGG enrichment analysis, the upregulated phosphorylated proteins (DPPs) were most strongly associated with the ’phenylpropanoid biosynthesis’ and ’nicotinate and nicotinamide metabolism’ pathways, while those that were downregulated were associated with the ’ABC transporters’ and ‘plant hormone signal transduction’ pathways. Our data can provide new insights for evaluating the response mechanism of plants to selenium pollution and improving their resistance to selenium. Full article

Increased consumption of vegetables has been recommended worldwide as a part of a healthy diet; therefore, determining gene function among breeding materials is crucial for vegetable improvement to meet the sustainable development of new vegetable varieties. However, genetic transformation is time-consuming and laborious, which limits the exploration of gene function for various vegetable crops. Virus-Induced Gene Silencing (VIGS) can perform large-scale and rapid gene silencing in plants due to a reduction in the experimental period and its independence from the stable genetic transformation, providing an excellent opportunity for functional research. VIGS can accelerate model plant research and make it easier to analyze gene function and validation in vegetable crops. Moreover, with the advent of technologies such as virus-mediated heterologous protein expression and the development of CRISPR/Cas9 technology, virus-mediated genetic tools have ushered in a new era in genetics and crop improvement. This study summarizes recent achievements in VIGS and Virus-Induced Gene Editing (VIGE) in vegetables. We also identify several challenges in the current state of VIGS technology in vegetables, serving as a guide for future research. Full article

Saffron is a spice that is obtained by dehydrating the stigmas of the Crocus sativus flower. Iran is the country that produces the largest amount of saffron, exceeding 90% of world production. Currently, there is a growing medicinal use which implies that there is more demand than supply worldwide, in turn, a large amount of labor is required to obtain it; for these two reasons, it reaches a high price in the international market. This demand is due to the high concentration of apocarotenoid metabolites that it biosynthesizes. In this work, the content of these metabolites of saffron from six production areas of Iran and neighbouring countries infected with saffron latent virus (SaLV) and dehydrated at two temperatures is compared. The corms of the six provenances were planted in a homogeneous plot and the stigmas analyzed were those of the second year after planting. The analysis showed that corms do not completely retain the memory of their original origin. In general, the ratio of the sum of mmol/kg of HTCC derivatives to the sum of the mmol of crocins is greater than two. This implies that the biosynthesis of saffron apocarotenoids due to the degradation of β-carotene towards HTCC is more important than that of zeaxanthin formation, which later gives HTCC and crocetin dialdehyde. Full article

The aim of this study was to identify the problems faced by retailers operating in the cut flower sector and to propose solutions to problems related to the sustainability of the sector. The study material consisted of data obtained by conducting a survey among 56 cut flower retailers in İzmir. In the study, factor analysis was used to determine the main problems that cut flower retailers encounter in the industry. Factor scores obtained through the factor analysis were divided into three clusters using cluster analysis. According to the results of the research, it was determined that the retailers included in the first cluster had the problem of obstacles to sales, the retailers in the second cluster had the problem of competition and cost increases, and finally, the retailers in the third cluster had the problem of quality. In light of these data, suggestions are made about what should be achieved for the sustainability of the retail cut flower sector. Full article

The adverse effects of high temperatures on fruit quality and yield have been reported in many studies of grapevines. MiRNAs play crucial roles in plant growth and development and also fulfill functions in regulating the high-temperature response. In this research, miRNA-based SSR (simple sequence repeat) polymorphisms were analyzed according to the grape genome sequence and then combined with polymerase chain reaction (PCR) amplification and Sanger sequencing methods to analyze the miRNA-SSR diversity of different heat-resistant grape varieties. A statistical analysis of SSR sequences showed that 391 and 12 SSRs were specific to pri-miRNA and pre-miRNA, respectively. In pri-miRNA containing SSR, hexa-nucleotide repeats were the most abundant (52.69%), followed by tetra-nucleotide (13.04%) and minimum penta-nucleotide (4.09%), which were also observed in pre-miRNA sequences. On the other hand, differences in heat resistance among grape varieties were observed. Based on the results of leaf Fv/Fm images, values and phenotypic changes under high-temperature stress, 20 heat-resistant (e.g., Niagara Rosada and Grand Noir) and 20 heat-sensitive (e.g., Shine Muscat and Jumeigui) grape varieties were identified. Further, PCR-Sanger sequencing was used to screen SSR differences in four thermos-tolerant and four thermos-sensitive grape varieties, and finally, eight SSR differential primers were found to be able to distinguish these varieties. Of these, four pairs of primers were selected for validation in 40 grape germplasm resources (20 thermo-tolerance and 20 thermo-sensitivity). The VMIRSSR167c3 highlights that the ratio of SSR (CT) repeat values greater than 17 in heat-resistant varieties was 90%. In conclusion, the VMIRSSR167c3 marker can accurately distinguish between heat-resistant and heat-sensitive grape varieties. The results provide a novel molecular marker for the genetic improvement of grape germplasm resources and will be beneficial to the breeding of heat-resistant varieties in the future. Full article

Despite extensive studies, the relationship between the quality/quantity of tea odorants and oolong tea quality remains unclear. To investigate the key components affecting Bao-chung tea quality, we collected samples of different grades from a tea-tasting competition and determined the content and composition of volatile components and individual catechins using gas chromatography–mass spectrometry and high-performance liquid chromatography. We used an electronic nose (E-nose) to collect odor component signals and established a quality recognition model. The different tea grades did not significantly differ in catechin content, but their specific odor intensity and proportion of odor components varied significantly. Linear discriminant analysis showed that the intensity and proportion of volatile organic compounds could be used for distinguishing the different grades of Bao-chung tea. By combining different quantities of indole, linalool, and butanoic acid and proportions of p-cymene, cis-β-ocimene, nonanal, allo-ocimene, cis-jasmone, and α-farnesene, the ability to distinguish among Bao-chung tea grades was significantly improved. Our results revealed that the quality of Bao-chung tea should be evaluated based on the combined perception of odor component intensity and proportion rather than solely relying on the concentration or composition of specific compounds. Therefore, individuals can judge a Bao-chung tea grade based on the combined perception of odor component intensity and proportion. The E-nose can be used to identify Bao-chung tea grades based on its ability to determine the odorant composition. Full article

Root rot and gummosis caused by Phytophthora spp. are considered one of the most important citrus diseases in Brazil. Symptoms of Phytophthora spp. infection in citrus plants are associated with lesions on the bark at the base of the plant, roots, and even lower branches. Inappropriately performed cultural practices, such as excessive irrigation and practices that result in reduced aeration and soil drainage, favor the disease. The objective of this study was to evaluate the effect of Urochloa ruziziensis mulching provided by an ecological mower on the severity of Phytophthora nicotianae root rot and the development of citrus plants and their root system. The experiments were carried out under controlled conditions on Rangpur lime seedlings kept in pots containing soil from ‘Hamlin’ orange orchards with the use of an ecological mower or a conventional mower in the management of inter-row vegetation for six years. Urochloa ruziziensis mulching (9 t ha⁻¹) was added or not to the pots. The inoculation of P. nicotianae in the roots occurred through infection of the soil with a solution containing mycelium and sporangia of the pathogen. A 2 × 2 × 2 factorial scheme was used, with the following factors A: soil type, B: inoculation of P. nicotianae and C: mulching of U. ruziziensis. The attributes of plant development, such as root growth, average number of leaves, leaves and dry mass of shoots and roots, in addition to assessments of the severity of disease in the roots, were evaluated. The mulch of U. ruziziensis did not promote an increase in root rot. The soil resulting from this management promoted the better development of Rangpur lime plants. Therefore, vegetation management of inter-row with an ecological mower is not associated with increased symptoms of Phytophthora root rot. Full article

Aiming at evaluating new candidate species for the cut flower market of Greece and beyond, in this study, the vase life of three Greek tulip plant species, Tulipa cretica ‘Hilde’ (CRH, local endemic of Crete, Greece), T. clusiana ‘Chrysantha’ (CLC, naturalized in Chios Island, Greece), and T. australis (AUS, native in the Mediterranean and Greece), was investigated in comparison to the commercial tulip hybrid Île-de-France (IDF). To this end, pre-cooled at 4 °C bulbs of the abovementioned Greek tulip plant species were bought from Dutch nurseries and grown in pots placed in unheated greenhouses located at two different climatic conditions in Northern Greece. The plants were uprooted when the flowers reached a slightly open stage. Half of the flowering stems were immediately placed into bottles with deionized water, while the rest were placed in a preservative solution containing citric acid 5% and sulfuric acid 1% and then remained under laboratory conditions until the entire tepal wilted (end of vase life). The measurements performed concerned: (a) flower stem length and flower maximum diameter, (b) fresh weight (FW) of initial stems, leaves, flowers, and bulbs and at the end of vase life, (c) flower color parameters (L, a, b, c, and H) in all treated flowers, (d) leaf chlorophyll content (SPAD values), and (e) initial and final water volume after removing the flowering stems. The aforementioned measurements showed that CRH cut flowers may exhibit consistent floral opening patterns and were associated with a long mean vase life of 5.7 days, which can be further prolonged to 6.5 days by carefully selecting a cultivation location with proper climatic conditions. The vase life of CLC cut flowers was significantly affected by the climatic parameters (temperature) of the area where the plants were cultivated. The immersion of cut flowering stems in a preservative solution with citric and sulfuric acids did not yield a notable increase in the longevity of cut flowers during the postharvest period. Moreover, this treatment did not have any significant impact on leaf chlorophyll content or flower color at the end of the flowers’ vase life. The data of this work show that cut flowers from the native species T. cretica and T. clusiana have satisfactory vase life, especially when plants were grown in favorable climate condition; the latter is an important criterion for their entry into the cut flower market. Full article

Melatonin, a multifunctional signaling molecule, has been shown to play a significant role in response to abiotic stress. Several species have been reported to unveil melatonin’s effect on osmotic stress; however, the signal transduction mechanism of phytohormone-mediated melatonin biosynthesis in plant species remains unclear. In this study, although plants can biosynthesize melatonin, the exogenous application of melatonin to watermelon cells can improve cell growth in response to osmotic stress by regulating the antioxidant machinery of cells. Regarding the melatonin synthesis pathway, ClOMT (ClASMT and ClCOMT) is a multi-gene family, and ClSNAT has two members. Both ClOMTs and ClSNATs harbor the cis-elements in their promoter regions responding to various hormones. Among abscisic acid (ABA), methyl jasmonate (MeJA), and salicylic acid (SA), ABA treatment observably upregulated the expression of ClOMTs and ClSNATs, and the accumulation of melatonin with ABA treatment reached a level comparable to that with osmotic stress by mannitol treatment. Furthermore, when hormone biosynthesis inhibitors were added to cells before osmotic stress, the expression of ClOMTs and ClSNATs, as well as melatonin accumulation, were significantly suppressed with the ABA biosynthesis inhibitor. This study demonstrated the crucial role of melatonin biosynthesis in response to osmotic stress via plant hormone signal transduction. It showed that ABA signaling plays a dominant role in melatonin synthesis under osmotic stress. Full article

Apomixis is a unique reproductive process that produces fertile offspring without the combination of sperm and egg cells. This process perfectly reproduces maternal DNA, making it possible to fix heterosis during reproduction. Malus shizongensis is a newly discovered species that is closely related to Malus hupehensis Rehd. After de-male bagging, it was found that the fruit set rate reached 78.7%. Preliminary analysis indicated that M. shizongensis have apomictic reproductive characteristics. In this work, we employed paraffin sectioning and electron scanning microscopy to explore apomixis in M. shizongensis during the development of male–female gametes and embryo sacs. Stigma fluorescence assays showed that pollen germination was normal, but less pollen entered the ovaries. Additionally, analysis of anthers indicated the presence of dysplasia and paraffin sectioning revealed that the pollen mother cells were aborted due to abnormal disintegration of the tapetum layer. Taken together, our results indicate that the primary causes of apomixis in M. shizongensis are anther dysplasia and male gamete development failure, resulting in reduced pollen tube entry into ovaries and reduced reproduction of female gametes. In conclusion, this study provide a theoretical basis and technical supports for apple stock breeding and apple industry development. Full article

In recent years, kenaf has gained significant global attention as a more cost-effective, adaptable, and manageable alternative to other fibre crops. India and China, with nearly 70% of the global kenaf production, have emerged as the leading producers of kenaf plants. While kenaf was traditionally valued for its paper production, it has evolved into a multipurpose crop with diverse industrial applications over the past two decades. Conventional soil-based cultivation methods for kenaf require up to six months for plant maturity. However, in vitro propagation techniques offer a promising alternative that enables faster growth and reduced labour costs. In vitro propagation can be achieved using solid and liquid media, with limited research available on the pure liquid culture method for kenaf. This review aims to introduce and compare the production of kenaf using solid and liquid media, with a specific focus on the emerging country of Malaysia, which seeks to harness the potential of kenaf cultivation for the 15th Sustainable Development Goal, “life on land”, and its contribution to the economy. Full article

Intercropping systems often contribute to soil health management including inhibiting root-knot nematode disease. The main purpose of this study was to investigate the potential effect of the cucumber-amaranth intercropping system on soil biota, specifically the nematode and microbial communities. Furthermore, the cucumber root-nematode disease was also evaluated. The study found significant effects of cultivation systems (cucumber-amaranth intercropping and cucumber monocropping) and growing seasons (winter-spring (WS) and autumn-winter (AW)) on both soil nematode and microbial community structures in cucumber root-zone soil. Intercropping resulted in a decrease in the relative abundance of Meloidogyne spp., which was consistent with the observed alleviation of root-knot nematode disease. Bacterivorous nematodes were dominant in the intercropping system. The microbial biomass and community-level physiological profiles (CLPP) were generally higher in the intercropping system. Beta diversity analysis showed that the composition of microbial communities varied widely among the treatments and growth seasons. These findings suggest that intercropping with amaranth can regulate soil biota, leading to decreased incidence of root-knot nematodes (RKNs) diseases. Full article

Crop productivity around the world is being seriously affected by adverse environmental conditions. High temperature (HT) stress has severely hampered plant growth, yield, and quality. Water spinach is a significant heat-resilient green leafy vegetable that can mitigate prolonged HT stress. However, the morphological, physiological, and biochemical alterations that occur in its response to heat stress remain unknown. In this study, the physiological response to HT stress in water spinach plants with different temperature (25-control, 30, 35, 40, 45 °C) tolerances was investigated. When plants were subjected to HT over a long period of time, their growth was stunted. The results showed that no significant difference was seen between the control (25 °C) and 30 °C for some traits (root shoot fresh weight, root morphological traits, and leaf gas exchanges parameters). Further, HT (35, 40, and 45 °C) stress significantly reduced the growth status, the gas exchange parameters, the pigment content, the photosystem function, and the root architecture system of water spinach. Conversely, HT stress considerably enhanced secondary metabolites in terms of total phenolics, flavonoids, soluble sugars, and anthocyanin content. Furthermore, heat stress remarkably increased the accumulation of reactive oxygen species (ROS) and caused cellular membrane damage. HT stress effectively altered the antioxidant defense system and caused oxidative damage. Generally, HT has an adverse effect on the enzyme activity of water spinach, leading to cell death. However, the current study found that temperatures ≥35 °C had an adverse effect on the growth of water spinach. Further research will be needed to examine the mechanism and the gene expression involved in the cell death that is caused by temperature stress in water spinach plants. Full article

Citrus fruits are vulnerable to green mold (caused by Penicillium digitatum) and blue mold (caused by Penicillium italicum) during storage, posing significant challenges to the industry. Therefore, biological control utilizing antagonistic bacteria has emerged as a dependable strategy for managing postharvest diseases. In this study, halophilic bacterial isolates were carefully selected from diverse saline ecosystems, including the Dead Sea, the Agadir Sea, the Rabat Sea, saline soil, and water of the Amassine Oued in Taounate, based on rigorous in vitro and in vivo antagonism bioassays. Out of 21 bacteria from different saline environments, 10 were chosen for further characterization based on the 16S rDNA gene. Notably, the EAM1 isolate demonstrated exceptional inhibitory effects, reaching a 90% inhibition rate against P. digitatum, while the ER2 isolate closely followed with an 89% inhibition rate against P. italicum. Furthermore, in bacterial supernatant experiments, six bacterial isolates effectively curbed the growth of P. digitatum, and three demonstrated efficacy against P. italicum development. In an in vivo trial spanning ten days of incubation, three highly effective isolates against P. digitatum displayed zero severity, and two of these isolates also demonstrated zero severity against P. italicum. Interestingly, a comparison of bacterial filtrates revealed that all isolates exhibited a severity level of over 50% against the pathogen causing green rot (P. digitatum), while the severity was lower than 50% for the supernatants of the two isolates used against P. italicum. In conclusion, this study highlights the promising role of halophilic bacteria, specifically Bacillus amyloliquefaciens EAM1 and B. amyloliquefaciens ER2, in controlling postharvest fruit pathogens. The findings shed light on the potential of utilizing these bioprotective agents to address the challenges posed by green and blue citrus molds, providing valuable insights for the citrus industry. Full article

Salinity stress prominently limits cucumber growth and productivity. However, the mechanism underlying salinity response mediated by the C-TERMINALLY ENCODED PEPTIDE (CEP) peptide in cucumber primary root remains largely unclear. In this study, we show that salinity prominently inhibits cucumber primary root growth, and CsCEP gene expression is differentially induced by salinity. We further demonstrate that the exogenous application of synthetic CsCEP3 peptide partially suppresses salinity-triggered growth inhibition in cucumber primary root, although CsCEP3 peptide itself shows no obvious effect on cucumber primary root growth under normal conditions. Our transcriptomic and qRT-PCR data further reveal that CsCEP3 peptide may modulate gene expression related to abscisic acid (ABA) signaling pathway, reactive oxygen species (ROS) production, and slat-responsive transcription factors to attenuate the inhibitory effect of salinity on cucumber primary root growth. Taken together, our work provides a fundamental insight into CEP peptide-mediated cucumber salinity adaptation. Full article

Organic production is expected to play a major role in reducing the impact of agricultural practices on the environment. Soil is considered a major component of the organic production process, and organic practices aim at increasing its health and fertility. However, the control of soil-borne pests, particularly plant-parasitic nematodes, can be difficult in organic horticultural crops due to the rules allowed in this farming system. Applying a holistic approach that fosters and exploits the activity of the soil microbiome to control plant-parasitic nematodes has been at the basis of the analysis of the available scientific knowledge carried out for this review article. This review thus focuses on the multifunctional capacity of microorganisms, including that of bacteria and fungi not normally considered biocontrol agents, and the need to also better understand their relations with the plant and other environmental and agronomic factors. The implementation of the “multi-biotics” concept, applying prebiotics, probiotics and postbiotics, which supports an integrated agroecological strategy for the protection of organic horticultural crops, is proposed as an efficient practice that should be further studied to be adapted under different crops and pedo-climatic conditions. Full article