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Horticulturae, Volume 8, Issue 8 (August 2022) – 87 articles

Cover Story (view full-size image): Since tomato is a high nitrogen (N)-demanding vegetable, N fertilizers have often been used in excess by farmers to improve commercial yield and the profitability of processing tomato crops with few concerns about environmental issues. However, N fertilization greatly affects the overall tomato quality, including technological traits, nutritional characteristics, and mineral fruit composition. The aim of this work was to study the effects of increasing mineral N fertilization rates on processing tomato yield and quality under growing conditions in Southern Italy. View this paper
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Article
Chemical Composition of Combretum erythrophyllum Leaf and Stem Bark Extracts
Horticulturae 2022, 8(8), 755; https://doi.org/10.3390/horticulturae8080755 - 20 Aug 2022
Viewed by 451
Abstract
Combretaceae is a large Angiosperm family that is highly sought after because of its pronounced medicinal value. Combretum is recognized as the largest genus, prevalent in southern Africa due to its extensive use in traditional medicine. This study aimed to provide a comparative [...] Read more.
Combretaceae is a large Angiosperm family that is highly sought after because of its pronounced medicinal value. Combretum is recognized as the largest genus, prevalent in southern Africa due to its extensive use in traditional medicine. This study aimed to provide a comparative analysis of the phytochemical constituents of the leaf and stembark extracts of Combretum erythrophyllum (Burch.) Sond. Leaf and stembark crude extracts were generated using hexane, chloroform, and methanol as the solvents of choice. Qualitative phytochemical tests indicated the presence of phytocompounds, including carbohydrates, alkaloids, sterols, phenols, fixed oils, and fats. Flavonoids were found within the leaf extracts only, while saponins, mucilage, and gums were specifically identified within the stembark extracts. The first reported gas chromatography–mass spectrometry (GC–MS) screening of C. erythrophyllum leaf and stembark extracts was conducted, yielding the identification of 266 phytocompounds. Major phytocompounds such as sitosterol and lupeol, which may have possible anti-cancer and anti-inflammatory properties, were identified. Furthermore, a pharmacogenetic evaluation was conducted. As a result, both the leaf and stem bark material were seen to fluoresce a wide array of colors (brown, red, green, and blue colorations), indicating the presence of beneficial phytometabolites and their use in medicinal applications. Given the wide array of proposed medicinal benefits associated with the presence of phytocompounds identified within C. erythrophyllum, this species should be considered for its medicinal importance. The isolation and extraction of these beneficial compounds open further avenues for their use in the pharmaceutical industry. Full article
(This article belongs to the Special Issue Biological Activities of Medicinal and Aromatic Plants)
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Article
Seed Germination and Seedling Growth of Yellow and Purple Passion Fruit Genotypes Cultivated in Ecuador
Horticulturae 2022, 8(8), 754; https://doi.org/10.3390/horticulturae8080754 - 20 Aug 2022
Viewed by 336
Abstract
Seed is a fundamental tool to carry out breeding processes and for the propagation of the crops; however, seed propagation generally has low and irregular germination. Passion fruit (Passiflora) species are economically important for Ecuador, which is the main exporter of [...] Read more.
Seed is a fundamental tool to carry out breeding processes and for the propagation of the crops; however, seed propagation generally has low and irregular germination. Passion fruit (Passiflora) species are economically important for Ecuador, which is the main exporter of passion fruit concentrate in Latin America. Ecuadorian farmers propagate new plants by seeds to establish new passion fruit orchards or to extend their cultivated area. The objective of this research was to determine the differences in germination and seedling development with the application of priming methods in five genotypes of passion fruit belonging to three different taxa that are of commercial use in Ecuador. The genotypes used were: INIAP 2009 and P10 (P. edulis f. flavicarpa), Gulupa (P. edulis f. edulis), and local germplasms POR1 (P. edulis f. flavicarpa) and PICH1 (P. maliformis). The priming methods were: water (control), hydrogen peroxide at 15%, potassium nitrate at 1%, PEG 6000 at −1.2 MPa, and gibberellic acid at 500 ppm. The results showed that there was a genotype-response depending on the priming method. Nevertheless, Polietilenoglicol (PEG 6000) could be considered as a promising method to encourage seed germination and promote seedling growth in the Passiflora species. More research regarding the use of this compound has to be carried out in order to determine in depth the physiological processes related to its functions to improve seed germination as well as production of vigorous seedlings. Full article
(This article belongs to the Special Issue Seed Dormancy and Germination of Horticultural Plants)
Article
Optimum Moisture Conditions for English Lavender Cuttings Are Drier for Root Development than Shoot Development
Horticulturae 2022, 8(8), 753; https://doi.org/10.3390/horticulturae8080753 - 19 Aug 2022
Viewed by 549
Abstract
Providing proper moisture conditions is critical for successful cutting propagation. This study aimed to investigate the optimal substrate moisture level for enhancing the survival and rooting rates of Lavandula angustifolia cuttings. Apical cuttings of L. angustifolia were propagated under four irrigation thresholds (−1.0, [...] Read more.
Providing proper moisture conditions is critical for successful cutting propagation. This study aimed to investigate the optimal substrate moisture level for enhancing the survival and rooting rates of Lavandula angustifolia cuttings. Apical cuttings of L. angustifolia were propagated under four irrigation thresholds (−1.0, −2.5, −5.0, and −10.0 kPa) over six weeks. At the final harvest, cuttings grown at −2.5 kPa demonstrated the highest survival rate (83.3%), and those grown at −10.0 kPa demonstrated a mortality > 50%. A high rooting percentage (53.0 and 47.2%) was observed in cuttings grown at −1.0 and −2.5 kPa, while the lowest rooting percentage (<10%) was present in those grown at −10.0 kPa. Adventitious root formation and root growth occurred within a month for all treatments, except for the −10.0 kPa treatment; the general root growth was similar among treatments at the final harvest. Shoot growth was negligible in all treatments until four weeks, and it increased rapidly with increasing substrate moisture levels after the formation of adventitious roots. The adventitious root system was established within four weeks, which was followed by accelerated leaf and shoot growth. The optimal substrate moisture level for high survival and rooting of English lavender cuttings was approximately −2.5 kPa, but higher moisture tension at −1.0 kPa could enhance the shoot growth after adventitious roots are established. Full article
(This article belongs to the Special Issue Horticultural Crops Water and Fertilizer Management)
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Article
First Isolation and Characterization of Serratia liquefaciens Associated with Rot Disease of Malus domestica (Apple) Fruit and Its Inhibition by Origanum vulgare (Oregano) Oil
Horticulturae 2022, 8(8), 752; https://doi.org/10.3390/horticulturae8080752 - 19 Aug 2022
Viewed by 295
Abstract
Microbial food spoilage has been a major source of concern because it widens the global food production-to-consumption gap. Thus, in the current study, we aimed to isolate, characterize and identify bacteria associated with spoiled apple fruit in Al-Ahsa city, Saudi Arabia. MDK33, a [...] Read more.
Microbial food spoilage has been a major source of concern because it widens the global food production-to-consumption gap. Thus, in the current study, we aimed to isolate, characterize and identify bacteria associated with spoiled apple fruit in Al-Ahsa city, Saudi Arabia. MDK33, a bacterial strain isolated from rotten apple fruit, was characterized at the phenotypic and genotypic levels. Furthermore, the antibacterial effect of oregano essential oil (OEO) against MDK33 was investigated. MDK33 formed circular colonies with entire margins, and the cells were Gram-negative rods with no endospores. Biochemical characterizations of MDK33, as revealed by the Biolog Gen III MicroPlate test system, indicated that the strain utilized 66 (~70%) of the 94 diverse metabolites and did not utilize 29 (~30%). MDK33 grew well on a variety of substrates, including pectin, gelatin, Tween 40 and dextrin, at pH 5 and 6; tolerated salts up to 4% NaCl; and was resistant to multiple antibiotics. Furthermore, based on the sequences of the 16S rRNA gene, MDK33 was identified as Serratia liquefaciens at a 99.73% identity level. Koch’s postulates were affirmed, confirming that S. liquefaciens MDK33 is the causative agent of apple rot disease in Al-Ahsa, Saudi Arabia. The minimum inhibitory concentration (MIC) of 0.23 mg/mL for oregano oil against S. liquefaciens MDK33 demonstrated remarkable antibacterial and antibiofilm activities. This is the first isolation of pathogenic S. liquefaciens as the causative agent of rot disease of apple fruit and its inhibition by oregano oil. Furthermore, the findings pave the way for oregano oil to be evaluated as a natural preservative to reduce post-harvest losses while maintaining high quality for sustainable food security in future studies. Full article
(This article belongs to the Section Plant Pathology and Disease Management (PPDM))
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Article
Cleaning of Tomato brown rugose fruit virus (ToBRFV) from Contaminated Clothing of Greenhouse Employees
Horticulturae 2022, 8(8), 751; https://doi.org/10.3390/horticulturae8080751 - 19 Aug 2022
Viewed by 571
Abstract
The highly infectious Tomato brown rugose fruit virus (ToBRFV) is a new viral threat to tomato production worldwide. In production, the very easy mechanical transmissibility combined with the high resistance in vitro is of great concern. We tested: (i) whether household cleaning products, [...] Read more.
The highly infectious Tomato brown rugose fruit virus (ToBRFV) is a new viral threat to tomato production worldwide. In production, the very easy mechanical transmissibility combined with the high resistance in vitro is of great concern. We tested: (i) whether household cleaning products, commercial agricultural detergents, and an authorized plant protectant are suitable for cleaning contaminated clothing, and (ii) whether infectious viruses remain in the resulting cleaning water. The evaluation of the sanitation effect was performed using bioassays, by counting ToBRFV-associated necrotic local lesions on Nicotiana tabacum cv. Xanthi NN. For this purpose, leaves were mechanically inoculated with treated fabrics and cleaning solutions which would normally be discharged to the sewer system. The detergents Fadex H+ (FH) and Menno Hortisept Clean Plus, as well as the disinfectant Menno Florades (MF), led to an almost complete removal of ToBRFV from contaminated fabrics, corresponding to a reduction in local lesions by 99.94–99.96%. In contrast, common household cleaning products (Spee ActivGel (SAG), Vanish Oxi Action Gel (VO) did not effectively remove the pathogen from the fabric, where the reduction was 45.1% and 89.7%, respectively. In particular, cleaning solutions after the use of household cleaners were highly contaminated with ToBRFV. After a 16-h treatment with the disinfectant MF, infectious ToBRFV was no longer present in VO, FH, and MF cleaning solutions, as demonstrated by extensive bioassays. Full article
(This article belongs to the Special Issue Innovative System for Disinfection in Greenhouses)
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Article
Antimicrobial Multiresistant Phenotypes of Genetically Diverse Pseudomonas spp. Isolates Associated with Tomato Plants in Chilean Orchards
Horticulturae 2022, 8(8), 750; https://doi.org/10.3390/horticulturae8080750 - 19 Aug 2022
Viewed by 508
Abstract
Tomatoes are susceptible to bacterial diseases, mainly related to some Pseudomonas syringae pathovars. Many Pseudomonas species are considered innocuous, but some have shown the ability to opportunistically infect tomato plants. Antimicrobial compounds have been used to control pathogenic organisms, and this can lead [...] Read more.
Tomatoes are susceptible to bacterial diseases, mainly related to some Pseudomonas syringae pathovars. Many Pseudomonas species are considered innocuous, but some have shown the ability to opportunistically infect tomato plants. Antimicrobial compounds have been used to control pathogenic organisms, and this can lead to environmental selection of phenotypically resistant bacteria. We assessed the diversity of Pseudomonas species associated with tomato plants from Chilean orchards and analyzed antimicrobial resistance among the isolated strains. A total of 64 Pseudomonas isolates (P. syringae, P. viridiflava, P. fluorescens, P. koreensis, P. gessardii, and P. azotoformans) were evaluated for their phenotypic resistance to seven antimicrobial compounds, including copper, streptomycin, and five other antibiotics typically not used in agriculture. The results showed that 95%, 86%, 70%, 53%, 45%, and 1.6% of the isolates were resistant to rifampin, ampicillin, copper, chloramphenicol, streptomycin, and tetracycline, respectively, with no isolates being resistant to gentamicin. A total of 96.9% of Pseudomonas isolates exhibited a multiresistant phenotype to at least two of the antimicrobials tested. The most frequent multiresistance phenotype was Cu-Str-Amp-Cm-Rif (23.4%). The presence of Pseudomonas strains tolerant to conventional bactericides, metals, and other antimicrobials makes these bacteria an emerging threat to the agriculture industry and to human health. Full article
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Article
Effect of Nutrient Solution Cooling in Summer and Heating in Winter on the Performance of Baby Leafy Vegetables in Deep-Water Hydroponic Systems
Horticulturae 2022, 8(8), 749; https://doi.org/10.3390/horticulturae8080749 - 18 Aug 2022
Viewed by 438
Abstract
Hydroponics has become a popular production technology for leafy greens in greenhouses. However, year-round production of cool-season leafy greens remains challenging due to costly heating and cooling during winter and summer seasons, depending on location. Therefore, the objective of this study is to [...] Read more.
Hydroponics has become a popular production technology for leafy greens in greenhouses. However, year-round production of cool-season leafy greens remains challenging due to costly heating and cooling during winter and summer seasons, depending on location. Therefore, the objective of this study is to investigate the effect of nutrient solution cooling and heating in deep-water hydroponic systems on the performance of several leafy green vegetables. Two experiments of nutrient solution cooling during the summer season and another two experiments of nutrient solution heating during the winter season were conducted in Texas, USA in 2020–2021. Lettuce (Lactuca sativa L.) ‘Bergams Green’ and ‘Red Mist’, Pak Choi (Brassica rapa subsp. chinensis) ‘Purple Magic’ and ‘White Stem’, and spinach (Spinacia oleracea L.) ‘Mandolin’ and ‘Seaside’ were grown in the summer experiments, and only the two lettuce cultivars were grown for the winter experiments. For both cooling and heating studies, six deep-water culture systems were used with two treatments: cooling (23 °C) vs. no cooling, and heating (22 °C) vs. no heating, with three replications in each experiment. In the nutrient solution cooling study, spinach was the most heat-sensitive species, and ‘Mandolin’ was more heat-tolerant than ‘Seaside,’ as evidenced by its lower mortality rate in both experiments. Lettuce and pak choi grew well and solution cooling increased shoot fresh weight in both lettuce cultivars and in ‘White Stem’ pak choi but not in ‘Purple Magic’ pak choi. Conversely, during the winter season, solution heating increased shoot fresh weight of both lettuce cultivars; however, ‘Red Mist’ was more responsive than ‘Bergams Green’ lettuce. These results indicate the potential to increase crop yield by controlling nutrient solution temperature throughout the year, depending on the season. Also, there were genotypic differences in both cooling and heating experiments, indicating that more research is needed to determine the species-dependent and even cultivar-dependent nutrient solution temperature control strategies to achieve optimum year-round production. Full article
(This article belongs to the Topic Innovation and Solution for Sustainable Agriculture)
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Review
Bio-Circular Perspective of Citrus Fruit Loss Caused by Pathogens: Occurrences, Active Ingredient Recovery and Applications
Horticulturae 2022, 8(8), 748; https://doi.org/10.3390/horticulturae8080748 - 18 Aug 2022
Viewed by 405
Abstract
The Sustainable Development Goals (SDGs) contribute to the improvement of production and consumption systems, hence, assisting in the eradication of hunger and poverty. As a result, there is growing global interest in the direction of economic development to create a zero-waste economy or [...] Read more.
The Sustainable Development Goals (SDGs) contribute to the improvement of production and consumption systems, hence, assisting in the eradication of hunger and poverty. As a result, there is growing global interest in the direction of economic development to create a zero-waste economy or circular economy. Citrus fruits are a major fruit crop, with annual global production surpassing 100 million tons, while orange and tangerine production alone account for more than half of the overall production. During pre- and postharvest stages of citrus fruit production, it is estimated that more than 20% of fruit biomass is lost, due, primarily, to biotic stresses. This review emphasizes causes of fruit losses by pathogenic caused diseases and proposes a bio-circular perspective in the production of citrus fruits. Due to substantial changes in fruit characteristics and environmental conditions, some of the most economically significant pathogens infect fruits in the field during the growing season and remain dormant or inactive until they resume growth after harvest. Peel biomass is the most significant by-product in citrus fruit production. This biomass is enriched with the value-adding essential oils and polysaccharides. For the complete bio-circular economy, these active ingredients can be utilized as citrus postharvest coating materials based upon their functional properties. The overall outreach of the approach not only reduces the amount of agricultural by-products and develops new applications for the pomology industry, it also promotes bio-circular green economic, which is in line with the SDGs for the citrus fruit industry. Full article
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Article
Role of RcTINY2 in the Regulation of Drought and Salt Stress Response in Arabidopsis and Rose
Horticulturae 2022, 8(8), 747; https://doi.org/10.3390/horticulturae8080747 - 18 Aug 2022
Viewed by 340
Abstract
In plants, transcription factors (TFs) belonging to the APETALA2/ethylene responsive factor (AP2/ERF) superfamily regulate a variety of life processes, including germination, maturation, and stress response. In the present study, RcTINY2, a novel dehydration response element binding protein (DREB) belonging to the A-4 group, [...] Read more.
In plants, transcription factors (TFs) belonging to the APETALA2/ethylene responsive factor (AP2/ERF) superfamily regulate a variety of life processes, including germination, maturation, and stress response. In the present study, RcTINY2, a novel dehydration response element binding protein (DREB) belonging to the A-4 group, was identified and characterized in rose (Rosa chinensis). RcTINY2 shares high homology with AtTINY2 of Arabidopsis (Arabidopsis thaliana), with several abiotic stress-responsive cis-regulatory elements. Transcript levels of RcTINY2 were induced by exposure to abscisic acid (ABA) in rose leaves and repressed by exposure to ABA, polyethylene glycol (PEG), and NaCl in rose roots. RcTINY2 is localized in the nucleus and showed transcriptional activation in yeast cells. Further analysis of transgenic Arabidopsis demonstrated that plants overexpressing RcTINY2 displayed increased ABA, PEG, and NaCl sensitivity in both germinating seeds and seedlings with reduced root growth and lateral root number. RcTINY2-silenced rose plants were found to be increasingly intolerant of both drought and salt stress. Furthermore, the transcript levels of several ABA- and abiotic stress-related genes were suppressed in RcTINY2-silenced rose plants. The results suggested that RcTINY2 may serve as a candidate gene for genetic improvement of abiotic stress tolerance in rose and other plant species. Full article
(This article belongs to the Section Biotic and Abiotic Stress)
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Article
Jania adhaerens Primes Tomato Seed against Soil-Borne Pathogens
Horticulturae 2022, 8(8), 746; https://doi.org/10.3390/horticulturae8080746 - 18 Aug 2022
Viewed by 341
Abstract
Managing soil-borne pathogens is complex due to the restriction of the most effective synthetic fungicides for soil treatment. In this study, we showed that seed priming with Jania adhaerens water-soluble polysaccharides (JA WSPs) was successful in protecting tomato plants from the soil-borne pathogens [...] Read more.
Managing soil-borne pathogens is complex due to the restriction of the most effective synthetic fungicides for soil treatment. In this study, we showed that seed priming with Jania adhaerens water-soluble polysaccharides (JA WSPs) was successful in protecting tomato plants from the soil-borne pathogens Rhizoctonia solani, Pythium ultimum, and Fusarium oxysporum under greenhouse conditions. WSPs were extracted from dry thallus by autoclave-assisted method, and the main functional groups were characterized by using FT-IR spectroscopy. WSPs were applied by seed treatment at 0.3, 0.6 and 1.2 mg/mL doses, and each pathogen was inoculated singly in a growing substrate before seeding/transplant. Overall, WSPs increased seedling emergence, reduced disease severity and increased plant development depending on the dose. Transcriptional expression of genes related to phenylpropanoid, chlorogenic acid, SAR and ISR pathways, and chitinase and β-1,3 glucanase activities were investigated. Among the studied genes, HQT, HCT, and PR1 were significantly upregulated depending on the dose, while all doses increased PAL and PR2 expression as well as β-1,3 glucanase activity. These results demonstrated that, besides their plant growth promotion activity, JA WSPs may play a protective role in triggering plant defense responses potentially correlated to disease control against soil-borne pathogens. Full article
(This article belongs to the Special Issue Sustainable Control Strategies of Plant Pathogens in Horticulture)
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Article
Hurdle Approach for Control of Enzymatic Browning and Extension of Shelf Life of Fresh-Cut Leafy Vegetables Using Vacuum Precooling and Modified Atmosphere Packaging: Commercial Application
Horticulturae 2022, 8(8), 745; https://doi.org/10.3390/horticulturae8080745 - 18 Aug 2022
Viewed by 292
Abstract
Fresh-cut leafy vegetable has an image as a healthy, nutritious, and delicious product. However, the product still faces the challenge of quality retention and short shelf life, especially in tropical climate regions. Enzymatic browning in fresh-cut leafy vegetables is considered one of the [...] Read more.
Fresh-cut leafy vegetable has an image as a healthy, nutritious, and delicious product. However, the product still faces the challenge of quality retention and short shelf life, especially in tropical climate regions. Enzymatic browning in fresh-cut leafy vegetables is considered one of the most important attributes limiting the shelf life of the product. The hurdle approach using commercial vacuum precooling in combination with modified atmosphere packaging (MAP) as an alternative to the use of chemical preservatives to prevent enzymatic browning, an undesirable attribute that is easily detected by consumers, was investigated. The hurdle technology exhibited synergistic effects on fresh-cut lettuce, namely frillice iceberg, romaine, and red oak, in slowing down cut-surface browning, maintaining quality, delaying microbial growth, and extending shelf life of salad products at the retail level. The findings of the study verified the potential of the hurdle approach in delaying the effect of cutting as well as extending shelf life of the product stored at 4 ± 1 °C with 85% RH from three days to nine days with an additional unit cost of 1.05%. Therefore, our hurdle approach is anticipated as the practice with non-chemical and economical approach in the supply chain of the fresh-cut, leafy vegetables industry. Full article
(This article belongs to the Special Issue Food Quality and Safety of Fresh and Fresh-Cut Produce)
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Article
Identification of Two Bacillus Strains with Antimicrobial Activity and Preliminary Evaluation of Their Biocontrol Efficiency
Horticulturae 2022, 8(8), 744; https://doi.org/10.3390/horticulturae8080744 - 18 Aug 2022
Viewed by 281
Abstract
Cabbage Fusarium Wilt (CFW) is a serious disease caused by Fusarium oxysporum f. sp. conglutinans in many parts of the world. The use of chemical fungicides has placed a heavy burden on the environment and is prone to drug resistance in plant pathogens. [...] Read more.
Cabbage Fusarium Wilt (CFW) is a serious disease caused by Fusarium oxysporum f. sp. conglutinans in many parts of the world. The use of chemical fungicides has placed a heavy burden on the environment and is prone to drug resistance in plant pathogens. As a method with great potential, biological control has attracted the attention of many academics both at home and abroad. In this study, we have found that strains B5 and B6 had a strong inhibitory effect on various pathogens and significantly inhibited mycelium growth. They were both identified as Bacillus velezensis by morphological features, biochemical determinations, 16S rRNA gene and gyrA gene sequence analysis. When different concentrations of bacterial suspension were applied to cabbage seeds, hypocotyl and taproot length increased to varying degrees. The in vivo results showed that B5 and B6 decreased the incidence of cabbage seedling wilt disease, with B6 performing significantly better. Furthermore, B. velezensis B6 had the ability to colonize cabbage plants and rhizosphere soil. Thus, strain B6 has great potential for biocontrol development and this research could lead to the development of a promising biological agent for CFW. Full article
(This article belongs to the Special Issue Horticultural Plants Pathology and Advances in Disease Management)
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Article
Genome-Wide Identification of the Hsp70 Gene Family in Grape and Their Expression Profile during Abiotic Stress
Horticulturae 2022, 8(8), 743; https://doi.org/10.3390/horticulturae8080743 - 18 Aug 2022
Viewed by 352
Abstract
Plants encounter a variety of abiotic stresses such as global climate change. Hsp70, as one of the main families of heat shock proteins (Hsps), has a great role in maintenance of the development and growth, and response to abiotic stress. Grape is a [...] Read more.
Plants encounter a variety of abiotic stresses such as global climate change. Hsp70, as one of the main families of heat shock proteins (Hsps), has a great role in maintenance of the development and growth, and response to abiotic stress. Grape is a very popular fruit worldwide with a high economic value. However, the Hsp70 gene family has not been thoroughly identified in grape (Vitis vinifera L.). In this study, a total of 33 VvHsp70 genes were identified and divided into four clades in V. vinifera. Phylogenetic analysis, gene structure, conserved motif, and duplication events were performed for VvHsp70 genes. The detailed information showed that the VvHsp70 genes clustered together based on the phylogenetic tree had similar subcellular localization, gene structures, and conserved motifs, although there are exceptions. The expression patterns of VvHsp70, VdHsp70, or VaHsp70 were explored in development and abiotic stress including heat, osmotic, and cold stresses by transcription data or qRT-PCR. The results showed that grape Hsp70 genes had strong response for these abiotic stresses, particularly in heat and cold treatments in a different expression pattern. Most of the VdHsp70 genes were upregulated in response to heat treatments while VaHsp70 genes were downregulated in response to cold treatments. Together, our results revealed a new insight for the Hsp70 gene family in grape and will afford fundamental knowledge for further functional analysis and breeding of stress-tolerant grapevines. Full article
(This article belongs to the Special Issue Stress Biology of Horticultural Plants)
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Article
Characterizations of MYB Transcription Factors in Camellia oleifera Reveal the Key Regulators Involved in Oil Biosynthesis
Horticulturae 2022, 8(8), 742; https://doi.org/10.3390/horticulturae8080742 - 18 Aug 2022
Viewed by 301
Abstract
MYB (myeloblastosis) transcription factors plays an important role in various physiological and biochemical processes in plants. However, little is known about the regulatory roles of MYB family genes underlying seed oil biosynthesis in Camellia oleifera. To identify potential regulators, we performed the [...] Read more.
MYB (myeloblastosis) transcription factors plays an important role in various physiological and biochemical processes in plants. However, little is known about the regulatory roles of MYB family genes underlying seed oil biosynthesis in Camellia oleifera. To identify potential regulators, we performed the genome-wide characterizations of the MYB family genes and their expression profiles in C. oleifera. A total of 186 CoMYB genes were identified, including 128 R2R3-type MYB genes that had conserved R2 and R3 domains. Phylogenetic analysis revealed the CoR2R3-MYBs formed 25 subgroups and possessed some highly conserved motifs outside the MYB DNA-binding domain. We investigated the promoter regions of CoR2R3-MYBs and revealed a series of cis-acting elements related to development, hormone response, and environmental stress response, suggesting a diversified regulatory mechanism of gene functions. In addition, we identified four tandem clusters containing eleven CoR2R3-MYBs, which indicated that tandem duplications played an important role in the expansion of the CoR2R3-MYB subfamily. Furthermore, we analyzed the global gene expression profiles at five stages during seed development and revealed seven CoR2R3-MYB genes that potentially regulated lipid metabolism and seed maturation in C. oleifera. These results provide new insights into understanding the function of the MYB genes and the genetic improvement of seed oil. Full article
(This article belongs to the Topic Advanced Breeding Technology for Plants)
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Article
Assessing the Impact of Variety, Irrigation, and Plant Distance on Predatory and Phytophagous Insects in Chili
Horticulturae 2022, 8(8), 741; https://doi.org/10.3390/horticulturae8080741 - 17 Aug 2022
Viewed by 390
Abstract
Chilies are plants that are becoming increasingly popular all over the world, including in Hungary. Since little is known about the abundance and seasonal dynamic of insect pests and their natural enemies associated with chilies under Hungarian climatic conditions, the aim of the [...] Read more.
Chilies are plants that are becoming increasingly popular all over the world, including in Hungary. Since little is known about the abundance and seasonal dynamic of insect pests and their natural enemies associated with chilies under Hungarian climatic conditions, the aim of the study was to monitor these organisms on different varieties under different growing conditions to provide data for improving IPM for chilies. Chili varieties “Yellow Scotch Bonnet” (YSB) and “Trinidad Scorpion Butch T” (TSBT) were planted with three replicates. Two different plant-to-plant distances (30 vs. 40 and 40 vs. 60 cm in YSB, TSBT, respectively) and two different irrigation frequencies (daily, 40 min; every second day, 20 min) were used. Fifty flowers/plot/date were collected. In 2019, Orius (Hemiptera: Anthocoridae) larvae, and in 2021, phytophagous thrips larvae were dominant in all the treatments. Significantly more Orius adults and larvae were found in the YSB than in the TSBT variety and the number of Aeolothrips and phytophagous thrips (Thysanoptera: Thripidae) adults was significantly higher under less irrigation in 2019. The plant spacing did not affect the abundance of predators or herbivores. Upon comparing the two years, no effect of the treatments on the studied insect taxa was observed. Full article
(This article belongs to the Special Issue Integrated Pest Management in Horticulture)
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Article
Shoot Induction, Multiplication, Rooting and Acclimatization of Black Turmeric (Curcuma caesia Roxb.): An Important and Endangered Curcuma Species
Horticulturae 2022, 8(8), 740; https://doi.org/10.3390/horticulturae8080740 - 17 Aug 2022
Viewed by 288
Abstract
Curcuma caesia Roxb., commonly known as Kali Haldi or black turmeric, is one of the important species in the genus Curcuma. This species has been classified as one of the endangered Curcuma species due to the drastic decrement of this plant in [...] Read more.
Curcuma caesia Roxb., commonly known as Kali Haldi or black turmeric, is one of the important species in the genus Curcuma. This species has been classified as one of the endangered Curcuma species due to the drastic decrement of this plant in its natural habitat. C. caesia has been overharvested for various purposes, including bioactive compound extraction to fulfill the pharmaceutical industry demand. Hence, this study was conducted to establish a protocol for the propagation of C. caesia via plant tissue culture techniques. In the shoot induction stage, three basal medium formulations, including Murashige and Skoog (MS medium), the combination of Murashige and Skoog macronutrients and B5 micronutrients (MSB5 medium) and woody plant medium (WPM medium) supplemented with 15 μM of 6-benzylaminopurine (BAP), were used. The results found that the MSB5 medium was the most suitable basal medium formulation for shoot induction of C. caesia. In the subsequent experiment, different types of cytokinin, including BAP, kinetin and 2-iP at concentrations of 5, 10, 15 and 20 μM, were fortified in the MSB5 medium for shoot multiplication. The shoot multiplication was further enhanced by supplementing the MSB5 medium with indole-3-butyric acid (IBA) or 1-napthaleneacetic acid (NAA) at the concentrations of 2, 4, 6 and 8 μM. The results showed that a combination of 15 μM of BAP and 6 μM of IBA significantly increased the shoot multiplication with 100% shoot induction, 3.53 shoots/explant, 10.81 cm of shoot length, 9.57 leaves, 0.486 g of leaves fresh weight and 0.039 g of leaves dry weight. After the multiplication, the rooting stage was carried out by altering the basal medium strength into half and full strength and supplementing with 2.5, 5, 7.5 and 10 μM of indole-3-acetic acid (IAA). The full strength of MSB5 medium supplemented with 5 μM of IAA exhibited the highest number of roots and length of roots, with 6.13 roots and 5.37 cm, respectively. After the rooting stage, the plantlets were successfully acclimatized in the potting medium with the combination of cocopeat and peatmoss, and the ratio of 1:1 was found to produce the highest survival rate with 77.78%. In conclusion, the protocol established in this study could be useful for large-scale raw material production, either for conservation or bioactive compound extraction. Full article
(This article belongs to the Special Issue In Vitro Technology and Micropropagated Plants)
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Article
Characterization of the Residue (Endocarp) of Acrocomia aculeata and Its Biochars as a Potential Source for Soilless Growing Media
Horticulturae 2022, 8(8), 739; https://doi.org/10.3390/horticulturae8080739 - 17 Aug 2022
Viewed by 332
Abstract
Endocarp residues remaining after coconut oil extraction from Acrocomia aculeate are traditionally used for combustion as fuel. As an alternative, we propose its conversion into biochar to substitute peat in planting substrates. To test the feasibility of this approach, untreated endocarp residues (particle [...] Read more.
Endocarp residues remaining after coconut oil extraction from Acrocomia aculeate are traditionally used for combustion as fuel. As an alternative, we propose its conversion into biochar to substitute peat in planting substrates. To test the feasibility of this approach, untreated endocarp residues (particle size approx. 10 mm) and materials shredded into particles of 4 and 1 mm were pyrolyzed at 200 °C, 325 °C and 450 °C and were subsequently characterized. The pyrolysis-induced loss of organic matter increased the ash contents and pH. Nuclear magnetic resonance (NMR) spectroscopy confirmed the aromatization and a loss of carboxyl C with an increasing pyrolysis temperature. This is commonly associated with an enhanced biochemical recalcitrance. The particle size of the feedstock had no significant effect on the chemical composition or microporosity (BET-adsorption with COs) of the biochars, but affected their water holding capacity. With respect to macro- and micronutrients, only the potassium and Olsen P levels occurred in concentrations that are optimal for tomato seed growth. The low nitrogen level of the products may be advantageous for hydroponic culturing since it allows for a higher flexibility for the adaptation of nutrient contents based on the needs of the used culture. Full article
(This article belongs to the Special Issue Application of Chars in Growing Media)
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Article
Determination of the Best Planting Season for the Protected Cultivation of Papaya
Horticulturae 2022, 8(8), 738; https://doi.org/10.3390/horticulturae8080738 - 17 Aug 2022
Viewed by 321
Abstract
Papaya is a tropical crop increasingly cultivated in the greenhouses of subtropical regions such as South East Spain, where the determination of the best planting season is important to ensure a stable fruit production and quality during the year. In this work, we [...] Read more.
Papaya is a tropical crop increasingly cultivated in the greenhouses of subtropical regions such as South East Spain, where the determination of the best planting season is important to ensure a stable fruit production and quality during the year. In this work, we studied plant growth, yield, and fruit quality, comparing spring and autumn planting seasons in ‘Intenzza’ cultivar. The results showed that planting in spring favors plant growth, leading to an earlier entry into production. Total yield and fruit quality were similar in both planting seasons, although the spring cycle provided higher profits due to greater commercial yield and lower discards. Our results confirm that adverse environmental conditions affect the crop in a similar way regardless of the planting season, so different growing cycles are not very useful for filling the production gaps and fighting against seasonality in our region, unless unfavorable climate conditions are avoided inside the greenhouse. Full article
(This article belongs to the Special Issue Advances in Tropical Fruit Cultivation and Breeding)
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Review
In Vitro Propagation of Caper (Capparis spinosa L.): A Review
Horticulturae 2022, 8(8), 737; https://doi.org/10.3390/horticulturae8080737 - 17 Aug 2022
Cited by 1 | Viewed by 415
Abstract
Caper (Capparis spinosa L.) is a shrubby plant species recalcitrant to vegetative propagation and generally difficult to propagate by seeds. This is due to the difficulties associated with seed germination, root induction from stem cuttings, and plant hardening. Propagation by tissue culture [...] Read more.
Caper (Capparis spinosa L.) is a shrubby plant species recalcitrant to vegetative propagation and generally difficult to propagate by seeds. This is due to the difficulties associated with seed germination, root induction from stem cuttings, and plant hardening. Propagation by tissue culture would be a good alternative and promising approach to overcome the limitations of conventional propagation. Tissue culture methods can be used for the clonal propagation of caper plants. Indeed, in many plant species, micropropagation has played a decisive role in the rapid and large-scale production of uniform and genetically stable plants. Tissue culture methods can also be used in genetic improvement and conservation programs. In this review, we first provided an overview on caper and its conventional means of propagation, then we described the different methods of caper micropropagation, i.e., in vitro seed germination and seedling development, propagation by nodal segmentation of elongated shoots (i.e., microcuttings), and adventitious organogenesis. These micropropagation methods can make it possible to overcome all the obstacles preventing large-scale propagation and genetic improvement of caper. Thus, the most updated information on the progress made in the field of caper micropropagation is reported and future perspectives are outlined. Full article
(This article belongs to the Special Issue In Vitro Technology and Micropropagated Plants)
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Article
Optimum Discrimination on the Subsection Taxonomy of Wild Tree Peony Species in China Using Pollen Characteristics
Horticulturae 2022, 8(8), 736; https://doi.org/10.3390/horticulturae8080736 - 16 Aug 2022
Viewed by 281
Abstract
Pollen characteristics have some significance for plant taxonomy classification. We intend to explore a more concise index value for the subsection taxonomy with the pollen morphology and pollen viability determined from all nine wild tree peony species, including 18 populations native to China. [...] Read more.
Pollen characteristics have some significance for plant taxonomy classification. We intend to explore a more concise index value for the subsection taxonomy with the pollen morphology and pollen viability determined from all nine wild tree peony species, including 18 populations native to China. We observed the pollen morphologic characters by scanning electron microscopy and measured the pollen viability in vitro. The results showed that the pollen polar length is the decisive characteristic in distinguishing the two subsections in section Moutan belonging to Paeoniaceae. The pollen polar length of five species belonging to subsect. Vaginatae is longer than 43 μm, while that of the four species belonging to subsect. Delavayanae is shorter than 43 μm. Meanwhile, the differences in pollen viability between the two subsections also play an auxiliary role in the classification of tree peony. The germination rate of the populations in subsect. Vaginatae is mostly greater than those of the populations in subsect. Delavayanae. The pollen germination rate of populations in subsect. Vaginatae is commonly more than 50%, while that of populations in subsect. Delavayanae less than 50%. Our study established taxonomic evidence between subsections in section Moutan and compared the pollen viability of subsect. Vaginatae and subsect. Delavayanae. Full article
(This article belongs to the Section Propagation and Seeds)
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Article
Efficient Editing of SoCSLD2 by CRISPR/Cas9 Affects Morphogenesis of Root Hair in Spinach
Horticulturae 2022, 8(8), 735; https://doi.org/10.3390/horticulturae8080735 - 16 Aug 2022
Viewed by 330
Abstract
CRISPR/Cas9 is a valuable tool and has been extensively employed to perform gene editing in plants. However, CRISPR/Cas9 has not been successfully used in spinach, an important leafy vegetable crop. Here, we established a CRISPR/Cas9-based gene-editing system for spinach hairy roots and edited [...] Read more.
CRISPR/Cas9 is a valuable tool and has been extensively employed to perform gene editing in plants. However, CRISPR/Cas9 has not been successfully used in spinach, an important leafy vegetable crop. Here, we established a CRISPR/Cas9-based gene-editing system for spinach hairy roots and edited two cellulose synthase-like D (CSLD) genes (SoCSLD2 and SoCSLD3) that were involved in root-hair formation of spinach hairy roots. Four mutation types (i.e., replacement, insertion, deletion, and combined mutations) were observed, among which the replacement accounted for the vast majority (about 64.1%). Mutation rate differed largely among different targets. Seven homozygous/bi-allelic and eight heterozygous/chimeric mutants of SoCSLD2 were obtained from 15 independent transgenic hairy root lines. All of the seven homozygous/bi-allelic mutant lines displayed bulking and short root hairs, which resembled the characteristics of Arabidopsis atcsld2 mutants. The transcriptomic analysis further revealed that multiple gene expressions for cell-wall modulation and membrane trafficking were disturbed, which might result in the inhibition of root hair growth in socsld2 mutants. This indicates that SoCSLD2 was successfully knocked out in spinach root hairs using the CRISPR/Cas9-based gene editing system. Full article
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Article
Metabolite Analysis of Lettuce in Response to Sulfur Nutrition
Horticulturae 2022, 8(8), 734; https://doi.org/10.3390/horticulturae8080734 - 16 Aug 2022
Viewed by 303
Abstract
Sulfur is an essential nutrient required for plant growth and metabolism, and plays an important role in relieving stress. Nutrient deficiency is one of the main factors that negatively affect crop growth, quality, and yield. This study aimed to evaluate the effect of [...] Read more.
Sulfur is an essential nutrient required for plant growth and metabolism, and plays an important role in relieving stress. Nutrient deficiency is one of the main factors that negatively affect crop growth, quality, and yield. This study aimed to evaluate the effect of sulfur nutrients on the growth and metabolites of lettuce after treatment with two different sulfur concentrations (16 μM and 2 mM) in spray hydroponics. The fresh weight, chlorophyll, and carotenoid content of lettuce leaves were analyzed. Root morphology was examined using the WinRHIZO program. Metabolites were comparatively evaluated with the help of LC-MS and GC-MS. The fresh weight, chlorophyll, and carotenoid contents of lettuce were higher in the high concentration sulfur treatment group than in the low concentration sulfur treatment group. In the characteristics analysis of the lettuce roots, treatment with a high concentration of sulfur had a more positive effect on the lettuce root development than treatment with a low concentration of sulfur. Moreover, mass-based metabolomics analysis showed that the lettuce metabolites content was significantly different according to low- and high-concentration sulfur treatments. Therefore, this study highlights the importance of sulfur nutrient content in lettuce growth and metabolites. Full article
(This article belongs to the Topic Plants Nutrients)
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Article
Bark Inclusions in Canes of Southern Highbush Blueberry and Their Impact on Cane Union Strength and Association with Botryosphaeria Stem Blight
Horticulturae 2022, 8(8), 733; https://doi.org/10.3390/horticulturae8080733 - 15 Aug 2022
Viewed by 289
Abstract
Bark inclusions are an understudied structural defect in trees and shrubs. They consist of areas of bark on adjacent parts of stems or scaffolds, typically on the inner faces of a narrow fork, which become overgrown and internalized to occupy part of the [...] Read more.
Bark inclusions are an understudied structural defect in trees and shrubs. They consist of areas of bark on adjacent parts of stems or scaffolds, typically on the inner faces of a narrow fork, which become overgrown and internalized to occupy part of the wood between the stems. Here, bark inclusions are described for the first time to occur in cane unions at the crown of southern highbush blueberry (Vaccinium corymbosum interspecific hybrids) cultivars ‘Farthing’ and ‘Meadowlark’, both of which are characterized by a narrow, vase-shaped architecture at the base of the plant, leading to crowding of the canes. When affected canes were dissected at their bases, bark inclusions were visible internally as a line of compressed bark within the wood of adjoining canes, or as bark invaginations and fissures across part of or the entire cross-section of the cane. Externally, blueberry crowns with included bark were characterized by either an inward ridgeline of bark between canes of similar diameters emerging from the crown at a narrow angle from each other, or by the presence of girdling roots. Bark inclusions were observed in plants of all ages, from the nursery to mature production fields. The internal length of the bark inclusion correlated strongly with the external length of the inward stem bark ridgeline symptom as measured by destructive sampling in the field (r = 0.916, p < 0.0001, n = 20). When plants with and without bark inclusions were subjected to a winch test in the field, the probability of breakage for canes without included bark was significantly lower (p < 0.0002) than for those with included bark, and at the maximum applied force of 972.4 N, 95.2% of the canes with bark inclusions failed (i.e., broke at the crown), compared with only 52.6% for canes without included bark. In a survey across three fields, the number of bark inclusions per plant was significantly associated with an index of cane crowding (r = 0.286. p = 0.0267, n = 60), suggesting that plants with tight, crowded bases had more bark inclusions. In addition, there was a significant association (p < 0.0001) between the presence or length of bark inclusions and the intensity of Botryosphaeria stem blight in these fields. This study showed that bark inclusions occur commonly in certain southern highbush blueberry cultivars in the production conditions of Georgia and Florida, with negative implications for cane integrity and plant health. Full article
(This article belongs to the Section Biotic and Abiotic Stress)
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Article
Genome-Wide Identification and Expression Analysis of Eggplant DIR Gene Family in Response to Biotic and Abiotic Stresses
Horticulturae 2022, 8(8), 732; https://doi.org/10.3390/horticulturae8080732 - 14 Aug 2022
Viewed by 466
Abstract
Dirigent proteins (DIR) play important roles in the biosynthesis of lignins and lignans, defensive responses, secondary metabolism, and disease resistance in plants. The DIR gene family has been identified and studied in many plants. However, the identification of DIR gene family [...] Read more.
Dirigent proteins (DIR) play important roles in the biosynthesis of lignins and lignans, defensive responses, secondary metabolism, and disease resistance in plants. The DIR gene family has been identified and studied in many plants. However, the identification of DIR gene family in eggplant has not been conducted yet. Therefore, in this study, based on the available genome information of eggplant, the DIR family genes in eggplant were identified with bioinformatics methods. The expression pattern analyses of eggplant DIR family genes in different organs and stresses were also conducted to understand their biological functions. The results showed that a total of 24 DIR genes were identified in the eggplant, which were divided into three subfamilies (DIR-a, DIR-b/d, and DIR-e). Synteny analysis of DIR genes among eggplant, Arabidopsis, and rice showed that 15 eggplant DIR genes were colinear with 18 Arabidopsis DIR genes, and 16 eggplant DIR genes were colinear with 15 rice DIR genes. Phylogenetic tree analysis showed that 19 pairs of orthologous genes were identified between eggplant and pepper. The cis-acting elements analysis implied that the eggplant DIR genes contained a lot of cis-elements associated with stress and hormone response. The organ-specific expression analysis of eggplant DIR family genes revealed that only the SmDIR3 gene was highly expressed in all the 19 organs of eggplant. Some SmDIR genes, including SmDIR7, SmDIR8, SmDIR11, SmDIR14, SmDIR18, SmDIR19, SmDIR20, and SmDIR23, were not or were lowly expressed in the eggplant organs, while the other eggplant DIR family genes showed an organ-specific expression pattern. Furthermore, 19 of 24 SmDIR genes were differentially expressed in response to abiotic and biotic stresses. 5 SmDIR genes, including SmDIR3, SmDIR5, SmDIR6, SmDIR12, and SmDIR22, were differentially expressed under multiple types of abiotic and biotic stresses. Especially notable, the SmDIR22 gene was differentially expressed under three types of abiotic stresses and two types of biotic stresses, which indicated that the SmDIR22 gene plays an important role in the response to abiotic and biotic stresses. These results provide valuable evidence for a better understanding of the biological role of DIR genes in eggplant. Full article
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Review
Emerging Technologies for Prolonging Fresh-Cut Fruits’ Quality and Safety during Storage
Horticulturae 2022, 8(8), 731; https://doi.org/10.3390/horticulturae8080731 - 14 Aug 2022
Viewed by 451
Abstract
Fresh-cut fruits have been in great demand by consumers owing to the convenience of buying them in shopping centers as ready-to-eat products, and various advantages, such as the fact that they are healthy and fresh products. However, their shelf lives are brief due [...] Read more.
Fresh-cut fruits have been in great demand by consumers owing to the convenience of buying them in shopping centers as ready-to-eat products, and various advantages, such as the fact that they are healthy and fresh products. However, their shelf lives are brief due to their physiological changes and maturation. Therefore, this review includes information from the physicochemical, microbiological, nutritional, and sensory points of view on the deterioration mechanisms of fresh-cut fruits. In addition, updated information is presented on the different emerging technologies, such as active packaging (edible films, coatings, and modified atmospheres), natural preservatives (antioxidants and antimicrobials), and physical treatments (high hydrostatic pressure, UV-C radiation, and ozone). The benefits and disadvantages of each of these technologies and the ease of their applications are discussed. Having alternatives to preserve fresh-cut fruit is essential both for the consumer and the merchant, since the consumer could then obtain a high-quality product maintaining all its properties without causing any damage, and the merchant would receive economic benefits by having more time to sell the product. Full article
(This article belongs to the Special Issue Fruits Quality and Sensory Analysis)
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Article
Effect of a Radical Mutation in Plastidic Starch Phosphorylase PHO1a on Potato Growth and Cold Stress Response
Horticulturae 2022, 8(8), 730; https://doi.org/10.3390/horticulturae8080730 - 14 Aug 2022
Viewed by 376
Abstract
The plant response to stresses includes changes in starch metabolism regulated by a complex catalytic network, in which plastidic starch phosphorylase PHO1a is one of the key players. In this study, we used the CRISPR-Cas9 system to edit the PHO1a gene in four [...] Read more.
The plant response to stresses includes changes in starch metabolism regulated by a complex catalytic network, in which plastidic starch phosphorylase PHO1a is one of the key players. In this study, we used the CRISPR-Cas9 system to edit the PHO1a gene in four potato (Solanum tuberosum L.) cultivars, which resulted in the introduction of a radical mutation, G261V, into the PHO1a functional domain. The mutants had altered morphology and differed from wild-type plants in starch content in the roots and leaves. Exposure to cold stress revealed the differential response of parental and transgenic plants in terms of starch content and the expression of genes coding for β-amylases, amylase inhibitors, and stress-responsive MADS-domain transcription factors. These results suggest that the G261V mutation causes changes in the functional activity of PHO1a, which in turn affect the coordinated operation of starch catabolism enzymes both under normal and cold stress conditions, possibly through differential expression of MADS-domain transcription factors. Our results highlight a critical regulatory role of PHO1a in starch metabolism, root and shoot development, and stress response in potatoes. Full article
(This article belongs to the Special Issue Horticultural Plants Pathology and Advances in Disease Management)
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Article
In Search of Antifungals from the Plant World: The Potential of Saponins and Brassica Species against Verticillium dahliae Kleb.
Horticulturae 2022, 8(8), 729; https://doi.org/10.3390/horticulturae8080729 - 14 Aug 2022
Viewed by 336
Abstract
Control methods alternative to synthetic pesticides are among the priorities for both organic and conventional farming systems. Plants are potential sources of compounds with antimicrobial properties. In this study, the antifungal potentialities of saponins derived from Medicago species and oat grains and of [...] Read more.
Control methods alternative to synthetic pesticides are among the priorities for both organic and conventional farming systems. Plants are potential sources of compounds with antimicrobial properties. In this study, the antifungal potentialities of saponins derived from Medicago species and oat grains and of brassica sprouts have been explored for the control of Verticillium dahliae, a widely distributed fungal pathogen that causes vascular wilt disease on over 200 plant species. All the tested plant extracts showed antifungal properties. Such compounds, able to reduce mycelium growth and conidia formation, deserve deeper in vivo evaluation, even in combination with a delivery system. Full article
(This article belongs to the Special Issue Sustainable Control Strategies of Plant Pathogens in Horticulture)
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Article
Effects of Plasticulture and Conservation Tillage on Nematode Assemblage and Their Relationships with Nitrous Oxide Emission following a Winter Cover Cropping and Vegetable Production System
Horticulturae 2022, 8(8), 728; https://doi.org/10.3390/horticulturae8080728 - 14 Aug 2022
Viewed by 318
Abstract
Agriculture production emits significant amounts of nitrous oxide (N2O), a greenhouse gas with high global warming potential. The objectives of this study were to examine whether different husbandry practices (tillage and plasticulture) following winter cover cropping would influence soil food web [...] Read more.
Agriculture production emits significant amounts of nitrous oxide (N2O), a greenhouse gas with high global warming potential. The objectives of this study were to examine whether different husbandry practices (tillage and plasticulture) following winter cover cropping would influence soil food web structure and whether a change in the soil community could help mitigate N2O emission in vegetable plantings. Three consecutive field trials were conducted. A winter cover crop mix of forage radish (Raphanus sativus), crimson clover (Trifolium incarnatum) and cereal rye (Secale cereale) were planted in all plots. Winter cover crop was terminated by flail mowing followed by (1) conventional till without surface residues [Bare Ground (BG)], (2) conventional till with black plastic mulch (BP) without surface residues, (3) strip-till (ST) with partial surface residues, or (4) no-till (NT) with surface residues. The cash crop planted subsequently were eggplant (Solanum melongena) in 2012 and 2014 and sweet corn (Zea mays) in 2013. The soil food web structure was consistently disturbed in the BP compared to other treatments as indicated by a reduction in the abundance of predatory nematodes in 2012 and 2014, and nematode maturity index in 2013 in BP. Changes in soil food web structure in the conservation tillage (NT or ST) treatments based on the weight abundance of nematode community analysis were not consistent and did not improve over the 3-year study; but were consistently improved based on functional metabolic footprint calculation at termination of cover crops of 2013 and 2014. None-the-less, the N2O emissions increased as the abundance of fungivorous nematodes increased during all three trials. It was also found that improved soil food web structure [higher abundance of omnivorous in 2012 or predatory nematodes in 2013 and 2014, and structure index (SI) in all 3 years] reduced N2O emissions. These findings suggested that proper soil husbandry practices following winter cover cropping could mitigate N2O emissions over time. Full article
(This article belongs to the Special Issue Advancements in Soil Health)
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Article
Balance of Carotenoid Synthesis and Degradation Contributes to the Color Difference between Chinese Narcissus and Its Yellow-Tepal Mutant
Horticulturae 2022, 8(8), 727; https://doi.org/10.3390/horticulturae8080727 - 12 Aug 2022
Viewed by 326
Abstract
Chinese narcissus (Narcissus tazetta var. chinensis) was introduced to China 1300–1400 years ago, and has grown naturally in southeastern China. It is a popular Chinese traditional potted flower and a well-known flowering bulb cultivated worldwide with only two white-tepal triploid cultivars, [...] Read more.
Chinese narcissus (Narcissus tazetta var. chinensis) was introduced to China 1300–1400 years ago, and has grown naturally in southeastern China. It is a popular Chinese traditional potted flower and a well-known flowering bulb cultivated worldwide with only two white-tepal triploid cultivars, ‘Jinzhan Yintai’ and ‘Yulinglong’. Recently, a mutant with yellow tepals was observed and promptly became popular. To clarify the key pigment for color difference and its molecular mechanism of accumulation, we conducted pigment metabolite analysis and comparative transcriptome analysis on ‘Jinzhan Yintai’ and the yellow-flowered mutant. The results showed that there was no significant difference in total flavonoid content between the mutant and ‘Jinzhan Yintai’, whereas the total carotenoid content of the mutant was more than 10-fold higher than that of ‘Jinzhan Yintai’. Based on the RNA-sequencing results, sixty-four unigenes, corresponding to 29 enzymes associated with the carotenoid biosynthesis pathway, were analyzed in detail. A comparative KEGG pathway enrichment analysis, in conjunction with quantitative real-time PCR data, revealed the opposite gene expression mode of the carotenoid biosynthesis pathway. Compared with ‘Jinzhan Yintai ’, PSY and PDS were up-regulated in the three mid-flowering stages of the mutant, whereas NCED genes were strongly down-regulated, which likely contributed to carotenoid accumulation in chromoplasts of the tepals in the mutant. Full article
(This article belongs to the Section Floriculture, Nursery and Landscape, and Turf)
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Editorial
Postharvest Handling of Horticultural Products
Horticulturae 2022, 8(8), 726; https://doi.org/10.3390/horticulturae8080726 - 12 Aug 2022
Viewed by 296
Abstract
Fruit and vegetables are in a live state after harvest [...] Full article
(This article belongs to the Special Issue Postharvest Handling of Horticultural Crops)
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