Horticulturae, Volume 10, Issue 3 (March 2024) – 110 articles

The total land used for land-based food farms is less than 1% in Singapore. As a result, more than 90% of Singapore’s food needs are imported. To strengthen food security, Singapore has set a target to develop the capability and capacity of the agri-food industry to locally produce 30% of its nutritional needs by 2030. To achieve this goal, technology is the key to helping farms to “grow more with less”. This review first discusses how aeroponic systems have been adapted for growing all kinds of leafy vegetables in the tropics through the manipulation of root-zone temperature and heat priming to save power energy. Growing vegetable crops indoors and in greenhouses not only allows the growers to achieve high productivity but also enables them to enhance nutritional values. The second part of this paper emphasizes how to achieve substantial yield through deficit irrigation with higher nutritional quality in a cost-effective manner. Growing crops vertically has become increasingly popular, as it increases land use. We establish a commercially viable LED-integrated aeroponic system to grow vegetables vertically. The last part of the paper discusses the impacts of LED spectral quality, quantity, and duration on vegetable production. Full article

Water is a limiting factor and to adopt the most appropriate agronomic strategy it is necessary to know the water status. The objective is (i) analysing of the influence of different agronomic treatments on canopy temperature in vineyards with a thermal camera on an unmanned aerial vehicle (UAV), (ii) analysing of the influence of different agronomic treatments on vineyard water potentials with a pressure chamber, (iii) advanced technical feasibility analysis of vineyard crop monitoring. The control treatment (T07) in cv. Grenache consisted of applying 30% of reference evapotranspiration (ET_o) with irrigation frequency every seven days and seven different treatments were proposed with different irrigation frequencies, pre-bud irrigation, and vine shoot distribution (T03, T15, T7A, T7V, T7P, T00, and T0P). As a result and in conclusion, the use of thermal cameras in UAVs and mid-day stem water potential allows differentiation between irrigated and unirrigated treatments, but no clear differences were shown between irrigation frequencies, pre-irrigation treatment, or vine shoot distribution. Comparing the thermal camera information in UAV and the stem water potential, certain patterns are identified with significant correlation values, the use of thermal cameras for the evaluation of plant water status is recommended, especially to obtain information in large areas. Full article

1-deoxy-D-xylulose-5-phosphate synthase (DXS) is a rate-limiting enzyme in terpene synthesis that can affect the accumulation of secondary metabolites in plants. In this study, three DXS gene family members were identified in the tomato genome-wide database. Using bioinformatics methods, we analyzed the gene structure, evolutionary affinities, and cis-acting elements of the SlDXS gene family members. Promoters of SlDXS genes contain plant hormone-responsive elements such as the CGTCA-motif, TGACG-motif, ABRE, TCA-element, TGA-element, ERE, CAT-box, and AACA-motif, which suggested that the SlDXS gene family may play an important role in hormone response. The RT-qPCR analysis showed that the tomato DXS2 gene was able to respond upon exposure to methyl jasmonate (MeJA). The construction of a virus-induced gene silencing (VIGS) vector for the SlDXS gene showed that the SlDXS2 gene was also able to respond to MeJA in silenced plants, but the induction level was lower relative to that of wild-type plants. The SlDXS1 gene is associated with the synthesis of photosynthetic pigments. This study provides a reference for the further elucidation of the DXS gene’s biological function in the terpenoid synthesis pathway in tomatoes. Full article

This study delves into the exploration of genetic diversity and phylogenetic relationships within Camellia reticulata cultivars, providing a vital reference for horticultural research on this hetero-hexaploid species. Utilizing available transcriptome data from C. reticulata, novel low-copy nuclear gene sequences were successfully identified. With tailored primer design, these genes were amplified and sequenced from 100 C. reticulata cultivars originating from Kunming, Chuxiong, Dali, and Tengchong in China. Five distinct low-copy nuclear gene sequences were found to collectively span 3481 bp, showcasing 71 polymorphic mutation sites (P_i = 0.0077) and 91 haplotypes (H_d = 0.9974). The genetic diversity among cultivars from the four provenances ranked Tengchong > Dali > Kunming > Chuxiong. AMOVA analysis revealed that 96.50% of the genetic variation exists within the provenances. Low genetic distance and differentiation (F_st= 0.0199) were observed among cultivars from the four provenances. Ninety-nine cultivars were clustered into four clades, corresponding to the three ancestors of C. reticulata (diploid C. reticulata, C. pitardii, and C. saluenensis). The novel low-copy nuclear gene sequence markers developed in this study provide an effective tool for analyzing genetic diversity, phylogenetic relationships, and origination of C. reticulata cultivars. Full article

To detect the moisture of dried Goji (Lycium barbarum L.) berries nondestructively, a near-infrared (NIR) hyperspectral imager was used for experiments. NIR hyperspectral data were obtained and processed by standard normal variate (SNV) calculation using the MATLAB software v.R2016a. On the basis of the actual moisture of dried Goji berries, the predicted moisture was obtained based on the partial least squares (PLS) algorithm and a prediction model for the moisture of dried goji berries was established. It was found that the moisture of dried Goji berries was responsive to the NIR hyperspectral imager. The established prediction model could accurately predict the moisture of dried goji berries, and its R²-value was 0.9981. The results provide a theoretical basis for the design of non-destructive moisture-detecting equipment for dried Goji berries. Full article

Spatially enabled yield forecasting is a key component of farm Management Information Systems (MISs) for broadacre grain production, enabling management decisions such as variable rate fertilization. However, such a capability has been lacking for soft (fleshy)-tree-fruit harvest load, with relevant tools for automated assessment having been developed only recently. Such tools include improved estimates of the heat units required for fruit maturation and in-field machine vision for flower and fruit count and fruit sizing. Feedback on the need for and issues in forecasting were documented. A mango ‘harvest forecast engine’ was designed for the forecasting of harvest timing and fruit load, to aid harvest management. Inputs include 15 min interval temperature data per orchard block, weekly manual or machine-vision-derived estimates of flowering, and preharvest manual or machine-vision-derived estimates of fruit load on an orchard block level across the farm. Outputs include predicted optimal harvest time and fruit load, on a per block and per week basis, to inform harvest scheduling. Use cases are provided, including forecast of the order of harvest of blocks within the orchard, management of harvest windows to match harvesting resources such as staff availability, and within block spatial allocation of resources, such as adequate placement of harvest field bin and frost fans. Design requirements for an effective harvest MIS software artefact incorporating the forecast engine are documented, including an integrated database supporting spatial query, data analysis, processing and mapping, an integrated geospatial database for managing of large spatial–temporal datasets, and use of dynamic web map services to enable rapid visualization of large datasets. Full article

The tree crown volume (CV), as a major indicator in the evaluation of ecological environment quality, can assess the health and carbon sequestration of urban trees. In this study, a new low-cost method, the plane calculation of angle disparity (PCAD), was employed to obtain the CV in China using satellite images from Google Earth. Meanwhile, primary data on street trees from four Western cities were acquired from online datasets. Nonparametric statistical methods showed no significant difference in CV per street tree between Beijing and Shanghai in China, ranging from 10 to 150 m³, almost one-seventh of that in the four cities (Paris and London in Europe and Los Angeles and Seattle in America). The CV of Platanus acerifolia in Paris and London exhibited values five times higher than those in Beijing and Shanghai. The annual crown volume increment (CVI) was less than 5 m³ in Beijing and Shanghai, significantly lower than in Seattle (66.55 m³). The purpose of the research was to verify the operability of the PCAD and compare the CVI in different cities all over the world, providing new ideas for urban tree management and carbon sequestration evaluation and a basis for government decision making in areas with a low CVI. Full article

Bactrocera dorsalis (Hendel) (B. dorsalis) is an important agricultural invasive pest that causes significant economic losses in tropical and subtropical fruit and vegetable crops. In this study, the proteins related to the sense of smell and taste of B. dorsalis, such as OBP, PBP, OR, IR, SNMP and CSP, were screened based on B. dorsalis transcriptome data. By integrating the compounds that were reported to be attractive to B. dorsalis, similar compounds of hydrocarbon compounds were obtained. Molecular docking was used to predict the binding between the similar compounds and the OBP, PBP, OR, IR, SNMP and CSP proteins. Network pharmacology was used to screen the potentially attractive compounds, and ecological experiments with B. dorsalis were finally conducted to verify the effect of these potentially attractive compounds on B. dorsalis. The results showed that the G protein-coupled receptor [BR: KO04030] and ion channel [BR: KO04040] pathways were closely related to the odor tropism of B. dorsalis. A total of 84 compounds, such as mitemcinal, exemestane and midecamycin, have potential binding effects on the B. dorsalis odor receptor proteins. The results of the ecological experiments showed that 1 mg/mL and 0.1 mg/mL 19-norandrostenedione, 1 mg/mL progesterone compounds was significantly attractive to B. dorsalis males, while 0.1 mg/mL exemestane was significantly attractive to B. dorsalis females. In this study, network pharmacology technology was used to discover the potential attractive compounds for B. dorsalis, which is important for the development and subsequent prevention and control of B. dorsalis. It can provide a reference in improving the success rates of clinical trials of new pest control products and in reducing the time and cost of drug development. Full article

The change in the quality of rambutan (Nephelium lappaceum L.) fruit after harvest is mainly dehydration. Rambutan fruit peel is often dark (brown) and fruit rot due to fungal disease. This study investigated the effects of Lactobacillus bacteria strains [Lactobacillus plantarum CC6 (CC6), Lactobacillus fermentum DC2 (DC2), Lactobacillus fermentum DGMC2 (DGMC2)] with/without supplement combinations [chitosan 0.03% (Chito), alginate 0.03% (SA) and carboxymethyl cellulose 0.5% (CMC)] on the quality of Java rambutan fruit during storage at 13 °C, and included a sample without treatment with bacteria and chemical considered as the control. The results showed that among 16 treatments on rambutan fruits immediately after harvesting, the four treatments that showed the best results were CC6-Chito, DC2-Chito, CC6-CMC and DC2–SA, and DC2-Chito was more effective than the others. However, all four of these treatments supported the preservation of rambutan fruit, reducing both weight loss and browning of the skin and stem, and kept the infection rate at the lowest level. The brightness and peel color values were highest for these treatments. Full article

Sweet clover (Melilotus albus) is a high-quality leguminous forage grass with salinity tolerance, drought tolerance, and cold hardiness. We selected four varieties of sweet clover with different sensitivities (061898, 061930, No. 55 white flower, and Ningxia white flower) and analyzed the effects of different concentrations of three sodium salts (Na₂CO₃, NaHCO₃, and NaCl) on their physiology and biochemistry responses. Growth and development indexes (such as germination rate, root length, shoot length), chlorophyll content, osmotic regulators (proline, soluble sugar), malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were determined under saline–alkali stress. Seed germination and seedling growth of all four clover species were significantly inhibited under saline–alkali stress. During germination, seed germination rate, root length, and shoot length decreased with increasing saline and alkaline concentration. Under saline–alkali stress, chlorophyll content tended to increase and then decrease, cell damage and death increased, and malondialdehyde, soluble sugar, and proline content tended to increase and then decrease. Moreover, the activities of SOD, POD, and CAT all increased and then decreased. Under Na₂CO₃ stress, the decrease in chlorophyll content of the resistant variety 061898 was less than in the sensitive Ningxia white flower variety. As the concentrations of Na₂CO₃, NaHCO₃, and NaCl increased, the maximum photochemical efficiency of PSII was significantly affected. The resistant 061898 is capable of maintaining higher photosynthetic efficiency. Furthermore, under treatments with the three kinds of saline–alkali solutions, cell damage and death for Ningxia white flower were greater than in 061898. For 061898, the increases in soluble sugar and proline content were greater and the increase in malondialdehyde content was less, while the antioxidant enzyme activities were higher than those in Ningxia white flower. All four sweet clover varieties had higher stress resistance with neutral than with alkaline salts. When stressed by medium to high saline–alkali concentrations, sweet clover seedlings had increased osmotic substance content, enhanced antioxidant enzyme activity, and regulated physiological metabolism. Additionally, sweet clovers regulated the expression of WRKY33, GH3, CYCD3, OXI1, MKK2, MYC2, JAZ, COI1, PYL, PP2C, TGA, and MPK3 to adapt to the saline–alkali environment and improve saline–alkali tolerance. Our analysis of the sweet clover salinity tolerance mechanism contributes to its further use and is of significant importance for addressing land salinization and promoting sustainable agricultural and pastoral practices in China. Full article

The aim of this study was to investigate the uptake of exogenously added indole-3-butyric acid (IBA) as an adventitious root (AR) inducer. The concentration of indole-3-butyric acid (IBA) in leafy cuttings of Prunus subhirtella ‘Autumnalis’ from stock material of different physiological ages was analyzed at three evaluation time points (1, 4, 24 h). We examined three stock plants: a physiologically mature stock plant (approximately 60 years old); physiologically rejuvenated plants (16 years old) that were previously propagated by cuttings from semi-mature stock material; and in vitro juvenile stock material. For IBA to effectively induce AR formation, it must first be converted into the active hormone indole-3-acetic acid (IAA). The total concentration of IAA in the first 24 h after cutting was evaluated according to the physiological age of the stock material and the IAA concentration in the cuttings according to the evaluation time points was assessed. We also examined rooting success and the quality of the adventitious root system depending on the physiological age of the stock material. High performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) was used to identify and quantify the phytohormones. The difference in rooting and quality of the developed AR was observed between semi-mature stock and mature stock material. Cuttings from semi-mature plants rooted in 95.00 ± 5.00% of cases, while cuttings from mature stock plants only rooted in 68.33 ± 4.09%. Successfully rooted cuttings from mature stock material were accompanied by callus formation, which was significantly lower in cuttings from semi-mature stock material. Our results show that the interaction between physiological age and time after severance had no effect on IBA concentration in the cuttings (p = 0.907). Duration of time elapsed since severing (evaluation time points) had a significant effect on the uptake of IBA (p = 0.002 **) and IAA (p = 0.0009 ***) in the cuttings. Physiological age had a significant effect on IAA concentration in the early stages of AR formation in the cuttings (p = 0.038 *). Our results suggest that the dynamics of other endogenous phytohormones and the physiological state of the stock plant are also important for AR formation, as the proportion of successfully rooted cuttings from semi-mature stock material was significantly higher than the proportion of successfully rooted cuttings from mature stock material, irrespective of IBA uptake in stock material of different ages. Full article

Salinity is a major social, economic, and environmental menace in climates with low rainfall and high evapotranspiration, and it influences plant growth and causes restriction to crop production in the world. Additionally, under salinity stress, numerous physiological processes such as photosynthesis, biomass accumulation, and photosynthate transfer are also harshly lessened, and it also limits the absorption of adequate water by plants and leads to a dimension in plant water status. Therefore, the current study was conducted to investigate the soil application of humic acid (HA) at 0, 0.5, 1 and 2 kg/tree alone or in combination with the foliar spraying of 0 mg ZnO₂ + 0 mg TiO₂, 200 mg ZnO₂ + 60 mg TiO₂ and/or 300 mg ZnO₂ + 80 mg TiO₂ through the two successive seasons 2022 and 2023. The results demonstrated that the use of HA alone or in combination with the spraying of TiO₂ and ZnO₂ greatly improved the leaf chlorophyll, flower number, fruit set percentages, fruit yields in kg or in ton per hectare, fruit weight, fruit size, and fruit firmness. Additionally, the same used treatments greatly improved the fruit content from TSS and oil percentages and also the leaf mineral content from N, P and K, while they minimized the fruit drop percentage and fruit moisture content as compared to control. The most positive influence was observed with the soil implementation of 2 kg HA combined with 300 mg ZnO₂ + 80 mg TiO₂ in the two experimental seasons. Full article

Phytoene desaturase (PDS) is a plant enzyme involved in carotenoid biosynthesis. The PDS gene has been used as a selective marker for genome editing in several plant species, including banana (Musa spp.). Its knockout promotes dwarfism and albinism, characteristics that are easily recognizable and highly favorable. In Musa spp., the A genome increases fruit production and quality, whereas the B genome is associated with tolerance to biotic and abiotic stresses. The objective of this study was to identify a molecular marker in the PDS gene to easily discriminate the A and B genomes of banana. A 2166 bp fragment for the “PDSMa” marker was identified as polymorphic for the A genome (identification accuracy of 99.33%), whereas ~332 and ~225 bp fragments were detected for the “PDSMb” marker with 100% accuracy using MedCalc software. In this study, we used genotypes with A and B genomes that are used in the genetic improvement of bananas and an accession with the BT genome. It was not possible to differentiate the accession with the BT genome from the others, suggesting that the markers do not have the capacity to separate the T genome from the A and B genomes. To the best of our knowledge, this is the first study to use the PDS gene to determine doses of the A genome and identify the B genome in Musa spp., which will aid in evaluating the genomic constitution of banana hybrids and accessions at the seedling stage and accelerating their classification in crop genetic improvement programs. Full article

Polyphenols play a crucial role in fruit flavor. To elucidate the mechanism of fruit polyphenol metabolism, we constructed a transcriptome atlas through PacBio single-molecule real-time (SMRT) sequencing and Illumina next-generation sequencing (NGS) using Canarium album (Lour.) Raeusch., which is a fantastic fruit rich in polyphenolic compounds. In this work, PacBio full-length transcriptome assembly generated 135,439 isoforms with an average length of all isoforms of 2687.94 bp and an N50 length of 3224 bp. To gain deeper insights into the molecular mechanisms of polyphenol biosynthesis in C. album, we constructed twelve RNA-Seq libraries from four developmental stages of the fruits. We identified a total of 28,658 differentially expressed genes (DEGs). We found that many DEGs were involved in metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, starch and sucrose metabolism, and plant hormone signal transduction. Here, we report the expression profiles of 215 DEGs encoding 27 enzymes involved in the polyphenol biosynthesis pathway in C. album. In addition, 285 differentially expressed transcription factors (TFs) continuously down-regulated in four developmental periods of C. album fruit, which may indicate their potential role in the response to polyphenol metabolism and phenylpropanoid biosynthesis pathways. This report will help us understand polyphenol biosynthesis’s functions and metabolic mechanism in C. album. The transcriptome data provide a valuable resource for genetic and genomics research. They will facilitate future work exploiting C. album and other fruits used as medicine and food. Full article

Potato biofortification is a comprehensive approach aimed at enhancing the nutritional content of potatoes, addressing widespread nutrient deficiencies and contributing to global food security. This systematic review examines the existing literature on various aspects of potato biofortification, encompassing genetic, agronomic, and biotechnological strategies. The review highlights the nutritional significance of potatoes, emphasizing their role as a staple food in many regions. Genetic approaches to biofortification involve the identification and use of natural variations in potato germplasm to develop varieties with elevated levels of essential nutrients. This includes targeting key micronutrients, such as iron, zinc, and vitamins, through traditional breeding methods. The review explores the genetic diversity within potato germplasm and the potential for breeding programs to develop nutrient-rich varieties. Agronomic practices play a crucial role in potato biofortification, with studies demonstrating the impact of tuber priming and the application of mineral fertilizers on nutrient concentrations in potatoes. The review delves into the intricacies of agronomic biofortification, emphasizing the importance of precise dosages and timing for optimal results. Biotechnological tools, including transgenic and non-transgenic approaches, are discussed in the context of potato biofortification. The review evaluates the efficiency and ethical considerations associated with the development of biofortified transgenic potatoes and emphasizes the significance of non-transgenic approaches in addressing consumer concerns and regulatory barriers. Overall, this systematic review provides a comprehensive overview of the current state of potato biofortification research. It synthesizes findings from diverse studies, offering insights into the potential of biofortified potatoes to address hidden hunger and contribute to improved nutritional outcomes. This review also identifies knowledge gaps and areas for future research, guiding the direction of efforts to harness the full potential of potato biofortification for global food and nutrition security. Full article

Pericarp colors are critical agronomic traits that affect the quality and economic values of fruits. Although a diversity of bitter melon pericarp (BMP) colors is available, the fruit pigmentation mechanisms remain elusive. Hence, this study aimed to unveil the key metabolites and molecular mechanisms underlying variation in BMP coloration through integrative metabolomics and transcriptomics analyses of four differently colored genotypes, including K1102 (grayish orange), 262 (grayish yellow), 1392 (very soft green), and K115 (dark grayish cyan). The four BMPs exhibited significant metabolite profile and transcriptional differences, as over 112 and 1865 DAMs (differentially accumulated metabolites) and DEGs (differentially expressed genes), respectively, were identified. The variation in the content of six anthocyanins, including malvidin 3-O-glucoside, petunidin 3-O-glucoside, rosinidin O-hexoside, cyanidin, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside, and pelargonidin 3-O-beta-D-glucoside, might be the major driving factor of BMP color changes. Notably, malvidin 3-O-glucoside, rosinidin O-hexoside, and petunidin 3-O-glucoside are the dominant pigments in K115, while carotenoids and other flavonoids may contribute to other colors. Candidate flavonoid structural and regulatory (MYBs, NACs, MADSs, bHLHs, and bZIPs) genes were identified. Of them, gene13201 (anthocyanin reductase), gene8173 (polyphenol oxidase), gene2136 (NAC43), gene19593 (NAC104), and gene15171 (tetrapyrrole-binding protein) might play essential roles in K115 pericarp color development. Our findings deepen our understanding of BMP pigmentation and provide fundamental resources for higher-valued bitter melon breeding perspectives. Full article

Nitrogen is a crucial element for the growth and development of plants, directly affecting crop growth and yield. To investigate the physiological and molecular mechanism of nitrogen-deficiency stress, we conducted an investigation into the effects of different nitrogen levels on the growth, photosynthetic characteristics, and gene transcription levels of banana seedlings. Compared with the control group with normal nitrogen levels (NN), the height of plants receiving Reduced-N (NR), Low-N (LN), and N-Free (NF) treatments was decreased by 0.45 cm, 2.5 cm, and 3.25 cm, respectively. Their dry weight was reduced by 1.63 g, 2.99 g, and 2.88 g, respectively. Conversely, the dry weight of the underground plant part in the LN and NF treatment groups exhibited an increase of 0.13 g and 0.16 g, respectively. Regarding photosynthetic characteristics, the Specialty Products Agricultural Division (SPAD) values of the NR, LN, and NF treatments showed reductions of 15.5%, 30.4%, and 35.9%, respectively, compared with those of the control treatments. The values of maximum photosynthetic efficiency (Fv/Fm), actual photosynthetic efficiency (Y(Ⅱ)), and relative electron transfer (ETR) of the banana seedlings decreased to different degrees after NR, LN, and NF treatment, and their values were positively correlated with N levels. Gene transcription analysis showed that N transport-related proteins, including NRT1.7, NRT2.3a, NRT2.3b, and NRT2.5, were significantly up-regulated to increase the nitrogen absorption capacity of plant roots. On the other hand, various transcription factors including GRAS, MYB, and WRKY were notably up-regulated, facilitating root growth and the expanding root absorption area, thereby enhancing nitrogen uptake. Furthermore, genes associated with endogenous hormone metabolic pathways such as gibberellin (GA), strigolactone (SL), and brassinosteroids (BR) were activated in banana plants subjected to low nitrogen stress, enhancing the plant’s ability to adapt to nitrogen-deficient conditions. These findings offer valuable insights into understanding the transcriptional regulatory mechanisms governing banana responses to low nitrogen stress and breeding new varieties with improved nutrient utilization. Full article

The spaceflight storage of seeds is known to cause mutations affecting both their quality and the mature plants originating from them. To study the effects of space stress, tomato seeds of two cultivars (Lotus and Autumn rhapsody) were subjected to half a year of storage at the International Space Station (ISS), and then, sown in a greenhouse to produce tomato fruits. The space-treated plants gave smaller fruits with a stable total yield not significantly different from that of the control plants. Space-treated tomatoes showed significantly higher levels of dry matter, dietary fiber, monosaccharides and citric and malic acids and lower values of oxalic acid compared to the control plants. The pulp of space-treated fruits had 1.44–1.70 times lower levels of carotenoids, while their peel contained a 1.27–1.90 times higher pigment amount compared to the control plants. No significant changes in the total antioxidant activity (AOA), photosynthetic pigments and phenolic (TP) and proline content were recorded in the fruits due to seed spaceflight storage. Contrarily, space-treated tomatoes showed decreased levels of Ca, Sr and Mo and increased Se both in the fruit pulp and peel. The concentration of Fe and especially Pb was lower in space-treated fruit pulp. Positive correlations between Se and dry matter, Ca and Sr, Ca and Co, Ca and Fe, and Cr and carotenoids, and negative correlations between Se and Mo, Se and K, and Mo and dry matter were recorded. The results indicate that seed stress caused by long-term spaceflight affects both the biochemical characteristics and mineral composition of tomato fruits and causes the peel/pulp redistribution of carotenoids as well as macro- and micro-elements, improving Se accumulation levels in the fruit peel. Full article

Plants of the Clematis genus are attractive ornamental plants due to their various flower colors and patterns, and they play an important role as ground cover plants in landscaping. However, the application of Clematis plants in landscaping in arid and semi-arid areas is limited. This study used five common wild Clematis species in Gansu Province as experimental materials, including Clematistangutica, Clematis glauca, Clematis intricata, Clematis nannophylla, and Clematis fruticosa. By simulating different intensities of drought stress with polyethylene glycol (PEG), the germination behavior of seeds and the physiological and biochemical responses of seedlings of these five species to drought stress were observed. The results showed that 15% PEG stress significantly inhibited the seed germination of the five species, which was also the drought threshold for seed germination of C. fruticosa. C. tangutica exhibited the strongest tolerance to drought stress in seed germination. Seedlings of the five Clematis plants showed different levels of tolerance to drought stress, mainly demonstrating higher tolerance to 10% and 20% concentrations of PEG stress, while a 30% concentration of PEG stress caused varying degrees of damage to the seedlings of the five Clematis species. PCA analysis indicated that seedlings of C. intricata and C. glauca had higher scores under drought stress. These findings can provide a theoretical basis for the selection of urban landscaping plant species in arid and semi-arid regions of northwest China. Full article

Heat shock proteins (HSPs) play important roles in plant stress resistance, but it is not clear whether small molecular HSPs (sHSPs) are involved in the cold stress resistance of lily flowers. In this study, we cloned LbHSP17.9 and found that its expression was up-regulated under cold stress. When LbHSP17.9 was silenced (TRV2::LbHSP17.9) using virus-induced gene silencing in cut lily flowers, the content of malondialdehyde was increased under 4 °C stress treatment. The catalase (CAT) activity in TRV2::LbHSP17.9 was significantly lower than in TRV2 in the first 7 days, and the peroxidase (POD) activity in TRV2::LbHSP17.9 was significantly lower than in TRV2 after 4 days of 4 °C stress. Further analysis showed that the transcription levels of LbCu/ZnSOD, LbMnSOD and LbCAT in TRV2::LbHSP17.9 were lower than those of TRV2 under 4 °C stress. When LbHSP17.9 was overexpressed in lily petal disks, the OE-LbHSP17.9 disks faded later than the controls at 4 °C and the relative conductivity decreased significantly. Overexpression of LbHSP17.9 in Arabidopsis thaliana resulted in fewer injury symptoms and lower MDA content than wild type under 4 °C stress. Therefore, we speculate that LbHSP17.9 can improve the resistance of lily flowers to cold stress. Full article

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, Eth’s inhibitory effects on tuber sprouting at room temperature were investigated. The potential molecular mechanisms of Eth-induced sprout suppression were revealed by phytohormone and transcriptome analyses. Results showed that exogenous Eth significantly suppressed sprout growth in potato tubers during two weeks of storage. The endogenous plant hormone levels of abscisic acid (ABA) and auxin (Aux) were markedly reduced by Eth treatment. Transcriptomic analysis revealed that more transcriptional changes occurred in the early stage of sprouting. The differentially expressed genes (DEGs) assigned to the pathways of plant hormone signal transduction, photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis, which were closely associated with sprouting, were extensively down-regulated by Eth treatment. In addition, the heat map of six hormone signal transduction pathways showed that the expression of most DEGs annotated into the Aux signal transduction pathway was suppressed by Eth treatment, while the expression of many DEGs annotated as ETR (Eth receptor) and ERF1/2 (Eth-responsive transcription factor 1 and 2) in the Eth signal transduction pathway was enhanced by Eth treatment. Taken together, our results indicated that Eth-induced sprout inhibition might be closely related to the suppression of internal Aux production and signal transduction and the activation of Eth signal transduction. Full article

Seed shape descriptions of species of Vitis have traditionally been based on adjectives comparing overall shape with geometric figures, such as oval, elongated oval, and pear-shaped, corresponding to higher values of the Stummer index (lower aspect ratio) for oval, and lower values of the Stummer index for pear shape (or elongated seeds, with a higher aspect ratio). Analytical, quantitative descriptions of shape have recently been applied to diverse genera of Vitaceae and cultivated varieties of Vitis. Here, we present the application of three quantitative methods to the seed shape description of ten species of the genus Vitis and three species of related genera (Ampelopsis, Cissus and Parthenocissus). First, general seed shape was described through comparisons using geometric models. For this, the average silhouettes of representative seed populations were used as models for shape quantification. Two additional quantitative methods were based on the measurement of bilateral symmetry and curvature analysis in the apex. Quantitative methods for shape description based on similarity with the models give an accurate account of the relationships between Vitis species. The resulting dendrogram is like the dendrogram obtained from a combined analysis using the data from general measurements and curvature and symmetry analyses. The original methods presented here for seed morphology are useful for analyzing the phylogenetic relationships between species of Vitis. Full article

This comprehensive review scrutinizes tissue culture and micropropagation methodologies in geophytes, focusing on bulbous plants. The examination encompasses key stages, including somatic embryogenesis, bulb growth, dormancy breaking, and planting. Studies underscore the pivotal role of plant growth regulators (PGRs) in plant regeneration and bulb growth. Bioreactor systems for healthy plant regeneration, rooting methods, acclimatization strategies, and considerations for ex vitro survival are elucidated. The review also delves into somaclonal variation dynamics and acknowledges the burgeoning field of gene editing, particularly Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) studies, as a promising avenue for enhancing valuable compound content in geophytes. In addition to addressing challenges in flower bulb micropropagation, this review briefly highlights emerging opportunities, including the potential integration of artificial intelligence (AI) to optimize culture conditions, predict growth parameters, and enhance efficiency in bulb production. The conclusion emphasizes the necessity of a multifaceted approach integrating biochemistry, physiology, and molecular biology to address existing challenges and improve tissue culture protocols for diverse geophyte species. This review article also intends to highlight how tissue culture techniques could contribute to the development and valorization of flower bulbs in today’s scenario of the ornamental industry. Full article

Plants’ genetic improvement continues to be crucial for modern agriculture, while biotechnology can offer efficient tools that enhance the selection and recommendation processes of elite clones. This work established a suitable methodology for the regeneration of blueberry (Vaccinium corymbsum) plants in cultures with colchicine. This could be considered a basis for producing populations for the selection of clones following a genetic improvement program assisted by biotechnology. The factors studied were: (a) explant type (leaf discs; nodal segments); (b) colchicine concentration (0, 0.5, 1, and 2 mg/L); and (c) time of exposure to colchicine (1, 2, 3, 5, and 30 days). The basal medium McCown’s Woody Plant (WP) supplemented with 2 mg/L 2iP and 1 mg/L BAP was used with the commercial genotype Duke as a model. A total of 1957 blueberry clones were produced in a medium with 1 mg/L colchicine, distributed at different exposure times. Flow cytometry analyses revealed the following patterns: single patterns for random samples of control plants (Duke donor) and some clones regenerated on colchicine; double patterns for chlorotic plants regenerated on colchicine. Triple and quadruple patterns were observed in callus tissues that did not regenerate plants on colchicine. Populations of plants regenerated in colchicine (6787) and control plants regenerated in in vitro culture without colchicine were adapted under greenhouse conditions. The variables evaluated at this stage were adaptability, height, diameter, number of leaves, incidence of diseases, flowering capacity, and agrobotanical traits. Selected clones demonstrating phenotypic variability (157 clones) were transplanted to field conditions. From the clonal field trial conducted under minimum tillage conditions, 38 clones were selected for improved traits related to the agricultural yield and nutritional quality of the fruits. Of these, six clones showed the highest agronomic performance and adaptability to adverse environmental conditions compared to the Duke donor genotype. It is recommended that these clones continue genotype × environment interaction trials at different locations. Full article

GATA transcription factors are widespread in plants, exerting crucial functions in multiple processes such as flower development, photoperiod regulation, and light signal transduction. The GATA gene family has a key role in the regulation of medicinal plant adaptation to environmental stress. However, since the publication of the Ginseng (Panax ginseng C.A. Meyer) genome-wide data, there has never been an analysis of the whole GATA gene family. To understand the function of the GATA gene family more broadly, the GATA gene family members in P. ginseng were predicted using an in silico bioinformatics approach. A comprehensive and systematic analysis encompassing chromosome scaffold, expression pattern, gene structure, and phylogeny was conducted. The results showed that a total of 52 GATA gene family members were recognized in P. ginseng, distributed across 51 scaffolds. Each member encoded a diverse number of amino acid residues, extending from 138 to 1064. Moreover, the expression levels of PgGATA genes were significantly altered by nitrogen (N) and phosphorus (P) stresses. The expression levels of PgGATA6, PgGATA11, PgGATA27, PgGATA32, PgGATA37, PgGATA39, PgGATA40, and PgGATA50 exhibited significant elevation under N deficiency, whereas PgGATA15, PgGATA18, PgGATA34, PgGATA38, PgGATA41, and PgGATA44 genes showed substantial upregulation under P deficiency. In addition, PgGATA3, PgGATA4, PgGATA14, PgGATA19, and PgGATA28 were substantially upregulated under both N and P deficiency. This research establishes a theoretical foundation for the thorough examination of the functions of the PgGATA gene family and its regulation by N and P fertilization during P. ginseng cultivation. Full article

Weeds are undesirable plants that can interfere with human activities and can hamper crop production and practices. The competition among ornamentals and weeds for space, nutrition, light, and moisture within a restricted area, such as in container production, can be intense and destructive. In response to increasing concerns regarding herbicide injuries and the effects of pesticide use on the environment, many growers are extremely interested in non-chemical pest-management approaches. There are various non-chemical strategies to control weeds in containers, which include scouting, sanitation practices, hand weeding, mulching, irrigation management, substrate stratification, mulch discs or geo discs, lid bags, and fertilizer placement. In a restricted growth environment, weeds have been shown to reduce crop growth significantly. Limited information is available on the effects of weed densities and container sizes on ornament–weed competition within containerized production and how the concepts of fertilizer placement can be used efficiently to control weeds in containers without using any herbicides on the ornamentals. There is an immediate need to evaluate the interference and competitive effects of pernicious weed species in container-grown ornamentals in the North Central United States and to develop effective non-chemical weed control strategies by altering fertilizer placement in container production. Full article

As peat (P) demand increases throughout the horticultural industry, alternative fibers must be evaluated. Sugarcane bagasse (B), wood fiber (W), and coconut coir (C) have received interest as domestically available alternatives to P, with demonstrated success in producing greenhouse crops. However, there is limited research comparing these materials to peat. This research evaluated the substrate properties and productivity of Petunia Supertunia Mini Vista ‘Indigo’ in pine bark substrates amended with C, W, B, or P and fertigated weekly at 100, 200, or 300 parts per million (ppm) nitrogen (N) to account for possible N immobilization. The container capacity was lowest and air-filled porosity was highest in W and B substrates. Substrate pH increased in W and B substrates, and C substrates were fertigated at 100 ppm N. Increasing the N rate increased the growth index in all substrates, especially B and W substrates later in the production period. Higher fertilization increased shoot mass, chlorophyll content, and blooms across all substrates, demonstrating that fertilizer supplementation may offset possible N immobilization. While plant growth and quality parameters were greatest in the P blend, increasing N applications produced similar-quality plants using alternative substrates, demonstrating that modifying fertilizer management practices can make alternative fibers a viable horticultural substrate. Full article

Cherry productivity is challenging in Europe due to the presence of the cherry fruit fly (Rhagoletis cerasi). Trunk injection is an alternative method of insecticide delivery that may improve pesticide performance in controlling pests. In our study, four pesticides (abamectin, acetamiprid, flupyradifurone, and cyantraniliprole) were investigated for trunk injection against R. cerasi. Acetamiprid trunk injection in a minimum dose of 0.56 g/tree was suitable for protection against the pest, the efficacy of the control was over 95%, and the pesticide residue concentrations in the fruits were below the maximum permissible limit in each experiment. The trunk injection and foliar spray of the same dose of acetamiprid were equally effective. In the case of the other three active ingredients (abamectin, flupyradifurone, and cyantraniliprole), the trunk injection method did not prove suitable for practical use due to various reasons, which are detailed in the manuscript. Full article

Strong winds, particularly in the absence of disaster-resistant designs, significantly impact the stability of greenhouse foundations and eventually lead to structural damage and potential harm to crops. As a countermeasure, rebar stakes are commonly used to reinforce the foundations of non-disaster-resistant greenhouses. This study evaluates the pull-out resistance (R_pull-out) of rebar stakes considering various factors like soil compaction, embedded length, installation duration and angle, and changes in soil water content against uplift pressure by strong winds. A combination of field (i.e., the cone penetration test and rebar stake pull-out test) and laboratory (i.e., the compaction test, soil compaction meter test, and soil box test) tests are performed for the assessment of R_pull-out. The results indicate that R_pull-out increases with higher soil compaction, greater embedded length, longer installation duration, and an inclined installation angle. The soil compaction exerts the most significant impact; 90% to 100% of the soil compaction rate has approximately 10 folds higher R_pull-out than the 60–70% compaction rate. If the embedded length is increased from 20 cm to 40 cm, there is a two-fold increase in the average of R_pull-out. Inclined installation of rebar stakes increases R_pull-out by 250% to 350% compared to vertical installation, and rebar stakes installed prior to the uplift event have 1.5 to 6.4 fold increases in R_pull-out than those with instant installation. Additionally, we observed variations in the surface soil moisture due to climatic changes introducing variability in R_pull-out. These findings lead to the proposition of efficient rebar stake installation methods, contributing to the enhanced stability of a greenhouse. Full article