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In many insect species including fruit flies (Diptera: Tephritidae), the behavioral responses to volatiles emitted by their host plants can be modulated by environmental conditions and by the physiological state of the insect. Here, we quantified (1) the effects of female age on the attraction of female melon fly, Zeugodacus cucurbitae (Diptera: Tephritidae) to volatiles emitted by intact and mechanically damaged tomato (Solanum lycopersicum), eggplant (S. melongena), zucchini (Cucurbita pepo), bitter melon (Momordica charantia), and cucumber (Cucumis sativus) fruit, and (2) the influence of time elapsed since fruit damage on the outcome. The investigations were conducted under semi-natural conditions in Hawai’i. Results from the first experiment revealed that, for freshly damaged tomato, eggplant, and zucchini, the level of female response was comparatively low and was not affected by female age. For bitter melon and cucumber, higher levels of response to freshly damaged fruit were documented, and the response levels gradually increased as female age increased from 1 to 4 weeks, reaching 70% for 4-week-old females exposed to cucumber odor. Results from our second experiment indicated that, on average, 56% of the females released responded in 20 min when cucumbers were freshly sliced, and the level of response was reduced 6-fold within a couple of hours. Females did not respond to tomato and cucumber odor when fruits were damaged >8 h before testing. Fruit volatiles involved in female Z. cucurbitae attraction seem to be released shortly upon mechanical damage and they are short-lived. The plasticity of the olfaction-driven behavior observed in Z. cucurbitae depending on female age and on the strength of the olfactory cues associated with preferred and less preferred hosts, adds another dimension to our understanding of the host-seeking behavior of this invasive species.

Background The consumption of the fruits of cucurbitaceae plants is widely popular among Indians due to their various nutritional and medicinal purposes. Some of these plants are well reported in Ayurveda due to their potential therapeutic importance. In particular, the plants of this family are well-characterized by the presence of its bitter principle, Cucurbitacin E which differs within the species due to its genetic variations. Objectives The objective of the study was to develop a validated RP-HPLC method for standardization in some widely consumed cucurbits with cucurbitacin E as a marker compound. Materials and methods The RP-HPLC method was developed with a reverse phase C18 column, using acetonitrile and water (1% glacial acetic acid) as mobile phase (70:30 v/v). The flow rate and λmax were optimized at 1 mL/min and 230 nm respectively. The HPLC method was validated in terms of accuracy, specificity, sensitivity, and repeatability as per ICH guideline. Results The calibration curve was found linear in the concentration range of 1–100 μg/mL. The % RSD of precision and recovery was found to be, Graphical abstract Image 1

This study was carried out to evaluate the effects of foliar sprays containing boron (B) nano-fertilizer (NF) on the growth and physiology of lettuce (Lactuca sativa) and zucchini (Cucurbita pepo). Plants were grown under greenhouse conditions for 60 days on a modified Hoagland solution with the presence and absence of boron (+B or –B). A synthesized B–NF foliar spray and a commercial B foliar fertilizer (Bortrac™ 150, BT) was applied at a concentration of 30 mg B L−1 at 10-d intervals throughout the experiment. The B–NF treatment increased the growth of lettuce 2.7- and 1.9-fold for shoots and roots, respectively, with an average production of lettuce biomass by ~58%. Similarly, the NF increased the growth of zucchini by 18 and 66% compared with Control–B (the absence of B), and 13 and 36% compared with BT, both for shoots and roots, respectively. Nevertheless, NF + B mostly decreased lettuce growth with symptoms of B toxicity in leaves. In lettuce, addition of B did not affect concentrations of phenols; however, in zucchini, Control–B induced a higher production of phenolic compounds possibly related to B deficiency. The B addition in lettuce reduced the DPPH activity by 32 and 21% in NF and BT, respectively, compared to Control-B. These responses were similar in zucchini; however, the effect of B was product of its presence in mineral solution rather than due the foliar product applied. This suggests that a NF-based delivery system for B may be highly effective at boosting plant productivity on B-limited soils.

In this study, size and shape controlled biogenic synthesis of gold nanoparticles and their antibacterial activity against food borne bacterial pathogens were investigated. Synthesis of gold nanoparticles was carried out using two medicinally important plants Cucurbita pepo and Malva crispa and the size and shape of the nanoparticles were controlled by altering various parameters in the reaction medium. Results obtained from UV–Vis, FE-SEM, EDS and HR-TEM analyses supported the nanoparticles formation. FT-IR analysis confirmed the presence of biomolecules in the plant leaves extracts responsible for reducing and capping agents. Interestingly, the plant extract synthesized gold nanoparticles showed effective inhibition zone against Gram-positive and Gram-negative pathogens. The minimum inhibitory concentration (MIC) of synthesized gold nanoparticles at 400 μg/ml concentration showed effective inhibitory activity against Escherichia coli and Listeria monocytogenes. Conductivity of the medium continuously increased during the nanoparticles treatment with food borne bacterial pathogens resulting in indirect indication of the disruption of bacterial cell membranes. In addition, mode of interactions of gold nanoparticles against food borne bacterial pathogens was demonstrated using Bio-TEM analysis which is clear evident for the disruption of bacterial cell membranes. Keywords: Cucurbita pepo, Malva crispa, Gold nanoparticles, Antibacterial activity, Conductivity, Bio-TEM

It is known that epibrassinolide (EBL) plays an important role in the variety of plant developmental processes and adaptation to various environmental stresses. Salt stress is one of the most important environmental problems which limit crop growth and productivity. Here, the effects of EBL pretreatment on amelioration of the adverse effects of salinity were investigated in pumpkin, especially at the establishment stage. For this purpose, uniform-sized seedlings were transplanted to plastic containers containing one-half-strength Hoagland's nutrient solution. EBL was added at 0.1 and 0.01 μM to the hydroponic medium for 5 days before stress. The plants were treated with 40 and 80 mM NaCl for inducing salinity stress. Salt stress reduced the plant growth, calcium and potassium content in leaves and roots, and these detrimental effects were alleviated when plants were pretreated with EBL. Salinity stress caused a significant increase in lipid peroxidation, sodium, and γ-amino butyric acid (GABA) content. EBL pretreatment ameliorated these effects by reducing lipid peroxidation, sodium content and increasing GABA content. The increase in activities of guaiacol peroxidase, catalase, ascorbate peroxidase, and superoxide dismutase was observed under salinity stress. Application of exogenous EBL pretreatment further increased antioxidant enzymes activities. The present work emphasizes the protective role of EBL in the regulation of antioxidant enzymes and GABA accumulation and its possible link in amelioration of stress in plants. This is the first report dealing with EBL effect on GABA content under salt stress.

This study investigates the effect of SPIONs (superparamagnetic iron oxide nanoparticles, ∼12.5 nm in size) on summer squash plant (Cucurbita pepo) in the presence and absence of supplementary iron (Fe(II)-EDTA). The plants were grown in nutrient solution with different iron sources: (i) Fe(II)-EDTA, (ii) without Fe(II)-EDTA (iii) SPIONs only, and (iv) Fe(II)-EDTA with SPIONs. Plant growth and development were assessed after 20 days of soaking by measuring phenological parameters such as plant biomass, chlorophyll content, amount of carotenoids, and the catalase enzyme activity. Transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, X-ray diffraction, and vibrating sample magnetometer methods were used to detect uptake and translocation of SPIONs in plant tissues. Our results showed that SPIONs treatment (without Fe(II)-EDTA) caused growth retardation and decreased the plant biomass and chlorophyll content. Hence, they are not efficient sources to compensate for iron demand of squash plant. Electron microscopy observations, magnetization and elemental analyses revealed that SPIONs are taken-up by plant roots but not translocate to upper organs. In roots, SPIONs use a symplastic route for intercellular transfer. These findings suggest that as an iron source, SPIONs alone are not efficient for plant growth, but can contribute it together with Fe(II)-EDTA.

Hydrophobic pollutants, such as polychlorinated biphenyls (PCBs), are detected at high concentrations in plants of the Cucurbitaceae family, including cucumber and zucchini. Given that the uptake of these compounds by crops can lead to their accumulation in animals via the food chain and that they may have potentially adverse health effects, it is desirable to take appropriate preventative measures. However, the mechanisms underlying the uptake of these pollutants are still unclear. We found that the Magda (MG) cultivar of Cucurbita pepo showed high accumulation of PCBs, especially 2-chlorinated PCBs, in leaves, stems, and xylem sap compared with the Patty Green (PG) cultivar. In the MG cultivar, we identified two major latex-like proteins (MLPs) produced in roots that are translocated to xylem sap, wherein they bind to PCBs, and it is assumed that these MLPs are associated with the accumulation of PCBs in the aerial parts of plants. These results indicate that PCBs are transported by specific mechanisms via the xylem sap. Collectively, our findings indicate that the expression of MLP genes and production of MLPs in roots, the excretion of MLPs into xylem sap, and the binding of hydrophobic pollutants by MLPs are critical steps in the accumulation of hydrophobic pollutants in cucurbits.

Aim The safety and effectiveness of a preparation containing a mix of Cucurbita Pepo Seed extract, Equisetum arvense and Linum usitatissimum - Flax A (CELcomplex®) on stress urinary incontinence (SUI) was evaluated in female patients recruited from 20 urological and gynaecological outpatient clinics in Slovakia. Methods A total of 86 women aged from 32 to 88 with SUI (grade 1 = 44, grade 2 = 42) were enrolled in the study and followed-up for six weeks (point 1) and twelve weeks (point 2). The primary outcome of the study was evaluated by changes in day-time and nocturnal urinary frequency (bathroom visits) and urinary incontinence episodes (leaks). Also, adverse events were quantified as well as the self-perceived effectiveness of the treatment. Research Ethics Board approval was obtained for this study. Results After 12 weeks of treatment there was a 30% (grade 1 SUI, p, Graphical abstract Image 1

Bio synthesized method has received great attention in recent years due to its capability to design alternative, safer, energy efficient, and less toxic routes towards synthesis. These routes have been associated with the rational utilization of various substances in the nanoparticle preparations and synthetic methods. The present work describes the green synthesis of Titanium dioxide (TiO2) nanoparticles from titanium try chloride (TiCl3) solution using Cucurbita pepo seeds extract. The synthesized TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Ultraviolet–visible spectroscopy (UV-VIS), Fourier transform infrared spectroscopy (FT-IR).

Exogenous ameliorants hold a great potential to strengthen endogenous plant defence under various environmental stresses, including salinity. The effects of Cypress Leaf Extract (CLE, as a biostimulant) and salicylic acid (SA) on growth, physio-biochemical and molecular responses of zucchini (Cucurbita pepo L. cv. Kavili) seedlings under salt stress were investigated. Salt stress resulted in decreased photosynthesis activity and increased oxidative stress. However, CLE- and SA-pretreatment of salt-stressed seedlings enhanced their growth, photosynthetic capacity, antioxidant enzyme (SOD, CAT, APX, GPX, GR, and DHAR) activities and the contents of ascorbate, glutathione and proline as compared to the salt-stressed untreated seedlings. CLE- and SA-pretreatment also alleviated the salt stress-induced negative effects on CO2 assimilation and significantly increased the activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Furthermore, CLE pretreatment also upregulated the expression of stress-inducible antioxidation-related genes (CuZnSOD2, CAT1, APX, GR, DHAR and PrxQ) in salt-stressed seedlings. Interestingly, CLE was found to outperform SA in augmenting these processes under both stress and stress-free conditions. Our study reveals that CLE-mediated enhancement of photosynthesis and antioxidative defence mechanisms plays a crucial role in the alleviation of salt stress, and thereby increasing salt tolerance and growth of zucchini plants.

Arid zones contain a diverse set of microbes capable of survival under dry conditions, some of which can form relationships with plants under drought stress conditions to improve plant health. We studied squash (Cucurbita pepo L.) root microbiome under historically arid and humid sites, both in situ and performing a common garden experiment. Plants were grown in soils from sites with different drought levels, using in situ collected soils as the microbial source. We described and analyzed bacterial diversity by 16S rRNA gene sequencing (N=48) from the soil, rhizosphere, and endosphere. Proteobacteria were the most abundant phylum present in humid and arid samples, while Actinobacteriota abundance was higher in arid ones. The Beta-diversity analyses showed split microbiomes between arid and humid microbiomes, and aridity and soil pH levels could explain it. These differences between humid and arid microbiomes were maintained in the common garden experiment, showing that it is possible to transplant in situ diversity to the greenhouse. We detected a total of 1009 bacterial genera; 199 exclusively associated with roots under arid conditions. With shotgun metagenomic sequencing of rhizospheres (N=6), we identified 2969 protein families in the squash core metagenome and found an increased number of exclusively protein families from arid (924) than humid samples (158). We found arid conditions enriched genes involved in protein degradation and folding, oxidative stress, compatible solute synthesis, and ion pumps associated with osmotic regulation. Plant phenotyping allowed us to correlate bacterial communities with plant growth. Our study revealed that it is possible to evaluate microbiome diversity ex-situ and identify critical species and genes involved in plant-microbe interactions in historically arid locations., published in Science of The Total Environment (2021)

The efficiency of enzymatic hydrolysis is reduced by the naturally recalcitrant complex polymers comprising lignocellulose. Increasing enzymatic conversion, which the complex macromolecules converted into simpler molecules, is still had to be overcome. High hydrostatic pressure (HHP), an emerging technology, is expected to ameliorate the situation. The effects of enzymatic hydrolysis after HHP pretreatment on pumpkin lignocellulose were studied and compared with hydrothermal and alkaline pretreatment. Further investigation was performed to evaluate the effect of enzymatic hydrolysis of pumpkin combined with HHP treatment. The samples underwent HHP treatment simultaneously exhibited overall better performance in enzymatic hydrolysis than the untreated. The highest glucose yield of 91.2% and xylose yield of 84.2% was achieved when 400 MPa HHP with high enzyme loading was applied. HHP exerted positive effects on enzyme-substrate interactions during the enzymatic hydrolysis of lignocellulose, which implied that HHP technology combined with enzymatic hydrolysis could be used to pretreat pumpkin pomace.

In this study, pumpkin seed oils obtained from roasted and unroasted seeds of the two genotypes called as “Nevsehir Cercevelisi” and “Urgup Sivrisi” belonging to the species Cucurbita pepo were analyzed for thermal and kinetic properties. Oil extraction from seeds subjected to three different pre-treatments (unsalted, dry salted and wet salted) before roasting and sun-dried unroasted seeds was carried out by means of a screw press. Thermal characteristics (cooling-melting curves and the oxidative induction time (IT) at four different isothermal temperatures (110 °C, 120 °C, 130 °C and 140 °C) were determined using differential scanning calorimetry (DSC). Kinetics parameters of the oil oxidation process such as reaction rate constants (k), activation energies (Ea), enthalpies (ΔH‡), entropies (ΔS‡) and Q10 values were also calculated. Our results indicate that an increase in the DSC isothermal temperature resulted in a decrease in induction time (IT), and the highest IT was observed in the oils obtained from sun-dried unroasted seeds.

The use of engineered nanomaterial (ENMs) has increased dramatically and the possible interaction of these materials with soil-borne organic co-contaminants is largely unknown. Imidacloprid (IMDA) is a neonicotinoid insecticide and one of the most widely used pesticides in the United States and significant concerns have risen due to unknown role of these insecticides in pollinator decline. As such, understanding ENM interactions with these agrochemicals is important. In this study, the bioaccumulation, translocation, and toxicity of IMDA (10 mg/kg) to Cucurbita pepo L (zucchini) was evaluated upon simultaneous exposure to CeO2 or Ag in bulk (CeBulk or AgBulk) or nanoparticle (CeNP or AgNP) form at 100 mg/kg under soil-grown conditions. Additionally, expression analysis of seven genes (related to stress, photosynthesis, and elemental transport) previously identified as putative biomarkers of nanoparticle (NPs) exposure in zucchini was also performed. Total IMDA and metabolites accumulation in plant root and aerial tissues (shoot-stem and leaf, flower, and stamen) was equivalent to controls (soil with IMDA minus NPs) in both CeO2 exposures. However, co-exposure to AgBulk and AgNP significantly suppressed IMDA accumulation in zucchini aerial tissues by 30% and 33%, respectively. The Ag and Ce concentration in aerial tissues exposed to NPs alone were 85.4% and 79.2%, respectively, higher than plants co-exposed to NPs with IMDA. The expression level of the seven genes studied shows that the response mechanisms of zucchini to IMDA and NPs are different. Moreover, no synergistic effects were observed in gene expression upon IMDA-NPs co-exposure. These findings show that ENMs may not only affect the bioavailability and translocation of currently used pesticides but that the reverse is true as well; these interactions should be considered when assessing the exposure and risk of these materials in the environment.

A complete diallel cross study of seven Iranian accessions of Cucurbita, including five C. pepo (four naked seed and one true seed type) and two C. moschata accessions, was carried out during two planting seasons at University of Tehran, Karaj, Iran. Investigated traits were fruit number, fruit yield, seed yield, fruit weight, seed weight, ratio of fruit weight/seed weight, 100 seeds weight and seed number. ANOVA for all of the characteristics except fruit number indicated significant differences among the genotypes. Analysis of variance of the diallel data set also revealed high and significant effects of general (GCA) and specific combining ability (SCA) between genotypes in respect of fruit yield, seed yield, seed weight, ratio of fruit weight/seed weight and seed number. The GCA of fruit weight and seed weight and the SCA of 100 seeds weight were significant. The reciprocal effects were significant for all the measured traits. Heritability in broad (h2b) and narrow (h2n) estimates were generally high for fruit yield, seed yield, seed weight, fruit weight/seed weight and seed number, while they were low for fruit weight and 100 seeds weight. Favourable heterosis over the best parent was found for fruit yield, fruit weight and 100 seeds weight.

Soilless zucchini (Cucurbita pepo L.) crops were grown in two distinct cropping periods (spring-summer; SS and autumn-winter; AW) using irrigation water with different Ca2+ concentrations (1.5, 3, 4.5 and 6 mM). The objectives of this study were to: (i) mathematically correlate the accumulation of Ca2+ in the root environment with the respective Ca2+/water uptake ratio (namely uptake concentration; UC), and (ii) determine the UC of macronutrients (i.e., N, P, K, Ca and Mg) under these conditions. Equations of the literature, initially developed to predict NaCl accumulation in a closed hydroponic system, were further extended to fit experimental results. The evolution of Ca2+ accumulation in the drainage exhibited a sigmoid pattern with time and the relationship between the concentration of Ca2+ in the root zone and the corresponding uptake ratio Ca2+/water was better described by curvilinear functions. Validation of the model showed a very good agreement between simulated and measured values. Increasing Ca2+ levels affected both tissue concentrations and UC of Ca and N, but this was not the case for P, K, and Mg. Photosynthesis, growth, yield and plant water uptake were restricted (avg. 15% decrease) at high external Ca2+ levels, due to high total salt concentration (EC) in the recycled solution (4.2–5.5 dS m−1). Fruit quality attributes, however, remained unaffected by treatments with the exception of fruit nitrate content. The empirical model parameterized and tested in this work may serve as a tool to predict Ca2+ ion concentrations in the root environment of zucchini crops as relationships of the water absorbed by the crop. Finally, the results showed that in soilless zucchini crops with zero discharge of fertigation effluents, there is no compelling reason not to use irrigation water resources with Ca2+ concentration up to 3 mM.

China is the country with the highest level of zucchini production globally. However, the cultivation of resistant zucchini varieties in China is still limited, and there is still a need to isolate more varieties of high quality. This study aimed to evaluate the abilities to resist aphids (Aphis gossypii Glover) and viral diseases in different varieties of zucchini. There were few aphids in variety SX-FRI08 and the lowest number in variety Algeria, while variety HeiYuan exhibited the highest number. Regarding the ability to resist diseases, a clearly lower disease index of aphid-spread viral diseases was exhibited in variety HeiYuan than in the other five varieties, while the disease index of variety Algeria was relatively high. In conclusion, the ability to resist aphids was not consistent with the ability to resist disease in zucchini. Varieties with a slow transformation rate and mild disease phenotype in the late growth stage had strong ability to resist disease.

Pumpkin seed (Cucurbita pepo L.) is high in oil, protein and total unsaturated fatty acids (TUFA), and provides an important source of nutrition and income globally. Use of pumpkin seed in the snacking and vegetable oil industry in the U.S. is expected to rise as the market for healthy foods increases. Currently, most of the pumpkin seed consumed in the U.S. is imported, and there is need to breed high-yielding and nutritious cultivars that are locally adapted to various agro-ecological growing zones in the country. In the current study, phenotypic variation of key seed nutrition traits among 35C. pepo accessions of different seed phenotypes (hulled, semi-hulled, thin layer and ‘naked’) was determined with the primary goal of identifying the best parental material for breeding as well as elucidating phenotypic relationships among the traits. Seed oil percentage ranged from 29.33% to 48.41% and was significantly (P

Twenty one accessions of Cucurbita pepo and eleven accessions of Cucurbita moschata were collected from different regions of Iran and variations in fruit and seed characters evaluated during 2016–2017. The basic statistics of traits has demonstrated considerable variability among accessions. Correlation analysis revealed some important associations among studied traits. In C. pepo, a positive correlation were between seed width and fruit weight, seed weight, fruit flesh thickness, fruit cavity diameter and seed length and in C. moschata, total soluble solid (TSS) was positively correlated with fruit flesh thickness, fruit weight and fruit yield and negatively correlated with fruit weight/seed weight. PCA generalized 15 quantitative characters to five PCs in C. pepo and four PCs in C. moschata having Eigen value >1 explaining 89.85% and 87.13% of the total variability, respectively. Cluster analysis classified C. pepo accessions into six and C. moschata accessions in five divergent groups. The result showed that in C. pepo accessions we can use cluster II members (P02 and P15) as normal seed types and P03 and P05 as naked seed types for next breeding programmes as well as seed production. Among C. moschata accessions we suggest M05 and M11 for next breeding programmes and consumption as pumpkin, also we suggest cluster I (M02 and M03) as the best accessions for consumption their fruits as pumpkin.

DNA typing has been long proposed as a component of food traceability especially for the ability to provide genetic information on processed and/or mixed commercial products. However, the use of DNA testing to deliver legal evidence has been very limited in the agro-food chain, also because in this field, a genetic concordance is rarely sustained with indications on the interpretation and statistics of a DNA profile. Zucchini is the most important and diverse horticultural group belonging to Cucurbita pepo , a plant species that yields a large variety of edible fruits such as squashes and pumpkins. Challenges in genetic discrimination of zucchini material exiting the agro-food chain typify the problems in DNA typing of horticultural food products, because of limited allelic diversity, presence of common alleles, highly processed food and genetic similarity with other edible species. The aims of this work were to identify zucchini varieties in commercial products by a means of Simple Sequence Repeat (SSR) analysis and to provide indications for the statistical interpretation of a match. We assessed the efficacy of SSRs analyzing some of the most diffused hybrids and open pollinated zucchini varieties. SSRs were also screened for transferability in DNA isolated from edible organs of different plant species that are frequently present in food products containing zucchini. Moreover, we demonstrate the possibility to identify the variety in food products of different origins. The statistical evaluation on the rarity of DNA profiles in zucchini indicated that the genetic match presented in this work cannot be attributed to chance alone. Based on this evidence, the advantages and pitfalls of food DNA typing for variety identification of a horticultural crop are discussed.

Insufficient freshwater resources require the improvement of deficit irrigation with approaches that induced high yields by increasing the adaptation of plants to physiological and photosynthetic responses to water scarcity in the soil. The aim of this study is to evaluate water productivity applying combinations of three different plant growth promoting rhizobacteria-PGPR (Bacillus megaterium TV91C, Bacillus megaterium TV6D, Bacillus subtilis RK1900) with a synthetic methylamine molecule for summer squash (Cucurbita pepo L.) at four irrigation levels (full irrigation, and 15, 30 and 45% deficit irrigation), comparing with control (without PGPR and MA). For that, the results of the small plot field experiment carried out in squash growing season of 2017 and 2018 in a semi-arid region were evaluated. PGPR + MA applications decreased the harmful effects on photosynthetic traits (Pn, gs, Ci and Tr), chlorophyll content, electrolyte leakage and leaf relative water content by water deficit and significantly improved also. Although the negative correlations between yield and physiological and photosynthetic traits, PGPR + MA applications provided higher marketable yield as much as the plants full irrigated even at low irrigation levels with a potential root growth from physiological and photosynthetic improving. Higher yield in PGPR + MA applications resulted in higher water productivity for water consumption and decreased irrigation quantities also increased water productivity for irrigation quantity applied. The most striking result was that all PGPR + MA applications resulted in significantly higher water consumption and water productivity for irrigation quantity applied values at all irrigation levels compared to the fully irrigated control treatment. Therefore, it would be possible to optimize water productivity, with water saving and squash yield increases from PGPR + MA applications in terms irrigation water management.

Bacterial spot, caused by Xanthomonas cucurbitae, is an important disease of cucurbits worldwide. Considering the absence of resistant cultivars, along with the limited effects of chemical treatments, we evaluated the use of potential biocontrol agents for management of the disease. We collected 1,134 bacterial isolates associated with bacterial spot symptomatic leaves and fruits and screened in vitro for their antagonistic activity against X. cucurbitae. A total of 271 isolates inhibited colony formation of X. cucurbitae in a disc diffusion assay. Species of these antagonistic isolates were identified based on 16S rRNA primers and phylogenetic analysis using four housekeeping genes. Based on results from the in vitro assays, the strong inhibitors of X. cucurbitae were selected for greenhouse and field evaluations. We found that Bacillus amyloliquefaciens, Bacillus velezensis, Pantoea agglomerans, and Pseudomonas putida were able to prevent or limit development of bacterial spot on pumpkin plants in the greenhouse and field studies. Additionally, Bacillus amyloliquefaciens and Pseudomonas putida increased growth of ‘Howden’ pumpkin (Cucurbita pepo). Our results suggest that these biocontrol agents can be used for managing bacterial spot disease and enhancing the growth of pumpkin plants.

In this work, structure and anti-diabetic effect of a polysaccharide (PP-PE) obtained by hot-water extraction from Cucurbita pepo was studied. The results showed that PP-PE was composed of α-(1→6)-glucan branched at C3 position and α-(1→4)-galactan. The polysaccharide molecule had a local rod-like conformation in solution with the cross-sectional radius of gyration of 0.27 nm and the chain aggregation was also observed from SAXS measurements. For alloxan-diabetic mice, blood glucose level was decreased by 29.8 % after 7 days PP-PE treatment at a dose of 100mg/kg/day. The histological examination indicated that degeneration and necrosis of pancreas tissues were observed in diabetic mice, however, histopathological changes were restored to near normal by PP-PE treatment. PP-PE also showed α-glucosidase and α-amylase inhibited activities with an IC50 value of 110.32±7.08 mg/mL and 103.06±1.60 mg/mL, respectively.

Natural plant growth biostimulants are intensively used nowadays for plant growing in normal and adverse conditions. Severely affected by salt and drought stresses, squash (Cucurbita pepo L.) is an important vegetable crop that highly ranked in economic importance worldwide. The current study aimed to evaluate whether leaf extract of Moringa oleifera (MLE), as a novel natural biostimulant for plant growth, could play a role in improving drought tolerance in squash plants under saline condition. In summer and fall seasons of 2016, MLE (3%) was foliar sprayed for plants under full (100% of ETc) or deficit irrigation (DI; 80 or 60% of ETc). The effect of MLE on the growth, yield characteristics and water use efficiency (WUE), physio-biochemical attributes, and leaf anatomy of squash plants exposed to DI stress was assessed. MLE-treated plants exposed to DI had higher growth and yield characteristics, harvest index (HI),WUE, chlorophyll fluorescence (Fv/Fm and PI), photosynthetic pigments, soluble sugars and free proline, leaf anatomy, relative water content (RWC%) and membrane stability index (MSI%) and had lower electrolyte leakage (EL%) compared to MLE-untreated plants. Application of 3% MLE was effective in alleviating damages of drought stresses in squash plants by maintaining higher RWC, WUE, and osmoprotectants, and lower EL.

The genetic basis of fruit size and shape was investigated for the first time in Cucurbita species and genetic loci associated with fruit morphology have been identified. Although extensive genomic resources are available at present for tomato (Solanum lycopersicum), cucumber (Cucumis sativus), melon (Cucumis melo) and watermelon (Citrullus lanatus), genomic databases for Cucurbita species are limited. Recently, our group reported the generation of pumpkin (Cucurbita pepo) transcriptome databases from two contrasting cultivars with extreme fruit sizes. In the current study we used these databases to perform comparative transcriptome analysis in order to identify genes with potential roles in fruit morphology and fruit size. Differential Gene Expression (DGE) analysis between cv. 'Munchkin' (small-fruit) and cv. 'Big Moose' (large-fruit) revealed a variety of candidate genes associated with fruit morphology with significant differences in gene expression between the two cultivars. In addition, we have set the framework for generating EST-SSR markers, which discriminate different C. pepo cultivars and show transferability to related Cucurbitaceae species. The results of the present study will contribute to both further understanding the molecular mechanisms regulating fruit morphology and furthermore identifying the factors that determine fruit size. Moreover, they may lead to the development of molecular marker tools for selecting genotypes with desired morphological traits.

Molecular marker examinations of genetic diversity are valuable for assessment of within-species diversity and relationships, genotype identification, to assist selection for crop improvement programs, and to handle coherently germplasm collections. Cucurbita maxima is a highly diverse cucurbit crop, but its genetic diversity at the molecular level is inadequately characterized. Presently, genomic simple sequence repeat (SSR) markers that were described and employed for Cucurbita moschata and Cucurbita pepo were screened on C. maxima. A set of 23 highly informative SSRs was selected to evaluate genetic diversity within a collection of 85 C. maxima accessions. This collection contained cultivars and breeding lines from Europe, North America, Asia, Australia, and New Zealand, of six horticultural groups. Based on the genotyping results and statistical analyses, a fundamental division was observed in C. maxima above the level of horticultural groups. One major cluster was comprised between accessions from the Banana, Buttercup, and Hubbard horticultural groups. The other major cluster was divided in two sub-clusters, the larger of which included all accessions of the Mammoth (Show) Pumpkin horticultural group and the smaller, more outlying cluster was comprised of accessions of the Australian Blue horticultural group, with the one representative of the Turban group most outlying. Generally, the horticultural groups formed sub-sub-clusters, as most accessions within these respective groups showed close affinity. The selected set of 23 Cucurbita-conserved SSR markers is expected to be of great value for further germplasm characterization in this species and for taxonomical identifications within the genus Cucurbita.

Carbon coils have many significant technological applications; however, most of them were fabricated using either expensive apparatus or complicated procedures. Herein, a versatile and simple method was used for fabricating valuable single-helix carbon microcoils (SHCMs) by Fe(III)-osmotically induced shape transformation of zucchini ( Cucurbita pepo L.). This versatile strategy allowed to readily reach high surface area (365 m 2 g −1 ), large pore volume (0.24 cm 3 g −1 ) and a narrow average mesoporous size of 5.5 nm via a combined impregnation and hydrothermal carbonization process, and to achieve uniform SHCMs in a reasonable system. In addition, the SHCMs showed excellent performance in antibacterial property and the clearance of chloramphenicol, which should be a promising candidate for efficient adsorbent in water purification. The equilibrium data were well fitted to the Langmuir isotherm model with a maximal adsorption capacity of 124.32 mg g −1 at ambient temperature. The antibacterial mechanisms was also explored. The findings revealed that the Fe(III)-osmotically induced transformation is a potential route for large-scale preparation of SHCMs from appropriate biomass precursors.

The aetiology of squash silverleaf (SSL) induced by the infestation of Bemisia tabaci (Gennadius) ‘biotype’ B (B. tabaci-B) is poorly understood. To help to find out how B. tabaci destroys Cucurbita pepo L. and induces SSL, changes induced by SSL and responses of C. pepo to B. tabaci-B infestation were studied by comparing chlorophyll fluorescence parameters and biochemical, morphological and anatomical aspects of grade 0–4 SSL leaves. The results showed that chlorophyll contents decreased and the chlorophyll a/b ratio increased with the increase of silvered leaf, which indicated that the decrease of chlorophyll contents led to silvered leaf. Anatomical observation showed that B. tabaci-B infestation changed the shape and arrangement of lower epidermis cells and spongy mesophyll cells. Moreover, air spaces appeared between upper epidermis and palisade tissue and in spongy tissue, which might be the cause of the increase in leaf thickness. Additionally, the altering of former spaces light reflection was another reason for leaf silvering. As response to B. tabaci-B infestation, the content of soluble proteins and soluble sugar decreased, and the content of Malondialdehyde (MDA) increased. Pearson correlation showed a significant correlation between fluorescence parameters (except α) and the other parameters measured in this study. The result also suggested that chlorophyll fluorescence can be widely used in field studies as an early diagnostic measure of stress in plant caused by adverse environmental conditions, especially by insect pests.

Watermelon mosaic virus (WMV) is one of the major viruses infecting cucurbit crops worldwide. Although WMV is very common worldwide, little is known about the biological traits of WMV isolates from China. Hence, this study aimed to characterize 11 WMV isolates infecting melon from different geographical origins in Xinjiang based on experimental hosts. Sap inoculation of the 11 WMV isolates onto a range of 13 plant species revealed some differences compared to the WMV isolates collected from other countries. Our results showed that, overall, there were no obvious correlations of host responses to inoculation with WMV isolates from different geographical origins. However, isolate JS-1 caused mild mosaic on Cucurbita moschata, whereas the remaining 10 isolates were asymptomatic on this plant species. Moreover, in Datura stramonium, isolate TYG-1 induced mosaic, whereas the remaining 10 isolates did not infect this species. All isolates infected systemically Cucurbita pepo and Cucumis melo plants, causing severe symptoms. All isolates did not induce any symptoms on Cucumis sativus, but the virus could be detected using RT-PCR. Additionally, all isolates infected systemically Nicotiana tabacum plants, causing mild mosaics. Chenopodium amaranticolor and Chenopodium quinoa reacted to all isolates by chlorotic local lesions in the inoculated leaves, and the virus was detected in the inoculated leaves using RT-PCR. In addition, the attempts to transmit the isolates to Luffa cylindrica, Vicia faba, Phaseolus vulgaris, Vigna unguiculata or Pisum sativum failed as confirmed by negative RT-PCR. Our results would be useful for understanding the biological variability of WMV.

Highlights • Thirteen food crops were analysed for aluminium, arsenic, cadmium and lead. • Mean concentrations were used to calculate EDI, THQ and HI. • TCR was calculated for arsenic for all food crops. • The THQ and HI were, Thirteen Jamaican-grown food crops − ackee (Blighia sapida), banana (Musa acuminate), cabbage (Brassica oleracea), carrot (Daucus carota), cassava (Manihot esculenta), coco (Xanthosoma sagittifolium), dasheen (Colocasia esculenta), Irish potato (Solanum tuberosum), pumpkin (Cucurbita pepo), sweet pepper (Capsicum annuum), sweet potato (Ipomoea batatas), tomato (Solanum lycopersicum) and turnip (Brassica rapa) − were analysed for aluminium, arsenic, cadmium and lead by atomic absorption spectrophotometry and instrumental neutron activation analysis. The fresh weight mean concentrations in these food crops (4.25–93.12 mg/kg for aluminium; 0.001–0.104 mg/kg for arsenic; 0.015–0.420 mg/kg for cadmium; 0.003–0.100 mg/kg for lead) were used to calculate the estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and target cancer risk (TCR) for arsenic, associated with dietary exposure to these potentially toxic elements. Each food type had a THQ and HI

The current study sought to explore the effects of leaf spray with sodium hydrosulfide (NaHS) and calcium chloride (CaCl2) on the growth, the content of essential elements, and nitrogen metabolism in zucchini plants under normal and nickel (Ni) stress conditions. The 10-day old zucchini plants were exposed to Ni concentrations (0, 50, and 100 mg L−1) for 15 days. The results showed that both Ni levels reduced the fresh and dry weights of roots and shoots, leaf area, leaf water content and decreased the content of photosynthetic pigments due to the Ni accumulation and depletion of essential elements in tissues. Moreover, Ni stress increased electrolyte leakage (EL) and decreased the total protein content, the activities of catalase (CAT) and nitrate reductase (NR) in the leaves of the zucchini plant. Foliar spray with NaHS (100 μM) and CaCl2 (15 mM) alone or combined improved growth parameters and the content of chlorophyll a, b and carotenoids under non-stress and Ni stress conditions. Leaf spray with NaHS and CaCl2 and especially their combined application reduced the accumulation of Ni in the roots and shoots, lessened Ni uptake and the translocation factor values in plants, lowered EL and increased CAT activity in leaves. Foliar spray with NaHS and/or CaCl2 improved the homeostasis of macro- and micro-nutrients (N, P, K, Ca, Mg, Fe, and Cu) in the roots and shoots, increased the total protein content and enhanced the NR activity in leaves of zucchini plants under Ni stress. These novel results indicated that the interactive effect of H2S and Ca2+ not only alleviates oxidative stress but also contributes to maintaining nutrient homeostasis and efficiency of N metabolism in plants.

Nitric oxide (NO), a major signalling molecule with various physiological functions in plants, participates in many responses to abiotic disorders such as cold stress. Chilling injury (CI) is the most costly postharvest problem in zucchini fruit (Cucurbita pepo L.), since it diminishes market acceptability and shelf life. This study investigates the effect of NO treatment on zucchini fruit during postharvest cold storage. Fruit were dipped in an aqueous solution of sodium nitroprusside (SNP; 25, 100, and 500 μM) as a NO donor and in potassium ferricyanide (a structural analogue of SNP) and distilled water, both used as controls and responding the same during postharvest cold storage. The results showed that the application of 25 μM SNP treatment reduced weight loss and CI in zucchini fruit during cold storage. S-nitrosylated proteins detected in the exocarp of NO-treated fruit were more abundant than in non-treated fruit. The application of SNP improved the quality of zucchini fruit stored at 4 °C, with a reduction of weight loss, electrolyte leakage, content of malondialdehyde and HO, and delayed loss of firmness during cold storage. NO-treated fruit showed a higher activity of superoxide dismutase, ascorbate peroxidase, glutathione reductase, and phenylalanine ammonia lyase during the first days of cold storage. Total antioxidant capacity was higher in the NO-treated fruit during the first days of cold storage, supported also by higher concentrations of phenols. NO appeared to play a regulatory role in the antioxidant balance in zucchini fruit, maintaining the cellular redox homeostasis and thus modulating ROS toxicity, thereby improving fruit quality during cold conservation., This research has been funded by the Ministerio de Economía y Competitividad and Fondo Europeo de Desarrollo Regional FEDER (Project AGL2014-54598-C2-R) and the Ministerio de Ciencia, Innovacion y Universidades (Project AGL2017-82885-C2-2-R). Alejandro Castro Cegrí and Raquel Jim´enez Munoz ˜ were supported by FPI Grants (MEC)

The phenology of crop flowering and pollinator reproduction can become asynchronous at the edge of their respective ranges. At a northern site in Peterborough County, Ontario, we evaluated offspring emergence of Cucurbita pollen specialist hoary squash bees (Eucera pruinosa) from nests in enclosures to determine their phenological synchrony with a squash crop (Cucurbita pepo). For the crop, we evaluated the percentage of bees that emerged in time to provide pollination services during the crop pollination window. For the bees, we compared the period when both male and females were present and could mate to the whole crop flowering period. We found that fewer than half the bees had emerged by the time the crop pollination window closed and only 34.1% of the flowering period of the crop could support the reproductive activities of the bees, suggesting that phenological synchrony was imperfect from the perspective of both the crop and the pollinator at this northern site.

Effect of gamma irradiation on the stability of cucurbitacins, in pumpkin ( Cucurbita pepo ), during storage was investigated. At the optimum dose of 1 kGy, earlier demonstrated by us to extend the shelf life of ready-to-cook (RTC) pumpkin, no effect on the content of major cucurbitacins identified namely cucurbitacin C and E glycosides was noted. During storage up to 21 day a reduction of 96–97% in the glycoside content was observed in non-irradiated and irradiated pumpkin thereby demonstrating a high stability of cucurbitacins during radiation processing. The decreased cucurbitacin glycoside content during storage also had no impact on the sensory quality of the vegetable. The presence of cucurbitacin C and E glycosides in Cucurbita pepo fruit is reported here for the first time.

Fatty acids (FA) and micronutrients are required for normal growth and development. Deficiency in FA and micronutrients is prevalent in several African countries. The objective of this study was to determine mineral and FA composition of seeds and oils available to residents of Rudewa-Mbuyuni village in Tanzania. Samples were analyzed for FA and mineral composition by gas chromatography mass spectrometry (GC/MS) and, inductively coupled plasma (ICP) emission spectroscopy, respectively. Linoleic acid (LA) and alpha-linolenic acid (ALA) were higher in sunflower ( Helianthus sp) oil, 252 mg/g and 0.58 mg/g, and pumpkin seeds ( Cucurbita pepo ), 126 mg/g and 0.17 mg/g, respectively. Pumpkin seeds contained 9170 mg/kg of potassium, 115 mg/kg of iron and 62 mg/kg of zinc, which are important cofactors for FA metabolism. Pumpkin seeds and sunflower oil are dietary sources of essential FA (EFA) that could be incorporated into Tanzanian diets, especially where there is a high prevalence of growth stunting, cognitive impairment, and EFA deficiency, such as in Rudewa-Mbuyuni. Since the sunflowers and pumpkin analyzed in this study are widely distributed throughout Africa, these data may be beneficial to various regions where EFA and mineral deficiencies are common.

The immature non-climacteric fruit of zucchini is very sensitive to postharvest chilling injury (PCI). Although the fruit produces very low ethylene at harvest, cold storage induces an increase in ethylene production in the refrigerated fruit, and upon rewarming up to room temperature. The production of ethylene after rewarming was proportional to cold damage and found to be higher in the fruit of the cultivars most susceptible to chilling. The effects of the ethylene inhibitor 1-methycyclopropene (1-MCP) has been analyzed using the postharvest quality parameters of nine zucchini cultivars stored at 20 °C and 4 °C for 14 days. We have also determined the evolution of ethylene production in the fruit of these cultivars, and assessed the expression profiles of twelve ethylene biosynthesis and signaling genes in both control fruit and in 1-MCP treated fruit, of two cultivars that responded to 1-MCP. The 1-MCP treatment reduced the rate and delayed the onset of PCI symptoms and reduced fruit weight loss, although only in the fruit of the most chilling-susceptible cultivars, and concomitantly we found a reduction in the respiration rate and in the level of cold-induced ethylene. This data suggests that ethylene is not only a response of the fruit to cold damage, as occurs upon rewarming, but could also play a regulation role in the onset of PCI in this non-climacteric fruit. The genes CpACO1 and CpACS1 were found to be involved in the biosynthesis of the cold-induced ethylene, but the role played by CpACO1 was found to be the key function, since it was induced higher than CpACS1 in response to cold storage. More over CpACO1 was the only ethylene biosynthesis gene that was downregulated by the 1-MCP treatment. Some of the ethylene perception and signaling genes, including CpETR1 , CpCTR1 and CpEIN3.1 were also induced in response to cold storage, and were downregulated in response to 1-MCP, indicating that the positive effect of 1-MCP in the fruit of certain zucchini cultivars is also associated with a downregulation of genes involved in ethylene perception and signal transduction pathways.

Endophytic bacteria often have beneficial effects on their host plants that can be exploited for bioremediation applications but, according to the literature, only 0.001-1% of all endophytic microbes should be cultivable. This study compared the cultivated endophytic communities of the roots and shoots of Cucurbita pepo with the total endophytic communities as determined by cultivation-dependent techniques and 454 pyrosequencing. The ten most abundant taxa of the total communities aligned well with the cultivated taxa; however, the abundance of these taxa in the two communities differed greatly. Enterobacter showed very low presence in the total communities, whereas they were dominantly present in the cultivated communities. Although Rhizobium dominated in total root and shoot communities, it was poorly cultivable and even then only in growth media containing plant extract. Since endophytes likely contribute to plant-growth promotion, cultivated bacterial strains were tested for their plant-growth promoting capabilities, and the results were correlated with their abundance in the total community. Bacillus and Pseudomonas showed promising results when considering cultivability, abundance in the total community and plant-growth promoting capability. This study demonstrated that, although a limited number of bacterial genera were cultivable, current cultivation-dependent techniques may be sufficient for further isolation and inoculation experiments that aim to improve phytoremediation efficiency.

The effects of 2.8% w/w granulated activated carbon (GAC) and two types of biochar (Burt's and BlueLeaf) on DDT bioavailability in soil (39 μg/g) were investigated using invertebrates (Eisenia fetida), plants (Cucurbita pepo spp. pepo) and a polyoxymethylene (POM) passive sampler method. Biochar significantly reduced DDT accumulation in E. fetida (49%) and showed no detrimental effects to invertebrate health. In contrast, addition of GAC caused significant toxic effects (invertebrate avoidance and decreased weight) and did not significantly reduce the accumulation of DDT into invertebrate tissue. None of the carbon amendments reduced plant uptake of DDT. Bioaccumulation of 4,4'DDT and 4,4'-DDE in plants (C. pepo spp. pepo) and invertebrates (E. fetida) was assessed using bioaccumulation factors (BAFs) and compared to predicted bioavailability using the freely-dissolved porewater obtained from a polyoxymethylene (POM) equilibrium biomimetic method. The bioavailable fraction predicted by the POM samplers correlated well with measured invertebrate uptake (50% variability), but was different from plant root uptake by 134%. A literature review of C. pepo BAFs across DDT soil contamination levels and the inclusion of field data from a 2.5 μg/g DDT-contaminated site found that these plants exhibit a concentration threshold effect at [DDT](soil)10 μg/g. The results of these studies illustrate the importance of including plants in bioavailability studies as the use of carbon materials for in situ contaminant sorption moves from predominantly sediment to soil remediation technologies.

This study aims at investigating the nutritional value of the pumpkin fruits from different local populations of the Cucurbita pepo L., C. maxima Duch. and C. moschata Duch. ex Poir species. The chosen cultivars were: P1, P2, P3, P4, P5, P6 of local populations from Oltenia, Romania namely from Dolj and Olt counties. The pumpkin culture was established in the teaching field of the Faculty of Horticulture in Craiova. The chemical analysis of the pumpkin fruits was carried out using standard methods. There were determined: the dry matter content, the soluble substance content, the total carotenoid content, the antioxidant activity through the DPPH and Trolox method. There have also been studied the correlation coefficients between the quality parameters using the multiple correlation coefficients. The results show differences in the studied quality parameters. There was observed that the “Local population 6” has the highest total carotenoid content of 6.587 mg/100 f.m. and the local population 1 has the highest antioxidant activity of 0.284 mmol/l Trolox.

The purpose of the work was to determine the degree of absorption of trace elements (Al, As, B, Ba, Be, Cd, Ga, Li, Pb, Rb, Sr, V) from the soil and their accumulation by different species and varieties of pumpkins. An additional aim was to estimate health risk assessment of toxic elements by HQ calculations. In species Cucurbita maxima the following pumpkin cultivars were used: Australian butter, Flat white boer, Garbo, Golden delicious, Golden nugget, Hokkaido, Solor and Zapallito de tronco. In species Cucurbita pepo the following pumpkin cultivars were used: American tondo, Baby bear, Delicata, Kakai, Kamokamo, Macaroni dumpling, Sweet dumpling, Thelma sanders, Winter luxury, and Shellless Olga. Our research showed moderate absorption for Rb, while weak for B, Sr and Ga. For most of the elements studied (Al, V, Li, Pb, Cd, As, Ba), BAC values were very low, which is why it can be stated that there is very weak absorption. According to results obtained for assessment of human health risk (HQ) caused by consumption of pumpkin, acute health risk can be characterized as low since HQ values for all investigated toxic elements did not exceed 1. The findings of this research revealed that the pumpkins grown in the county of Hrubieszow (Lublin Voivodeship, south-eastern Poland) region contain low concentrations of potentially toxic elements. Concentrations of toxic elements in pumpkins did not exceed the maximum permissible concentrations regulated by EU normative document. Because acute health risk for all investigated toxic elements and its biological absorption are very low, pumpkin in the county of Hrubieszow can be a valuable and safe ingredient in the diet.

Accelerated oil oxidation and degraded fatty acids (FA) composition are considered as well-known consequences in oilseed crops resulting from the imposed aging conditions. Hence, evaluating the effective techniques and understanding the biological mechanisms associated to mitigating seed deterioration process in medicinal pumpkin (Cucurbita pepo subsp. Pepo. Convar. Pepo var. styriaca Greb) may be necessary. In the current study, different durations of artificial accelerated aging (0, 48, 72, and 96 h) and priming solutions (water priming as control and γ-aminobutyric acid (GABA) priming at 1, 2, and 3 mmol L−1) were tested. From the results, a significant decrease in oil percentage and seedling dry weight was observed with increasing seed aging duration, whereas malondialdehyde content and electrolyte leakage significantly increased. Moreover, with increasing seed deterioration severity, percentage of saturated FA (SFA) significantly increased, while mono- and polyunsaturated FA (MUFA and PUFA) decreased. In contrast, GABA priming alleviated the deleterious effects of seed deterioration on seedling growth and FA composition. For instance, after 96-h aging period, GABA priming at 3 mmol L−1 decreased SFA/MUFA and SFA/PUFA by 14.2 and 13.3%, respectively, compared with control. Overall, the results obtained here may confirm the crucial role of GABA priming to improve the successful establishment of seedlings raised from medicinal pumpkin seeds.

Biofumigation is a soil sterilization technique using isothiocyanates (ITCs) generated from naturally occurring glucosinolates (GLs, thioglucosides) in members of Brassicaceae. Efficacy of biofumigation on plant-parasitic nematodes could be affected by the way biofumigant crops are terminated. The objective of this research was to determine biofumigant crop termination method suppressive to Meloidogyne spp. and Rotylenchulus reniformis on zucchini (Cucurbita pepo). Three field trials were conducted where ‘Sodbuster’ oil radish (OR; Raphanus sativus) and ‘Caliente 199’ brown mustard (MS; Brassica juncea) were grown as biofumigant crops and subjected to various termination methods. In the first trial (Trial I), OR and MS were each terminated by: 1) clipping off shoots at soil line and covering residues with woven weed mat in no-till (NT); 2) macerating shoots followed by tilling (MT); and 3) MT plus covering with black plastic (MTBP). In the second and third trials (Trials II and III), MS was terminated by: 1) NT; 2) MT; or 3) MTBP, in the same way, described in Trial I; 4) macerating shoots in no-till (MNT); 5) MNT plus covering residues with black plastic (NTBP); and tilling without prior tissue maceration (T). A bare ground (BG) control was included in each trial. Brown mustard MTBP suppressed soil populations of Meloidogyne spp. (Trial I-III) or R. reniformis (Trial I), reduced severity of root galls (Trial I-II) and increased zucchini canopy (Trials I and III) (P ≤ 0.05). None of the OR treatments suppressed Meloidogyne spp. and R. reniformis, but MT and MTBP reduced severity of root galls and increased zucchini canopy (Trial I). When soil glucose and sulfate were analyzed as indicators of biofumigation efficacy, sulfate depicted biofumigation efficacy in the order of MTBP > MT > T, higher than in no-till treatments (NT, MNT, and NTBP) and BG. A similar trend in the glucose was observed only when toluene (methylbenzene) was added immediately to soil samples to arrest microbial degradation of glucose. In summary, Meloidogyne spp. were sensitive to biofumigation than R. reniformis. Biofumigation effect was stronger with MS than OR, and MTBP was the most suppressive treatment on the targeted nematodes. Soil sulfate was more stable in the soil than glucose, thus a good indicator of biofumigation.

Accessions of Cucurbita pepo vary in the sensitivity of their young fruit (summer squash) to chilling injury (CI). The dominant gene B (Bicolor), which confers yellow fruit coloration, is known to increase susceptibility of summer squash to CI as compared with green, b/b, fruit. Another dominant gene, D (Dark stem), confers dark plant stems and somewhat enhanced coloration of the young fruit. However, the effect of this gene on chilling sensitivity of summer squash is unknown. Freshly harvested fruit of vegetable marrow-type summer squash from four near-isogenic genotypes, B/B D/D, B/B d/d, b/b D/D, and b/b d/d, were stored for 14 d at three temperature regimes, 4–5, 8–9, and 11–12 °C. Storage at 4–5 °C resulted in CI development in the fruit of all four genotypes. The yellow, B/B genotypes suffered injury also at 8–9 °C, especially the fruit of the light yellow, B/B d/d genotype that showed slight CI symptoms even at 11–12 °C. Chilling tolerance of the genotypes was in accordance with the total tocopherol contents of their exocarp, being highest in the green-skinned b/b accessions and lowest in the light yellow B/B d/d genotype. Relatively higher tocopherol content and lower CI severity were observed in the fruit of the enhanced-yellow B/B D/D genotype. The dominant D allele can partially alleviate the CI sensitivity of summer squash that is conferred by the dominant B allele.

The effect of hot water (HW) treatment on chilling injury (CI), arginine metabolism, enzymes activity and related gene expressions of zucchini squashes were investigated during cold storage. Immature zucchini fruit were treated with hot water at 45 ± 1 °C for 15 min and then stored at 4 ± 1 °C and above 90 % relative humidity for 15 d. Another batch immersed in distilled water at 25 °C for 15 min served as control. The results revealed that HW treatment significantly reduced the development of CI during storage. The activity of arginase, arginine decarboxylase (ADC) and ornithine decarboxylase (ODC) enzymes were increased leading to higher accumulation of polyamines. Similarly, the proline contents were also increased due to increased activity of △1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine d -aminotransferase (OAT) enzymes. The expression of genes under study also responded accordingly with relatively higher expression level compared with control. Moreover, the activity and gene expression of proline dehydrogenase (PDH) enzyme was lower in tissues of HW treated zucchini fruit. Thus, HW treatment induced the arginine metabolism, resulting in accumulation of polyamines and proline, which subsequently increased the chilling tolerance.

The state diagram and water sorption properties can be useful in assessing the stability of food products. In this study, we determined the initial freezing temperatures (Tf) and glass transition temperatures (Tg) of pumpkin using differential scanning calorimetry at various water contents. The vapor sorption analyzer was used to determine water sorption properties while the spectrophotometer used to measure color changes in pumpkin after 13 months of storage. We constructed a state diagram using Tf and Tg; and determined critical water activity from Tg, water content and water activity diagram. The Tf decreased from −1.3 to −21.0 °C as the solids content increased from 0.08 to 0.63 g solid/g pumpkin. The Tg decreased from 71.0 to −55.2 °C as the water content increased from 0.08 to 0.30 g.H2O/g pumpkin. The water sorption showed type III isotherm, while the monolayer ranged from 0.10 to 0.12 g.H2O/g dry-pumpkin. Pumpkin powder storage study indicated that color change increased with increasing water activity, while pumpkin color change was minimal in the glassy state. The state diagram and water sorption isotherm data may be utilized for the optimization of storage, processing, and packaging conditions of dehydrated or frozen pumpkin.

Zucchini seedlings are commonly subjected to low temperatures and low light densities, which are environmental factors that severely impair plant growth and agricultural production. Little is known, however, about the molecular mechanisms regulating responses to these conditions. In this study, we sequenced a zucchini transcriptome after merging data from untreated control and from plants exposed to low temperature (4 °C) or low light intensity (80 μmol photons m―2 s―1. A total of 234,583 transcripts N50 = 2609 bp were generated, and 83,650 unigenes N50 = 1257 bp were predicted. Under low-temperature conditions, 982 and 340 genes were up- and down-regulated, respectively. Fewer genes were up- 834 and down-regulated 216 under low light intensity stress, indicating that the zucchini seedlings were more sensitive to the applied low temperature than the low light intensity stress. Functional enrichment analyses identified many common or specific biological processes and gene sets responsive to low temperature and low light intensity. In addition, 18 full-length cDNA genes from six gene families (LHCB, POD, SOD, ABAR, ICE1, and COR) and five transcription factor families (AP2/ERF, NAC, ZFP, WRKY, and MYB) identified as potentially associated with both stresses were observed to be differentially expressed in zucchini leaves. Furthermore, KEGG pathway analysis uncovered many important pathways, including those related to plant hormone signal transduction, starch and sucrose metabolism, and phenylpropanoid biosynthesis. We also confirmed the expressions of these unigenes by quantitative real-time polymerase chain reaction analysis. Our findings and the identified functional genes can provide useful clues for improving the abiotic stress tolerance of zucchini by exploitation of the underlying mechanisms.

The mobility of Polychlorinated Biphenyls (PCBs) in soil cultivated with different plant species was evaluated by means of a column experiment to investigate the specific plant influence on PCB environmental fate and the potential for leaching. The soil was collected at a National Relevance Site for remediation located in Northern Italy (SIN Brescia-Caffaro) and underwent a rhizoremediation treatment for 18 months with different plant species (Festuca arundinacea, Cucurbita pepo ssp pepo and Medicago sativa). The same but unplanted soil was also considered as control for comparison. The columns were leached with tap water and PCB concentrations were measured in the leachate after 7 days of soil/water contact. Soil previously cultivated with different plant species exhibited statistically different behavior in terms of chemical leaching among the different fractions. Total PCB bulk concentrations ranged from 24 to 219 ng/L. Leachate samples were enriched in tetra- to hepta-PCBs. While PCB concentrations in the dissolved phases varied within a factor of 2 between controls and treatments, PCB associated to particulate organic carbon (POC) differed by more than one order of magnitude. More specifically, Medicago sativa enriched the soil with POC doubling PCB leaching with respect to the other plant species and the unplanted controls.

Manganese, zinc, and iron are the most essential micronutrients required for plant growth and applied as foliar fertilizers. Herein, a simple template-free microwave-assisted hydrothermal green synthesis technique was adapted to produce manganese zinc ferrite nanoparticles (Mn0.5Zn0.5Fe2O4 NPs) at different temperatures (100, 120, 140, 160 and 180 °C). The prepared nanomaterials were employed at different concentrations (0, 10, 20, and 30 ppm) as foliar nanofertilizers during the squash (Cucurbita pepo L) planting process. X-ray diffraction patterns of the prepared nanomaterials confirmed successful production of the nanoferrite material. The prepared nanofertilizers showed type IV adsorption isotherm characteristic for mesoporous materials. FE-SEM and HR-TEM imaging showed that the nanoparticles were cubic shaped and increased in particle size with the increase in microwave temperature during production. The impact of application of the synthesized ferrite nanoparticles on vegetative growth, proximate analysis, minerals content and the yield of squash plant was investigated for two consecutive successful planting seasons. The nanoferrite synthesized at 160 °C and applied to the growing plants at a concentration of 10 ppm gave the highest increase in % yield (49.3 and 52.9%) compared to the untreated squash for the two consecutive seasons, whereas the maximum organic matter content (73.0 and 72.5%) and total energy (260 and 258.3 kcal/g) in squash leaves were obtained in plants treated with 30 ppm ferrite nanoparticles synthesized at 180 °C. On the other hand, the maximum organic matter content (76.6 and 76.3%) and total energy (253.6 and 250.3 kcal/g) in squash fruits were attained with plants supplied by 20 ppm ferrite nanoparticles synthesized at 160 °C. These results indicate that the simple template-free microwave-assisted hydrothermal green synthesis technique for the production of manganese zinc ferrite nanoparticles yields nanoparticles appropriate for use as fertilizer for Cucurbita pepo L.

There has been a substantial research focus on the presence of pesticides in flowers and the subsequent exposure to honeybees. Here we demonstrate for the first time that honeybees can also be exposed to pharmaceuticals, commonly present in wastewater. Residues of carbamazepine (an anti-epileptic drug) up to 371 ng/mL and 30 µg/g were detected in nectar and pollen sampled from zucchini flowers (Cucurbita pepo) grown in carbamazepine spiked soil (0.5–20 µg/g). Under realistic exposure conditions from the use of recycled wastewater, carbamazepine concentrations were estimated to be 0.37 ng/L and 30 ng/kg in nectar and pollen, respectively. Incorporation of environmentally relevant carbamazepine residues in nectar and pollen into a modelling framework able to simulate beehive dynamics including the honeybee foraging activity at the landscape scale (BEEHAVE and BEESCOUT) enabled the simulation of carbamazepine translocation from zucchini fields into honeybee hives. Carbamazepine accumulation was modelled in 11 beehives across a 25 km2 landscape over three years chosen to represent distinct climatic conditions. During a single flowering period, carbamazepine concentrations were simulated to range between 0 and 2478 ng per beehive. The amount of carbamazepine gathered not only varied across the simulated years but there were also differences in accumulation of carbamazepine between beehives within the same year. This work illustrates a fundamental first step in assessing the risk of pharmaceuticals to bees through realistic scenarios by demonstrating a method to quantify potential exposure of honeybees at the landscape scale. Pharmaceuticals are being inadvertently but increasingly applied to agricultural lands globally via the use of wastewater for agricultural irrigation in response to water scarcity problems. We have demonstrated a route of pharmaceutical exposure to honeybees via contaminated nectar and pollen. Given the biological potency of pharmaceuticals, accumulation of these chemicals in nectar and pollen suggest potential implications for honeybee health, with unknown ecosystem consequences. Keywords: Nectar, Pollen, Plant accumulation, Emerging contaminants, Carbamazepine, Honeybee

The accessions variability in crop species is crucial for crop improvement and consequently enables the development of more new valuable agricultural products. This study aimed to evaluate the ascorbic acid (AA), chlorophyll a (Chl-A), chlorophyll b (Chl-B), total phenolic compounds (TPC) as well as dry matter (DM) in different tissues (exocarp and mesocarp) of Cucurbita pepo fruits belonging to 27 morphologically diverse germplasm accessions (14 traditional accessions and 13 commercial hybrids from different countries). DM content ranged from 4.2 to 11.76%, while natural pigments were between 5.85 and 2602.2 μg/g DW (corresponding to Chl-B and Chl-A, respectively). Other antioxidant compounds registered higher values, 0.47–1.29 mg/g DW for AA and 1.98–5.49 mg/g DW for TPC. Additionally, pattern-recognition techniques including distribution, principal component analysis (PCA) and dendogram cluster analysis were used to compare accessions. PCA revealed that the first two components represented 76% and 84% of the total variability in exocarp and mesocarp tissues, respectively; while clusters regrouped those accessions with greater similarity. Exocarp samples exhibited a significantly higher content in all compounds studied, thus positively suggesting the beneficial consumption of fruit peel. This work also highlights the potential contribution of ‘zucchini’ morphotype to dietary intake requirements, being moderate in ‘vegetable marrow’ and ‘pumpkin’. Accessions rich in AA, Chl-A, Chl-B and TPC like those namely Ac-2, Ac-8, Ac-23 and Ac-27 could be exploited as potential donors for novel variety development in future breeding programmes.