Search Results (28)

Rootstocks are vital in cucumber production. Although figleaf gourd (Cucurbita ficifolia) is among the species used, its application remains limited due to the perception that white-seeded pumpkin (C. maxima × C. moschata) offers superior commercial traits. This perception is partly due to the insufficient collection and evaluation of local figleaf gourd germplasm, which has obscured its potential as a rootstock. Based on prior screening, four wild figleaf gourd genotypes from Yunnan Province were selected and compared with seven commercial white-seeded pumpkin rootstocks. Scions grafted onto figleaf gourd exhibited vegetative growth (stem diameter, plant height, and leaf area) and fruit morphology (length, diameter, biomass, and surface bloom) comparable to the top-performing white-seeded pumpkin genotypes. Fruits from figleaf gourd rootstocks also displayed comparable or significantly higher nutritional quality, including vitamin C, total soluble solids, soluble sugars, and proteins. Notably, figleaf gourd itself showed significantly greater intrinsic resistance to Fusarium wilt than white-seeded pumpkin. When used as a rootstock, it protected the scion from pathogen stress by triggering a stronger antioxidant response (higher SOD and POD activity) and mitigating cellular damage (lower MDA levels and electrolyte leakage). These results provide evidence that these figleaf gourd genotypes are not merely viable alternatives but are high-performing rootstocks, particularly in enhancing nutritional value and providing elite disease resistance. Full article

Cucurbita L. is a valuable gourd vegetable crop, with high nutritional and economic value. However, the lack of a molecular identification system and population genetic information has impeded the development of proper conservation strategies and marker-assisted genetic breeding for Cucurbita varieties. In this study, we developed a set of simple sequence repeat (SSR) markers for distinguishing the main cultivated Cucurbita cultivars in China and providing technical support for domestic variety preservation, registration, and intellectual property protection. A total of 152 allelic variations and 308 genotypes were identified from 306 Cucurbita cultivars by using 24 SSR markers. Using 24 core markers, we successfully distinguished 300 varieties from 306 Cucurbita varieties, and the identification rate reached 98.36%. The PIC values of the 24 core markers ranged from 0.281 to 0.749, and the average value was 0.643, which was considered high genetic diversity. Based on the results of cluster analysis, principal component analysis, and population genetic structure analysis using 24 pairs of core primers for 306 Cucurbita varieties, the results were basically consistent, all categorized into three genetic clusters, corresponding to the three species: C. moschata, C. pepo, and C. maxima. These results showed a certain correlation with phenotypic traits. DNA fingerprints were constructed for the 306 Cucurbita cultivars based on the core markers. Our research results provide a new tool for population genetic analysis, variety identification, and protection in Cucurbita cultivars with high efficiency, accuracy, and lower costs compared to conventional methods. Full article

By-products from the fruit and vegetable processing industry represent a substantial source of bioactive compounds, which can be extracted and utilized in the development of functional foods or nutraceuticals, thereby contributing to sustainable nutrition and waste valorization. Pumpkin peels are particularly abundant in bioactive components and contain significant fiber, protein, and minerals such as calcium and magnesium. This study determined the chemical composition, the content of water- and fat-soluble vitamins, and the antioxidant activity of peels from five pumpkin species: Cucurbita pepo ‘Kamo Kamo’, C. maxima ‘Bambino’, C. moschata ‘Butternut’, C. argyrosperma ‘Chinese Alphabet’, and C. ficifolia ‘Chilacayote Squash’. The highest moisture content was observed in the peels of C. ficifolia (89.2 mg 100 g⁻¹ WW). In contrast, the highest amounts of protein (14.82 mg 100 g⁻¹ DW), fat (1.59 mg 100 g⁻¹ DW), and ash (7.46 mg 100 g⁻¹ DW) were recorded in C. maxima peels. The peels of C. moschata contained the highest levels of total sugars (9.17 mg 100 g⁻¹ DW), reducing sugars (8.48 mg 100 g⁻¹ DW), and fiber (19.04 mg 100 g⁻¹ DW). The peels of all analyzed pumpkin species were rich in amino acids and water- and fat-soluble vitamins. The highest levels of polyphenols and flavonoids and the most potent antioxidant properties (DPPH and FRAP) were found in the extract from C. argyrosperma peels. The findings of this study highlight the potential of pumpkin peels as a valuable source of bioactive compounds. Full article

The oxidative stability of nutritive and bioactive lipids is essential for their functionality. This study evaluated the potential of lipid fractions from pumpkin seeds obtained from eleven high-performing cultivars of Cucurbita maxima Duchesne, C. pepo L., and C. moschata Duchesne cultivated in Poland, aiming to evaluate their stability for nutraceutical applications. This study investigated the intrinsic relationship between chemical composition and oxidative stability to identify cultivars with promising functional potential and commercial value. The fatty acid, sterol, and lipid antioxidant profiles were characterized using gas chromatography (GC), GC–mass spectrometry (GC-MS), and ultra-high-performance liquid chromatography (UPLC), respectively. Antiradical activity was assessed via the DPPH assay, and oxidative stability was evaluated using differential scanning calorimetry (DSC). The oils exhibited high levels of polyunsaturated fatty acids (PUFAs) (59.5–68.6%), with n-6/n-3 fatty acid ratios ranging from 66.5 to 211.6. The lipid extracts contained up to 97.1% Δ⁷-sterols, while key antioxidants included squalene (616.6–3092.0 mg/kg) and γ-tocopherol (54.1–423.6 mg/kg). Notably, the C. pepo cultivar ‘Moonshine’ was the least abundant in these bioactive compounds. The carotenoid content ranged from 5.7 to 19.4 mg/kg across the extracts. Among the studied cultivars, ‘Show Winner’ and ‘Pink Jumbo Banana’ (C. maxima) stood out as promising candidates for nutraceutical applications due to their elevated levels of tocopherols, carotenoids, and squalene. A moderate n-6/n-3 fatty acid ratio (100–170), coupled with balanced levels of γ-tocopherol and squalene, was found to significantly enhance the oxidative stability of pumpkin seed lipids. These lipid fractions also show potential as stabilizing additives for oils rich in α-linolenic acid but deficient in natural antioxidants. Full article

Plants, including pumpkins (Cucurbita spp.), are an interesting source of nutrients and bioactives with various health benefits. In this research, carotenoid extracts obtained from the pulp of eight pumpkin varieties, belonging to the C. moschata and C. maxima species, were tested for cytotoxicity on SH-SY5Y neuroblastoma cells. The results showed that pumpkin bioactives exert a cytotoxic action against the tested cells, in particular Butternut extract at a 100 μM (53.69 μg/mL) concentration after 24 h of treatment and Mantovana extract at 50 μM (26.84 μg/mL) after 48 h. Moreover, the carotenoid extracts also showed interesting in vitro antioxidant activity, evaluated by ABTS and ORAC assays. To fully characterize the qualitative and quantitative profile of carotenoids in the tested extracts, a high-performance chromatographic technique was performed, revealing that pumpkin pulp carotenoids were mainly represented by β-carotene, mono- and di-esterified hydroxy- and epoxy-carotenoids. Moreover, the carotenoid dataset was also useful for discriminating samples from two different species. In conclusion, the results of the present study highlight the potential anti-cancer activity of pumpkin carotenoid extracts and the possibility of using them as chemotherapeutic adjuvants. Full article

Pumpkin (Cucurbita sp.) represents an unquestionable source of valuable nutrients and bioactive compounds having a broad spectrum of health-promoting effects. The goal of this work was to characterize the byproducts (peels and filaments) of different pumpkin varieties belonging to C. moschata (Butternut, Lunga di Napoli, Moscata di Provenza, and Violina rugosa) and C. maxima (Delica, Delica vanity, Hokkaido, and Mantovana) species in terms of total carotenoid content, antioxidant activity, and carotenoid profiling. The research revealed that peels and filaments were a good source of β-carotene and other non-esterified carotenoids, as well as esterified carotenoids. Considering the growing market demand for safe and healthy food products, pumpkin byproducts, having also an interesting antioxidant bioactivity, could be useful in the development of novel functional products. Full article

The heavy-metal-associated (HMA) proteins are a class of P_B1-type ATPases related to the intracellular transport and detoxification of metals. However, due to a lack of information regarding the HMA gene family in the Cucurbitaceae family, a comprehensive genome-wide analysis of the HMA family was performed in ten Cucurbitaceae species: Citrullus amarus, Citrullus colocynthis, Citrullus lanatus, Citrullus mucosospermus, Cucumis melo, Cucumis sativus, Cucurbita maxima, Cucurbita moschata, Cucurbita pepo, and Legenaria siceraria. We identified 103 Cucurbit HMA proteins with various members, ranging from 8 (Legenaria siceraria) to 14 (Cucurbita pepo) across species. The phylogenetic and structural analysis confirmed that the Cucurbitaceae HMA protein family could be further classified into two major clades: Zn/Co/Cd/Pb and Cu/Ag. The GO-annotation-based subcellular localization analysis predicted that all HMA gene family members were localized on membranes. Moreover, the analysis of conserved motifs and gene structure (intron/exon) revealed the functional divergence between clades. The interspecies microsynteny analysis demonstrated that maximum orthologous genes were found between species of the Citrullus genera. Finally, nine candidate HMA genes were selected, and their expression analysis was carried out via qRT-PCR in root, leaf, flower, and fruit tissues of C. pepo under arsenic stress. The expression pattern of the CpeHMA genes showed a distinct pattern of expression in root and shoot tissues, with a remarkable expression of CpeHMA6 and CpeHMA3 genes from the Cu/Ag clade. Overall, this study provides insights into the functional analysis of the HMA gene family in Cucurbitaceae species and lays down the basic knowledge to explore the role and mechanism of the HMA gene family to cope with arsenic stress conditions. Full article

Cucurbita species are widely used as rootstocks for cucumber, watermelon, and other plants for the restriction of toxic Na⁺ transport from root to shoot. Previous studies have found distinct salt tolerance strategies between Cucurbita moschata and Cucurbita maxima; the former accumulates a large amount of Na⁺ in the root, while the latter accumulates Na⁺ in the shoot. To further study the mechanism of Na⁺ transport in plants, four reciprocal grafts were made between MB (C. moschata) and JHL (C. maxima), denoted as MB/MB, JHL/JHL, MB/JHL, and JHL/MB (scion/rootstock). The results showed that using MB as the rootstock effectively reduced the accumulation of Na⁺ in the scion. Conversely, JHL rootstock tended to transfer more Na⁺ to the scion. To clarify this phenomenon, the velocities of Na⁺ flows on the root surface, stem, and vein of grafting combinations were measured using non-invasive micro-test technology. Compared with the seedlings using JHL as rootstock, the grafted combination with MB as rootstock had a higher root Na⁺ efflux and lower Na⁺ fluxes in the stem and vein. qRT-PCR analyses revealed the critical roles of salt overly sensitive 1 and high-affinity potassium as components of the mechanism enabling Na⁺ exclusion from the root and Na⁺ unloading from the stem xylem. Compared with the seedlings using MB as rootstocks, the JHL-grafted plants showed more rapid stomatal closure and decreased transpiration rate in the first three hours after salt stress but maintained a higher level under prolonged salt treatment (120 h). The tissue tolerances of JHL and MB were assessed using the isolated leaves under NaCl to exclude the influence of the root and stem. The results showed that the salinity inflicted more serious damage to MB leaves than to JHL leaves. qRT-PCR analyses indicated that the intracellular Na⁺/H⁺ transporter in the leaf vein was involved in this process. All these findings indicated that C. moschata and C. maxima adopted different strategies for regulating Na⁺ transport, and grafting can be used as a tool to create more salt-tolerant plants. Full article

Antioxidant properties and phenolic acid content in the pulp of five pumpkin species were evaluated. The following species cultivated in Poland were included: Cucurbita maxima ‘Bambino’, Cucurbita pepo ‘Kamo Kamo’, Cucurbita moschata ‘Butternut’, Cucurbita ficifolia ‘Chilacayote Squash’, and Cucurbita argyrosperma ‘Chinese Alphabet’. The content of polyphenolic compounds was determined by ultra-high performance liquid chromatography coupled with HPLC, while the total content of phenols and flavonoids and antioxidant properties were determined by spectrophotometric methods. Ten phenolic compounds (protocatechuic acid, p-hydroxybenzoic acid, catechin, chlorogenic acid, caffeic acid, p-coumaric acid, syringic acid, ferulic acid, salicylic acid, kaempferol) were identified. Phenolic acids were the most abundant compounds; the amount of syringic acid was found to be the highest, ranging from 0.44 (C. ficifolia) to 6.61 mg∙100 g⁻¹ FW (C. moschata). Moreover, two flavonoids were detected: catechin and kaempferol. They were found at their highest level of content in C. moschata pulp (catechins: 0.31 mg∙100 g⁻¹ FW; kaempferol: 0.06 mg∙100 g⁻¹ FW), with the lowest amount detected in C. ficifolia (catechins: 0.15 mg∙100 g⁻¹ FW; kaempferol below the limit of detection). Analysis of antioxidant potential showed significant differences depending on the species and the test used. The DPPH radical scavenging activity of C. maxima was 1.03 times higher than C. ficiofilia pulp and 11.60 times higher than C. pepo. In the case of the FRAP assay, the multiplicity of FRAP radical activity in C. maxima pulp was 4.65 times higher than C. Pepo pulp and only 1.08 times higher compared to C. ficifolia pulp. The study findings show the high health-promoting value of pumpkin pulp; however, the content of phenolic acids and antioxidant properties are species dependent. Full article

Heat shock protein 90 (HSP90) plays critical roles in plant growth and development, as well as in response to abiotic stresses such as heat and cold. To comprehensively analyze the HSP90 gene family and determine the key HSP90 gene responsive to temperature stress in pumpkin (Cucurbita moschata Duch.), bioinformatics and molecular biology techniques were used in this study. A total of 10 CmoHSP90 genes were identified from the pumpkin genome, encoding amino acids of 567–865, with protein molecular weight of 64.32–97.36 kDa. Based on the phylogenetic analysis, they were classified into four groups. The members in each group contained similar conserved motifs and gene structures. The 10 CmoHSP90 genes were distributed on the 9 chromosomes of C. moschata. Four pairs of segmental duplication genes (CmoHSP90-1/CmoHSP90-10, CmoHSP90-2/CmoHSP90-7, CmoHSP90-3/CmoHSP90-6, and CmoHSP90-4/CmoHSP90-9) were detected. Synteny analysis revealed that 10 C. maxima HSP90 genes and 10 C. moschata HSP90 genes were orthologous genes with 17 syntenic relationships. Promoter analysis detected 23 cis-acting elements including development-, light-, stress-, and hormone-related elements in the promoter regions of pumpkin HSP90 genes. Further analysis showed that the transcript levels of CmoHSP90-3 and CmoHSP90-6 were remarkably up-regulated by heat stress, while CmoHSP90-6 and CmoHSP90-10 were significantly up-regulated by cold stress, suggesting that these HSP90 genes play critical roles in response to temperature stress in pumpkins. The findings will be valuable for understanding the roles of CmoHSP90s in temperature stress response and should provide a foundation for elucidating the function of CmoHSP90s in C. moschata. Full article

Watermelon grafting is practiced in order to improve tolerance to poor environments such as low temperature. This study was conducted to investigate the effect of low-temperature tolerant bottle gourd (Lagenaria siceraria) rootstocks on the growth and fruit quality of watermelon in semi-forcing and retarding culture where plants were exposed to low or high temperature. Five bottle gourd accessions (FR79, IT207112, BG702, BG703, and FRD22) with low temperature tolerance were evaluated as rootstock for the watermelon scion ‘Sambokkul’. Non-grafted watermelon and watermelon grafted onto commercial rootstock ‘Shintozwa’ (Cucurbita maxima D. × C. moschata D.) or ‘Bullojangsaeng’ (L. siceraria) were used as controls. Watermelons were cultivated in spring (April to June, semi-forcing culture) and autumn (August to October, retarding culture). The responses to low-temperature, growth, yield, and fruit quality differed depending on the rootstocks and growing season. In semi-forcing culture, the monthly averages of daily and minimum temperature in April were, respectively, 13.4 and 1.5 °C. Although the low temperature of the early growth stage suppressed the initial growth of watermelons, grafting mitigated the low-temperature stress. The fruit quality of non-grafted watermelons was greater, but the fruit mass was the lowest (4.8 kg). Grafting onto ‘Shintozwa’ increased the fruit weight (7.0 kg) but reduced the fruit quality. Grafting onto bottle gourd rootstocks had high affinity, good root growth, tolerance to low temperature, and little effect on fruit quality. In retarding culture, the temperature conditions in early and late growth were very high and low, respectively. The growth and fruit quality of grafted watermelons were not superior to those of non-grafted watermelons. Accordingly, these results suggest that watermelon grafting onto the bottle gourd rootstocks may increase the low-temperature tolerance, especially in the early growth stage, and the marketable yield without a reduction in fruit quality. The most promising accession for this purpose was found to be ‘FR79’. Full article

By-products of cultivated plants are one of the major environmental concerns worldwide. Due to the high concentration of bioactive chemicals, such waste may be considered hazardous due to the interference with the plant growth, deterioration of the drinking water quality or toxic effects on sensitive marine organisms. Moreover, plant-derived by-products, with proper handling, may represent a low-cost source of bioactive compounds potentially important for pharmaceutical and cosmetics industries. The aim of the study was to evaluate the phytochemical composition, antioxidant activity, the influence of tyrosinase activity, in vitro sun protecting factor and cytotoxicity of 15 extracts from peels of five cultivars of Cucurbita maxima and C. moschata. The extracts were prepared using “green solvents” (water, 50% propylene glycol, and 20% ethanol) and ultrasound-assisted extraction. The performed analysis showed that the peel extracts from various cultivars differ significantly in respect to the phytochemical content and activity. The type of solvent also had a significant impact on the extract’s composition and bioactivity. Aqueous peel extracts contained the highest amounts of flavonoids, showed the greatest antioxidant potential and the most significant in vitro SPF values. In vitro studies showed that the analyzed peel extracts are not cytotoxic for human keratinocytes up to the concentration of 1000 µg/mL and thus might be considered as non-irritant for the skin. The study confirms the potential application of peel extracts from Cucurbita spp. cultivars in cosmetic products. Full article

Traditional pumpkin (Cucurbita moschata) and Japanese pumpkin (C. maxima) consist of natural polysaccharides. From a scientific basis, natural polysaccharides could be applied to improve hydration in the cosmetic field. The purified polysaccharide was extracted and deproteinized with the CaCl₂ method. Japanese pumpkin showed the higher value of physicochemical properties including yield (12.96 ± 0.60%), total polysaccharide content (0.89 ± 0.04 mg/mL), swelling capacity (4.00 ± 0.00%), swelling index (1.04 ± 0.00%), solubility (126.67 ± 5.77%), viscosity (1.25 ± 0.00 cps), water capacity (0.93 ± 0.15 g/g) and oil absorption capacity (5.93 ± 0.06 g/g) than traditional pumpkin. Additionally, Japanese pumpkin (IC₅₀ 9.30 ± 0.58 µg/mL) provided higher antioxidant activity by DPPH assay than traditional pumpkin (IC₅₀ 9.98 ± 0.25 µg/mL). The evaluation of efficacy on skin hydration in fifteen Thai volunteers indicated that Japanese pumpkin showed non-skin irritation. An extract concentration of 0.05–0.1% showed a significantly increased effect in moisturizing ability according to concentration (p < 0.05). This result supported that it was safe and effective to use as a moisturizer for cosmetic products. Full article

Two rootstock hybrids of sweet melons and watermelons (“Kickstart” and “Carnivor” Cucurbita moschata × Cucurbita maxima) grafted onto two watermelon cultivars (scions), “Honeygoal” and “Honeyval”, were examined in this study to determine whether functional compounds, antioxidant properties, and volatile compounds were retained after five days of cold storage at 5 °C and 85% RH following harvest. An interaction exists between cultivars, rootstocks, and storage for total phenolic content, ascorbic acid, chlorophyll content, antioxidant activities, and volatile compounds. Generally, all functional compounds and antioxidant properties decreased during storage; however, “Honeygoal/Carnivor” in cold storage for 7 days retained the total phenols, ascorbic acid, chlorophyl contents, DPPH (15.47 IC₅₀ mg/mL), ABTS (1.06 IC₅₀ mg/mL) scavenging activities, and antioxidant power (IC₅₀ mg/mL) higher than ungrafted, “Honeyval” or “Honeygoal/Kickstart”, “Honeyval/Carnivor” or “Honeyval/Kickstart” melons. The heat map showed a higher abundance of volatile compounds in “Honeygoal/Carnivor” and “Honeyval/Carnivor” melons stored for 7 and 14 days while “Honeygoal/Kickstart” or “Honeyval/Kickstart” requires 14 days of storage. “Honeygoal/Carnivor” and “Honeyval/Carnivor” melons stored for up to 7 days in cold storage were preferred by panelists. Hence, grafting “Honeygoal” melons onto “Carnivor” rootstocks helped to improve the functional compounds, antioxidant properties, and volatiles during storage for 7 days after harvest. Full article

Grafting is effectively used worldwide to overcome abiotic and biotic factors impacting yield, including soil temperature. Field studies were conducted in 2020 and 2021 in a cool Mediterranean climate (average daily air temperature range of 12.8–17.1 °C) to identify suitable rootstock combinations for grafted cantaloupe (Cucumis melo var. reticulatus) and evaluate fruit yield and quality. Cantaloupe cultivars Sugar Rush (SR), Goddess (G), and Athena (A) were compatible with interspecific hybrid squash (Cucurbita maxima × C. moschata) rootstock cultivars Super Shintosa (SS) and Carnivor (CN) but were incompatible with ‘Carolina Strongback (CS)’ (Citrullus amarus) and ‘Pelop (P)’ (Lagenaria siceraria) rootstocks. Nongrafted cultivars exhibited vine decline at harvest in 2020 but not in 2021, and grafting tended to delay harvest by 15–18 days. Overall, while grafting with interspecific hybrid squash rootstocks may have delayed fruit harvest, fruit quality was not compromised. Further, yield was increased for ‘Goddess’ and ‘Athena’, but not ‘Sugar Rush’. ‘A/CN’ had the highest fruit yield/ha and number per plant. The grafted treatments of each cantaloupe cultivar with interspecific hybrid squash rootstocks met the U.S. fancy grade criteria. Full article