Pepino Research Articles

A Review of the Pharmacological Effects of Solanum muricatum Fruit (Pepino Melon).

Solanaceae, commonly known as nightshade, is a diverse family of flowering plants comprising around 90 genera and an estimated 3000-4000 species. Solanaceae spp. and its various fruits, including pepino (Solanum muricatum), commonly known as pepino melon, are widely recognized by the public for their nutritional value and pharmacological effects. Pepino melon, in particular, is often enjoyed as a fresh dessert or salad due to its juicy flesh. Given its beneficial properties, the potential of pepino melon to be developed as a functional food has been extensively studied. This review aims to provide a comprehensive summary of the reported pharmacological effects of the active compounds found in pepino plant and melon. Among these compounds, polyphenols, notably quercetin, and vitamin C have demonstrated notable antioxidant properties such as scavenging free radicals, effectively protecting against free-radical damage. Moreover, these active ingredients provide pepino with anti-inflammatory properties by inhibiting the expression of proinflammatory cytokines and enzymes, thereby reducing nitric oxide production. Additionally, they have shown promise in selectively targeting cancer cells, exhibiting anti-cancer properties. Furthermore, the active compounds such as quercetin in pepino have been associated with anti-diabetic effects, improving insulin sensitivity and inhibiting insulin resistance. Overall, this review highlights the diverse and significant pharmacological effects of the active compounds found in pepino melon, emphasizing its potential as a valuable functional food.

Quantitative Determination of Minerals and Toxic Elements Content in Tropical and Subtropical Fruits by Microwave-Assisted Digestion and ICP-OES.

In the presented study, 15 tropical and subtropical fruits were studied for their mineral composition ranging from trace to major elements by ICP-OES after microwave digestion. The moisture amounts were assigned to be between 21.90 (tamarind) and 95.66% (pepino). The differences between the macroelement quantities of the fruits were established to be statistically significant (p<0.01). P and K quantities of fruits were displayed to be between 53.40 (pepino) and 927.74 mg/kg (tamarind) to 720.27 (pepino) and 13441.12 mg/kg (tamarind), respectively. While Ca quantities of fruits vary between 123.71 (pineapple) and 1519.76 mg/kg (blood orange), Mg quantities of fruits were established to be between 78.66 (pepino) and 875.02 mg/kg (tamarind). In general, the lowest macroelement quantities were determined in pepino fruit, but the highest P and K contents were determined in Gooseberry and Tamarind fruits, respectively. The microelement amounts of the fruits were established to be at very low levels compared to the macroelement contents. In general, the most abundant element in fruits was Fe, followed by Zn, Cu, Mn and B in decreasing order. In general, heavy metal quantities of fruits were detected at very low levels (except As and Ba). As and Ba quantities of fruits were assigned to be between 0.972 μg/g (mandarin) and 5.86 (kiwi) to 0.103 (pineapple) and 4.08 (avocado), respectively. As with macro and microelements, results regarding heavy metal concentrations varied depending on fruit types.

Effect of Different Concentrations of Auxin as Well as Cytokinin on Shoot Initiation, Formation and Multiplication of Pepino (Solanum muricatum Ait.) cv. Valentia with MS Semi-solid Medium

The pepino (Solanum muricatum Aiton) is conventionally propagated through vegetative means. But, this approach of propagation is not feasible for commercial production of plants and has at more time the chances of reduction yield. Therefore, the availability of quality planting material is of urgent need. Recently, there has been a promising approach for pepino multiplication at large scales through tissue culture because it generates a large number of contamination free plantlets in a minimum space and time. The combination of different growth regulators may be tried to maximize the initiation, growth and development of shoot in commercial propagation of pepino plants. The Minimum days taken for shoot initiation (5.21 days) was noted under BAP 3.00 mgl-1 + IBA 0.50 ppm, and minimum days taken for shoot development (40.82 days) was noted under of BAP 3.00 ppm + IBA 1.00 ppm. The highest length of shoot (9.52 cm) was produced in media supplemented with BAP 3.00 ppm + IBA 1.00 ppm. Maximum percent of developed shoots obtained from the established culture (67.79) was noted under the treatment of BAP 3.00 ppm + IBA 1.00 ppm; While maximum shoots per explants/ innoculums from the established culture (4.06) was noted under the treatment of BAP 3.00 ppm + IBA 1.00 ppm. Maximum number of leaves / plantlet from the established culture (10.85) was noted under the treatment of BAP 3.00 ppm + IBA 1.00 ppm and maximum fresh weight (mg) of shoot / plantlet obtained from the established culture (26.05 mg) was noted under the treatment of BAP 3.00 ppm + IBA 1.00 ppm.

De novo assembly of the complete mitochondrial genome of pepino (Solanum muricatum) using PacBio HiFi sequencing: insights into structure, phylogenetic implications, and RNA editing

BackgroundSolanum muricatum is an emerging horticultural fruit crop with rich nutritional and antioxidant properties. Although the chromosome-scale genome of this species has been sequenced, its mitochondrial genome sequence has not been reported to date.ResultsPacBio HiFi sequencing was used to assemble the circular mitogenome of S. muricatum, which was 433,466 bp in length. In total, 38 protein-coding, 19 tRNA, and 3 rRNA genes were annotated. The reticulate mitochondrial conformations with multiple junctions were verified by polymerase chain reaction, and codon usage, sequence repeats, and gene migration from chloroplast to mitochondrial genome were determined. A collinearity analysis of eight Solanum mitogenomes revealed high structural variability. Overall, 585 RNA editing sites in protein coding genes were identified based on RNA-seq data. Among them, mttB was the most frequently edited (52 times), followed by ccmB (46 times). A phylogenetic analysis based on the S. muricatum mitogenome and those of 39 other taxa (including 25 Solanaceae species) revealed the evolutionary and taxonomic status of S. muricatum.ConclusionsWe provide the first report of the assembled and annotated S. muricatum mitogenome. This information will help to lay the groundwork for future research on the evolutionary biology of Solanaceae species. Furthermore, the results will assist the development of molecular breeding strategies for S. muricatum based on the most beneficial agronomic traits of this species.

Antioxidant, Tyrosinase Inhibition Activity, and In Vitro SPF Evaluation of Pepino Fruit Extract (Solanum muricatum Aiton) in Different Solvent Types and Concentrations

Solvent is a key factor that affects the effectiveness of active compound extraction from plant materials (simplisia). This study aimed to determine the optimal type and concentration of solvent used in the extraction of pepino fruit based on the parameter of antioxidant and tyrosinase inhibition activity, as well as Sun Protection Factor (SPF) value. The extraction was carried out using the maceration method with ethanol or ethyl acetate as the solvent, each at concentrations of 50%, 70%, and 96%, respectively. The antioxidant activity of the extracts was evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. The inhibition of tyrosinase and the determination of the SPF value were carried out using in vitro test. The results showed that the ethyl acetate extract was better than that of the ethanol extract in terms of antioxidant activity, tyrosinase inhibition, and SPF value. In the ethyl acetate solvent, a concentration of 96% provided the strongest antioxidant, tyrosinase inhibition activity, and the second highest in SPF test. It can be concluded that the optimal solvent for extracting pepino fruit as promising compound for sunscreen formulation is 96% ethyl acetate.

First Report of Alternaria linariae Causing Postharvest Fruit Rot of Pepino (Solanum muricatum) in China.

Pepino (Solanum muricatum L.) is a popular solanaceous crop that is native to South America and is commercially grown in many countries including China for its attractive, sweet and flavorful fruits. In September 2023, a postharvest fruit rot was observed at an incidence of 7% to 10% on pepino at supermarket in Nanchang, Jiangxi, China (28.69°N, 115.81°E). Symptoms on fruits initially appeared as small black spots that later enlarged and became necrotic. To isolate the pathogen, symptomatic tissues were surface-sterilized using 75% ethanol for 15 s, then 1% sodium hypochlorite for 30 s, rinsed three times in sterile water, air dried, finally placed on potato dextrose agar (PDA) plates and incubated at 25℃ for 4 days. Ten strains (about 83% isolationfrequencyfromsymptomaticpepinofruits) with similar morphological characteristics were isolated. The colonies on PDA were initially white, gradually turning gray and eventually becoming black, and had abundant aerial mycelia. Conidia were fusiform to linetype, dark brown, measuring 50 to 100 × 10 to 28 μm (n = 30) with 5 to 10 transverse septa and 0 to 3 longitudinal septa. Based on the morphological characteristics, the pathogen was identified as Alternaria sp. (Ma et al. 2021). To further confirm species, two representative isolates (JXAL-1 and JXAL-2) were selected for molecular identification. The internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), elongation factor 1-alpha (TEF1), Alternaria major allergen gene (Alt a 1) and DNA-directed RNA polymerase II core subunit (RPB2) were amplified and sequenced by using primers ITS5/ITS4, gpd1/gpd2, Alt-for/Alt-rev, EF1-728F/EF1-986R and fRPB2-5F2/fRPB2-7cR (Woudenberg et al. 2013; Woudenberg et al. 2014), respectively. These sequences were deposited into GenBank with accession number PP231808-PP231809 (ITS), PP238480-PP238481 (GAPDH), PP238482-PP238483 (Alt a 1), PP238484-PP238485 (TEF1) and PP238486-PP238487 (RPB2). A BLASTn homology search for these nucleotides showed 100% identity to ITS (KJ718182, 525 nt/525 nt), GAPDH (KJ718026, 579 nt/579 nt), Alt a 1 (KJ718694, 472 nt/472 nt), TEF1 (KJ718530, 334 nt/334 nt) and RPB2 (KJ718355, 772 nt/772 nt) sequences of Alternaria linariae CBS 107.61. The maximum likelihood analyses were performed for the combined ITS, GAPDH, Alt a 1, TEF1 and RPB2 using the IQtree web server (Trifinopoulos et al. 2016). In the phylogenetic tree, the isolates and isolates of A. linariae clustered together with 100% bootstrap support. Therefore, the fungus was identified as A. linariae. To evaluate pathogenicity, five healthy fruits of pepino were surface-sterilized with 75% ethanol, then wounded and a 5 mm diameter agar with isolate JXAL-1 was put on the wound. Another five fruits was inoculated with sterile agar plugs as control. All treated fruits were incubated at 25 ℃ with 80% humidity , and repeated twice. Five days later, all the wounded fruits inoculated with A. linariae showed similar symptoms and A. linariae was reisolated, while the control fruits remained healthy and no pathogen was isolated, fulfilling Koch's postulates. A. linariae is known as an important pathogen causing early blight of tomato and potato(Adhikari et al. 2020). To our knowledge, this is the first report of A. linariae causing postharvest fruit rot on S. muricatum in China, which expands the natural host range of A. linariae and will be helpful to develop efficient management strategies on pepino.

Anti-Hypertensive Effect of Solanum muricatum Aiton Leaf Extract In Vivo and In Vitro.

Hypertension is a global health problem and leads to cardiovascular disease and renal injury. Solanum muricatum Aiton leaf extract, rich in flavonoids, is known for its antioxidant capacity. However, the effects of Solanum muricatum Aiton leaf extract on hypertension combined with inflammatory complications were unknown. This study aimed to investigate the impact of Solanum muricatum Aiton leaf extract on hypertension in vivo and in vitro. In vivo, Solanum muricatum Aiton leaf extract led to decrease high blood pressure, improve heart, aorta, and kidney pathology, and enhance the antioxidative activity in spontaneously hypertensive rats (SHR). Our study demonstrated Solanum muricatum Aiton leaf extract inhibited angiotensin-converting enzyme (ACE), epithelial sodium channel (ENaC), sodium glucose co-transporters-1 (SGLT-1), nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). In vitro, Solanum muricatum Aiton leaf extract improved the angiotensin II-induced reactive oxygen species (ROS) and mitochondrial membrane depolarization in NRK-52E cells. Besides, Solanum muricatum Aiton leaf extract could also decrease the expressions of ENaC, SGLT-1, and NF-κB in angiotensin II-treated NRK-52E cells. Solanum muricatum Aiton leaf can be suggested as a novel antihypertensive agent ameliorating hypertension via ACE inhibition, inflammation reduction, and ROS. PLE is a novel anti-hypertensive agent to ameliorate hypertension and its complications, including inflammation.

Fairyfly egg parasitoids (Hymenoptera: Mymaridae) of the invasive lace bug Corythucha marmorata (Uhler) (Hemiptera: Tingidae) in Japan

The fairyfly Anagrus (Anagrus) virginiae Triapitsyn and Puttler (Hymenoptera: Mymaridae) is identified as a principal egg parasitoid of the chrysanthemum lace bug Corythucha marmorata (Uhler) (Hemiptera: Tingidae) in Japan on Solidago altissima L., Solidago sp., and Bidens pilosa L. (Asteraceae), and on sweet potato, Ipomoea batatas (L.) Lamarck (Convolvulaceae). Both C. marmorata and Solidago spp. as well as Bidens pilosa are invasive in Japan, so it is very likely that A. virginiae was unintentionally introduced and established in the country either with or after the introduction of its insect host. Both sexes of A. virginiae are redescribed and illustrated with digital images based on Japanese specimens to facilitate their recognition, and an updated key to females of Anagrus Haliday species in Japan is given to include A. virginiae and the recently recorded leafhopper egg parasitoid A. (Anagrus) turpanicus Triapitsyn and Hu. In Japan, C. marmorata is a pest of eggplant, Solanum melongena L. (Solanaceae), pepino or sweet cucumber, Solanum muricatum Aiton, sweet potato, and other crops, so potential for classical biological control against this lace bug is discussed. One male specimen of another fairyfly, Erythmelus (Parallelaptera) sp., was also reared from an egg of C. marmorata, the first such record from this lace bug host.

Antioxidant Activities of Stem, Leaves and Fruits Extracts of Pepino (Solanum muricatum Aiton).

&lt;b&gt;Background and Objective:&lt;/b&gt; Pepino (&lt;i&gt;Solanum muricatum&lt;/i&gt; Aiton), rich with vitamin C and flavonoids, constitutes an abundant source of potent antioxidants. This research was conducted to determine antioxidant activity from three different parts of pepino based on equivalence with ascorbic acid, to analyze the relationship between total phenolic content (TPC) and total flavonoid content (TFC) on antioxidant activities and to determine flavonoid compounds. &lt;b&gt;Materials and Methods:&lt;/b&gt; Antioxidant activities were determined using 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and Cupric Ion Reducing Antioxidant Capacity (CUPRAC) methods. The TPC and TFC were determined by UV-visible spectrophotometry. The correlation between TPC, TFC and antioxidant activity was analyzed using Pearson's method. Flavonoid compound content was performed by HPLC. &lt;b&gt;Results:&lt;/b&gt; The ethyl acetate pepino fruit extract expressed the highest antioxidant activity by DPPH and CUPRAC assays. The highest TPC was obtained from the ethyl acetate extract of pepino stem (18.493 g GAE/(100 g)), while the highest TFC was obtained from the hexane extract of pepino leaves (9.541 g QE/(100 g)). &lt;b&gt;Conclusion:&lt;/b&gt; The DPPH and CUPRAC assays demonstrated that pepino exhibits potential as a source of natural antioxidants, especially in its fruit part.

SmuMYB113 is the determinant of fruit color in pepino (Solanum muricatum).

Pepino (Solanum muricatum) is an herbaceous crop phylogenetically related to tomato and potato. Pepino fruit vary in color, size and shape, and are eaten fresh. In this study, we use pepino as a fruit model to understand the transcriptional regulatory mechanisms controlling fruit quality. To identify the key genes involved in anthocyanin biosynthesis in pepino, two genotypes were studied that contrasted in foliar and fruit pigmentation. Anthocyanin profiles were analyzed, as well as the expression of genes that encode enzymes for anthocyanin biosynthesis and transcriptional regulators using both RNA-seq and quantitative PCR. The differential expression of the transcription factor genes R2R3 MYB SmuMYB113 and R3MYB SmuATV suggested their association with purple skin and foliage phenotype. Functional analysis of these genes in both tobacco and pepino showed that SmuMYB113 activates anthocyanins, while SmuATV suppresses anthocyanin accumulation. However, despite elevated expression in all tissues, SmuMYB113 does not significantly elevate flesh pigmentation, suggesting a strong repressive background in fruit flesh tissue. These results will aid understanding of the differential regulation controlling fruit quality aspects between skin and flesh in other fruiting species.

Metabolomics analysis of quality components metabolism during the growth process of pepino (Solanum muricatum) fruit

ABSTRACT Pepino (Solanum muricatum), a horticultural crop that has experienced significant growth in the highlands of China over the past two decades, is widely embraced by consumers due to its distinctive taste and nutritional advantages. This study focused on the cultivar ‘Qingcanxiang’ of pepino grown on the Qinghai-Tibetan Plateau was analyzed using UPLC-QTOF-MS and RNA-seq transcriptome sequencing. Fruit samples were collected at three distinct stages of development, and the results of the metabolomics and transcriptomics were compared and correlated. The study’s findings indicate that the ‘Qingcanxiang’ fruit contained a total of 187 metabolites, comprising 12 distinct categories of compounds, including amino acids and their derivatives, organic acids, sugars and alcohols, phenols and phenolic acids. Of these metabolites, 94 were identified as differential. Significant variations in nutrient composition were observed across the three growth stages of the fruit. Specifically, the stage spanning from the growth to the maturation was identified as the critical stages for nutrient accumulation and flavor development. Transcriptome sequencing analysis revealed a set of highly associated genes between aspartate and quinic acid, namely SIR2, IRAK4, RP-L29, and CCNH. These genes are potentially involved in the regulation of both amino acid and phenolic acid synthesis. Through the application of metabolomics and transcriptomics, this investigation elucidates the alterations in metabolites and the underlying molecular regulatory mechanisms of pepino fruits during three growth stages. The findings furnish a theoretical foundation for the evaluation of nutritional quality and the enhancement of breeding strategies for pepino.

Assessment of suitable cultivation region for Pepino (Solanum muricatum) under different climatic conditions using the MaxEnt model and adaptability in the Qinghai–Tibet plateau

Pepino (Solanum muricatum), a member of the Solanaceae family originating from South America, is cultivated globally. However, the cultivation range and suitable habitat of Pepino have not been extensively studied, which hampers the further development of its cultivation industry. Therefore, we aimed at enrich and expand the planting scope of Pepino. Currently, the main cultivation areas of Pepino in China are the Yunnan–Guizhou Plateau and the Loess Plateau, where the altitude is above 1000 m. In this study, ArcGIS combined with the MaxEnt model was used for prediction, whose area under curve value was 0.949. The main climatic factors affecting the distribution of Pepino are temperature seasonality, annual means temperature, mean temperature of the coldest quarter, elevation, isothermality, and the climate factors, and their cumulative contribution rate of 87.6%. Pepino's main potential distribution areas are located in Yunnan–Guizhou Plateau, Yunnan Province, Hexi Corridor of Loess Plateau, and low altitude areas of Qinghai–Tibet Plateau. The main distribution ranges from 1000 to 2000 m above sea level, and the total suitable area accounts for 20.09% of China's total land area. The prediction results reveal an expanded potential area for Pepino, with no significant migration in the central region of the main potential distribution area by 2050 and 2070. No studies have been conducted on the open-area cultivation of Pepino in northern China. Our findings revealed that the yield and quality in the four experimental sites and final actual cultivation conditions were consistent with the predicted results of MaxEnt. The yiel d per plant in Xunhua and Minhe was significantly different from that in Xining, which was low, and that in Minhe was the highest. Overall, the fruit quality in the Xining region was the lowest among the three regions, which was related to the climatic differences in each region. These results align with the predicted outcomes, indicating that Xining is the least suitable area. Further, these data verify the accuracy of the prediction results. The climate data of the four regions were analyzed simultaneously to elucidate the influence of different climate conditions on the growth of Pepino. Our findings are of considerable significance for introducing characteristic horticultural crops in the Qinghai–Tibet Plateau and using the MaxEnt model to predict the cultivation range of crops.

Effect of ethanol solvent concentrations in pepino melon fruit (Solanum muricatum Aiton) extraction on total flavonoid, phenolic, and beta-carotene content

Effect of ethanol solvent concentrations in pepino melon fruit (Solanum muricatum Aiton) extraction on total flavonoid, phenolic, and beta-carotene content

Evaluation of the Attractant Effect of Solanum muricatum (Solanales: Solanaceae) on Gravid Female Adults of Zeugodacus tau (Diptera: Tephritidae) and Screening of Attractant Volatiles.

Zeugodacus tau (Walker) (Diptera: Tephritidae) is a pest seriously harmful to Solanaceae crops and was found to oviposit on the pepino melon Solanum muricatum (Aiton). To date, the differences in the ability of the fruits of S. muricatum and other Solanaceae crops to attract gravid Z. tau females have seldom been reported. Oviposition and trapping bioassays were performed to clarify whether such differences existed. A combination of GC-MS and the Y-tube olfactometer system was used to identify and determine the compounds inducing behavioral responses in gravid Z. tau females to the volatile odors of S. muricatum. The results show that S. muricatum odors play a role in attracting gravid Z. tau females. The odors of Solanaceae crops influence their ability to attract these organisms. The nine compounds from the volatiles of S. muricatum induce tendency or repellency responses in gravid Z. tau females. Hexyl acetate, butyl acetate, amyl actate, and isoamyl acetate caused tendency behavior in gravid Z. tau females, while hexyl hexanoate, butyl isovalerate, butyl valerate, and isoamyl hexanoate caused repellency behavior. Heptyl acetate caused repellency behavior in gravid Z. tau females at higher concentrations (5 mg/mL) but caused tendency behavior at a low concentration (0.5 mg/mL). These results suggest that vigilance against the harm caused by Z. tau is required during the cultivation of S. muricatum. The nine compounds of the volatile odors of S. muricatum could help to develop attractants and repellents for gravid Z. tau females. These results are beneficial for preventing Z. tau females from harming S. muricatum, developing attractants and repellents for Z. tau females, and establishing a system of ecological control for Z. tau females.

Flower abortion of pepino melon (Solanum muricatum Ait.) as influenced by NPK fertilizer rates and growing environment

Flower abortion is the detachment of flowers from the plant. A study was conducted at Egerton University, Kenya in 2018 to 2020 to investigate the effect of NPK fertilizer rates (0, 100, 200. 300 and 400 kg ha-1) on flower abortion of field and greenhouse grown pepino melons. The experiment was laid out in a randomized complete block design with three replications. Data was collected on number of flowers, number of aborted flowers, viable and non-viable pollen and in vitro pollen germination. Data were analysed using analysis of variance with the SAS statistical package. Significant means were separated using Tukey’s Honestly Significant Difference at p≤0.05. Results indicated that field grown plants supplied with 200 and 300 kg NPK ha-1 had 10.28 and 11.18 flowers per truss respectively in trial one. In trial two, field grown plants supplied with 300 kg NPK ha-1 had 11.32 flowers per truss. Greenhouse grown plants supplied with 300 kg NPK ha-1 had 20.61 and 14.19 aborted flowers in trial one and two respectively. High pollen viability was recorded from non-aborted flowers obtained from field grown plants supplied with 300 kg NPK ha-1 with a pollen viability of 94.48% and 93.97% in trial one and two respectively. Pollen from non-aborted flowers obtained from field grown plants supplied with 300 kg NPK ha-1 had the highest pollen germination of 68.72 and 67.72% in trial one and two respectively. Application of 200 and 300 kg NPK ha-1 for field and greenhouse grown pepino melon plants led to reduced flower abortion, high number of flowers per truss, high pollen viability and pollen germination.

Systematic Investigation of TCP Gene Family: Genome-Wide Identification and Light-Regulated Gene Expression Analysis in Pepino (Solanum Muricatum)

Plant-specific transcription factors such as the TCP family play crucial roles in light responses and lateral branching. The commercial development of S. muricatum has been influenced by the ease with which its lateral branches can be germinated, especially under greenhouse cultivation during the winter with supplemented LED light. The present study examined the TCP family genes in S. muricatum using bioinformatics analysis (whole-genome sequencing and RNA-seq) to explore the response of this family to different light treatments. Forty-one TCP genes were identified through a genome-wide search; phylogenetic analysis revealed that the CYC/TB1, CIN and Class I subclusters contained 16 SmTCP, 11 SmTCP and 14 SmTCP proteins, respectively. Structural and conserved sequence analysis of SmTCPs indicated that the motifs in the same subcluster were highly similar in structure and the gene structure of SmTCPs was simpler than that in Arabidopsis thaliana; 40 of the 41 SmTCPs were localized to 12 chromosomes. In S. muricatum, 17 tandem repeat sequences and 17 pairs of SmTCP genes were found. We identified eight TCPs that were significantly differentially expressed (DETCPs) under blue light (B) and red light (R), using RNA-seq. The regulatory network of eight DETCPs was preliminarily constructed. All three subclusters responded to red and blue light treatment. To explore the implications of regulatory TCPs in different light treatments for each species, the TCP regulatory gene networks and GO annotations for A. thaliana and S. muricatum were compared. The regulatory mechanisms suggest that the signaling pathways downstream of the TCPs may be partially conserved between the two species. In addition to the response to light, functional regulation was mostly enriched with auxin response, hypocotyl elongation, and lateral branch genesis. In summary, our findings provide a basis for further analysis of the TCP gene family in other crops and broaden the functional insights into TCP genes regarding light responses.

First Report of Phytophthora infestans Causing Late Blight on Pepino (Solanum muricatum) in China.

Solanum muricatum, known as pepino or melon pear, is a species of evergreen shrub grown for its sweet edible fruits, which was introduced in Yunnan about 20 years ago. Since 2019 to now, serious blight disease was observed on foliages, haulms and fruits of pepino plants in Shilin (25°N, 103°E), which is the biggest pepino production area in China. The symptomatic blighted plants showed water-soaked and brown foliar lesions, haulm brown necrosis, black-brown and rotting fruits, and overall plant decline. The samples with typical disease symptoms were collected for pathogen isolation. After surface sterilization, disease samples were cut into small pieces and placed on rye sucrose agar medium amended with both 25 mg/liter rifampin and 50 mg/liter ampicillin, then incubated in the dark at 25℃ for 3 to 5 days. White fluffy colonies of mycelia that grew from the edge of diseased tissues were further purified and subcultured on rye agar plates. All purified isolates were identified as Phytophthora spp. based on morphological characteristics (Fry 2008). Sporangiophores were nodular and sympodial branches with swellings at the points where sporangia were attached. Sporangia that were hyaline and the average size were 22×40 μm were formed on the tip of sporangiophores and appeared as subspherical, ovoid, ellipsoid or lemon shaped with half-papillate on the spire. Mature sporangia were easilly detached from sporangiophores. For pathogenicity tests, healthy leaves, haulms and fruits of pepino were inoculated with 1×104 cfu/ml zoospore suspension of Phytophthora islolate (RSG2101), and controls were treated with sterile distilled water, respectively. After 5 to 7 days postinoculation, all Phytophthora-inoculated leaves and haulms showed water-soaked and brown lesions with white mold layer, fruits showed dark-brown firm lesions which got expanded and rotted the entire fruit. The symptoms were same as those occurred in natural fields. In contrast, no disease symptoms appeared in the control tissues. Phytophthora isolates could be reisolated and showed same morphological characteristics from the infected tissues of leaves, haulms, and fruits, sufficing Koch's postulates. Two common molecular targets of the internal transcribed spacer (ITS) region of ribosomal DNA and partial cytochrome c oxidase subunit II (CoxII) of the Phytophthora isolate (RSG2101) were amplified and sequenced with primers ITS1/ITS4 and FM75F/FM78R (Kroon et al. 2004). The ITS and CoxII sequence data were deposited in GenBank under accession numbers OM671258 and OM687527, respectively. Blastn analysis of both ITS and CoxII sequences showed 100% identity with isolates of P. infestans (MG865512, MG845685, AY770731 and DQ365743, respectively). Phylogenetic analysis also indicated that RSG2101 isolate and known P. infestans isolates localized in the same evolutionary branch based on sequences of ITS and CoxII, respectively. Based on these results, the pathogen was identified as P. infestans. It is known that P. infestans infection of pepino occurrs in Latin America and then it was recorded in other parts of the world such as New Zeeland and India (Hill, 1982; Abad and Abad,1997; Mohan et al. 2000).To our knowledge, this is the first report of late blight on pepino caused by P. infestans in China, which will be helpful to develop efficient blight management strategies on pepino.

PHYSICOCHEMICAL PROPERTIES AND ANTIOXIDANT ACTIVITY OF SOME TROPICAL FRUITS

They were determined the physical and chemical properties, antioxidant capacity and mineral content of tropical fruit respectively: : passion fruit (Passiflora edulis), carambola (Averrhoa carambola), sweet pepino (Solanum muricatum), guava (Psidium guajava), goldenberry (Physalis peruviana) and goji berries (Lycium chinense. Fruits were purchased on the market from imports. It was found a wide variability concerning fruits size and weight by species. The fruit size index ranged from 9.24 in goji berries to 75.78 in sweet pepino. The individual fruit weight ranged between 0.45 g in goji berries to 208.7 g in sweet pepino. The highest content of dry matter was found in passion fruit (27.59%) and the lowest value was recorded in sweet pepino (5.93%). Also, in goji berries and goldenberry we found high values of dry matter content. It is found that all analyzed species contain appreciable amounts of polyphenols, ranging from 26 201 mg/ l equiv gallic acid in goldenberry fruits and 141.966 mg / l gallic acid equiv in goji berries. The highest values of potassium content was found in goji berries (422.34 mg/100 g fm) while carambola fruit were recorded the lowest values (140 832 mg/100 g fm).

Identification of the key metabolites and related genes network modules highly associated with the nutrients and taste components among different Pepino (Solanum muricatum) cultivars

There is considerable knowledge about plant compounds that produce flavor, scent, and aroma. Aside from the similarities, however, groups of plant-produced nutrients and taste components have little in common with each other. Network analysis holds promise for metabolic gene discovery, which is especially important in plant systems where metabolic networks are not yet fully resolved. To bridge this gap, we propose a joint model of gene regulation and metabolic reactions in two different pepino varieties. Differential metabolomics analysis is carried out for detection of eventual interaction of compound. We adopted a multi-omics approach to profile the transcriptome and metabolome analyze differences in phenolic acids, flavonoids, organic acids, lipids, alkaloids, and sugars between LOF and SRF. The two most predominant classes of metabolites are phenolic acids and lipids in pepino. Overall results show enrichment in most DEGs was carbohydrate and biosynthesis of secondary metabolites pathway. Results of DEMs predominantly comprised N-p-coumaroyl agmatine and tryptamine, and significant differences were observed in their expression between LOF and SRF. Integrated DEMs and DEGs specific networks were constructed by combining two types of networks: transcriptional regulatory networks composed of interactions between DEMs and the regulated genes, and pepino metabolite–metabolite interaction networks. Newly discovered features, such as DEGs (USPA, UBE2 and DELLA) involved in the production of secondary metabolites are found in coregulated gene clusters. Moreover, lipid metabolites were most involved in DEMs correlations by OPLS-DA while identifying a significant number of DEGs co-regulated by SENP1, HMGCS et al. These results further that the metabolite discrepancies result from characterized the nutrients and taste components between two pepino genotype. Among the possible causes of the differences between species in pepino metabolite concentrations is co-regulated by these DEGs, continue to suggest that novel features of metabolite biosynthetic pathway remain to be uncovered. Finally, the integrated metabolome and transcriptome analyses have revealed that many important metabolic pathways are regulated at the transcriptional level. The metabolites content differences observed among varieties of the same species mainly originates from different regulated genes and enzymes expression. Overall, this study provides new insights into the underlying causes of differences in the plant metabolites and suggests that genetic data can be used to improve its nutrients and taste components.

An Exploration of Pepino (Solanum muricatum) Flavor Compounds Using Machine Learning Combined with Metabolomics and Sensory Evaluation

Flavor is one of the most important characteristics that directly determines the popularity of a food. Moreover, the flavor of fruits is determined by the interaction of multiple metabolic components. Pepino, an emerging horticultural crop, is popular for its unique melon-like flavor. We analyzed metabolomics data from three different pepino growing regions in Haidong, Wuwei, and Jiuquan and counted the status of sweetness, acidity, flavor, and overall liking ratings of pepino fruit in these three regions by sensory panels. The metabolomics and flavor ratings were also integrated and analyzed using statistical and machine learning models, which in turn predicted the sensory panel ratings of consumers based on the chemical composition of the fruit. The results showed that pepino fruit produced in the Jiuquan region received the highest ratings in sweetness, flavor intensity, and liking, and the results with the highest contribution based on sensory evaluation showed that nucleotides and derivatives, phenolic acids, amino acids and derivatives, saccharides, and alcohols were rated in sweetness (74.40%), acidity (51.57%), flavor (56.41%), and likability (33.73%) dominated. We employed 14 machine learning strategies trained on the discovery samples to accurately predict the outcome of sweetness, sourness, flavor, and liking in the replication samples. The Radial Sigma SVM model predicted with better accuracy than the other machine learning models. Then we used the machine learning models to determine which metabolites influenced both pepino flavor and consumer preference. A total of 27 metabolites most important for pepino flavor attributes to distinguish pepino originating from three regions were screened. Substances such as N-acetylhistamine, arginine, and caffeic acid can enhance pepino‘s flavor intensity, and metabolites such as glycerol 3-phosphate, aconitic acid, and sucrose all acted as important variables in explaining the liking preference. While glycolic acid and orthophosphate inhibit sweetness and enhance sourness, sucrose has the opposite effect. Machine learning can identify the types of metabolites that influence fruit flavor by linking metabolomics of fruit with sensory evaluation among consumers, which conduces breeders to incorporate fruit flavor as a trait earlier in the breeding process, making it possible to select and release fruit with more flavor.