Passion fruit ( Passiflora edulis ) is an economically important perennial vine. ‘Mi Yu’ is a hybrid passion fruit cultivar (purple passion fruit × yellow passion fruit) with excellent quality, however, its peel often exhibits poor coloration during summer, which affects both harvest decisions and commercial value. In this study, the effect of paper bagging on the peel coloration and the underlying molecular mechanism of this improvement were explored. Measurements of peel color and pigment-related indicators showed that the white paper bagging treatment significantly increased the a* value and anthocyanin and proanthocyanidin contents of the peel, while decreasing the b* value compared to the control group and other treatment groups, effectively promoting peel coloration. Gene families of key structural genes involved in the anthocyanin biosynthesis pathway in purple passion fruit were identified and validated through clustering analysis. QPCR analysis showed that under white paper bagging conditions, the expression levels of multiple structural genes were significantly increased, included PeCHS1 , and PeCHS7 from the CHS gene family, PeF3H4 and PeF3H5 from the F3H gene family, PeDFR1 and PeDFR2 from the DFR gene family, and PeANS3 , PeANS4 , PeANS5 , and PeANS6 from the ANS gene family. Furthermore, the expression levels of anthocyanin biosynthesis genes were compared between the yellow and purple peel cultivars under natural conditions based on the transcriptome sequencing results. Compared to normal conditions, the expression level of PeCHS1 was found to be particularly significantly increased under white paper bagging treatment. Our results indicate that bagging with white paper bags effectively enhance peel coloration of ‘Mi Yu’ passion fruit during summer by upregulating anthocyanin biosynthetic genes. This provides a practical technical and theoretical foundation for managing peel color in passion fruit production, as well as deeper insight into the molecular mechanism through which bagging treatment improves fruit peel color.

Chinese olive is a characteristic fruit of southern China, exhibits significant flavor variation among cultivars. To investigate the molecular basis of flavor formation in fresh edible Chinese olive cultivars and identify the key metabolites and genes involved in this process, the metabolomics and transcriptomics were used to compare metabolite profiles and gene expressions among non-fresh edible (CY), sweet aftertaste (HG), and mild flavor (MF) cultivars. A total of 934 differentially accumulated metabolites were identified, primarily categorized into terpenoids, flavonoids, amino acids, lipids, sugars and alcohols, organic acids, and polyphenols. Compared with CY, flavonoid was significantly decreased in both HG and MF cultivars, while the levels of glutamic acid and aspartic acid were significantly increased in HG cultivars. Integrated metabolomic and transcriptomic analysis identified the candidate genes related to the biosynthesis of these compounds. The findings indicated that the reduction in flavonoid reduced astringency in fresh edible cultivars. Meanwhile, the increase in umami-related amino acids contributed to the sweet aftertaste of HG culitvars.

Sunburn stress is one of the main environmental stress factors that seriously affects the fruit development and quality of Chinese olive, a tropical and subtropical fruit in south China. Therefore, the understanding of the changes in physiological, biochemical, metabolic, and gene expression in response to sunburn stress is of great significance for the industry and breeding of Chinese olive. In this study, the different stress degrees of Chinese olive fruits, including serious sunburn injury (SSI), mild sunburn injury (MSI), and ordinary (control check, CK) samples, were used to identify the physiological and biochemical changes and explore the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) by using transcriptomics and metabolomics. Compared with CK, the phenotypes, antioxidant capacity, and antioxidant-related enzyme activities of sunburn stress samples changed significantly. Based on DEG-based KEGG metabolic pathway analysis of transcriptomics, the polyphenol and flavonoid-related pathways, including phenylpropanoid biosynthesis, sesquiterpenoid, and triterpenoid biosynthesis, monoterpene biosynthesis, carotenoid biosynthesis, isoflavonoid biosynthesis, flavonoid biosynthesis, were enriched under sunburn stress of Chinese olive. Meanwhile, 33 differentially accumulated polyphenols and 99 differentially accumulated flavonoids were identified using metabolomics. According to the integration of transcriptome and metabolome, 15 and 8 DEGs were predicted to regulate polyphenol and flavonoid biosynthesis in Chinese olive, including 4-coumarate-CoA ligase (4CL), cinnamoyl-CoA reductase (CCR), cinnamoyl-alcohol dehydrogenase (CAD), chalcone synthase (CHS), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS). Additionally, the content of total polyphenols and flavonoids was found to be significantly increased in MSI and SSI samples compared with CK. Our research suggested that the sunburn stress probably activates the transcription of the structural genes involved in polyphenol and flavonoid biosynthesis in Chinese olive fruits to affect the antioxidant capacity and increase the accumulation of polyphenols and flavonoids, thereby responding to this abiotic stress.

Objective:To explore the potential biological activity of flavonoid components in Chinese olive(Canarium album Raeusch.),and the differences in flavonoid components among different germplasm resources of Chinese olive.Methods:The bioactive flavonoid components were identified using network pharmacology and molecular docking analysis,and the accumulation levels of flavonoid components in the germplasm resources were studied by metabolomics.Results:A total of 44 flavonoid components were identified,and 18 potential bioactive flavonoids and 180 targets for them were selected through the TCMSP database,drug-likeness and oral bioavailability.Luteolin,quercetin,catechin and epicatechin were found to be important components that could potentially affect the pharmacological activity of Chinese olive.The 35 key targets identified based on the connectivity between flavonoid components and their targets were enriched in 348 Gene Ontology(GO)terms and 136 Kyoto Encyclopedia of Genes and Genomes(KEGG)signal pathways,involving pharmacological activities such as anticancer,antiviral,antibacterial,and anti-inflammatory function,blood glucose regulation,and liver protection.Through molecular docking and visual analysis,stable combinations between the selected bioactive flavonoid components of Chinese olive and the key targets were found.Conclusion:The integration of metabolomics and network pharmacology can provide a scientific basis for exploring the medicinal value of Chinese olive.Flavonoids of Chinese olive exert various pharmacological activities through a multi-component,multi-target,and multi-pathway mechanism.

Simple sequence repeats（SSR） and single nucleotide polymorphism（SNP） markers have been confirmed to be high sensitivity and specificity. Development of molecular markers related to different types of fruit quality traits of Canarium album（Lour.） Raeusch. can provide reference for its molecular assisted breeding to a considerable extent. The fully mature fruits of C. album cv. Changying and Huiyuan were collected to use as materials. After total RNA extraction and cDNA library construction, the transcriptome was sequenced on the Illumina Novaseq platform, and the SSR, SNP and InDel loci characteristics of the transcriptome were analyzed by MISA 1.0 and GATK3 software. Results showed that a total of 13 935 SSR loci were identified from 10 124 unigenes of C. album fruit transcriptome, the average 1 kb sequence appeared 0.25 SSR loci, the frequency and average length was 22.98% and 14.34 bp, respectively.Among them, the single base repeat type had the largest number of SSR loci（accounting for 66.80%）, with a length of10–64 bp, and an average length of 12.85 bp, the repeat times of repeat motifs were concentrated in 9–12, and the motif with the highest frequency was A/T（accounting for 66.67%）. The number of SSR loci of six base repeat motif type was the least（0.47%）, the length was 30–54 bp, which average length was 31.76 bp, the number of motif repeats was concentrated in 5–8 times, and the motif with the highest frequency was AGATGG/ATCTCC（0.04%）. A total of 284 992SNP loci were detected in the transcriptome of C. album fruit, the average 1 kb sequence contained 5.21 SNP loci;Among them, the number of SNP loci of transformation type was 166 162, including C/T and A/G. The number of SNP loci of transversion type was 118 830, including A/T, A/C, T/G and C/G. In addition, 18 548 InDel loci were found in the transcriptome of C. album fruit, the average 1 kb sequence existed 2.95 InDel loci. The number of unigenes containing one InDel locus was the largest. It was predicted that the unigene containing the most InDel loci might be the callose synthase gene. These results showed that SSR and SNP/InDel markers could be effectively developed through RNA-seq. The SSR loci and SNP/InDel loci were widely distributed in C. album fruits with different quality traits. The results would provide a data basis for the development of identification markers of C. album fruit traits.

Canarium album fruit has great potential to be consumed as a raw material not only for food but also medicine. The diverse active metabolites composition and content of C. album fruits greatly affect their pharmacological effects. However, up to now, there has been no report on the global metabolome differences among fruits from distinct C. album cultivars. In our present study, by using non-targeted metabolomics techniques, we identified 87 DAMs (differentially accumulated metabolites) including 17 types of flavonoids from fruits of four different C. album cultivars. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis revealed that the flavone and flavonol biosynthesis- and flavonoid biosynthesis-related DAMs were major factors determining their metabolome differences. Comparative transcriptomic analysis revealed that 15 KEGG pathways were significantly enriched by genes of the identified 3655 DEGs (differentially expressed genes) among different C. album cultivars. Consistent with the metabolome data, flavonoid biosynthesis-related DEGs, including eight key structural genes (such as FLS, CCoAOMT, CHI, C4H, DFR, LAR, and C3′H, etc.) and several regulatory transcription factor (TF) genes (including 32 MYBs and 34 bHLHs, etc.), were found to be significantly enriched (p < 0.01). Our study indicated that the differential expression of flavonoid biosynthesis-related genes and accumulation of flavonoids played dominant roles in the various metabolome compositions of fruits from different C. album cultivars.

为揭示中国橄榄(Canarium album)种质资源的遗传多样性,采用ISSR和RAPD标记对橄榄主要分布区的86份种质资源进行遗传多样性分析并构建核心种质.结果表明,基于UPGMA遗传相似系数,86份种质资源可分为3个大类;基于STRUCTURE模型聚类,可分为4个类群,这基本符合橄榄的地域性分布规律.采用ISSR和RAPD获得的中国橄榄种质资源的整体遗传多样性水平分别为0.284±0.169和0.244±0.163,多态性位点百分率分别为92.56％和100％,总遗传分化系数分别为0.127和0.142,基因流分别为3.423和3.025,群体间遗传相似系数分别为0.930和0.939,个体间遗传相似系数分别为0.736和0.732.因此,中国橄榄种质资源丰富的遗传多样性主要来源于个体间的遗传分化或变异,且这种遗传多样性存在明显的地域性差异.

为揭示发酵型橄榄果酒的品质特征与香气组分,试验以'长营'橄榄果实为原料进行发酵型果酒制备,并进行主要品质指标测定、香气组分鉴定和感官品评分析.品质测定结果表明,果酒的总多酚、总黄酮、钙、维生素C和总氨基酸的含量分别为0.270±0.014％、0.032±0.002％、106.50±6.36 mg·kg-1、28.00 mg·kg-1和113.57 mg·(100 mL)-1,总酸、总糖的含量分别为6.0±0.1 g·(100 g)-1、3.3±0.1 g·(100 g)-1.气相色谱-质谱联用仪共检测到30种香气组分,其中酯类化合物最多,占82.66％.感官品评分析结果显示,果酒澄清、透明,橄榄果香、酒香良好,酒体单薄但酸涩适中.研究表明,橄榄发酵型果酒果香较浓,其中酯类物质是橄榄果酒香气风味的主要化合物.

"灵峰"和"闽清2号"橄榄是从福州地区的"长营"橄榄实生群体中筛选出的鲜食新品系.2014年起在福建省闽侯县、闽清县和广东省饶平县进行两个品系高接换种试验,观测其农艺性状和果实品质性状.结果表明,"灵峰"橄榄果实椭圆形,平均单果质量7.40 g,可食率81.00％,总糖4.74％,总酸1.16％,可溶性固形物11.40％,钙1 230.00 mg/kg;果皮黄绿色,果肉黄白色,质地脆,化渣无涩味,回甘好,为晚熟类型."闽清2号"橄榄果实纺锤形,平均单果质量7.60 g,可食率82.40％,总糖3.10％,总酸1.19％,可溶性固形物8.83％,钙627.33 mg/kg;果皮绿色,果肉黄白色,质地脆,化渣无涩味,风味清淡,并且表现出丰产和稳产特性,为中熟类型."灵峰"橄榄可作为鲜食品系,"闽清2号"橄榄可作为鲜食兼加工品系进行推广.

以紫色百香果为试材,采后分别用浓度0.2、1、2和5 mmol/L的水杨酸和蒸馏水(对照)浸泡10 min,常温贮藏6、12和18 d后测定其可溶性固形物、可滴定酸、抗坏血酸和可溶性糖等生理指标.结果表明,水杨酸处理18 d可显著提高百香果硬度和商品率,保持良好的外观色泽,并显著降低果实皱缩指数,同时有效延缓果实可溶性固形物、可滴定酸、抗坏血酸和可溶性糖含量的下降,保持较低的固酸比.综合各项指标,1 mmol/L浓度水杨酸处理的保鲜效果更优,果实品质更佳.

Production of passion fruit (Passiflora edulis) is restricted by postharvest decay, which limits the storage period. We isolated, identified, and characterized fungal pathogens causing decay in two passion fruit cultivars during two fruit seasons in China. Morphological characteristics and nucleotide sequences of ITS-rDNA regions identified eighteen isolates, which were pathogenic on yellow and purple fruit. Fusarium kyushuense, Fusarium concentricum, Colletotrichum truncatum, and Alternaria alternata were the most aggressive species. Visible inspections and comparative analysis of the disease incidences demonstrated that wounded and non-wounded yellow fruit were more susceptible to the pathogens than the purple fruit. Purple cultivar showed higher expression levels of defense-related genes through expression and metabolic profiling, as well as significantly higher levels of their biosynthesis pathways. We also found fungi with potential beneficial features for the quality of fruits. Our transcriptomic and metabolomics data provide a basis to identify potential targets to improve the pathogen resistance of the susceptible yellow cultivar. The identified fungi and affected features of the fruit of both cultivars provide important information for the control of pathogens in passion fruit industry and postharvest storage.

A de novo transcriptome analysis was performed in C. album, a temperature sensitive fruit tree in China, after treatment with varied temperatures. A total number of 168,385 transcripts were assembled, comprising of 109,439 unigenes, of which 70,530 were successfully annotated. Compared with control check group (CK), which was treated under 25 °C, the chilling stress (4 °C) treated group (CT), showed about 2810 up-regulated and 2567 down-regulated genes. Whereas, group treated under freezing (− 3 °C) stress (FT) showed an up-regulation and a down-regulation of 1748 and 1459 genes, respectively. GO classification analysis revealed that DEGs related to metabolic processes, single-organism metabolic process, and catalytic activity are significantly enriched in both CT and FT conditions. KEGG pathway enrichment analysis for both CT and FT treatments showed an enrichment of genes encoding or related to glycine/serine and threonine metabolism, alpha-linolenic acid metabolism, carotenoid biosynthesis, photosynthesis-antenna proteins, and circadian rhythm. However, genes related to photosynthesis, carbon fixation in photosynthetic organisms, glutathione metabolism, pyruvate metabolism, nicotinate and nicotinamide metabolism were specifically enriched in CT condition. Nevertheless, FT treatment induced genes related to plant-pathogen interaction, linoleic acid metabolism, plant hormone signal transduction and pentose phosphate pathway. Many of the genes involved in plant hormone signal transduction showed significantly different expression in both FT and CT conditions. However, the change was more evident in FT. Here we present the first of the reports for a de novo transcriptomic analysis in C. album, suggesting that the plant shows differential responses in chilling and freezing temperatures, where the hormone signaling and transduction contribute greatly to FT responses. Our study thus paves way for future research regarding functions of these potentially identified genes.

Due to progress in the industrial development of light-emitting diodes (LEDs), much work has been dedicated to understanding the reaction of plants to these light sources in recent years. In this study, the effect of different LED-based light regimes on growth and performance of passion fruit ( Passiflora edulis ) seedlings was investigated. Combinations of different light irradiances (50, 100, and 200 µmol m −2 s −1 ), quality (red, green, and blue light-emitting LEDs), and photoperiods (10 h/14 h, 12 h/12 h and 14 h/10 h light/dark cycles) were used to investigate the photosynthetic pigment contents, antioxidants and growth traits of passion fruit seedlings in comparison to the same treatment white fluorescent light. Light irradiance of 100 µmol m −2 s −1 of a 30% red/70% blue LED light combination and 12 h/12 h light/dark cycles showed the best results for plant height, stem diameter, number of leaves, internode distance, and fresh/dry shoot/root weights. 14 h/10 h light/dark cycles with the same LED light combination promoted antioxidant enzyme activities and the accumulation of phenols and flavonoids. In contrast, lower light irradiance (50 µmol m −2 s −1 ) had negative effects on most of the parameters. We conclude that passion fruit seedlings' optimal performance and biomass production requires long and high light irradiances with a high blue light portion.

Organic acids are key components that determine the taste and flavor of fruits and play a vital role in maintaining fruit quality and nutritive value. In this study, the fruits of two cultivars of passion fruit Yellow (Passiflora edulis f. flavicarpa) and purple (Passiflora edulis f. edulis) were harvested at five different developmental stages (i.e., fruitlet, green, veraison, near-mature and mature stage) from an orchard located in subtropical region of Fujian Province, China. The contents of six organic acids were quantified using ultra-performance liquid chromatography (UPLC), activities of citric acid related enzymes were determined, and expression levels of genes involved in citric acid metabolism were measured by quantitative real-time PCR (qRT-PCR). The results revealed that citric acid was the predominant organic acid in both cultivars during fruit development. The highest citric acid contents were observed in both cultivars at green stage, which were reduced with fruit maturity. Correlation analysis showed that citrate synthase (CS), cytosolic aconitase (Cyt-ACO) and cytosolic isocitrate dehydrogenase (Cyt-IDH) may be involved in regulating citric acid biosynthesis. Meanwhile, the PeCS2, PeACO4, PeACO5 and PeIDH1 genes may play an important role in regulating the accumulation of citric acid. This study provides new insights for future elucidation of key mechanisms regulating organic acid biosynthesis in passion fruit.

为研究百香果低温胁迫响应机制,以紫果百香果(Passiflora edulia Sims)为试验材料在0℃下低温胁迫处理,以常温处理为对照组(CK),采用Illumina HiSeq测序平台进行转录组测序,并对茉莉酸代谢相关基因进行挖掘.结果显示,共获得百香果转录组数据45.30 Gb,组装得到39 521条Unigene和5 311个差异基因;GO分类显示注释的Unigene分为细胞组件、分子功能及生物过程三大类,其中差异基因数量最多为生物过程大类的代谢过程,包括甾醇生物合成、类黄酮糖脂化、酪氨酸代谢、L-苯丙氨酸生物合成、软木脂生物合成、芥子油苷代谢及长链脂肪-酰基辅酶A代谢等.KEGG途径富集分析结果显示,核糖体途径、淀粉与蔗糖代谢途径、植物激素信号转导途径及植物与病原体互作途径为百香果响应低温胁迫的重要代谢途径.实时定量PCR(qRT-PCR)分析表明,百香果低温胁迫后其茉莉酸代谢途径相关基因A4OC、AOS、JAR1、MYC2、PYL和JAZ均上调表达,该结果与测序获得FPKM值变化趋势较为相似,说明测序结果较为准确.但低温胁迫后,COI1的表达水平呈下调趋势.研究发现,在百香果中茉莉酸对低温胁迫的响应机制大体上与模式植物一致,关于COI1和MYC2等基因的调控方式还有待进一步功能验证.本研究结果为进一步明确百香果抗寒机制提供了科学参考.

Passion fruit (Passiflora edulis) is an important fruit crop with high economic value. Genetic engineering plays an important role in crop improvement with desired traits and gene functional studies. The lack of a simple, efficient, and stable transformation system for passion fruit has greatly limited gene functional studies. In this study, a simple and efficient Agrobacterium-mediated in planta transformation system for passion fruit was established, using Agrobacterium virulent strain EHA105 harboring the binary vectors pCAMBIA1301 and pCAMBIA1302 with GUS and GFP reporter genes. The system requires less time and labor costs than conventional transformation systems, and no additional phytohormones and sterile conditions are required. Regeneration efficiency of 86% and transformation efficiency of 29% were achieved, when the wounds were wrapped with Parafilm and the plants were kept in darkness for 15 days. Approximately 75% of the regenerated plants had a single shoot and 26% multiple shoots. The transformation was confirmed at the DNA and RNA levels as well as by GUS staining and GFP fluorescent measurements. The developed protocol will contribute to the genetic improvement of passion fruit breeding.

基于转录组数据对百香果ARF基因家族(PeARFs)进行鉴定,利用生物信息学软件分析其编码蛋白的理化性质、保守结构域、保守基序、系统进化情况,同时比较了它们在‘福建3号’(黄果)和‘福建1号’(紫果)不同果实成熟阶段的表达差异.共鉴定得到13个PeARF成员,其编码的蛋白质含有365～970个氨基酸,分子质量约为39.95～106.33 ku,等电点为5.40～8.94.保守结构域分析结果显示,所有PeARF蛋白质均具有典型的B3和Auxin-resp结构域,仅4个成员(PeARF6、PeARF8、PeARF12、PeARF13)具有Aux/IAA结构域.保守基序分析表明,PeARFs共包含15个保守基序,每个成员包含保守基序类型和数目不同.亚细胞定位预测结果显示,13个PeARFs均定位于细胞核.系统进化分析结果显示,PeARFs蛋白可分为4个亚家族.13个PeARFs基因在果实不同发育期呈现一定的时间和品种表达特异性,其中PeARF1、PeARF6、PeARF7、PeARF8和PeARF10在两品种中的表达均随着果实的成熟而下降,而PeARF12则随着果实的成熟而上升.本研究表明PeARFs家族中的部分成员可能与果实的成熟密切相关,结果可为进一步揭示百香果ARF基因的功能提供依据.

橄榄是我国热带亚热带特色果树,栽培历史悠久。40年来,我国橄榄研究取得长足进步,在一些领域获得重大突破,有力地支撑了橄榄产业的发展。本文全面梳理40年来我国橄榄研究发展历程及取得的主要成绩,总结橄榄种质资源、栽培技术、果实品质、保鲜加工、药理活性和生物技术等方面取得的重要进展。针对我国橄榄产业存在的问题及发展趋势,建议加强橄榄应用基础研究及产业关键性技术研发,推动橄榄产业转型升级与绿色发展。

贵州省是中国百香果主产区之一,该区域石漠化使土质养分相对匮乏,导致百香果果实品质和产量不高.针对这一现状,笔者总结了多年来取得较好应用效果的省力化种植模式,并与传统种植模式及平顶+垂帘改进模式进行对比分析.结果显示,在省力化种植模式下的平均年产量和优果率均为最高,其次是平顶+垂帘改进模式,最后是传统种植模式;此外,省力化种植模式还能够提高水肥利用率,减少成本投入,降低病虫害发病几率,提质增效效果显著.本研究结果对扩大百香果的种植面积,提高果农经济收入有重要意义.

[目的]南酸枣具有较高的经济价值,随着产业发展,果用型南酸枣品种选育工作滞后成为制约产业转型发展的障碍;通过对资源果实表型性状多样性研究,为果用型南酸枣品种选育提供基础.[方法]以49份南酸枣果实为材料,对果纵径、果横径、果形指数、单果重等17个表型性状指标进行观测分析,并采用主成分分析和聚类分析等方法进行分类研究.[结果]表型数量性状的变异系数为7.07％～29.91％,其变异程度为单果重＞果核重＞果皮重＞果核纵径＞果横径＞果纵径＞可食率＞果核指数＞果核横径＞果形指数.相关性分析发现,可食率与单果重、果纵横径呈极显著正相关,而与果皮重和果核重无相关性.主成分分析表明,前7个主成分累计贡献率为81.61％,第1主成分贡献率为32.98％,特征向量单果重、果纵径、果横径、果核重、果皮重和果核纵径等.聚类分析在欧氏距离11.60处将49份南酸枣资源分为5组.[结论]南酸枣果实各性状间相互影响,即单一性状的改变可能导致果实综合表型性状差异,南酸枣种质资源具有丰富的形态多样性和遗传多样性.