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.

Catalase（CAT）is one of the main antioxidant enzymes in plants. In order to reveal the sequence characteristics and expression patterns of kiwifruit CAT family genes（AcCATs）, genome-wide identification and expression analysis were performed. The genomewide identification and bioinformatics analysis of AcCAT family genes were carried out, and its expression changes in different organs and during fruit storage were analyzed. Nine genes of AcCAT family were identified from kiwifruit genome using bioinformatics method and named as AcCAT1-AcCAT9 respectively according to their chromosome location information. There were high similarities in protein physicochemical properties, gene structure, conserved motifs and cis-acting elements in different members. AcCAT genes were unevenly distributed on four chromosomes, five AcCAT genes formed two tandem duplication gene clusters, and six AcCAT genes had segmental duplication. By psRNAtarget analysis, AcCAT genes were predicted to be mainly regulated by miR166 family members. Phylogenetic analysis showed that 23 CAT proteins from kiwifruit, Camellia sinensis, Gossypium hirsutum and Oryza sativa could be classified into three groups, and the classification was not completely conducted by species. Transcriptome analysis of different kiwifruit organs revealed that AcCAT3 expressed highly in the root, AcCAT1and AcCAT4 expressed highly in the flower, AcCAT2, AcCAT5, AcCAT6, AcCAT8 and AcCAT9 were mainly expressed in the leaf, while AcCAT7was up-expressed both in the root and flower. During the storage of kiwifruit, the expression levels of AcCAT5 and AcCAT6 decreased gradually,but AcCAT1 and AcCAT2 were up-expressed in early stage, while the expression of AcCAT3, AcCAT4 and AcCAT8 increased in late stage.Additionally, the expressions of miR166 family members increased during this process. AcCAT family genes are conservative in evolution, and they play important regulatory roles in the growth and during the storage of kiwifruit.

本文收集了2022年福州、闽侯、永泰、闽清等4个国家气象观测站4～9月的气象数据,分析了气温、降水等2个主要气候因子,研究2022年异常气候对福州地区橄榄花期、幼果期、果实发育期生长发育的影响.结果发现:4～6月气温偏低造成橄榄花期延长;5～6月连续降水和少日照不利于橄榄授粉和果实发育,而有利于病害发生,畸形果、病害果数量增多;7～9月高温干旱造成橄榄果实灼伤严重,影响产量和品质.

The mature fruits of different varieties(lines)of Canarium album L.were selected for transcriptome sequencing,and 296 314 sequences were obtained.MISA software was used to analyze SSR loci,and 86 084 SSR loci were obtained,distributed in 70 686 sequences.The frequency of SSR in the detected sequences was 23.86％,of which 54 735 sequences contained two or more SSR loci,accounting for 68.4％.The SSR sequences in the Chinese olive transcriptome were mainly composed of compound nucleotide,single nucleotide and dinucleotide repeats,accounting for 88.88％of the total SSRs.The dominant motifs in mononucleotide and dinucleotide repeat types were A/T and AG/CT/TC/GA,respectively.The effectiveness and polymorphism of 99 pairs of SSR primers randomly selected from six different Chinese olive lines(species)were screened.Finally,53 effective SSR molecular markers and 12 polymorphic SSR molecular markers were developed.The polymorphism evaluation and population structure analysis of 59 Chinese olive germplasm were carried out by using 12 polymorphic EST-SSR markers.A total of 48 polymorphic loci were detected.The average Shannon diversity index was 0.876,and the average polymorphic information content was 0.426.The population structure of 59 Chinese olive germplasms was analyzed by three methods of mixed group model grouping,UPGMA clustering and PCA.The results of mixed group model analysis were crossed with those of UPGMA clustering and principal component analysis,but the number of groups was different.The mixed group model was divided into three groups.UPGMA cluster analysis was divided into two populations at the genetic similarity coefficient of 0.68,which was the same as the PCA method.The results of the study concluded that the 12 pairs of SSR markers developed were genetically diverse and valid,and provided a reliable basic tool for Chinese olive germplasm resource identification.

为了更好地进行橄榄低温冻害预警,保障福州市橄榄生产,采用福州市橄榄主要产地闽侯县、闽清县气象观测站1991-2021年冬日极端最低气温和橄榄冻害资料,采用数理统计和冻害实例分析验证等方法,建立橄榄不同等级低温冻害日极端最低气温指标.结果表明,初步确立的福州地区橄榄不同等级低温指标为:0级,日极端最低气温T≥0.0;1级,-1.0≤T＜0.0;2级,-2.0≤T＜-1.0;3级,-3.0≤T＜-2.0;4级,T＜-3.0.2016年和2021年1月福州橄榄冻害实况分级与确立的冻害等级低温指标一致率分别达到66.7％和87.5％.说明初步确立的福州地区橄榄不同等级低温冻害日极端最低气温指标与实际冻害情况吻合度较高,可为气象部门开展橄榄生产低温冻害预警服务提供参考.

Long non-coding RNAs (lncRNAs) are crucial players regulating many biological processes in plants. However, limited knowledge is available regarding their roles in kiwifruit ripening and softening. In this study, using lncRNA-seq technology, 591 differentially expressed (DE) lncRNAs (DELs) and 3107 DE genes (DEGs) were identified from kiwifruit stored at 4 °C for 1, 2, and 3 weeks in comparison with non-treated control fruits. Of note, 645 DEGs were predicted to be targets of DELs (DEGTLs), including some DE protein-coding genes (such as β-amylase and pectinesterase). DEGTL-based GO enrichment analysis revealed that these genes were significantly enriched in cell wall modification and pectinesterase activity in 1 W vs. CK and 3 W vs. CK, which might be closely related to the fruit softening during low-temperature storage. Moreover, KEGG enrichment analysis revealed that DEGTLs were significantly associated with starch and sucrose metabolism. Our study revealed that lncRNAs play critical regulatory roles in kiwifruit ripening and softening under low-temperature storage, mainly by mediating the expression of starch and sucrose metabolism and cell wall modification related genes.

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.

Chinese olive (Canarium album), a characteristic fruit tree in tropical and subtropical areas, suffers greatly from low-temperature stress (LTS). The regulatory roles of microRNA (miRNA) in plant LTS responses have been confirmed in many plant species but not in C. album. In this study, a cold-tolerant cultivar ‘Rui’an 3′ (RA) and a susceptible cultivar ‘Qinglan 1’ (QL) treated at 25 °C (control, CK) and −3 °C (cold temperature treatment, CT) were subjected to small RNA (sRNA) and transcriptome sequencing for the exploration of the cold responses of C. album. Comparative sRNA sequencing analysis identified much fewer LTS-responsive, differentially expressed miRNAs (DEMs) in RA (4 DEMs) than in QL (23 DEMs). Cal-miR482-22 was found to be specifically induced by LTS in RA. Cal-miR397-3 was upregulated, while cal-miR398_2-3 and cal-undef-190 were downregulated after LTS only in QL. However, when compared with QL, a higher basic expression of cal-miR397-3, and lower expression of cal-miR398_2-3 and cal-undef-190 were found in RA, suggesting that they may contribute to the cold tolerance of RA. Comparative transcriptome analysis showed that the number of LTS-responsive differentially expressed genes (DEGs) identified in QL was larger than that in RA, and some DEGs were also predicted as the target genes of the identified DEMs, forming multiple differentially expressed miRNA–target gene pairs, such as cal-miR397-3_laccase 2, 4, 17, cal-miR482-22_suppressor of npr1-1, etc. Quantitative real time PCR results showed that the expression changes of DEGs and DEMs in different samples were generally consistent with the sequencing results. Our study indicated that the basic expression levels of some miRNAs (especially the cal-miR397-3, cal-miR398_2-3, and cal-miR482-22), and their target genes contribute greatly to the cold-tolerance characteristics of C. album. Our study is helpful for understanding the roles of miRNAs in the cold resistance and responses of C. album.

利用CodonW程序和EMBOSS在线软件对橄榄叶绿体基因组进行密码子偏好性分析,并研究其密码子偏好性形成的影响因素.结果表明,橄榄叶绿体基因组有效密码子数(ENc)、密码子GC含量(GC)和密码子第3位上的GC含量(GC3s)分别为50.36、0.385和0.305,CGT、CCT和GGT等可作为橄榄叶绿体基因的最优密码子.中性绘图分析、ENc对应分析、偏倚分析和同义密码子相对使用度对应性分析发现,橄榄叶绿体基因组密码子偏好性不是单一因素影响的结果.橄榄叶绿体基因组密码子偏好性较弱,整体上偏好使用A和T,这种偏好性可能受突变压力、自然选择和其他因素的共同作用.

锰超氧化物歧化酶(MnSOD)在植物生长发育与衰老及应对逆境胁迫中发挥重要作用.为探究MnSOD基因在猕猴桃果实后熟软化及采后贮藏过程的作用,本研究以米良1号猕猴桃为试材,克隆了2个MnSOD基因,分别命名为AdMSD1和AdMSD2.AdMSD1包含675 bp的开放阅读框(ORF),编码224个氨基酸,登录号为KY471358;AdMSD2包含690 bp的ORF,编码229个氨基酸,登录号为KY471359.生物信息学分析结果表明,AdMSD1和AdMSD2均编码稳定的碱性亲水蛋白,包含保守金属结合域DVWEHAYY、Mn2+金属结合位点和特征氨基酸.AdMSD1和AdMSD2均由6个外显子和5个内含子组成.进化树结果显示,2个蛋白聚在双子叶植物组的不同分支,属于MnSOD家族的不同成员.定量分析结果表明,AdMSD1在叶片的转录水平最高,在花中的转录水平最低;AdMSD2在花中的转录水平最高,在成熟果中的转录水平最低.2个基因在果实后熟软化过程的转录呈动态变化,但均在软化初期上调,软化Ⅰ期和Ⅱ期下调,进入软化Ⅲ期后再次回升.果实中AdMSD1和AdMSD2的转录水平均在低温贮藏过程中下降.AdMSD1在脱落酸处理的第1和第5天表达上调,而AdMSD2在脱落酸处理后表达下调;AdMSD1在赤霉素处理后表达下调,而AdMSD2在赤霉素处理的第1天表达上调,之后下调.研究结果表明,AdMSDs基因参与猕猴桃果实的后熟软化和采后贮藏过程,为进一步研究SOD在猕猴桃果实采后品质调控中的作用机制奠定了基础.

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.

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.

[目的]明确24％氟茚唑菌胺·四氟醚唑悬乳剂对黄瓜白粉病和黄瓜靶斑病的田间防治效果,为生产上应用提供理论依据.[方法]依照杀菌剂田间药效试验准则进行田间药效试验.[结果]24％氟茚唑菌胺·四氟醚唑悬乳剂216、288 g a.i./hm2处理对黄瓜白粉病的防治效果分别为84.65％和87.30％,对黄瓜靶斑病的防治效果分别为76.74％和81.92％,且对黄瓜无药害.[结论]24％氟茚唑菌胺·四氟醚唑悬乳剂对黄瓜白粉病和黄瓜靶斑病均有较好的防治效果,建议使用浓度为216～288 g a.i./hm2.

对福州市主栽的灵峰、闽清2号和清榄1号橄榄进行氨基酸组分分析和品质评价.结果表明,灵峰的氨基酸总含量最高,达到20.078mg/g,清榄1号的必需氨基酸含量最均衡.在各类氨基酸中,谷氨酸和天门冬氨酸为3个鲜食橄榄品种(系)的主要氨基酸,苏氨酸和赖氨酸的含量相对过剩,而甲硫氨酸和半胱氨酸可能为第一限制氨基酸.在橄榄特征风味形成过程中,组氨酸、丙氨酸和赖氨酸均会影响鲜食橄榄甜味的形成,精氨酸对苦味的形成存在较高的贡献率,天门冬氨酸和谷氨酸的大量存在可能是其鲜味形成的重要因素之一.