Jujube Cultivars Research Articles

Application of K-means algorithm in amino acid data set of different jujube cultivars

Application of K-means algorithm in amino acid data set of different jujube cultivars

Establishment of the cell suspension culture system for the jujube cultivar ‘Fengmiguan’

Establishment of the cell suspension culture system for the jujube cultivar ‘Fengmiguan’

Early performance of jujube cultivars in the southwestern Unites States

Early performance of jujube cultivars in the southwestern Unites States

Quantification and identification analysis of Ziziphus jujuba Mill. peel pigmentation at different developmental stages.

The fruit peel of a color mutant jujube cultivar, 'Sanbianhong' (SBF), was investigated using an ultra-high performance liquid chromatography quadrupole Orbitrap mass spectrometry (UHPLC-Q-Orbitrap MS) at five ripening stages (S1, Young fruit stage; S2, swelling stage; S3, white-mature stage; S4, pre-mature stage and S5, mature stage). Lutein, β-carotene, chlorophyll a, chlorophyll b, and 13 anthocyanins were identified. Chlorophyll a and cyanidin 3-O-galactoside were considered key color metabolites in S1 with the content of 1.083mg/g of fresh weight (FW) and 4.585mg/g of FW, respectively. Delphinidin (0.488mg/g FW) and cyanidin (6.259mg/g FW) were identified as the key pigments in S3. Delphinidin 3-O-glucoside (0.256mg/g FW) was identified as the key anthocyanin in maturity S5. Herein, the identification and quantitation of pigment-related metabolites of SBF were studied for the first time, and the results provide a theoretical basis for understanding the pigment changes of jujube fruit during ripening.

Comparative transcriptome analysis of leaves of sour jujube seedlings under salt stress

Sour jujube is a tree species native to China, which has often been used as the rootstock for the propagation of other cultivars of jujube. In addition, its fruit can be used in the practice of traditional Chinese medicine. Thus, sour jujube has been regarded as a highly valuable plant scientifically and ecologically. Sour jujube is mostly planted in Northwest China and has extremely high salt tolerance. However, the molecular mechanism of its salt tolerance is yet to be fully understood. This study was carried out in the Laboratory of Agricultural College of Dalian Nationalities University. Two treatments were performed on the leaves of sour jujube seedlings with the experimental group (H3) being treated by 300 mM NaCl for 3 h, and the control group (CK) by sterile water for 3 h. A total of 47.02 GB of valid data and 32,730 annotated genes were obtained. Based on the gene expression in the comparison group, 2295 significantly differentially expressed genes (DEGs) were obtained, of which 807 and 1488 were upregulated and downregulated, respectively. According to gene function annotation and enrichment analysis, 148 genes were obtained, which are mainly involved in signal transduction of plant hormones (38), homeostasis of cell walls (27), secondary metabolism of organic matter (32), and redox reactions (20) in the leaves of sour jujube seedlings under salt stress. Among these DEGs, some stress-related transcription factors (31) were also identified. In addition, under salt stress, raffinose family oligosaccharide (RFO) metabolism in sour jujube seedlings was found to be greatly accelerated. By investigating the molecular responses of jujube seedlings under salt stress, our study provides a scientific basis for jujube cultivation in saline-alkali land, which is beneficial to further improvement of the salt tolerance of grafted jujube trees.

Bioactive compounds, antioxidant activities and flavor volatiles of lager beer produced by supplementing six jujube cultivars as adjuncts

Lager beer with high content of cyclic adenosine monophosphate (c-AMP) and strong antioxidant activity was produced by supplementing six jujube cultivars (Ziziphus Jujuba cv. Hetian, Muzao, Huizao, Goutou, Jinsixiaozao, and Banzao) as adjuncts. Jujube supplementation significantly increased total phenolic and flavonoids contents of final beers, and therefore improved antioxidant activities based on DPPH, ABTS and FRAP methods, especially for Banzao supplementation, exhibiting the highest antioxidant activities, increasing by 31.00%, 20.81% and 43.66%, respectively, which were positively correlated with protocatechuic acid, p-coumaric acid and rutin levels. Furthermore, hierarchical cluster analysis revealed that jujube supplementation significantly influenced flavor formation in final beers. There were 17 new volatile compounds formation after jujube supplementation, including one alcohol, 11 esters, two acids and three aldehydes, suggesting the improved complexity of beer flavor. In addition, high contents of c-AMP ranging from 4.02 to 15.14 μg/mL were observed in final beers fermented by jujube supplementation, endowing beer with a new health function.

Accurate Cultivar Authentication of Jujube Fruits Using Nano-Fluidic Genotyping of Single Nucleotide Polymorphism (SNP) Markers

Chinese jujube (Ziziphus jujuba Mill.) is an economically important fruit tree that is highly adapted to marginal crop lands and can be grown under a very broad range of climate conditions. Jujube fruits produced from several traditional cultivars in Ningxia, China have enjoyed a premium market price due to their unique flavor and quality attributes. One problem with the high-end jujube market is the adulteration of premium cultivars. The accurate identification of the genetic identity of single jujube fruits is essential for cultivar traceability and authentication. The multi-locus SNP barcoding approach offers an effective solution for cultivar authentication of jujube fruits. To identify variant SNP sequences a nanofluidic array approach was used to test the efficacy of this method with DNA extracted from the fruit pulp of eight jujube cultivars from Ningxia, China. The SNP marker profiles identified the genetic identity of each fruit unambiguously based on multilocus matching and ordination analysis. Results for repeated sampling of multiple fruits from the same tree (using independent DNA extractions) showed a high level of concordance, which demonstrated the reliability of SNP based genotyping platform. This method can handle 100 s to 1000 s of samples per day (based on the platform used). It is robust and cost-effective and has a high potential for its practical application in the jujube industry. The developed method and protocol can be readily applied for botanical authentication of other stone fruits in general.

Active compound analysis of Ziziphus jujuba cv. Jinsixiaozao in different developmental stages using metabolomic and transcriptomic approaches

Jujube (Ziziphus jujuba Mill.) is a popular fruit with health benefits ascribed to its various metabolites. These metabolites determine the flavors and bioactivities of the fruit, as well as their desirability. However, the dynamics of the metabolite composition and the underlying gene expression that modulate the overall flavor and accumulation of active ingredients during fruit development remain largely unknown. Therefore, we conducted an integrated metabolomic and transcriptomic investigation covering various developmental stages in the jujube cultivar Z. jujuba cv. Jinsixiaozao, which is famous for its nutritional and bioactive properties. A total of 407 metabolites were detected by non-targeted metabolomics. Metabolite accumulation during different jujube developmental stages was examined. Most nucleotides and amino acids and their derivatives accumulated during development, with cAMP increasing notably during ripening. Triterpenes gradually accumulated and were maintained at high concentrations during ripening. Many flavonoids were maintained at relatively high levels in early development, but then rapidly decreased later. Transcriptomic and metabolomic analyses revealed that chalcone synthase (CHS), chalcone isomerase (CHI), flavonol synthase (FLS), and dihydroflavonol 4-reductase (DFR) were mainly responsible for regulating the accumulation of flavonoids. Therefore, the extensive downregulation of these genes was probably responsible for the decreases in flavonoid content during fruit ripening. This study provide an overview of changes of active components in ‘Jinsixiaozao’ during development and ripening. These findings enhance our understanding of flavor formation and will facilitate jujube breeding for improving both nutrition and function.

Physicochemical properties and antioxidant activities of jujubes (Ziziphus jujuba Mill.): effect of blackening process on different cultivars

ABSTRACT This study aimed to quantitatively assess the physicochemical properties and antioxidant activities of seven jujube cultivars (NYDZ, MZ, TZ, HZ, HTDZ, GTZ, and JSXZ) before and after the blackening process and to select the most suitable cultivar for blackening. Red jujubes were blackened by aging at high temperature (75°C) and humidity (80%) conditions for 6 days. The contents of soluble solids, total phenolics, total flavonoids, polysaccharides, cyclic adenosine monophosphate, 5-hydroxymethylfurfural, and antioxidant activities were analyzed using the spectrophotometric method and high-performance liquid chromatography (HPLC). Results showed that the antioxidant activities of all cultivars were significantly enhanced (p < .05) and the contents of selected bioactive compounds in all cultivars increased after blackening, indicating that blackened jujube had higher nutritional value than red jujube. Correlation analysis showed that the total phenolic compounds were the primary source of jujube antioxidant activities. The heat map showed that HTDZ could be selected as the most suitable cultivar for future production of blackened jujube. Red jujube cultivar with high total phenolic content was the best choice for blackening.

Composition and environmental interpretation of the weed communities in the main planting base of jujube (Ziziphus jujuba Mill. cv. 'LingwuChangzao'), Ningxia province of China.

BackgroundZiziphus jujuba Mill. cv. ‘LingwuChangzao’ is a traditional jujube cultivar in northwest China. It is of great significance to explore the weed community composition and environmental characterization for the ecological control and comprehensive management of weeds in jujube orchards. In this article, a total of 37 species were recorded in 40 sample plots (1 m × 1 m). Moreover, fourteen environmental indicators to characterize the spatial locations, climate and soil nutrient characteristics of the plant communities were adopted.MethodologyThrough the two-way indicator species analysis (TWINSPAN) quantity classification and canonical correspondence analysis (CCA) ranking methods, the types of weed communities in the main planting base of jujube ‘LingwuChangzao’ and the main environmental factors affecting the change and distribution of weed types were analyzed.ResultsThe weed communities within the study area were divided into 15 types by the TWINSPAN classification. There were significant differences in soil factors to the species diversity indices of the weed communities, the diversity of weed communities was negatively correlated with available potassium, whereas positively correlated with soil water content. The CCA results showed that community structure and spatial distribution of weed communities were affected by soil water content, total potassium, soil organic carbon, total phosphorus, total nitrogen. Our results can be used as a reference for orchard weed management and provide a theoretical basis for weed invasion control and creating a higher biodiversity in arable land under the background of environmental change.

Genetic diversity of ber (Ziziphus mauritiana L.) cultivars using physico-chemical characteristics

Abstract The present experiment was conducted to estimate the physico-chemical diversity of twelve Indian jujube cultivars. A sum of fifteen quantitative characters were explored and subjected to multivariate analyses. Significant variability was observed across the ber cultivars under study. Pearson’s correlation analysis identified days to first flower initiation, a higher number of flowers per cluster and a higher number of retained fruits per cluster which could be used as the basis of selection for identification of high yielding ber cultivars. The principal component analysis (PCA) estimates 60.2% of the total variability in ber cultivars is contributed by PC1 and PC2. The scatter plot of the first two components highlights the number of retained fruits per cluster, yield per tree, pulp weight, fruit width, stone weight and number of flowers per cluster as principal characters that played a significant role in the total variability. Further, PCA also helped to identify Mehrun, Manuki and Chhuhara as superior ber cultivars which performed well with respect to the PC1 and PC2. The Mahalanobis D2 statistics grouped all the twelve ber cultivars into five clusters indicating the existence of ample genetic diversity among the cultivars. Considering the inter-cluster distance along with cluster mean it could be concluded that the cultivars of cluster II and Cluster III may be utilized to estimate the combining ability for effective exploitation of heterosis or to isolate desirable transgressive segregants.

Proximate composition, minerals, phytochemicals, and functional activities of jujube fruits grown in Bangladesh

Different varieties of jujube fruits are being grown and consumed in Bangladesh for their nutritional and biological functions. The functional properties of jujube fruits are credited to the abundance of phytochemical compounds. Unfortunately, the quantification and functional characterization of phytochemicals in jujube fruits grown in Bangladesh have not been investigated. To address this, four cultivars of jujube (Ziziphus mauritiana) fruits grown in Bangladesh were characterized with respect to proximate composition, mineral and phytochemical contents with their antioxidant and antidiabetic activities. Investigations showed that all cultivars of jujube fruits contained a significant amount (% DM) of carbohydrate (76.10–77.3), protein (4.23–5.00), fat (1.35–2.33), ash (3.08–3.28), and fiber (5.66–7.35). Calcium, potassium, sodium, and iron were the major minerals in four cultivars of jujube fruits. Apple Kul showed considerably (p < 0.05) highest contents of total phenolic (17.4 mg GAE/g DM), total flavonoid (4.75 mg QE/g DM), and anthocyanin (17.18 mg cyanidin 3-glucoside/g DM) followed by Kolmi Kul, Deshi Kul, and BAU Kul. The vitamin C content followed the order (p < 0.05): BAU Kul > Deshi Kul > Komli Kul > Apple Kul. The carotenoid content was highest in Kolmi Kul. The antioxidant activity was highest in Apple Kul while BAU Kul and Kolmi Kul represented the highest antidiabetic activity. Correlation analysis showed that vitamin C, total phenolic, and total flavonoid content were the main phytochemicals for antioxidant and antidiabetic functions in jujube fruits. Jujube fruits were also found to have maximum contents of phytochemicals and antioxidant activity at the “mature” stage than “ripening start”, “full ripe” and “overripe” stages. Therefore, the results demonstrated that the jujube fruits in Bangladesh have promising potential to be used as functional foods or natural antioxidants with beneficial effects on human health.

Rapid and sensitive quantitation of DDMP (2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one) in baked red jujubes by HS-SPME-GC-MS/MS

Baked red jujube is a common food ingredient used to enrich the nutritional value and enhance the aroma. DDMP (2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one) with intense bitterness and potential toxicity may be present in several baked red jujube-based products but there are no well-defined methods to measure it quickly, sensitively, and accurately. Headspace solid-phase microextraction with gas chromatography-tandem mass spectrometry (HS-SPME-GC-MS/MS) was applied for the analysis of DDMP. The standard curve was linear between the concentrations of 0.01 and 100 μg/mL, with a limit of detection at 0.1 ng/g that below the sensory threshold of DDMP (2.06 μg/g). Five cultivars of baked red jujubes from China were evaluated with the method for DDMP content (4.55–46.50 μg/g). The results indicated that jujube cultivars with a higher molar ratio of proline to glucose, lower moisture content, and stronger ability to resist water stress should be avoided from baking to modulate the formation of DDMP.

The Crosstalk of the Salicylic Acid and Jasmonic Acid Signaling Pathways Contributed to Different Resistance to Phytoplasma Infection Between the Two Genotypes in Chinese Jujube

Jujube witches’ broom disease (JWB), one of the most serious phytoplasma diseases, usually results in the destruction of Chinese jujube (Ziziphus jujuba Mill.). Although most jujube cultivars are sensitive to JWB, we found a few genotypes that are highly resistant to JWB. However, the molecular mechanism of phytoplasma resistance has seldom been studied. Here, we used Chinese jujube “T13,” which has strong resistance to JWB, and a typical susceptible cultivar, “Pozao” (“PZ”), as materials to perform comparative transcriptome, hormone, and regulation analyses. After phytoplasma infection, the differential expression genes (DEGs) were detected at all three growth phases (S1, S2, and S3) in “PZ,” but DEGs were detected only at the first growth phase in “T13.” Meanwhile, no phytoplasma was detected, and the symptoms especially witches’ broom caused by JWB were not observed at the last two growth phases (S2 and S3) in “T13.” Protein–protein interaction analysis also showed that the key genes were mainly involved in hormone and reactive oxygen species (ROS) signaling. In addition, during the recovered growth phase in “T13” from S1 to S2, the level of hydrogen peroxide (H2O2) was significantly increased and then decreased from S2 to S3. Moreover, jasmonic acid (JA) was significantly accumulated in “PZ” diseased plants, especially at the S2 phase and at the S2 phase in “T13,” while the content of salicylic acid (SA) decreased significantly at the S2 phase of “T13” compared to that in “PZ.” The changes in H2O2 and JA or SA were consistent with the changes in their key synthesis genes in the transcriptome data. Finally, exogenous application of an SA inhibitor [1-aminobenzotriazole (ABT)] rescued witches’ broom symptoms, while the contents of both JA and MeJA increased after ABT treatment compared to the control, demonstrating that exogenous application of an SA inhibitor rescued the symptoms of jujube after phytoplasma infection by decreasing the contents of SA and increasing the contents of JA and MeJA. Collectively, our study provides a new perspective on the transcriptional changes of Chinese jujube in response to JWB and novel insights that the crosstalk of JA and SA signaling communicated together to contribute to “T13” JWB resistance.

Physicochemical and antioxidant activity of fruit harvested from eight jujube (Ziziphus jujuba Mill.) cultivars at different development stages

Jujube is a crop highly resistant to drought and salinity, making it one of the main fruit trees in Xinjiang. The present study evaluated the changes in the physicochemical and antioxidant activities of jujube fruit of eight different cultivars from Xinjiang, China. The developmental stages were selected according to the days after full bloom and fruit peel colour during ripening; these stages included young (S1), fruit core-hardening (S2), green ripening (S3), half-red maturity (S4) and complete red. In present study, different cultivars of jujube fruit showed similar chemical profiles, but their amounts showed great variation. HZ had the highest content of sugars, and JY had the highest content of cAMP and cGMP, while relatively higher levels of ascorbic acid, catechin, epicatechin, rutin, proanthocyanidin and antioxidant activity were found in ‘FS’ than in other cultivars, indicating that ‘FS’ could be used as a potential natural antioxidant. Regarding the development stages of jujube fruit, the moisture, ascorbic acid, total polyphenol, catechin, epicatechin, proanthocyanidin and rutin contents decreased during the development of all jujube cultivars, while the fructose, glucose, sucrose, cAMP, and cGMP contents greatly increased. The antioxidant activity determined by DPPH and ABTS radical scavenging decreased as the fruits matured. Therefore, the results suggest that green jujube (S1) could be used for natural antioxidants (catechin, epicatechin, proanthocyanidin) and that the advanced ripening stage(S5) is the proper picking period for fresh fruit and commercial processing.

Investigation of the Volatile Profile of Red Jujube by Using GC-IMS, Multivariate Data Analysis, and Descriptive Sensory Analysis.

The aroma characteristics of six red jujube cultivars (Jinchang—‘JC’, Junzao—‘JZ’, Huizao—‘HZ’, Qiyuexian—‘QYX’, Hetiandazao—‘HTDZ’, and Yuanzao—‘YZ’), cultivated in Xinjiang Province, China, were studied by E-nose and GC-IMS. The presence of acetoin, E-2-hexanol, hexanal, acetic acid, and ethyl acetate played an important role in the classification results. JC, JZ, HZ, and YZ were different from others, while QYX and HTDZ were similar to each other. HZ had the most abundant specific VOCs, including linalool, nonanoic acid, methyl myristoleate, 2-acetylfuran, 1-octen-3-one, E-2-heptenal, 2-heptenone, 7-octenoic acid, and 2-pentanone. HZ had higher intensity in jujube ID, floral, sweet, and fruity attributes. Correlation analysis showed that jujube ID (identity) might be related to phenylacetaldehyde and isobutanoic acid that formed by the transamination or dehydrogenation of amino acids; meanwhile, the sweet attribute was correlated with amino acids, including threonine, glutamic acid, glycine, alanine, valine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine.

Transcriptome Analysis of Jujube (Ziziphus jujuba Mill.) Response to Heat Stress.

Heat stress (HS) is a common stress influencing the growth and reproduction of plant species. Jujube (Ziziphus jujuba Mill.) is an economically important tree with strong abiotic stress resistance, but the molecular mechanism of its response to HS remains elusive. In this study, we subjected seedlings of Z. jujuba cultivar “Hqing1-HR” to HS (45°C) for 0, 1, 3, 5, and 7 days, respectively, and collected the leaf samples (HR0, HR1, HR3, HR5, and HR7) accordingly. Fifteen cDNA libraries from leaves were constructed for transcriptomics assays. RNA sequencing and transcriptomics identified 1,642, 4,080, 5,160, and 2,119 differentially expressed genes (DEGs) in comparisons of HR1 vs. HR0, HR3 vs. HR0, HR5 vs. HR0, and HR7 vs. HR0, respectively. Gene ontology analyses of the DEGs from these comparisons revealed enrichment in a series of biological processes involved in stress responses, photosynthesis, and metabolism, suggesting that lowering or upregulating expression of these genes might play important roles in the response to HS. This study contributed to our understanding of the molecular mechanism of jujube response to HS and will be beneficial for developing jujube cultivars with improved heat resistance.

Integrative Morphological, Physiological, Proteomics Analyses of Jujube Fruit Development Provide Insights Into Fruit Quality Domestication From Wild Jujube to Cultivated Jujube.

Jujube (Ziziphus jujuba) was domesticated from wild jujube (Z. jujuba var. spinosa). Here, integrative physiological, metabolomic, and comparative proteomic analyses were performed to investigate the fruit expansion and fruit taste components in a jujube cultivar ‘Junzao’ and a wild jujube ‘Qingjiansuanzao’ with contrasting fruit size and taste. We revealed that the duration of cell division and expansion largely determined the final fruit size, while the intercellular space in the mesocarp dictated the ratio of mesocarp volume in mature fruits. The high levels of endogenous gibbereline3 (GA) and zeatin in the growing fruit of ‘Junzao’ were associated with their increased fruit expansion. Compared with ‘Junzao,’ wild jujube accumulated lower sugars and higher organic acids. Furthermore, several protein co-expression modules and important member proteins correlated with fruit expansion, sugar synthesis, and ascorbic acid metabolism were identified. Among them, GA20OX involved in GA biosynthesis was identified as a key protein regulating fruit expansion, whereas sucrose-6-phosphate synthase (SPS) and neutral invertase (NINV) were considered as key enzymes promoting sugar accumulation and as major factors regulating the ratio of sucrose to hexose in jujube fruits, respectively. Moreover, the increase of Nicotinamide adenine dinucleotide-Malate dehydrogenase (NAD-MDH) activity and protein abundance were associated with the malic acid accumulation, and the high accumulation of ascorbic acid in wild jujube was correlated with the elevated abundance of GalDH, ZjAPXs, and MDHAR1, which are involved in the ascorbic acid biosynthesis and recycling pathways. Overall, these results deepened the understanding of mechanisms regulating fruit expansion and sugar/acids metabolisms in jujube fruit.

Mining Single Nucleotide Polymorphism (SNP) Markers for Accurate Genotype Identification and Diversity Analysis of Chinese Jujube (Ziziphus jujuba Mill.) Germplasm

Chinese jujube (Ziziphus jujuba Mill.) is an economically important fruit tree with outstanding adaptability to marginal lands and a broad range of climate conditions. There are over 800 cultivars, mostly landraces from China. However, a high rate of mislabeling in Chinese jujube germplasm restricts the sharing of information and materials among jujube researchers and hampers the use of jujube germplasm in breeding. In the present study, we developed a large panel of single nucleotide polymorphism (SNP) markers and validated 288 SNPs by genotyping 114 accessions of Chinese jujube germplasm. The validation resulted in the designation of a set of 192 polymorphic SNP markers that revealed a high rate of synonymous mislabeling in the jujube germplasm collection in Ningxia, China. A total of 17 groups of duplicates were detected, encompassing 49 of the 114 Chinese jujube cultivars. Model-based population stratification revealed two germplasm groups, and the core members of the two groups showed a significant genetic differentiation (Fst = 0.16). The results supported the hypothesis that the cultivated Chinese jujube had multiple origins and multiple regions of domestication. The Neighbor-Joining dendrogram further revealed that this collection is comprised of multiple sub-groups, each including 1-13 closely related cultivars. Parentage analysis of cultivars with known pedigree information proved the efficacy of using these SNP markers for parentage verification. A subset of 96 SNPs with high information index was selected for future downstream application including gene bank management, verification of pedigrees in breeding programs, quality control for propagation of planting materials and support of the traceability and authentication of jujube products.

Determination of drought resistance of fig and jujube cultivars according to leaf dehydration

ISHS VIII International Scientific and Practical Conference on Biotechnology as an Instrument for Plant Biodiversity Conservation (Physiological, Biochemical, Embryological, Genetic and Legal Aspects) Determination of drought resistance of fig and jujube cultivars according to leaf dehydration