Search Results (19)

Cuticular wax plays an important role in the quality of kumquat (Fortunella crassifolia Swingle) fruit. In this study, the wax morphology, compositional profile of epi- and intracuticular wax, and crucial gene expression in ‘Rongan’ kumquat (RAK) and ‘Huapi’ kumquat (HPK) were analyzed during fruit development. The results showed that the surfaces of two kumquat fruits were covered with an amorphous wax layer containing a small number of platelets. Compared to RAK, HPK contained more abundant and larger wax crystals during fruit development. In two kumquat fruits, the epicuticular wax and its major compositions consistently displayed significantly higher levels than the intracuticular wax. Additionally, their main wax composition shifted from alkanes in the early developmental stages to triterpenoids at harvest in both layers, while aldehydes were specifically enriched in the epicuticular wax. During the fruit development from 90 to 180 DAF, HPK fruit exhibited significantly higher levels of epicuticular wax and its majority fractions than RAK fruit. Meanwhile, the intracuticular wax contents of HPK from 90 DAF to 150 DAF were significantly higher than those in RAK, with triterpenoids accounting for the largest proportion of this increase. qRT-PCR results indicated that the up-regulation of wax-related genes in HPK was linked to its increased epicuticular wax deposition during the development. Overall, this study provided a comprehensive overview of the morphology, composition, and biosynthesis of cuticular wax in kumquat fruit during development. Full article

Arbuscular mycorrhizal fungi (AMF) are known to enhance plant growth via stimulation of root system development. However, the extent of their effects and underlying mechanisms across different citrus genotypes remain to be fully elucidated. This study investigates the impact of Funneliformis mosseae (F. mosseae) inoculation on plant growth performance, root morphology, phosphorus (P), and indole-3-acetic acid (IAA) concentrations, as well as the expression of related synthesis and transporter genes in three citrus genotypes: red tangerine (Citrus tangerine ex. Tanaka), kumquat (Fortunella margarita L. Swingle), and fragrant citrus (Citrus junos Sieb. ex. Tanaka). Following 12 weeks of inoculation, significant improvements were observed in plant height, shoot and root biomass, total root length, average root diameter, second-order lateral root development, root hair density, and root hair length across all genotypes. Additionally, F. mosseae inoculation significantly increased root P and IAA concentrations in the three citrus genotypes. Notably, phosphatase activity was enhanced in F. margarita but reduced in C. tangerine and C. junos following inoculation. Gene expression analysis revealed a universal upregulation of the P transporter gene PT5, whereas expressions of the auxin synthesis gene YUC2, transporter gene LAX2, and phosphatase gene PAP1 were commonly downregulated. Specific to genotypes, expressions of YUC5, LAX5, PIN2, PIN3, PIN6, and expansin genes EXPA2 and EXPA4 were significantly upregulated in C. tangerine but downregulated in F. margarita and C. junos. Principal component analysis and correlation assessments highlighted a strong positive association between P concentration, P and auxin synthesis, and transporter gene expressions with most root morphology traits, except for root average diameter. Conversely, IAA content and phosphatase activities were negatively correlated with these root traits. These findings suggest that F. mosseae colonization notably enhances plant growth and root system architecture in citrus genotypes via modifications in P transport and IAA accumulation, indicating a complex interplay between mycorrhizal symbiosis and host plant physiology. Full article

Fruit peels might be a valuable source of active ingredients for cosmetics, leading to more sustainable usage of plant by-products. The aim of the study was to evaluate the phytochemical content and selected biological properties of hydroglycolic extracts from peels and pulps of Annona cherimola, Diospyros kaki, Cydonia oblonga, and Fortunella margarita as potential cosmetic ingredients. Peel and pulp extracts were compared for their antiradical activity (using DPPH and ABTS radical scavenging assays), skin-lightening potential (tyrosinase inhibitory assay), sun protection factor (SPF), and cytotoxicity toward human fibroblast, keratinocyte, and melanoma cell lines. The total content of polyphenols and/or flavonoids was significantly higher in peel than in pulp extracts, and the composition of particular active compounds was also markedly different. The HPLC-MS fingerprinting revealed the presence of catechin, epicatechin and rutoside in the peel of D. kaki, whereas kaempferol glucoside and procyanidin A were present only in the pulp. In A. cherimola, catechin, epicatechin and rutoside were identified only in the peel of the fruit, whereas procyanidins were traced only in the pulp extracts. Quercetin and luteolinidin were found to be characteristic compounds of F. margarita peel extract. Naringenin and hesperidin were found only in the pulp of F. margarita. The most significant compositional variety between the peel and pulp extracts was observed for C. oblonga: Peel extracts contained a higher number of active components (e.g., vicenin-2, kaempferol rutinoside, or kaempferol galactoside) than pulp extract. The radical scavenging potential of peel extracts was higher than of the pulp extracts. D. kaki and F. margarita peel and pulp extracts inhibited mushroom and murine tyrosinases at comparable levels. The C. oblonga pulp extract was a more potent mushroom tyrosinase inhibitor than the peel extract. Peel extract of A. cherimola inhibited mushroom tyrosinase but activated the murine enzyme. F. margarita pulp and peel extracts showed the highest in vitro SPF. A. cherimola, D. kaki, and F. margarita extracts were not cytotoxic for fibroblasts and keratinocytes up to a concentration of 2% (v/v) and the peel extracts were cytotoxic for A375 melanoma cells. To summarize, peel extracts from all analyzed fruit showed comparable or better cosmetic-related properties than pulp extracts and might be considered multifunctional active ingredients of skin lightening, anti-aging, and protective cosmetics. Full article

The volatiles of different aerial parts of three kumquat species (Fortunella margarita Swingle–Nagami, Fortunella japonica Swingle–Marumi, and Fortunella crassifolia Swingle–Meiwa) growing in Greece were analyzed via GC-MS and evaluated for their antimicrobial properties against nine human pathogenic microorganisms. A total number of 23 compounds were identified in the peel, 38 in the leaves, and 30 in the flowers of the examined species. Limonene was the dominant metabolite in the peels of all three species, germacrene-D was present in the leaves of Nagami and Marumi kumquats, while limonene was the most abundant in the flower of Marumi and Meiwa kumquat but with significant differences in the composition of the total fracture of the essential oil, since compounds with high antimicrobial activity were only present in the flower of Meiwa kumquat. The essential oils from the leaf and peel of the three kumquat species were either inactive or showed weak antimicrobial activity, respectively, against Gram-positive and Gram-negative bacterial strains and pathogenic fungi. Only the essential oil from the flower of F. crassifolia Swingle (Meiwa) showed a stronger effect (MIC values 3.5–7.48 mg/mL) against all the assayed microorganisms. Furthermore, through multivariate statistical analysis, we studied the relationships between the samples regarding their origin (species and plant part), as well as between the chemical composition of the corresponding essential oils and their antimicrobial activity. Considering its chemical profile and antimicrobial activity, the Greek Meiwa flowers’ essential oil seemed a promising essential oil for further exploitation in the food and/or medicinal industry. Full article

In order to understand the genetic diversity of germplasm resources of kumquats in Guangxi, 14 kumquat germplasm resources in Guangxi and 12 accessions from other provinces were analyzed by using SRAP markers. In total, 19 primer pairs with high stability, good reproducibility, and high polymorphism were chosen for analysis of all 26 kumquat genotypes. Among the 104 amplified bands, 90 (86.54%) were polymorphic. SRAP markers were analyzed by employing Principal Coordinate Analysis, Population Structure Analysis, and Hierarchical Cluster Analysis (UPGMA). The classification results showed that the 26 kumquat germplasm resources could be divided into 5 groups, including cultivated kumquat, intergeneric hybrid, wild kumquat from other provinces, wild kumquat, and hybrid kumquat from Guangxi. The Guangxi kumquat germplasm had high genetic diversity, and were clearly divided into three groups: cultivated kumquat, wild kumquat, and hybrid kumquat. Additionally, the eight cultivated kumquat varieties in Guangxi were further divided into two subgroups. Wild kumquat in Guangxi or in other provinces belonged to different groups; meanwhile, the Guangxi kumquat hybrid formed an independent group, thus indicating that Guangxi wild kumquat and hybrid kumquat possess certain specificity, or they possibly belong to different species. Among the tested 26 kumquat accessions, 23 unique genotype-specific SRAP markers were detected for 14 kumquat genotypes, which were positively identified. For the remaining 12 accessions without genotype-specific markers, they were distinguished by various combinations of markers. These results may have certain importance for kumquat genetic research and cultivar selection. Full article

Nowadays, the use of antimicrobial natural agents as alternative food preservatives represents an intriguing case. The purpose of this study was to investigate possible antimicrobial activity of Pistacia lentiscus and Fortunella margarita essential oils (EOs) and to evaluate their commercial potential in the food industry. The main constituents identified by GC/MS in Pistacia lentiscus EO were a-pinene (67.7%), myrcene (18.8%), and β-pinene (3.0%), whereas limonene (93.8%) and myrcene (2.7%) were the dominant compounds in Fortunella margarita EO. The antimicrobial properties were initially assayed and the minimum inhibitory, non-inhibitory, and minimum lethal concentration values against the Escherichiacoli, Listeria monocytogenes, Pseudomonas fragi, Aspergillus niger, and Saccharomyces cerevisiae were determined using a previously published model, combining absorbance measurements with the common dilution method and non-linear regression analysis to fit the data. Their efficiency was further validated in ice cream containing 0.2% (w/w) Pistacia lentiscus, 0.006% (w/w) Fortunella margarita EOs and 2% (w/w) aqueous residue of F. margarita EO deliberately inoculated with 4 logcfu/g Escherichiacoli, Listeria monocytogenes or Pseudomonas fragi, separately. Similarly, the activity of the oils was monitored in fruit juice (lemon, apple, and blackcurrant) containing 0.2% (w/w) Pistacia lentiscus, 0.006% (w/w) Fortunella margarita EOs and 2% (w/w) aqueous residue of F. margarita EO deliberately spiked with 100 spores/mL of Aspergillus niger or 4 logcfu/mL of Saccharomyces cerevisiae, separately. The results showed that microbial viable counts in the supplemented products ranged at significantly lower levels compared to the control samples during storage. Overall, the data indicated that both EOs constitute effective antimicrobial sources with many potent applications in the food industry. Full article

Xanthomonas citri pv. citri (Xcc) and X. citri pv. aurantifolii (Xca) are causal agents of Citrus Bacterial Canker (CBC), a devastating disease that severely affects citrus plants. They are harmful organisms not reported in Europe or the Mediterranean Basin. Host plants are in the Rutaceae family, including the genera Citrus, Poncirus, and Fortunella, and their hybrids. In addition, other genera of ornamental interest are reported as susceptible, but results are not uniform and sometimes incongruent. We evaluated the susceptibility of 32 ornamental accessions of the Rutaceae family belonging to the genera Citrus, Fortunella, Atalantia, Clausena, Eremocitrus, Glycosmis, Microcitrus, Murraya, Casimiroa, Calodendrum, and Aegle, and three hybrids to seven strains of Xcc and Xca. Pathotyping evaluation was assessed by scoring the symptomatic reactions on detached leaves. High variability in symptoms and bacterial population was shown among the different strains in the different hosts, indicative of complex host–pathogen interactions. The results are mostly consistent with past findings, with the few discrepancies probably due to our more complete experimental approach using multiple strains of the pathogen and multiple hosts. Our work supports the need to regulate non-citrus Rutaceae plant introductions into areas, like the EU and Mediterranean, that are currently free of this economically important pathogen. Full article

The use of biomaterials in the synthesis of nanoparticles is one of the most up-to-date focuses in modern nanotechnologies and nanosciences. More and more research on green methods of producing metal oxide nanoparticles (NP) is taking place, with the goal to overcome the possible dangers of toxic chemicals for a safe and innocuous environment. In this study, we synthesized copper nanoparticles (CuNPs) using Fortunella margarita leaves’ extract, which reflects its novelty in the field of nanosciences. The visual observation of a color change from dark green to bluish green clearly shows the instant and spontaneous formation of CuNPs when the phytochemicals of F. margarita come in contact with Cu⁺² ions. The synthesis of CuNPs was carried out at different conditions, including pH, temperature, concentration ratio and time, and were characterized with UV-Vis absorption spectra, scanning electron microscope (SEM) and X-ray diffraction (XRD). The UV-Vis analysis reveals the surface plasmon resonance property (SPR) of CuNPs, showing a characteristic absorption peak at 679 nm, while SEM reveals the spherical but agglomerated shape of CuNPs of the size within the range of 51.26–56.66 nm. Full article

We previously obtained two intergeneric hybrids with different ploidies, i.e., aneuploid (2n = 28) and eutriploid, from diploid−diploid crosses between ‘Kiyomi’ tangor (Citrus unshiu Marcow. × C. sinensis (L.) Osbeck) and Meiwa kumquat (Fortunella crassifolia Swingle) as novel breeding materials for a seedless kumquat. In this study, we attempted to clarify the construction of the parental genomes of these hybrids by SSR genotyping and genomic in situ hybridization (GISH)−chromomycin A3 (CMA) analysis. SSR genotyping in NSX43 (LG5) and CiBE2227 (LG8) loci revealed that both hybrids inherited one allele from ‘Kiyomi’ tangor and two heterozygous alleles from Meiwa kumquat. The GISH analysis failed due to the high genomic homology between Citrus and Fortunella. At the same time, the CMA karyotype compositions of the two intergeneric hybrids (H15-701: 2A + 1B + 3C + 13D + 7E + 1F + 1Dst; H15-702: 3A + 1B + 2C + 15D + 4E +1F + 1Dst) and both parents (‘Kiyomi’ tangor: 1A + 2B + 2C + 6D + 7E; Meiwa kumquat: 2A + 2C + 12D + 1F + 1Dst) were completely revealed. We identified the parental genome construction and polyploidization processes in both intergeneric hybrids on the basis of these SSR genotypes and CMA karyotype compositions according to the following theory: the SSR genotypes and chromosome compositions were the same as those of the somatic chromosome and two-fold after the first division (even number) in unreduced gametes caused by first-division restitution (FDR) and second-division restitution (SDR), respectively. Consequently, we determined that both intergeneric hybrids may have had two genomes derived from the 2n male unreduced gamete as a result of the FDR of the Meiwa kumquat. In addition, most horticultural traits of the leaves, flowers, and fruits of both hybrids showed intermediate traits of the parents, but the fruit sizes and flowering habits were more like those of the two inherited genomes of Meiwa kumquat. Full article

Piercing–sucking insects are important crop pests, and an understanding of their feeding behavior and population development plays a crucial role in studying insect population dynamics and crop resistance. In our study, we examined the probing behavior of the brown citrus aphid, Toxoptera citricida, using electropenetrography and assessed its population development after 8 days on seven host plants: Yuzu, Citrus junos Sieb. ex Tanaka; Rough Lemon, C. jambhiri Lush.; ‘Luofu’ kumquat, Fortunella margarita Swingle; ‘Olinda’ valencia orange, C. sinensis (L.) Osbeck; ‘Yanxiwanlu’ Ponkan, C. reticulata Blanco; ‘Rohde Red’ valencia orange, C. sinensis; and ‘Eureka’ lemon, C. limon (L.) Osbeck. The results demonstrated that probing by the brown citrus aphid differed significantly according to the target hosts. Toxoptera citricida produced significantly more pathway activities on Eureka than on Rough Lemon and Yuzu. Toxoptera citricida spent more time from the first probe to first salivation into phloem sieve elements on Eureka compared to Yuzu. In addition, the total duration of ingestion from sieve cells of each aphid in the phloem-feeding phase was shortest on Eureka, and this was significantly shorter than that on Yuzu, Rough Lemon, Luofu, and Olinda. The population number of T. citricida on Eureka after 8 days was significantly lower than that on the other hosts. Overall, Eureka was found to have obvious resistance to T. citricida, whereas Yuzu and Rough Lemon were susceptible host plants. These results provide a theoretical basis for exploring aphid-resistant fruit tree resources using resistant varieties. Full article

Fortunella venosa (Rutaceae) is an endangered species endemic to China and its taxonomic status has been controversial. The genus Fortunella contains a variety of important economic plants with high value in food, medicine, and ornamental. However, the placement of Genus Fortunella into Genus Citrus has led to controversy on its taxonomy and Systematics. In this present research, the Chloroplast genome of F. venosa was sequenced using the second-generation sequencing, and its structure and phylogenetic relationship analyzed. The results showed that the Chloroplast genome size of F. venosa was 160,265 bp, with a typical angiosperm four-part ring structure containing a large single copy region (LSC) (87,597 bp), a small single copy region (SSC) (18,732 bp), and a pair of inverted repeat regions (IRa\IRb) (26,968 bp each). There are 134 predicted genes in Chloroplast genome, including 89 protein-coding genes, 8 rRNAs, and 37 tRNAs. The GC-content of the whole Chloroplast genome was 43%, with the IR regions having a higher GC content than the LSC and the SSC regions. There were no rearrangements present in the Chloroplast genome; however, the IR regions showed obvious contraction and expansion. A total of 108 simple sequence repeats (SSRs) were present in the entire chloroplast genome and the nucleotide polymorphism was high in LSC and SSC. In addition, there is a preference for codon usage with the non-coding regions being more conserved than the coding regions. Phylogenetic analysis showed that species of Fortunella are nested in the genus of Citrus and the independent species status of F. venosa is supported robustly, which is significantly different from F. japonica. These findings will help in the development of DNA barcodes that can be useful in the study of the systematics and evolution of the genus Fortunella and the family Rutaceae. Full article

Citrus fruit is preferred in the choice of consumers. Kumquat (F. margarita) is an unconventional citrus of increasing consumer interest because of its exotic flavor, and its functional potential that offers health benefits to consumers. It is a fruit traditionally consumed by whole fruit (peel and pulp), giving this fruit a distinctive flavor. For this reason, this study analyzed the physical, chemical, and nutritional characteristics of kumquat (peel and pulp). The physicochemical analysis was performed according to the Adolfo Lutz Institute. Analysis of moisture, ashes, macronutrients, and total dietary fiber was carried out according to AOAC. Minerals were analyzed by inductively coupled plasma optical emission spectrometry. Vitamins C and E, carotenoids and flavonoids were analyzed by HPLC. Phenolic compounds (Folin-Ciocalteu) and antioxidant capacity (DPPH) were determined by spectrophotometry. The kumquat had low pH, soluble solids content and low caloric value. It was a source of dietary fiber, minerals (K, Ca, P, Mg) and carotenoids; the most expressive was α-carotene (661.81 μg 100 g⁻¹). The ascorbic acid concentration was 2326.24 μg 100 g⁻¹. α-tocopherol (569.00 μg 100 g⁻¹) was the most expressive component of vitamin E. There was a presence of apigenin and eriodictyol. The fruit (peel and pulp) has a high concentration of total phenolic compounds (98.55 ± 1.93 mg GAE 100 g⁻¹) and good antioxidant capacity (62%) was found. Kumquat is a good source of fiber and vitamin A, and due to its antioxidant capacity and the presence of other essential and beneficial nutrients for a diet, consumption of kumquat can be suggested to complement the diet. This fruit is a viable food alternative, and its consumption should be encouraged, contributing a source of income, sovereignty, and food security. Full article

The summertime flowers of the ever-flowering Meiwa kumquat (Fortunella crassifolia Swingle) are the most useful for fruit production in Japan; however, summertime flowers bloom in three or four successive waves at approximately 10 day intervals, resulting in fruit of different maturity occurring on the same tree. Soil water deficit (SWD) treatment has been shown to reduce the flowering frequency and improve harvest efficiency; therefore, in this study, the effects of SWD treatment on the accumulation of soluble sugars in each tree organ above-ground were examined and it was discussed how SWD affects the whole-tree water relations and sugar accumulation by osmoregulation. The number of first-flush summertime flowers was higher in SWD-treated trees than non-treated control (CONT) trees (177.0 and 58.0 flowers, respectively), whereas the second- and third-flush flowers were only observed in CONT trees. The soluble sugar content was higher in SWD treated trees than CONT trees for all organs and tended to be higher in current-year organs than previous-year organs; however, when the sugar content of the current-year spring stems exceeded approximately 100 mg g⁻¹ dry weight, the current-year leaf water potential decreased sharply and the rate of increase in the number of first-flush flowers also tended to decrease. SWD treatment significantly increased the total sugar content of the xylem tissue of the scaffold branches to three times the value in CONT trees (p = 0.001); however, the increase was observed even in sucrose, a disaccharide, similar to that in monosaccharides such as glucose and fructose. These results suggest that the increased sugar levels in the xylem tissue resulted from not only osmoregulation but also other factors as well; therefore, these sugars may affect whole-tree water relations as well as the development of flower buds. Full article

A ploidy chimera of the Meiwa kumquat (Fortunella crassifolia Swingle), which had been induced by treating the nucellar embryos with colchicine, and had diploid (2n = 2x = 18) and tetraploid (2n = 4x = 36) cells, was examined for its ploidy level, morphological characteristics, and sizes of its cells in its leaves, flowers, and fruits to reveal the ploidy level of each histogenic layer. Furthermore, the chimera was crossed with the diploid kumquat to evaluate the ploidy level of its reproductive organs. The morphological characteristics and the sizes of the cells in the leaves, flowers, and fruits of the chimera were similar to those of the tetraploid Meiwa kumquat and the ploidy periclinal chimera known as “Yubeni,” with diploids in the histogenic layer I (L1) and tetraploids in the histogenic layer II (L2) and III (L3). However, the epidermis derived from the L1 of the chimera showed the same result as the diploid Meiwa kumquat in all organs and cells. The sexual organs derived from the L2 of the chimera were significantly larger than those of the diploid. Moreover, the ploidy level of the seedlings obtained from the chimera was mostly tetraploid. In the midrib derived from the L3, the chimera displayed the fluorescence intensity of a tetraploid by flow cytometric analysis and had the same size of the cells as the tetraploid and the Yubeni. According to these results, the chimera is thought to be a ploidy periclinal chimera with diploid cells in the outermost layer (L1) and tetraploid cells in the inner layers (L2 and L3) of the shoot apical meristem. The chimera had desirable fruit traits for a kumquat such as a thick pericarp, a high sugar content, and a small number of developed seeds. Furthermore, triploid progenies were obtained from reciprocal crosses between the chimera and diploid kumquat. Full article

In this study the native carotenoids composition in kumquat (Fortunella margarita) (peel + pulp) from Brazil was determined for the first time by a HPLC-DAD-APCI/MS (high performance liquid chromatography-diode array detector-atmospheric pressure chemical ionization/mass spectrometry), methodology. Eleven carotenoids were successfully identified and quantified in kumquat: four carotenoids in the free form and seven carotenoids in the esterified form. β-citraurin-laurate was the carotenoid found in the highest content (607.33 µg/100 g fresh matter), followed by β-cryptoxanthin-laurate (552.59 µg/100 g). The different esterified forms of β-citraurin and β-cryptoxanthin represented 84.34% of the carotenoids found, which demonstrates the importance of esterification in natural fruits. β-carotene and free xanthophylls (β-cryptoxanthin, lutein and zeaxanthin) represented 5.50% and 14.96%, respectively, of total carotenoids in kumquat. The total carotenoid content of kumquat from Brazil was very high (2185.16 µg/100 g), suggesting that this fruit could contribute significantly to the intake of important bioactive compounds by the population. Full article