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BACKGROUND: Xylella fastidiosa is a multi-host bacterium that can be detected in hundreds of plant species including several crops. Diseases caused by X. fastidiosa are considered a threat to global food production. The primary method for managing diseases caused by X. fastidiosa involves using insecticides to control the vector. Hence, it is necessary to adopt new and sustainable disease management technologies to control not only the insect but also the bacteria and plant health. We demonstrated that N-acetylcysteine (NAC), a low-cost cysteine analogue, is a sustainable molecule that can be used in agriculture to decrease the damage caused by X. fastidiosa and improve plant health. RESULTS: Using 15N-NAC we proved that this analogue was absorbed by the roots and transported to different parts of the plant. Inside the plant, NAC reduced the bacterial population by 60-fold and the number of xylem vessels blocked by bacterial biofilms. This reflected in a recovery of 0.28-fold of the daily sap flow compared to health plants. In addition, NAC-treated citrus variegated chlorosis (CVC) plants decreased the oxidative stress by improving the activity of detoxifying enzymes. Moreover, the use of NAC in field conditions positively contributed to the increase in fruit yield of CVC-diseased plants. CONCLUSION: Our research not only advances the understanding of NAC absorption in plants, but also indicates its dual effect as an antimicrobial and antioxidant molecule. This, in turn, negatively affects bacterial survival while improving plant health by decreasing oxidative stress. Overall, the positive field-based evidence supports the viability of NAC as a sustainable agricultural application. © 2024 Society of Chemical Industry.

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The present study evaluates the chemical compositions and antioxidant and antipathogenic properties of commercial orange (Citrus sinensis (L.) Osbeck) essential oils obtained using the cold-press method (EOP) and the cold-press method followed by steam distillation (EOPD). The chemical compositions of the volatilizable fractions, determined by gas chromatography-mass spectrometry, were similar in both samples. A relatively large amount of γ-terpinene was found in the EOPD (1.75%) as compared to the EOP (0.84%). Monoterpene hydrocarbons with limonene (90.4-89.8%) followed by myrcene (3.2-3.1%) as the main compounds comprised the principal phytochemical group. The non-volatile phenolics were eight times higher in the EOP than in the EOPD. Several assays with different specificity levels were used to study the antioxidant activity. Although both essential oils presented similar reducing capacities, the radical elimination ability was higher for the EOP. Regarding the antipathogenic properties, the EOs inhibited the biomass and cell viability of Staphylococcus aureus and Pseudomonas aeruginosa biofilms. Furthermore, both EOs similarly attenuated the production of elastase, pyocyanin, and quorum-sensing autoinducers as assessed using Gram-negative bacteria. The EOP and EOPD showed important antioxidant and antipathogenic properties, so they could represent natural alternatives to extend the shelf life of food products by preventing oxidation and contamination caused by microbial spoilage.

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Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (X. citri), is a plant disease affecting Citrus crops worldwide. However, little is known about defense compounds in Citrus. Here, we conducted a mass spectrometry-based metabolomic approach to obtain an overview of the chemical responses of Citrus leaves to X. citri infection. To facilitate result interpretation, the multivariate analyses were combined with molecular networking to identify biomarkers. Metabolite variations among untreated and X. citri-inoculated Citrus samples under greenhouse conditions highlighted induced defense biomarkers. Notably, the plant tryptophan metabolism pathway was activated, leading to the accumulation of N-methylated tryptamine derivatives. This finding was subsequently confirmed in symptomatic leaves in the field. Several tryptamine derivatives showed inhibitory effects in vitro against X. citri. This approach has enabled the identification of new chemically related biomarker groups and their dynamics in the response of Citrus leaves to Xanthomonas infection.

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An inflammation response occurs when the body reacts to exogenous and endo enous noxious stimuli, and it helps the body respond to infection and repair tissues, adapt to stress, and remove dead or damaged cells. Anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs are traditionally used to treat inflammation; however, these drugs often cause negative side effects. For this reason, developing and establishing effective alternative medicines for treating many chronic diseases with underlying inflammation is critically dependent on the identification of new organic molecules and bioactive substances. Aromatic and volatile compounds found in essential oils isolated from Pimenta dioica (allspice), Cuminum cyminum (cumin), and Citrus sinensis (sweet orange) are a source of bioactive compounds. Allspice essential oil reduces ear inflammation more than 65% and the anti-inflammatory activity of allspice essential oil is enhanced when combined with sweet orange peel and cumin essential oils, resulting in the reduction of edema inflammation by more than 85%, similar to indomethacin. As an alternative to anti-inflammatory treatment, essential oil mix is pharmacologically safe as it is neither toxic nor mutagenic.

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The correct recognition of sweet orange (Citrus sinensis L. Osbeck) variety accessions at the nursery stage of growth is a challenge for the productive sector as they do not show any difference in phenotype traits. Furthermore, there is no DNA marker able to distinguish orange accessions within a variety due to their narrow genetic trace. As different combinations of canopy and rootstock affect the uptake of elements from soil, each accession features a typical elemental concentration in the leaves. Thus, the main aim of this work was to analyze two sets of ten different accessions of very close genetic characters of three varieties of fresh citrus leaves at the nursery stage of growth by measuring the differences in elemental concentration by laser-induced breakdown spectroscopy (LIBS). The accessions were discriminated by both principal component analysis (PCA) and a classifier based on the combination of classification via regression (CVR) and partial least square regression (PLSR) models, which used the elemental concentrations measured by LIBS as input data. A correct classification of 95.1% and 80.96% was achieved, respectively, for set 1 and set 2. These results showed that LIBS is a valuable technique to discriminate among citrus accessions, which can be applied in the productive sector as an excellent cost-benefit tool in citrus breeding programs.

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Xylella fastidiosa is a worldwide multihost pathogen that causes diseases in different crops. It is considered a new global threat and substantial efforts have been made in order to identify sources of resistance. Indeed, many genes have been associated with resistance to X. fastidiosa, but without functional validation. Here, we describe a C. reticulata gene homologous to the transcriptional factor RAP2.2 from Arabidopsis thaliana that increases resistance to citrus variegated chlorosis (CVC). This gene was previously detected in C. reticulata challenged with X. fastidiosa. Bioinformatics analysis together with subcellular localization and auto-activation assays indicated that RAP2.2 from C. reticulata (CrRAP2.2) is a transcriptional factor orthologous to AtRAP2.2. Thus, we used A. thaliana as a model host to evaluate the functional role of CrRAP2.2 in X. fastidiosa resistance. The inoculation of X. fastidiosa in the A. thaliana rap2.2 mutant resulted in a larger bacterial population, which was complemented by CrRAP2.2. In addition, symptoms of anthocyanin accumulation were higher in the mutant, whose phenotype was restored by CrRAP2.2, indicating that they have conserved functions in plant defense response. We therefore transformed C. sinensis with CrRAP2.2 and verified a positive correlation between CVC resistance and gene expression in transgenic lines. This is the first study using A. thaliana as model host that characterizes the function of a gene related to X. fastidiosa defense response and its application in genetic engineering to obtain citrus resistance to CVC.

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The lack of naturally occurring resistance to citrus psorosis virus (CPsV) necessitates a transgenic approach for the development of CPsV-resistant citrus. To evaluate the feasibility of conferring resistance to a non-transgenic scion, we have assembled citrus plants by grafting combining a non-transgenic Sweet Orange as scion, CPsV-resistant transgenic Sweet Orange lines expressing intron-hairpin (ihp) RNA derived from the viral coat protein (ihpCP) as interstock, and a non-transgenic citrus as rootstock. We demonstrated that ihpCP-transcripts translocate through the graft from interstock to scion, triggering the silencing of coat protein mRNA target. Two independent CPsV challenge assays showed that expression of ihpCP in the interstock provides resistance against CPsV in the interstock, and different levels of protection in the non-tg scion, depending of the virus delivery site. These results indicated that grafting is a promising biotechnological alternative to protect woody plants against virus infections in vegetative propagated plants.

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Abstract Sweet orange juice is an important part of diet since it is nutritious beverage offering good taste and play significant part in a healthy diet. High hygroscopicity, thermo-plasticity and presence of low molecular weight components in sweet orange juice offer low glass transition temperature (Tg), likely to form soft particle with sticky surface leading to sticky powder during drying. Maltodextrins are amorphous drying aids that tend to inhibit sugar crystallization and form a high Tg product after drying. In this study, the effect of the different spray drying parameters on the quality of powder derived from control and concentrated juice at three inlet air temperatures 120, 130 and 140 °C and at three levels of juice total soluble solids (TSS): maltodextrin levels at 1:0.5; 1:1 and 1:1.5 were studied. The impact of inlet air temperature and maltodextrin concentration has significantly affected various properties of sweet orange powder. For control juice, process yields increased with increase in inlet air temperature and maltodextrin concentration. However, for reverse osmosis (RO) concentrate, process yield increased with increase in maltodextrin concentration and decreased with increase in inlet air temperature. For control juice, process yields obtained were in the range of 12.59-41.16% and in case of concentrated juice, the process yield obtained was in the range of 21.35-56.95% at different combinations of inlet air temperature and maltodextrin concentrations. Spray-dried powder was considered as "possible" and "fair" in terms of flowability and cohesiveness. Vitamin C retention was high at lower inlet air temperature with lower concentration of maltodextrin.

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MAIN CONCLUSION: miRNA targets from Citrus sinensis are predicted and validated using degradome data. They show an up-regulation upon infection with CPsV, with a positive correlation between target expression and symptom severity. Sweet orange (Citrus sinensis) may suffer from disease symptoms induced by virus infections, thus resulting in drastic economic losses. Infection of sweet orange plants with two isolates of citrus psorosis virus (CPsV), expressing different symptomatologies, alters the accumulation of a set of endogenous microRNAs (miRNAs). Here, we predicted ten putative targets from four down-regulated miRNAs: three belonging to the CCAAT-binding transcription factor family (CBFAs); an Ethylene-responsive transcription factor (RAP2-7); an Integrase-type DNA-binding superfamily protein (AP2B); Transport inhibitor response 1 (TIR1); GRR1-like protein 1-related (GRR1); Argonaute 2-related (AGO2), Argonaute 7 (AGO7), and a long non-coding RNA (ncRNA). We validated six of them through analysis of leaf degradome data. Expressions of the validated targets increase in infected samples compared to healthy tissue, showing a more striking up-regulation those samples with higher symptom severity. This study contributes to the understanding of the miRNA-mediated regulation of important transcripts in Citrus sinensis through target validation and shed light in the manner a virus can alter host regulatory mechanisms leading to symptom expression.

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KEY MESSAGE: Complementation of the "Micro-Tom" tomato tangerine mutant with a Citrus CRTISO allele restores the wild-type fruit carotenoid profile, indicating that the Citrus allele encodes an authentic functional carotenoid isomerase. Citrus fruits are rich in carotenoids; the genus offers a large diversity in composition, yet to be fully explored to improve fruit nutritional quality. As perennial tree species, Citrus lack the resources for functional genetic studies, requiring the use of model plant systems. Here, we used the "Micro-Tom" (MT) tomato carrying the tangerine mutation (t), deficient for the carotenoid isomerase (CRTISO) gene, to functionally characterize the homologous C. sinensis genes. We identified four putative loci in the C. sinensis genome, named CsCRTISO, CsCRTISO-Like 1, CsCRTISO-Like 2, and CsCRTISO-Like 2B, with the latter as a presumed duplication of CRTISO-Like 2. In general, all the Citrus paralogs showed less expression specialization than the tomato ones, with CsCRTISO being the most expressed gene in all tissues analyzed. MT-t plants were successfully complemented with the CsCRTISO, and fruits showed a carotenoid profile similar to the control, indicating that the Citrus allele indeed encodes an authentic functional carotenoid isomerase and that the signal peptide is functional in tomato. MT was silenced using an inverted repeat of a fragment from the Citrus CRTISO resulting in a stronger phenotype than MT-t. MT-t and MT silenced for CRTISO presented an overall decrease in transcript accumulation of all genes from the biosynthesis pathway. The expression of the Citrus CRTISO gene is able to restore the biosynthesis of carotenoids with the appropriate regulation in MT-t. The decrease in transcript accumulation in MT-t and MT-CRTISO-suppressed lines reinforces previous suggestions that transcriptional regulation of the carotenoid biosynthesis involves regulatory loops by intermediate products.

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Citrus fragrances have been used in aromatherapy for the treatment of anxiety, and the essential oil of Citrus sinensis (sweet orange) has shown promising results, although its mechanism of action was not known. The objective of this study was to evaluate the involvement of nitric oxide (NO) neurotransmission in the anxiolytic-like effect of C. sinensis essential oil. Swiss male mice were submitted to 15 min of C. sinensis essential oil inhalation (1%, 2.5%, 5%, and 10%) and tested in the marble-burying test, neophobia-induced hypophagia, and light/dark test. Locomotor activity was evaluated in an automated locomotor activity box. The coadministration of C. sinensis essential oil with L-arginine (200 mg/kg, i.p.), an NO precursor, was used for the behavioral evaluation of nitrergic system mediation. Additionally, the NO synthase activity was measured by nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) analysis in the cerebral cortex. C. sinensis essential oil exerted anxiolytic-like effect at dose that did not change locomotor activity. Moreover, L-arginine pretreatment prevented this anxiolytic-like effect on marble-burying test. Finally, C. sinensis essential oil reduced the NADPH-d positive cells. Thus, the nitrergic neurotransmission plays a relevant role in the anxiolytic-like effect C. sinensis essential oil.

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KEY MESSAGE: Regulatory sequences from the citrus constitutive genes cyclophilin (CsCYP), glyceraldehyde-3-phosphate dehydrogenase C2 (CsGAPC2), and elongation factor 1-alpha (CsEF1) were isolated, fused to the uidA gene, and qualitatively and quantitatively evaluated in transgenic sweet orange plants. The 5' upstream region of a gene (the promoter) is the most important component for the initiation and regulation of gene transcription of both native genes and transgenes in plants. The isolation and characterization of gene regulatory sequences are essential to the development of intragenic or cisgenic genetic manipulation strategies, which imply the use of genetic material from the same species or from closely related species. We describe herein the isolation and evaluation of the promoter sequence from three constitutively expressed citrus genes: cyclophilin (CsCYP), glyceraldehyde-3-phosphate dehydrogenase C2 (CsGAPC2), and elongation factor 1-alpha (CsEF1). The functionality of the promoters was confirmed by a histochemical GUS assay in leaves, stems, and roots of stably transformed citrus plants expressing the promoter-uidA construct. Lower uidA mRNA levels were detected when the transgene was under the control of citrus promoters as compared to the expression under the control of the CaMV35S promoter. The association of the uidA gene with the citrus-derived promoters resulted in mRNA levels of up to 60-41.8% of the value obtained with the construct containing CaMV35S driving the uidA gene. Moreover, a lower inter-individual variability in transgene expression was observed amongst the different transgenic lines, where gene constructs containing citrus-derived promoters were used. In silico analysis of the citrus-derived promoter sequences revealed that their activity may be controlled by several putative cis-regulatory elements. These citrus promoters will expand the availability of regulatory sequences for driving gene expression in citrus gene-modification programs.

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BACKGROUND: Citrus breeding programs have many limitations associated with the species biology and physiology, requiring the incorporation of new biotechnological tools to provide new breeding possibilities. Diversity Arrays Technology (DArT) markers, combined with next-generation sequencing, have wide applicability in the construction of high-resolution genetic maps and in quantitative trait locus (QTL) mapping. This study aimed to construct an integrated genetic map using full-sib progeny derived from Murcott tangor and Pera sweet orange and DArTseq™ molecular markers and to perform QTL mapping of twelve fruit quality traits. A controlled Murcott x Pera crossing was conducted at the Citrus Germplasm Repository at the Sylvio Moreira Citrus Centre of the Agronomic Institute (IAC) located in Cordeirópolis, SP, in 1997. In 2012, 278 F1 individuals out of a family of 312 confirmed hybrid individuals were analyzed for fruit traits and genotyped using the DArTseq markers. Using OneMap software to obtain the integrated genetic map, we considered only the DArT loci that showed no segregation deviation. The likelihood ratio and the genomic information from the available Citrus sinensis L. Osbeck genome were used to determine the linkage groups (LGs). RESULTS: The resulting integrated map contained 661 markers in 13 LGs, with a genomic coverage of 2,774 cM and a mean density of 0.23 markers/cM. The groups were assigned to the nine Citrus haploid chromosomes; however, some of the chromosomes were represented by two LGs due the lack of information for a single integration, as in cases where markers segregated in a 3:1 fashion. A total of 19 QTLs were identified through composite interval mapping (CIM) of the 12 analyzed fruit characteristics: fruit diameter (cm), height (cm), height/diameter ratio, weight (g), rind thickness (cm), segments per fruit, total soluble solids (TSS, %), total titratable acidity (TTA, %), juice content (%), number of seeds, TSS/TTA ratio and number of fruits per box. The genomic sequence (pseudochromosomes) of C. sinensis was compared to the genetic map, and synteny was clearly identified. Further analysis of the map regions with the highest LOD scores enabled the identification of putative genes that could be associated with the fruit quality characteristics. CONCLUSION: An integrated linkage map of Murcott tangor and Pera sweet orange using DArTseq™ molecular markers was established and it was useful to perform QTL mapping of twelve fruit quality traits. The next generation sequences data allowed the comparison between the linkage map and the genomic sequence (pseudochromosomes) of C. sinensis and the identification of genes that may be responsible for phenotypic traits in Citrus. The obtained linkage map was used to assign sequences that had not been previously assigned to a position in the reference genome.

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Although there is substantial diversity among cultivated sweet oranges genotypes with respect to morphological, physiological, and agronomic traits, very little variation at DNA level has been observed. It is possible that this low DNA molecular variability is due to a narrow genetic basis commonly observed in this citrus group. The most different morphological characters observed were originated through mutations, which are maintained by vegetative propagation. Despite all molecular tools available for discrimination between these different accessions, in general, low polymorphism has been observed in all groups of sweet oranges and they may not be identified by molecular markers. In this context, this paper describes the results obtained by using laser-induced fluorescent spectroscopy (LIFS) as a tool to discriminate sweet orange accessions ( Citrus sinensis L. Osbeck) including common, low acidity, pigmented, and navel orange groups, with very little variation at DNA level. The findings showed that LIFS combined with statistical methods is capable to discriminate different accessions. The basic idea is that citrus leaves have multiple fluorophores and concentration depends on their genetics and metabolism. Thus, we consider that the optical properties of citrus leaves may be different, depending on variety. The results have shown that the developed method, for the best classification rate, reaches an average sensitivity and specificity of 95% and 97.5%, respectively. An interesting application of this study is the development of an economically viable tool for early identification in seedling certification, in citrus breeding programs, in cultivar protection, or in germplasm core collection.

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Citrus psorosis virus (CPsV) is the causal agent of psorosis, a serious and widespread citrus disease. Two syndromes of psorosis, PsA and PsB, have been described. PsB is the most aggressive and rampant form. Previously, we obtained Pineapple sweet orange plants transformed with a hairpin construct derived from the CPsV coat protein gene (ihpCP). Some of these plants were resistant to CPsV 90-1-1, a PsA isolate homologous to the transgene. In this study, we found that expression of the ihpCP transgene and siRNA production in lines ihpCP-10 and -15 were stable with time and propagation. In particular, line ihpCP-15 has been resistant for more than 2 years, even after re-inoculation. The ihpCP plants were also resistant against a heterologous CPsV isolate that causes severe PsB syndrome. Line ihpCP-15 manifested complete resistance while line ihpCP-10 was tolerant to the virus, although with variable behaviour, showing delay and attenuation in PsB symptoms. These lines are promising for a biotech product aimed at eradicating psorosis.

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Sweet orange (Citrus sinensis), one of the most important fruit crops worldwide, may suffer from disease symptoms induced by virus infections, thus resulting in dramatic economic losses. Here, we show that the infection of sweet orange plants with two isolates of Citrus psorosis virus (CPsV) expressing different symptomatology alters the accumulation of a set of endogenous microRNAs (miRNAs). Within these miRNAs, miR156, miR167 and miR171 were the most down-regulated, with almost a three-fold reduction in infected samples. This down-regulation led to a concomitant up-regulation of some of their targets, such as Squamosa promoter-binding protein-like 9 and 13, as well as Scarecrow-like 6. The processing of miRNA precursors, pre-miR156 and pre-miR171, in sweet orange seems to be affected by the virus. For instance, virus infection increases the level of unprocessed precursors, which is accompanied by a concomitant decrease in mature species accumulation. miR156a primary transcript accumulation remained unaltered, thus strongly suggesting a processing deregulation for this transcript. The co-immunoprecipitation of viral 24K protein with pre-miR156a or pre-miR171a suggests that the alteration in the processing of these precursors might be caused by a direct or indirect interaction with this particular viral protein. This result is also consistent with the nuclear localization of both miRNA precursors and the CPsV 24K protein. This study contributes to the understanding of the manner in which a virus can alter host regulatory mechanisms, particularly miRNA biogenesis and target expression.

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Citrus crops in São Paulo State, Brazil, have been severely affected by postbloom fruit drop disease (PFD), which is caused by Colletotrichum acutatum. This disease leads to the drop of up to 100% of young fruits. Previous studies have assumed that this pathogen exhibits a clonal reproductive mode, although no population genetic studies have been conducted so far. Thus, the genetic structure of six C. acutatum populations from sweet orange orchards showing PFD symptoms was determined using nine microsatellite markers, enabling inference on predominant mode of reproduction. C. acutatum populations exhibit a nearly panmictic genetic structure and a high degree of admixture, indicating either ongoing contemporary gene flow at a regional scale or a recent introduction from a common source, since this pathogen was introduced in Brazil only very recently. Sharing haplotypes among orchards separated by 400 km suggests the natural dispersal of fungal propagules, with the possible involvement of pollinators. A significant population expansion was detected, which was consistent with an increase in host density associated with crop expansion toward new areas across the state. Findings of moderate to high levels of haplotypic diversity and gametic equilibrium suggest that recombination might play an important role in these pathogen populations, possibly via parasexual reproduction or a cryptic sexual cycle. This study provides additional tools for epidemiological studies of C. acutatum to improve prevention and management strategies for this disease.

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Brazilian exports of fresh citrus represent less than 1% of the overall Brazilian production. Phytosanitary barriers and poor appearance stand out among the several reasons contributing to such low exporting/production ratio. The purpose of this work was to characterize postharvest injuries in 'Valencia' sweet oranges and 'Murcott' tangors produced for foreign markets after different processing stages in a packinghouse, as well as to identify critical points and impact extent on packing lines. Sampling was performed both after pre-washing and degreening the fruits, and also at the arrival on the packing table and in the pallet. They were stored for 21 days at 25ºC and 85% RH. The incidence of injuries was visually assessed every three days. An instrumented sphere with acceleration register was used to evaluate the extent of impacts (G, m/s²) at the 19 transference points of the citrus processing line. There was low rot incidence (under 3.5%) at the different stages of fruit processing, with slight increase after degreening in 'Valencia' orange and a decrease after fungicides treatment in 'Murcott' tangor. The main pathogens found in the oranges were Lasiodiplodia theobromae and Penicillium digitatum, which were surpassed by Colletotrichum gloeosporioides in the tangors. Impacts in the processing line were caused mainly by drops on hard surfaces, with 94.7% of them varying from 30 to 95 G. The greatest impacts were observed when fruits were transferred from the processing line to bins destined to degreening. Mechanical injuries related to oleocellosis increased until the arrival of fruits at the packing table.

A exportação de frutos cítricos frescos representa menos que 1% da produção brasileira. Dentre os fatores atribuídos a esta baixa relação entre exportação e produção destacam-se as barreiras sanitárias e o aspecto visual de qualidade inferior. Este trabalho objetivou caracterizar os danos pós-colheita de frutos de laranja 'Valencia' e tangor 'Murcott', destinados à exportação, após diferentes etapas do beneficiamento em packinghouse e identificar os pontos críticos e a magnitude de impacto em linhas de beneficiamento. Os frutos foram coletados na chegada ao packinghouse, tanto após a pré-lavagem como após o desverdecimento, na banca de embalagem e no palete; e armazenados individualmente durante 21 dias a 25ºC e 85% de UR. A incidência de injúrias foi avaliada visualmente a cada três dias. Para a avaliação da magnitude de impactos (G, m/s²) nos 19 pontos de transferência da linha de beneficiamento de citros empregou-se uma esfera instrumentada com registrador de aceleração. Observou-se uma baixa incidência de podridões nas diferentes etapas do beneficiamento dos frutos, com valores abaixo de 3,5% e levemente superior após o desverdecimento em laranja 'Valencia' e também redução de podridões após a aplicação de fungicidas em tangor 'Murcott'. Os principais patógenos encontrados em laranja foram Lasiodiplodia theobromae e Penicillium digitatum, sendo superados em tangor por Colletotrichum gloeosporioides. Na avaliação dos impactos na linha de beneficiamento, 94,7% dos impactos variaram entre a faixa de 30-95 G, causados principalmente por quedas em superfícies rígidas. Os maiores impactos foram observados quando os frutos foram transferidos da linha de beneficiamento para bins, destinados ao desverdecimento. Os danos mecânicos de oleocelose foram crescentes até a banca de embalagem.

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Brazilian exports of fresh citrus represent less than 1% of the overall Brazilian production. Phytosanitary barriers and poor appearance stand out among the several reasons contributing to such low exporting/production ratio. The purpose of this work was to characterize postharvest injuries in 'Valencia' sweet oranges and 'Murcott' tangors produced for foreign markets after different processing stages in a packinghouse, as well as to identify critical points and impact extent on packing lines. Sampling was performed both after pre-washing and degreening the fruits, and also at the arrival on the packing table and in the pallet. They were stored for 21 days at 25ºC and 85% RH. The incidence of injuries was visually assessed every three days. An instrumented sphere with acceleration register was used to evaluate the extent of impacts (G, m/s²) at the 19 transference points of the citrus processing line. There was low rot incidence (under 3.5%) at the different stages of fruit processing, with slight increase after degreening in 'Valencia' orange and a decrease after fungicides treatment in 'Murcott' tangor. The main pathogens found in the oranges were Lasiodiplodia theobromae and Penicillium digitatum, which were surpassed by Colletotrichum gloeosporioides in the tangors. Impacts in the processing line were caused mainly by drops on hard surfaces, with 94.7% of them varying from 30 to 95 G. The greatest impacts were observed when fruits were transferred from the processing line to bins destined to degreening. Mechanical injuries related to oleocellosis increased until the arrival of fruits at the packing table.

A exportação de frutos cítricos frescos representa menos que 1% da produção brasileira. Dentre os fatores atribuídos a esta baixa relação entre exportação e produção destacam-se as barreiras sanitárias e o aspecto visual de qualidade inferior. Este trabalho objetivou caracterizar os danos pós-colheita de frutos de laranja 'Valencia' e tangor 'Murcott', destinados à exportação, após diferentes etapas do beneficiamento em packinghouse e identificar os pontos críticos e a magnitude de impacto em linhas de beneficiamento. Os frutos foram coletados na chegada ao packinghouse, tanto após a pré-lavagem como após o desverdecimento, na banca de embalagem e no palete; e armazenados individualmente durante 21 dias a 25ºC e 85% de UR. A incidência de injúrias foi avaliada visualmente a cada três dias. Para a avaliação da magnitude de impactos (G, m/s²) nos 19 pontos de transferência da linha de beneficiamento de citros empregou-se uma esfera instrumentada com registrador de aceleração. Observou-se uma baixa incidência de podridões nas diferentes etapas do beneficiamento dos frutos, com valores abaixo de 3,5% e levemente superior após o desverdecimento em laranja 'Valencia' e também redução de podridões após a aplicação de fungicidas em tangor 'Murcott'. Os principais patógenos encontrados em laranja foram Lasiodiplodia theobromae e Penicillium digitatum, sendo superados em tangor por Colletotrichum gloeosporioides. Na avaliação dos impactos na linha de beneficiamento, 94,7% dos impactos variaram entre a faixa de 30-95 G, causados principalmente por quedas em superfícies rígidas. Os maiores impactos foram observados quando os frutos foram transferidos da linha de beneficiamento para bins, destinados ao desverdecimento. Os danos mecânicos de oleocelose foram crescentes até a banca de embalagem.

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O objetivo deste estudo foi determinar as espécies de Tephritidae e Lonchaeidae (Diptera: Tephritoidea) de ocorrência em pomares de laranja doce (Citrus sinensis Osbeck) e tangerina (Citrus reticulata Blanco), no município de Araruama, RJ, durante o período de dezembro de 2002 a novembro de 2003. Os espécimes foram coletados em armadilhas McPhail contendo solução aquosa de proteína hidrolisada a 5 por cento e em amostras de frutos de seis variedades de citros. Nas armadilhas, o total de 2.543 adultos de Tephritoidea (1.430 fêmeas e 1.023 machos) foi capturado, sendo dez espécies de Tephritidae, quatro espécies e dois morfotipos de Lonchaeidae. Dos Tephritidae e capturados nas McPhail, quatro espécies (Anastrepha fraterculus, A. obliqua, A. sororcula e Ceratitis capitata) infestaram frutos cítricos, enquanto que, dos Lonchaeidae, somente os morfotipos não infestaram as amostras de citros. Os resultados demonstram que a densidade populacional das moscas-das-frutas pode ser superestimada, quando baseada no número de moscas por armadilha, devido à captura de espécies que não infestam os frutos de interesse comercial.(AU)

This study was aimed at determining the species of Tephritidae and Lonchaeidae (Diptera: Tephritoidea) that occur on groves of sweet orange (Citrus sinensis Osbeck ) and tangerine (Citrus reticulata Blanco) in the municipality of Araruama, state of Rio de Janeiro, Brazil, from December, 2002 to November, 2003. The specimens were collected by McPhail traps with aqueous solution of hydrolyzed protein to 5 percent and in fruits samples of six varieties of citrus. In the traps the total of 2,543 adults of Tephritoidea (1,430 females and 1,023 males) was captured, being ten species of Tephritidae, four species and two morphotypes of Lonchaeidae. From the Tephritidae caught by the McPhail, four species (Anastrepha fraterculus, A. obliqua, A. sororcula and Ceratitis capitata) infested citric fruits while the Lonchaeidae, the morphotypes did not infest the citrus. The results showed that the population density of fruit flies may be overestimated when based on the number of flies per trap due to the capture of species that not infest the fruits of commercial interest.(AU)

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