WorldWideScience

Sample records for citrus tristeza virus

  1. Citrus tristeza virus-host interactions

    OpenAIRE

    Dawson, William O.; Garnsey, Stephen M.; Satyanarayana eTatineni; Folimonova, Svetlana Y.; Scott J Harper; S eGowda

    2013-01-01

    Citrus tristeza virus (CTV) is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably...

  2. Citrus tristeza virus-host interactions

    Directory of Open Access Journals (Sweden)

    William O. Dawson

    2013-05-01

    Full Text Available Citrus tristeza virus (CTV is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably from that of well-studied viruses of herbaceous plants where movement occurs largely through adjacent cells. In contrast, CTV systemically infects plants mainly by long-distance movement with only limited cell-to-cell movement. The virus is transported through sieve elements and occasionally enters an adjacent companion or phloem parenchyma cell where virus replication occurs. In some plants this is followed by cell-to-cell movement into only a small cluster of adjacent cells, while in others there is no cell-to-cell movement. Different proportions of cells adjacent to sieve elements become infected in different plant species. This appears to be related to how well viral gene products interact with specific hosts. CTV has three genes that are not necessary for infection of most of its hosts, but are needed in different combinations for infection of certain citrus species. These genes apparently were acquired by the virus to extend its host range. Some specific viral gene products have been implicated in symptom induction. Remarkably, the deletion of these genes from the virus genome can induce large increases in stem pitting symptoms. The p23 gene, which is a suppressor of RNA silencing and a regulator of viral RNA synthesis, has been shown to be the cause of seedling yellows symptoms in sour orange. Most isolates of CTV in nature are populations of different strains of CTV. The next frontier of CTV biology is the understanding how the virus variants in

  3. Thirty years of citrus tristeza virus observations in Peru

    Science.gov (United States)

    The Peruvian citrus industry was devastated by epidemics of Citrus tristeza virus (CTV) decline (CTV-D) on sour orange rootstock between 1950 and 1965 and CTV stem pitting (SP) between 1965 and 1985. CTV-SP debilitates citrus and fruit production regardless of rootstock. Control of CTV-SP by mild st...

  4. Citrus Tristeza Virus on the Island of Crete

    DEFF Research Database (Denmark)

    Shegani, M.; Tsikou, D.; Velimirovic, A.;

    2012-01-01

    Over a period of two years, more than 5,000 citrus trees were tested for the presence of Citrus tristeza virus (CTV) on the island of Crete, resulting in thirty eight positives. Comparisons of the relative transcript levels of CTV p23, coat protein (CP), polymerase (POL) and an intergenic (POL/p33......) region using quantitative RT-PCR, revealed consistent differences in abundance for each of these RNAs among flowers, stems, young fruits and leaves of infected orange trees. CTV p23 RNAs accumulated at highest levels, reaching a maximum in the flowers and the lowest levels in the leaves, while POL RNAs...... consistently accumulated at low levels in all tissues tested. A PCR-amplified dig-labelled CTV p23 DNA probe was applied to stem and leaf prints, and to crude and total RNA leaf extracts, using non isotopic hybridization. This technique, when applied to stem or leaf prints, and particularly to total RNA...

  5. HISTOLOGY OF SWEET ORANGE STEM PITTING CAUSED BY AN AUSTRALIAN ISOLATE OF CITRUS TRISTEZA VIRUS

    Science.gov (United States)

    Some strains of the citrus tristeza virus (CTV) cause stem pitting in sweet orange (Citrus sinensis (L.) Osbeck). This abnormality causes tree decline and reduction in fruit size and yield of affected citrus trees. Stem-pitting symptoms can occur on trunks, on all sizes of limbs, and on the twigs ...

  6. Inactivation of citrus tristeza virus by gamma ray irradiation

    International Nuclear Information System (INIS)

    The total exposure of gamma ray and the intensity of gamma ray per hour for the inactivation of citrus tristeza virus (CTV) and also the effect on citrus tissues are described. The budwoods of Morita navel orange infected with a severe seedling-yellow strain of CTV were irradiated with gamma ray from a 60Co source for 20 -- 52 hours. The buds or small tissue pieces of the irradiated budwoods were subsequently grafted onto Mexcan lime. CTV was easily inactivated by the irradiation from 10 to 18 kR for from 20 to 52 hours. The higher the total exposure, the higher the rate of inactivation. The CTV in the budwoods was almost inactivated after the irradiation with 20 kR. When the total exposure to gamma ray on budwoods was the same, CTV was more efficiently inactivated by the irradiation for long period with low intensity of gamma ray per hour than that for short period with high intensity per hour. Gamma ray irradiation was effective to eliminate CTV from citrus tissues. (Mori, K.)

  7. Stability of Citrus tristeza virus protective isolates in field conditions Estabilidade de isolados protetores contra Citrus tristeza virus em condições de campo

    OpenAIRE

    Alessandra Tenório Costa; William Mário de Carvalho Nunes; Carlos Alexandre Zanutto; Gerd Walter Müller

    2010-01-01

    The objective of this work was to monitor the maintenance of Citrus tristeza virus (CTV) protective isolates stability in selected clones of 'Pêra' sweet orange (Citrus sinensis), preimmunized or naturally infected by the virus, after successive clonal propagations. The work was carried out in field conditions in the north of Paraná State, Brazil. Coat protein gene (CPG) analysis of 33 isolates collected from 16 clones of 'Pêra' sweet orange was performed using single strand conformational po...

  8. Genetic diversity of Citrus tristeza virus isolates spreading in Central California

    Science.gov (United States)

    A rapid increase in the number of trees infected with Citrus tristeza virus (CTV) was observed in several locations in Tulare, County, CA during 2007. Since trees had been tested annually, these infections represent new infections. Leaf and bark tissue were sampled from infected trees and used for...

  9. Real-time RT-PCR assay for detection and differentiation of Citrus tristeza virus isolates

    Science.gov (United States)

    For universal detection of Citrus tristeza virus (CTV) strains by real time RT-PCR, a protocol was developed based on a set of primers and a Cy5-labeled TaqMan probe. This test included primers and a TET-labeled TaqMan probe selected on the mitochondrial nad5 gene for the simultaneous detection of ...

  10. Citrus tristeza virus p23: a unique protein mediating key virus-host interactions.

    OpenAIRE

    Flores, Ricardo; Ruiz-Ruiz, Susana; Soler, Nuria; Sánchez-Navarro, Jesús; Fagoaga, Carmen; López, Carmelo; Navarro, Luis; Moreno, Pedro; Peña, Leandro

    2013-01-01

    The large RNA genome of Citrus tristeza virus (CTV; ca. 20 kb) contains 12 open reading frames, with the 3′-terminal one corresponding to a protein of 209 amino acids (p23) that is expressed from an abundant subgenomic RNA. p23, an RNA-binding protein with a putative zinc-finger domain and some basic motifs, is unique to CTV because no homologs have been found in other closteroviruses, including the type species of the genus Beet yellows virus (despite both viruses having many homologous gene...

  11. Phylogenetic Analysis of Citrus tristeza virus Isolates of Wild Type Citrus in China

    Institute of Scientific and Technical Information of China (English)

    YI Long; ZHOU Chang-yong

    2014-01-01

    The genetic variation and phylogenetic relationships of Citrus tristeza virus (CTV) isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions (p23, p20, p13, p18, p25, p27, POL, HEL and k17) with the CTV isolates of cultivated citrus from different countries. The results showed that the divergence pattern of genomic RNA of the CTV isolates from wild type citrus was similar to that of other isolates from cultivated citrus, the 3´ proximal region was relatively conserved, and the 5´ proximal region had greater variability. The nine genomic regions of CTV isolates analyzed were found to have been under purifying selection in the evolution process. Phylogenetic analysis showed that the eleven Chinese wild CTV isolates were located at different clades and did not relfect their geographical origins, suggesting genetic diversity among the Chinese wild CTV populations. These results will aid in the understanding of molecular evolution of the Chinese CTV populations.

  12. Genomic variability of Citrus tristeza virus (CTV) isolates introduced into Morocco

    OpenAIRE

    Lbida, B.; Fonseca, Filomena; C. Santos; Zemzami, M.; Bennani, A; Nolasco, Gustavo

    2004-01-01

    Genomic variability of the coat protein gene of Citrus tristeza virus isolates obtained from old Meyer lemon introductions in Morocco and more recent budwood introductions from Spain were studied. The coat protein gene of the virus was amplified directly from infected tissue by immunocapture RT-PCR and analysed by single stranded conformation polymorphism (SSCP) and sequencing. Each isolate consisted of several related genomic variants, typical of a quasi-species. Although SSCP analysis has o...

  13. Sequence diversity on four ORFs of citrus tristeza virus correlates with pathogenicity

    OpenAIRE

    Martínez-Soriano Juan; Rivera-Bustamante Rafael; Ochoa-Sánchez Juan; Herrera-Isidrón Lisset

    2009-01-01

    Abstract The molecular characterization of isolates of citrus tristeza virus (CTV) from eight locations in Mexico was undertaken by analyzing five regions located at the opposite ends of the virus genome. Two regions have been previously used to study CTV variability (coat protein and p23), while the other three correspond to other genomic segments (p349-B, p349-C and p13). Our comparative nucleotide analyses included CTV sequences from different geographical origins already deposited in the ...

  14. Citrus tristeza virus-based RNA-interference (RNAi) vector and its potential in combating citrus Huanglongbing (HLB)

    OpenAIRE

    Hajeri, Shubash; El-Mohtar, Choaa; Dawson, William O.; Gowda, Siddarame

    2014-01-01

    Citrus tristeza virus (CTV), a plus-sense ssRNA virus, is member of the genus Closterovirus, family Closteroviridae. RNA viruses are inducers as-well-as targets of gene silencing defense mechanism of host plants and this has been exploited as a tool in functional genomics. CTV was developed into virus-induced gene silencing (VIGS) or RNA-interference (RNAi) vector, which interferes with expression of endogenous genes in citrus or GFP-transgene in Nicotiana benthamiana (16c) in a sequence spec...

  15. Citrus tristeza virus p23: a unique protein mediating key virus–host interactions

    OpenAIRE

    2013-01-01

    The large RNA genome of Citrus tristeza virus (CTV; ca. 20 kb) contains 12 open reading frames, with the 3′-terminal one corresponding to a protein of 209 amino acids (p23) that is expressed from an abundant subgenomic RNA. p23, an RNA-binding protein with a putative zinc-finger domain and some basic motifs, is unique to CTV because no homologs have been found in other closteroviruses, including the type species of the genus Beet yellows virus (despite both viruses having many homologous gene...

  16. Virus-viroid interactions: Citrus Tristeza Virus enhances the accumulation of Citrus Dwarfing Viroid in Mexican lime via virus-encoded silencing suppressors.

    Science.gov (United States)

    Serra, Pedro; Bani Hashemian, Seyed M; Fagoaga, Carmen; Romero, Juan; Ruiz-Ruiz, Susana; Gorris, Maria T; Bertolini, Edson; Duran-Vila, Núria

    2014-01-01

    An assay to identify interactions between Citrus Dwarfing Viroid (CDVd) and Citrus Tristeza Virus (CTV) showed that viroid titer was enhanced by the coinfecting CTV in Mexican lime but not in etrog citron. Since CTV encodes three RNA silencing suppressors (RSSs), p23, p20 and p25, an assay using transgenic Mexican limes expressing each RSS revealed that p23 and, to a lesser extent, p25 recapitulated the effect observed with coinfections of CTV and CDVd. PMID:24227850

  17. Citrus tristeza virus (CTV) Causing Proteomic and Enzymatic Changes in Sweet Orange Variety "Westin".

    Science.gov (United States)

    Dória, Milena Santos; Sousa, Aurizângela Oliveira de; Barbosa, Cristiane de Jesus; Costa, Márcio Gilberto Cardoso; Gesteira, Abelmon da Silva; Souza, Regina Martins; Freitas, Ana Camila Oliveira; Pirovani, Carlos Priminho

    2015-01-01

    Citrus Tristeza disease, caused by CTV (Citrus tristeza virus), committs citrus plantations around the world and specifically attacks phloem tissues of the plant. The virus exists as a mixture of more or less severe variants, which may or may not cause symptoms of Tristeza. The objective of this study was to analyze the changes caused by CTV in the proteome of stems of sweet orange, as well as in the activity and gene expression of antioxidant enzymes. The CTV-infected sweet orange displayed mild symptoms, which were characterized by the presence of sparse stem pitting throughout their stems. The presence of virus was confirmed by RT-PCR. Proteomic analysis by 2DE-PAGE-MS / MS revealed the identity of 40 proteins differentially expressed between CTV- infected and -non-infected samples. Of these, 33 were up-regulated and 7 were down-regulated in CTV-infected samples. Among the proteins identified stands out a specific from the virus, the coat protein. Other proteins identified are involved with oxidative stress and for this their enzymatic activity was measured. The activity of superoxide dismutase (SOD) was higher in CTV-infected samples, as catalase (CAT) showed higher activity in uninfected samples. The activity of guaiacol peroxidase (GPX) did not vary significantly between samples. However, ascorbate peroxidase (APX) was more active in the infected samples. The relative expression of the genes encoding CAT, SOD, APX and GPX was analyzed by quantitative real time PCR (RT-qPCR). The CTV-infected samples showed greater accumulation of transcripts, except for the CAT gene. This gene showed higher expression in the uninfected samples. Taken together, it can be concluded that the CTV affects the protein profile and activity and gene expression of antioxidant enzymes in plants infected by this virus. PMID:26207751

  18. Citrus tristeza virus (CTV) Causing Proteomic and Enzymatic Changes in Sweet Orange Variety “Westin”

    Science.gov (United States)

    Dória, Milena Santos; de Sousa, Aurizângela Oliveira; Barbosa, Cristiane de Jesus; Costa, Márcio Gilberto Cardoso; Gesteira, Abelmon da Silva; Souza, Regina Martins; Freitas, Ana Camila Oliveira; Pirovani, Carlos Priminho

    2015-01-01

    Citrus Tristeza disease, caused by CTV (Citrus tristeza virus), committs citrus plantations around the world and specifically attacks phloem tissues of the plant. The virus exists as a mixture of more or less severe variants, which may or may not cause symptoms of Tristeza. The objective of this study was to analyze the changes caused by CTV in the proteome of stems of sweet orange, as well as in the activity and gene expression of antioxidant enzymes. The CTV-infected sweet orange displayed mild symptoms, which were characterized by the presence of sparse stem pitting throughout their stems. The presence of virus was confirmed by RT-PCR. Proteomic analysis by 2DE-PAGE-MS / MS revealed the identity of 40 proteins differentially expressed between CTV- infected and -non-infected samples. Of these, 33 were up-regulated and 7 were down-regulated in CTV-infected samples. Among the proteins identified stands out a specific from the virus, the coat protein. Other proteins identified are involved with oxidative stress and for this their enzymatic activity was measured. The activity of superoxide dismutase (SOD) was higher in CTV-infected samples, as catalase (CAT) showed higher activity in uninfected samples. The activity of guaiacol peroxidase (GPX) did not vary significantly between samples. However, ascorbate peroxidase (APX) was more active in the infected samples. The relative expression of the genes encoding CAT, SOD, APX and GPX was analyzed by quantitative real time PCR (RT-qPCR). The CTV-infected samples showed greater accumulation of transcripts, except for the CAT gene. This gene showed higher expression in the uninfected samples. Taken together, it can be concluded that the CTV affects the protein profile and activity and gene expression of antioxidant enzymes in plants infected by this virus. PMID:26207751

  19. Citrus tristeza virus (CTV Causing Proteomic and Enzymatic Changes in Sweet Orange Variety "Westin".

    Directory of Open Access Journals (Sweden)

    Milena Santos Dória

    Full Text Available Citrus Tristeza disease, caused by CTV (Citrus tristeza virus, committs citrus plantations around the world and specifically attacks phloem tissues of the plant. The virus exists as a mixture of more or less severe variants, which may or may not cause symptoms of Tristeza. The objective of this study was to analyze the changes caused by CTV in the proteome of stems of sweet orange, as well as in the activity and gene expression of antioxidant enzymes. The CTV-infected sweet orange displayed mild symptoms, which were characterized by the presence of sparse stem pitting throughout their stems. The presence of virus was confirmed by RT-PCR. Proteomic analysis by 2DE-PAGE-MS / MS revealed the identity of 40 proteins differentially expressed between CTV- infected and -non-infected samples. Of these, 33 were up-regulated and 7 were down-regulated in CTV-infected samples. Among the proteins identified stands out a specific from the virus, the coat protein. Other proteins identified are involved with oxidative stress and for this their enzymatic activity was measured. The activity of superoxide dismutase (SOD was higher in CTV-infected samples, as catalase (CAT showed higher activity in uninfected samples. The activity of guaiacol peroxidase (GPX did not vary significantly between samples. However, ascorbate peroxidase (APX was more active in the infected samples. The relative expression of the genes encoding CAT, SOD, APX and GPX was analyzed by quantitative real time PCR (RT-qPCR. The CTV-infected samples showed greater accumulation of transcripts, except for the CAT gene. This gene showed higher expression in the uninfected samples. Taken together, it can be concluded that the CTV affects the protein profile and activity and gene expression of antioxidant enzymes in plants infected by this virus.

  20. Stability of Citrus tristeza virus protective isolates in field conditions Estabilidade de isolados protetores contra Citrus tristeza virus em condições de campo

    Directory of Open Access Journals (Sweden)

    Alessandra Tenório Costa

    2010-07-01

    Full Text Available The objective of this work was to monitor the maintenance of Citrus tristeza virus (CTV protective isolates stability in selected clones of 'Pêra' sweet orange (Citrus sinensis, preimmunized or naturally infected by the virus, after successive clonal propagations. The work was carried out in field conditions in the north of Paraná State, Brazil. Coat protein gene (CPG analysis of 33 isolates collected from 16 clones of 'Pêra' sweet orange was performed using single strand conformational polymorphism (SSCP. Initially, the isolates were characterized by symptoms of stem pitting observed in clones. Then viral genome was extracted and used as template for the amplification of CPG by reverse transcription polimerase chain reaction (RTPCR. RTPCR products electrophoretic profiles were analyzed using the Jaccard coefficient and the UPGMA method. The majority of the clones had weak to moderate stem pitting symptoms and its CTV isolates showed alterations in the SSCP profiles. However, the stability of the protective complex has been maintained, except for isolates from two analised clones. Low genetic variability was observed within the isolates during the studied years.O objetivo deste trabalho foi monitorar a manutenção da estabilidade de isolados protetores contra Citrus tristeza virus (CTV em clones selecionados de laranja 'Pêra' (Citrus sinensis pré-imunizados ou infectados naturalmente pelo vírus, após sucessivas propagações clonais. O trabalho foi realizado em condições de campo, no norte do Estado do Paraná. A análise do gene da capa protéica (GPC de 33 isolados, coletados de 16 clones de laranjeira 'Pêra', foi realizada com o uso da técnica polimorfismo conformacional da fita simples (SSCP. Inicialmente, os isolados foram caracterizados por meio de sintomas de caneluras observados nos clones. Em seguida, o genoma viral foi extraído e utilizado como molde para a amplificação do GCP com uso da transcrição reversa da rea

  1. Population structure and genetic diversity within California Citrus tristeza virus (CTV) isolates.

    Science.gov (United States)

    Kong, P; Rubio, L; Polek, M; Falk, B W

    2000-10-01

    The Closterovirus, Citrus tristeza virus (CTV) is an aphid-borne RNA virus that is the causal agent of important worldwide economic losses in citrus. Biological and molecular variation has been observed for many CTV isolates. In this work we detected and analyzed sequence variants (haplotypes) within individual CTV isolates. We studied the population structure of five California CTV isolates by single strand conformation polymorphism (SSCP) analysis of four CTV genomic regions. Also, we estimated the genetic diversity within and between isolates by analysis of haplotype nucleotide sequences. Most CTV isolates were composed of a population of genetically related variants (haplotypes), one being predominant. However in one case, we found a high nucleotide divergence between haplotypes of the same isolate. Comparison of these haplotypes with those from other isolates suggests that some CTV isolates could have arisen as result of a mixed infection of two divergent isolates. PMID:11129629

  2. Developing an understanding of cross-protection by Citrus tristeza virus

    Directory of Open Access Journals (Sweden)

    Svetlana Y Folimonova

    2013-04-01

    Full Text Available Citrus tristeza virus (CTV causes two citrus diseases that have caused devastating losses in global citrus production. The first disease is quick decline of trees propagated on the sour orange rootstock. The second disease is stem pitting, which severely affects a number of economically important citrus varieties regardless of the rootstock used and results in reduced tree growth and vigor as well as in reduced fruit size and quality. Both diseases continue to invade new areas. While quick decline could be effectively managed by the use of resistant and/or tolerant rootstocks, the only means to protect commercial citrus against endemic stem pitting isolates of CTV has been cross-protection with mild isolates of the virus. In some citrus areas cross-protection has been successful and allowed production of certain citrus cultivars despite the presence of severe stem pitting isolates in those regions. However, many other attempts to find isolates that would provide sustained protection against aggressive isolates of the virus had failed. In general, there has been no understanding why some mild isolates were effective and others failed to protect. We have been working on the mechanism of cross-protection by CTV. Recent considerable progress has significantly advanced our understanding of how cross-protection may work in the citrus/CTV pathosystem. As we demonstrated, only isolates that belong to the same strain of the virus cross protect against each other, while isolates from different strains do not. We believe that the results of our research could now make finding protecting isolates relatively straightforward. This review discusses some of the history of CTV cross-protection along with the recent findings and our ‘recipe’ for selection of protecting isolates.

  3. Evaluación de patrones para lima tahití (Citrus latifolia Tanaka) frente a Citrus tristeza virus (CTV)

    OpenAIRE

    Beltrán Montoya, Johnny Camilo

    2012-01-01

    En el presente trabajo se evaluó la respuesta de patrones para lima Tahití frente a infecciones de Citrus tristeza virus. El documento se divide en tres capítulos. El primer capítulo es una revisión general del estado del arte de CTV, que abarca generalidades sobre sus hospederos, distribución, genoma viral, síntomas que generan las diferentes cepas y antecedentes de lima Tahití en Colombia. El segundo capítulo abarca la identificación de cepas de CTV que infectan en campo mediante el uso de ...

  4. Fighting HLB with Citrus tristeza virus (CTV): Heterogeneity in the genome ends of CTV is an important consideration

    Science.gov (United States)

    As California prepares for a potential showdown with Huanglongbing (HLB), contemporary disease control strategies that use low inputs, yet produce high value control, are needed to manage the disease. With biotechnology, Citrus tristeza virus (CTV) may be developed into a tool for protection or trea...

  5. Investigation of seedling yellows cross protection by mild components of the Dekopon strain of Citrus tristeza virus

    Science.gov (United States)

    Virulent strains of Citrus tristeza virus (CTV) can be controlled by pre-infection by mild strains of CTV which is called cross protection. However, the mode of action of cross protection is unknown and its durability unpredictable. RNA silencing is a regulatory mechanism to maintain genome integri...

  6. A genetic system for Citrus Tristeza Virus using the non-natural host Nicotiana benthamiana: an update

    OpenAIRE

    Silvia eAmbrós; Susana eRuiz-Ruiz; Leandro ePeña; Pedro eMoreno

    2013-01-01

    In nature Citrus tristeza virus (CTV), genus Closterovirus, infects only the phloem cells of species of Citrus and related genera. Finding that the CTV T36 strain replicated in Nicotiana benthamiana (NB) protoplasts and produced normal virions allowed development of the first genetic system based on protoplast transfection with RNA transcribed from a full-genome cDNA clone, a laborious and uncertain system requiring several months for each experiment. We developed a more efficient system base...

  7. Genetic Diversity and Global Distribution of Citrus tristeza virus (CTV) Strains

    Institute of Scientific and Technical Information of China (English)

    Wu Xiao-yun; Cheng Xiao-fei; Luo Lu; Wu Xiao-xia

    2012-01-01

    Citrus tristeza virus (CTV), the most devastating viral pathogen in citrus, causes tremendous economic losses to citrus industry worldwide. The CTV isolates exhibit variable pathogenicities on their hosts indicating a mixed population of the CTV in nature. Several fragments within the CTV genome have been used for studying the genetic diversity of the CTV, however, the best region for rapid the CTV strain differentiation is still absent at present. In present study, a systemic analysis was carried out to evaluate the best region within the CTV genome for rapid CTV strain differentiation. Results of our study showed that the major coat protein (CP) coding region was the best region for this purpose. Using pair-wise distance frequency distribution plot, a reasonable genetic distance cut-off value was set for the CTV CP gene for the CTV strain differentiation. Using this criterion, eight CTV strains, including seven well characterized and a new strain, were successfully differentiated using 537 CTV isolates reported from 38 countries. The global strain distribution pattern was then determined and discussed. Our results also provided a new insight into the evolution and spreading of the virus, as well as the information for developing proper disease management strategy.

  8. Análisis espacio-temporal de aislamientos del Citrus tristeza virus de Yucatán y Tamaulipas Spatio-temporal analysis of Citrus tristeza virus isolates from Yucatán and Tamaulipas

    Directory of Open Access Journals (Sweden)

    Patricia Rivas-Valencia

    Full Text Available Se estudiaron huertas comerciales de cítricos (Citrus sinensis L., ubicadas en las principales regiones productoras de Yucatán de 2003 a 2006 y en Tamaulipas en 2004. En Yucatán se realizó un estudio espacio-temporal de la dispersión de la tristeza de los cítricos, ocasionada por el Citrus tristeza virus, en presencia de Toxoptera citricida Kirkaldy. La incidencia inicial (X0 fue de 4.41% y la final (Xf de 39.33%. Los índices de agregación de Morisita y Lloyd dependientes del tamaño óptimo de cuadrante, mostraron un patrón agregado con valores entre 1.41 y 2.39. Además, se caracterizaron molecularmente aislamientos del Citrus tristeza virus, para examinar la diversidad del virus presente. Se analizaron aislamientos del virus con single-strand conformation polymorphism, observándose hasta dos haplotipos por aislamiento y tres tipos de patrones en Yucatán. En Tamaulipas, con la caracterización molecular, se identificaron tres haplotipos por aislamiento y siete patrones. El coeficiente de similaridad calculado para estas dos poblaciones de aislamientos fue de 0.7, asumiéndose un origen común de ambas poblaciones. El análisis de varianza molecular, indicó mayor variabilidad dentro de las poblaciones (69% y entre ellas (31%, comprobando que ambas regiones citrícolas, comparten variantes caracterizadas como de tipo moderado, mismo que puede justificar la ausencia de sintomatología atribuible a tristeza. Los análisis realizados para identificar el patrón de dispersión de los aislamientos en campo no evidenciaron la dispersión entre árboles e hileras.Citric (Citrus sinensis L. commercial vegetable gardens were studied, located in the main producing regions of Yucatán from 2003 to 2006 and in Tamaulipas in 2004. In Yucatán it was carried out a space-time study of dispersion of citric tristeza, caused by Citrus tristeza virus, in presence of Toxoptera citricida Kirkaldy. The initial incidence (X0 was of 4.41% and the final (Xf

  9. Volatile Organic Compound (VOC) profiling of Citrus tristeza virus (CTV) infection in sweet orange citrus varietals using thermal desorption gas chromatography time of flight mass spectrometry (TD-GC/TOF-MS)

    Science.gov (United States)

    Citrus tristeza virus (CTV) is a plant pathogen which predominately infects economically important citrus crops such as sweet orange, clementine, lime and grapefruit varietals. Within the last 70 years, an estimated 100 million citrus trees on sour orange rootstock have been destroyed due to CTV inf...

  10. Sequence diversity on four ORFs of citrus tristeza virus correlates with pathogenicity

    Directory of Open Access Journals (Sweden)

    Martínez-Soriano Juan

    2009-07-01

    Full Text Available Abstract The molecular characterization of isolates of citrus tristeza virus (CTV from eight locations in Mexico was undertaken by analyzing five regions located at the opposite ends of the virus genome. Two regions have been previously used to study CTV variability (coat protein and p23, while the other three correspond to other genomic segments (p349-B, p349-C and p13. Our comparative nucleotide analyses included CTV sequences from different geographical origins already deposited in the GenBank databases. The largest nucleotide differences were located in two fragments located at the 5' end of the genome (p349-B and p349-C. Phylogenetic analyses on those five regions showed that the degree of nucleotide divergence among strains tended to correlate with their pathogenicity. Two main groups were defined: mild, with almost no noticeable effects on the indicator plants and severe, with drastic symptoms. Mild isolates clustered together in every analyzed ORF sharing a genetic distance below 0.022, in contrast with the severe isolates, which showed a more disperse distribution and a genetic distance of 0.276. Analyses of the p349-B and p349-C regions evidenced two lineages within the severe group: severe common subgroup (most of severe isolates and severe divergent subgroup (T36-like isolates. This study represents the first attempt to analyze the genetic variability of CTV in Mexico by constructing phylogenetic trees based on new genomic regions that use group-specific nucleotide and amino acid sequences. These results may be useful to implement specific assays for strain discrimination. Moreover, it would be an excellent reference for the CTV situation in México to face the recent arrival of brown citrus aphid.

  11. Detection of Citrus tristeza virus by using fluorescence resonance energy transfer-based biosensor.

    Science.gov (United States)

    Shojaei, Taha Roodbar; Salleh, Mohamad Amran Mohd; Sijam, Kamaruzaman; Rahim, Raha Abdul; Mohsenifar, Afshin; Safarnejad, Reza; Tabatabaei, Meisam

    2016-12-01

    Due to the low titer or uneven distribution of Citrus tristeza virus (CTV) in field samples, detection of CTV by using conventional detection techniques may be difficult. Therefore, in the present work, the cadmium-telluride quantum dots (QDs) was conjugated with a specific antibody against coat protein (CP) of CTV, and the CP were immobilized on the surface of gold nanoparticles (AuNPs) to develop a specific and sensitive fluorescence resonance energy transfer (FRET)-based nanobiosensor for detecting CTV. The maximum FRET efficiency for the developed nano-biosensor was observed at 60% in AuNPs-CP/QDs-Ab ratio of 1:8.5. The designed system showed higher sensitivity and specificity over enzyme linked immunosorbent assay (ELISA) with a limit of detection of 0.13μgmL(-1) and 93% and 94% sensitivity and specificity, respectively. As designed sensor is rapid, sensitive, specific and efficient in detecting CTV, this could be envisioned for diagnostic applications, surveillance and plant certification program. PMID:27380305

  12. Defective RNAs of Citrus tristeza virus analogous to Crinivirus genomic RNAs

    International Nuclear Information System (INIS)

    The family Closteroviridae includes the genera Closterovirus and Ampelovirus with monopartite genomes and the genus Crinivirus with bipartite genomes. Plants infected with the Closterovirus, Citrus tristeza virus (CTV), often contain one or more populations of defective RNAs (dRNAs). Although most dRNAs are comparatively small (2-5 kb) consisting of the genomic RNA termini with large internal deletions, we recently characterized large dRNAs of ∼12 kb that retained the open reading frames (ORFs) 1a plus 1b. These were self-replicating RNAs and appeared to be analogous to the genomic RNA 1 of the bipartite criniviruses. The present report describes the finding of an additional group of large dRNAs (LdRNAs) that retained all or most of the 10 3' ORFs and appeared to be analogous to genomic RNA 2 of criniviruses. Isolates associated with LdRNAs were found associated with double-recombinant dRNAs (DR-dRNAs) of various sizes (1.7 to 5.1 kb) that comprised the two termini and a noncontiguous internal sequence from ORF2. The genetic and epidemiological implications of the architectural identities of LdRNAs and DR dRNAs and their apparent analogy with the genomic RNA 2 of criniviruses are discussed

  13. Past and future of a century old Citrus tristeza virus collectionA California citrus germplasm tale

    Directory of Open Access Journals (Sweden)

    Jinbo eWang

    2013-12-01

    Full Text Available Citrus tristeza virus (CTV isolates collected from citrus germplasm, dooryard and field trees in California from 1914 have been maintained in planta under quarantine in the Citrus Clonal Protection Program (CCPP, Riverside, California. This collection, therefore, represents populations of CTV isolates obtained over time and space in California. To determine CTV genetic diversity in this context, genotypes of CTV isolates from the CCPP collection were characterized using multiple molecular markers (MMM. Genotypes T30, VT, and T36 were found at high frequencies with T30 and T30+VT genotypes being the most abundant. The MMM analysis did not identify T3 and B165/T68 genotypes; however, biological and phylogenetic analysis suggested some relationships of CCPP CTV isolates with these two genotypes. Phylogenetic analysis of the CTV coat protein gene sequences classified the tested isolates into seven distinct clades. Five clades were in association with the standard CTV genotypes T30, T36, T3, VT, and B165/T68. The remaining two identified clades were not related to any standard CTV genotypes. Spatiotemporal analysis indicated a trend of reduced genotype and phylogenetic diversity as well as virulence from southern California at early (1907-1957 in comparison to that of central California isolates collected from later (1957-2009 time periods. CTV biological characterization also indicated a reduced number and less virulent stem pitting (SP CTV isolates compared to seedling yellows isolates introduced to California. This data provides a historical insight of the introduction, movement, and genetic diversity of CTV in California and provides genetic and biological information useful for CTV quarantine, eradication, and disease management strategies such as CTV-SP cross protection.

  14. Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing).

    Science.gov (United States)

    Hajeri, Subhas; Killiny, Nabil; El-Mohtar, Choaa; Dawson, William O; Gowda, Siddarame

    2014-04-20

    A transient expression vector based on Citrus tristeza virus (CTV) is unusually stable. Because of its stability it is being considered for use in the field to control Huanglongbing (HLB), which is caused by Candidatus Liberibacter asiaticus (CLas) and vectored by Asian citrus psyllid, Diaphorina citri. In the absence of effective control strategies for CLas, emphasis has been on control of D. citri. Coincident cohabitation in phloem tissue by CLas, D. citri and CTV was exploited to develop a novel method to mitigate HLB through RNA interference (RNAi). Since CTV has three RNA silencing suppressors, it was not known if CTV-based vector could induce RNAi in citrus. Yet, expression of sequences targeting citrus phytoene desaturase gene by CTV-RNAi resulted in photo-bleaching phenotype. CTV-RNAi vector, engineered with truncated abnormal wing disc (Awd) gene of D. citri, induced altered Awd expression when silencing triggers ingested by feeding D. citri nymphs. Decreased Awd in nymphs resulted in malformed-wing phenotype in adults and increased adult mortality. This impaired ability of D. citri to fly would potentially limit the successful vectoring of CLas bacteria between citrus trees in the grove. CTV-RNAi vector would be relevant for fast-track screening of candidate sequences for RNAi-mediated pest control. PMID:24572372

  15. Nucleotide heterogeneity at the genomic 5’- and 3’-termini of California (CA) isolates of Citrus tristeza virus (CTV)

    Science.gov (United States)

    Nucleotide (nt) sequences in the genomic ends of sense (+)-RNA viruses serve essential biological functions and are important considerations in the construction of infectious clones. Two isolates of Citrus tristeza virus (CTV) from California (CA) having a T30- and a T36-genotype were inoculated in ...

  16. A 5'-proximal region of the Citrus tristeza virus genome encoding two leader proteases is involved in virus superinfection exclusion.

    Science.gov (United States)

    Atallah, Osama O; Kang, Sung-Hwan; El-Mohtar, Choaa A; Shilts, Turksen; Bergua, María; Folimonova, Svetlana Y

    2016-02-01

    Superinfection exclusion (SIE), a phenomenon in which a primary virus infection prevents a secondary infection with the same or closely related virus, has been observed with various viruses. Earlier we demonstrated that SIE by Citrus tristeza virus (CTV) requires viral p33 protein. In this work we show that p33 alone is not sufficient for virus exclusion. To define the additional viral components that are involved in this phenomenon, we engineered a hybrid virus in which a 5'-proximal region in the genome of the T36 isolate containing coding sequences for the two leader proteases L1 and L2 has been substituted with a corresponding region from the genome of a heterologous T68-1 isolate. Sequential inoculation of plants pre-infected with the CTV L1L2T68 hybrid with T36 CTV resulted in superinfection with the challenge virus, which indicated that the substitution of the L1-L2 coding region affected SIE ability of the virus. PMID:26748332

  17. Evolutionary analysis of genetic variation observed in citrus tristeza virus (CTV) after host passage.

    Science.gov (United States)

    Sentandreu, V; Castro, J A; Ayllón, M A; Rubio, L; Guerri, J; González-Candelas, F; Moreno, P; Moya, A

    2006-05-01

    We have studied the genetic variability in two genes (p18 and p20) from two groups of Citrus tristeza virus (CTV) isolates. One group (isolates T385, T317, T318, and T305) was derived from a Spanish source by successive host passages while the other (isolates T388 and T390) was obtained after aphid transmission from a Japanese source. A total of 274 sequences were obtained for gene p18 and 451 for p20. In the corresponding phylogenetic trees, sequences derived from the severe isolates (T318, T305, and T388) clustered together and separately from those derived from mild or moderate isolates (T385, T317, and T390), regardless of their geographic origin. Hierarchical analyses of molecular variance showed that up to 53% of the total genetic variability in p18 and up to 87% of the variation in p20 could be explained by differences in the pathogenicity features of the isolates. Neutrality tests revealed that different selection forces had been acting between isolates and between genes, with purifying selection being suggested for p18 from isolates T385 and T390 and for p20 from isolates T385, T317, and T388, and balancing selection for p18 from isolates T318, T305, and T388 and for p20 from isolates T318 and T390. Furthermore, several models of codon selection were observed, with purifying selection being the most notable one, compatible with low effective population size of the virus populations resulting from transmission bottlenecks. We found no evidence of recombination playing a significant role during p18 and p20 evolution in these isolates. These results suggest that hosts can be an important evolutionary factor for CTV isolates. PMID:16329002

  18. Deep sequencing of viral small-RNAs of citrus tristeza virus (CTV) reveals genomic differences between two Italian isolates of CTV

    Science.gov (United States)

    A recent Citrus tristeza virus (CTV) epidemic of quick decline (QD) killed many sweet orange trees grafted on sour orange rootstock in Sicily but left some asymptomatic trees in the same field. Recent reports indicated cross-protection involves exclusion of a severe CTV strain by a mild strain of th...

  19. Comparison of gene expression changes in susceptible, tolerant and resistant hosts in response to infection with Citrus tristeza virus and huanglongbing

    OpenAIRE

    Bowman, K D; Albrecht, U

    2015-01-01

    The pathogens Candidatus Liberibacter asiaticus (Las) and Citrus tristeza virus (CTV) are both phloem limited and have significant economic impact on citrus production wherever they are found. Studies of host resistance have indicated that Poncirus trifoliata has tolerance or resistance to both pathogens, suggesting that there may be some common factors in the 2 kinds of resistance. We have conducted studies of host gene expression changes that occur in response to infection to gain further i...

  20. Citrus tristeza virus p23: a unique protein mediating key virus-host interactions

    Directory of Open Access Journals (Sweden)

    Ricardo eFlores

    2013-05-01

    Full Text Available The large RNA genome of CTV (ca. 20 kb contains 12 open reading frames (ORFs, with the 3’-terminal one corresponding to a protein of 209 amino acids (p23 that is expressed from an abundant subgenomic RNA. p23, an RNA-binding protein with a putative Zn-finger domain and some basic motifs, is unique to CTV because no homologues have been found in other closteroviruses, including the type species of the genus Beet yellows virus (despite both viruses having many homologous genes. Consequently, p23 might have evolved for the specific interaction of CTV with its citrus hosts. From a functional perspective p23 has been involved in many roles: i regulation of the asymmetrical accumulation of CTV RNA strands, ii induction of the seedling yellows syndrome in sour orange and grapefruit, iii intracellular suppression of RNA silencing, iv elicitation of CTV-like symptoms when expressed ectopically as a transgene in several Citrus spp., and v enhancement of systemic infection (and virus accumulation in sour orange and CTV release from the phloem in p23-expressing transgenic sweet and sour orange. Moreover, transformation of Mexican lime with intron-hairpin constructs designed for the co-inactivation of p23 and the two other CTV silencing suppressors results in complete resistance against the homologous virus. From a cellular point of view, recent data indicate that p23 accumulates preferentially in the nucleolus, being the first closterovirus protein with such a subcellular localization, as well as in plasmodesmata. These major accumulation sites most likely determine some of the functional roles of p23.

  1. Development and validation of a multiplex reverse transcription quantitative PCR (RT-qPCR) assay for the rapid detection of Citrus tristeza virus, Citrus psorosis virus, and Citrus leaf blotch virus.

    Science.gov (United States)

    Osman, Fatima; Hodzic, Emir; Kwon, Sun-Jung; Wang, Jinbo; Vidalakis, Georgios

    2015-08-01

    A single real-time multiplex reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay for the simultaneous detection of Citrus tristeza virus (CTV), Citrus psorosis virus (CPsV), and Citrus leaf blotch virus (CLBV) was developed and validated using three different fluorescently labeled minor groove binding qPCR probes. To increase the detection reliability, coat protein (CP) genes from large number of different isolates of CTV, CPsV and CLBV were sequenced and a multiple sequence alignment was generated with corresponding CP sequences from the GenBank and a robust multiplex RT-qPCR assay was designed. The capacity of the multiplex RT-qPCR assay in detecting the viruses was compared to singleplex RT-qPCR designed specifically for each virus and was assessed using multiple virus isolates from diverse geographical regions and citrus species as well as graft-inoculated citrus plants infected with various combination of the three viruses. No significant difference in detection limits was found and specificity was not affected by the inclusion of the three assays in a multiplex RT-qPCR reaction. Comparison of the viral load for each virus using singleplex and multiplex RT-qPCR assays, revealed no significant differences between the two assays in virus detection. No significant difference in Cq values was detected when using one-step and two-step multiplex RT-qPCR detection formats. Optimizing the RNA extraction technique for citrus tissues and testing the quality of the extracted RNA using RT-qPCR targeting the cytochrome oxidase citrus gene as an RNA specific internal control proved to generate better diagnostic assays. Results showed that the developed multiplex RT-qPCR can streamline viruses testing of citrus nursery stock by replacing three separate singleplex assays, thus reducing time and labor while retaining the same sensitivity and specificity. The three targeted RNA viruses are regulated pathogens for California's mandatory "Section 3701

  2. Evaluation of the protective capacity of new mild Citrus tristeza virus (CTV isolates selected for a preimmunization program

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Zanutto

    2013-04-01

    Full Text Available The use of tolerant rootstocks and preimmunization has satisfactorily controlled losses associated with the Citrus tristeza virus (CTV. Several researchers have shown that CTV mild isolates that are selected in the same region where they are used are superior to isolates obtained from other areas. Thus, budwoods of 20 outstanding citrus trees were collected in north and northwestern Paraná state (Brazil citrus-producing areas and established to be used in a preimmunization program. These budwoods were tested to evaluate the potential protection of the inherently present viral complex. Based on biological indexing and molecular characterization of the capsid protein gene by RFLP (restriction fragment length polymorphism, which indicated that the plants were infected with mild isolates of CTV, some of the selected plants could be used in a preimmunization program. These potentially mild and protective isolates were challenged with severe 'Rolândia' isolate inoculations by grafting and by the brown citrus aphid (Toxoptera citricida Kirkaldy vector, which was faster in transmitting the virus. Some isolates had a better protective value than others, particularly when challenged with the severe CTV isolate. The SSCP (single strand conformational polymorphism molecular analysis was an excellent complementary tool for monitoring the performance of the experiments and the stability of the viral complex present in the plants. Isolate number 1, collected in the municipality of Cruzeiro do Sul (CS-1, was the most promising for protecting commercial Pêra sweet orange (C. sinensis L. orchards in northern and northwestern Paraná. The Rolândia severe CTV isolate was stable and had a high genetic divergence among the severe isolates used as a control (Capão Bonito and Barão B and all of the isolates tested.

  3. A genetic system for Citrus Tristeza Virus using the non-natural host Nicotiana benthamiana: an update

    Directory of Open Access Journals (Sweden)

    Silvia eAmbrós

    2013-07-01

    Full Text Available In nature Citrus tristeza virus (CTV, genus Closterovirus, infects only the phloem cells of species of Citrus and related genera. Finding that the CTV T36 strain replicated in Nicotiana benthamiana (NB protoplasts and produced normal virions allowed development of the first genetic system based on protoplast transfection with RNA transcribed from a full-genome cDNA clone, a laborious and uncertain system requiring several months for each experiment. We developed a more efficient system based on agroinfiltration of NB leaves with CTV-T36-based binary plasmids, which caused systemic infection in this non-natural host within a few weeks yielding in the upper leaves enough CTV virions to readily infect citrus by slash inoculation. Stem agroinoculation of citrus and NB plants with oncogenic strains of Agrobacterium tumefaciens carrying a CTV-T36 binary vector with a GUS marker, induced GUS positive galls in both species. However, while most NB tumours were CTV positive and many plants became systemically infected, no coat protein or viral RNA was detected in citrus tumours, even though CTV cDNA was readily detected by PCR in the same galls. This finding suggests i strong silencing or CTV RNA processing in transformed cells impairing infection progress, and ii the need for using NB as an intermediate host in the genetic system. To maintain CTV-T36 in NB or assay other CTV genotypes in this host, we also tried to graft-transmit the virus from infected to healthy NB, or to mechanically inoculate NB leaves with virion extracts. While these trials were mostly unsuccessful on non-treated NB plants, agroinfiltration with silencing suppressors enabled for the first time infecting NB plants by side-grafting and by mechanical inoculation with virions, indicating that previous failure to infect NB was likely due to virus silencing in early infection steps. Using NB as a CTV host provides new possibilities to study virus-host interactions with a simple and

  4. Agrobacterium-mediated transformation of grapefruit with the wild-type and mutant RNA-dependent RNA polymerase genes of Citrus tristeza virus

    OpenAIRE

    ÇEVİK, Bayram; Richard F. Lee; NIBLETT, Charles L.

    2012-01-01

    Citrus paradisi Macfad. ‘Duncan’ was transformed with constructs coding for the wild-type and mutant RNA-dependent RNA polymerase (RdRp) of Citrus tristeza virus (CTV) for exploring replicase-mediated pathogen-derived resistance (RM-PDR). The RdRp gene was amplified from a CTV genome and used to generate the wild-type and 2 mutant RdRp constructs for plant transformation. One mutant had the key amino acids GDD changed to AAA (RdRp-mGDD), and the second mutant had a deletio...

  5. Expressing p20 hairpin RNA of Citrus tristeza virus confers Citrus aurantium with tolerance/resistance against stem pitting and seedling yellow CTV strains

    Institute of Scientific and Technical Information of China (English)

    CHENG Chun-zhen[1,2,5; YANG Jia-wei[3; YAN Hu-bin[4; BEI Xue-jun[1,2; ZHANG Yong-yan[1,2; LU Zhi-ming[1; ZHONG Guang-yan[2,5

    2015-01-01

    The Citrus tristeza virus (CTV) uses 3 silencing suppressor genes, p20, p23 and p25, to resist the attacks from its Citrus hosts. Inactivating these genes is therefore obviously a potential defensive option in addition to the current control strat- egies including aphid management and the use of mild strain cross protection. In this study, we cloned partial DNA frag- ments from the three genes, and used them to construct vectors for expressing hairpin RNAs (hpRNAs). To facilitate the formation of hpRNAs, the constructs were introduced in a loop structure. Following transformation of sour orange (Citrus aurantium) with these constructs, 8 p20 hpRNA (hp20) and 1 p25 hpRNA (hp25) expressing lines were obtained. The 7 hp20 transgenic lines were further characterized. Their reactions to CTV were tested following inoculation with CT14A and/ or TR-L5"I4, both of which are severe strains. Results showed that 3 lines (hp20-5, hp20-6 and hp20-8) were completely resistant to TR-L514 under greenhouse conditions for no detectable viral load was found in their leaves by PCR. However, they exhibited only partial suppression of TR-L514 under screen house conditions since the virus was detected in their leaves, though 2 months later compared to non-transgenic controls. Further tests showed that hp20-5 was tolerant also to CT14A under screen house conditions. The growth of hp20-5 was much better than others including the controls that were concurrently challenged with CT14A. These results showed that expressing p20 hpRNAwas sufficient to confer sour orange with CTV resistance/tolerance.

  6. Expressing p20 hairpin RNA of Citrus tristeza virus confers Citrus aurantium with tolerance/resistance against stem pitting and seedling yellow CTV strains

    Institute of Scientific and Technical Information of China (English)

    CHENG Chun-zhen; YANG Jia-wei; YAN Hu-bin; BEI Xue-jun; ZHANG Yong-yan; LU Zhi-ming; ZHONG Guang-yan

    2015-01-01

    The Citrus tristeza virus (CTV) uses 3 silencing suppressor genes, p20, p23 and p25, to resist the attacks from its Citrus hosts. Inactivating these genes is therefore obviously a potential defensive option in addition to the current control strat-egies including aphid management and the use of mild strain cross protection. In this study, we cloned partial DNA frag-ments from the three genes, and used them to construct vectors for expressing hairpin RNAs (hpRNAs). To facilitate the formation of hpRNAs, the constructs were introduced in a loop structure. Fol owing transformation of sour orange (Citrus aurantium) with these constructs, 8 p20 hpRNA (hp20) and 1 p25 hpRNA (hp25) expressing lines were obtained. The 7 hp20 transgenic lines were further characterized. Their reactions to CTV were tested fol owing inoculation with CT14A and/or TR-L514, both of which are severe strains. Results showed that 3 lines (hp20-5, hp20-6 and hp20-8) were completely resistant to TR-L514 under greenhouse conditions for no detectable viral load was found in their leaves by PCR. However, they exhibited only partial suppression of TR-L514 under screen house conditions since the virus was detected in their leaves, though 2 months later compared to non-transgenic controls. Further tests showed that hp20-5 was tolerant also to CT14A under screen house conditions. The growth of hp20-5 was much better than others including the controls that were concurrently chal enged with CT14A. These results showed that expressing p20 hpRNA was sufifcient to confer sour orange with CTV resistance/tolerance.

  7. The conserved structures of the 5' nontranslated region of Citrus tristeza virus are involved in replication and virion assembly

    International Nuclear Information System (INIS)

    The genomic RNA of different isolates of Citrus tristeza virus (CTV) reveals an unusual pattern of sequence diversity: the 3' halves are highly conserved (homology >90%), while the 5' halves show much more dissimilarity, with the 5' nontranslated region (NTR) containing the highest diversity (homology as low as 42%). Yet, positive-sense sequences of the 5' NTR were predicted to fold into nearly identical structures consisting of two stem-loops (SL1 and SL2) separated by a short spacer region. The predicted most stable secondary structures of the negative-sense sequences were more variable. We introduced mutations into the 5' NTR of a CTV replicon to alter the sequence and/or the predicted secondary structures with or without additional compensatory changes designed to restore predicted secondary structures, and examined their effect on replication in transfected protoplasts. The results suggested that the predicted secondary structures of the 5' NTR were more important for replication than the primary structure. Most mutations that were predicted to disrupt the secondary structures fail to replicate, while compensatory mutations were allowed replication to resume. The 5' NTR mutations that were tolerated by the CTV replicon were examined in the full-length virus for effects on replication and production of the multiple subgenomic RNAs. Additionally, the ability of these mutants to produce virions was monitored by electron microscopy and by passaging the progeny nucleocapsids to another batch of protoplasts. Some of the mutants with compensatory sequence alterations predicted to rebuild similar secondary structures allowed replication at near wild-type levels but failed to passage, suggesting that the 5' NTR contains sequences required for both replication and virion assembly

  8. Detección, dispersión y muestreo en la erradicación del Citrus Tristeza Virus en plantaciones comerciales de cítricos

    OpenAIRE

    Ruiz García, Noé

    2012-01-01

    La dispersión espacio-temporal del Citrus tristeza virus se caracterizó en Tamaulipas de diciembre de 2001 a marzo de 2004, en 11 huertos comerciales de naranja dulce injerta- dos en naranjo agrio. Adicionalmente, se comparó el desempeño de la técnica serológica inmunoimpresión-ELISA con respecto a DAS-ELISA propuesta en la normatividad ofi- cial mexicana de la Campaña Nacional contra CTV. El objetivo fue proporcionar bases epidemiológicas e incorporar criterios de diagnós...

  9. Genetic variation and recombination of RdRp and HSP 70h genes of Citrus tristeza virus isolates from orange trees showing symptoms of citrus sudden death disease

    Directory of Open Access Journals (Sweden)

    Pappas Georgios J

    2008-01-01

    Full Text Available Abstract Background Citrus sudden death (CSD, a disease that rapidly kills orange trees, is an emerging threat to the Brazilian citrus industry. Although the causal agent of CSD has not been definitively determined, based on the disease's distribution and symptomatology it is suspected that the agent may be a new strain of Citrus tristeza virus (CTV. CTV genetic variation was therefore assessed in two Brazilian orange trees displaying CSD symptoms and a third with more conventional CTV symptoms. Results A total of 286 RNA-dependent-RNA polymerase (RdRp and 284 heat shock protein 70 homolog (HSP70h gene fragments were determined for CTV variants infecting the three trees. It was discovered that, despite differences in symptomatology, the trees were all apparently coinfected with similar populations of divergent CTV variants. While mixed CTV infections are common, the genetic distance between the most divergent population members observed (24.1% for RdRp and 11.0% for HSP70h was far greater than that in previously described mixed infections. Recombinants of five distinct RdRp lineages and three distinct HSP70h lineages were easily detectable but respectively accounted for only 5.9 and 11.9% of the RdRp and HSP70h gene fragments analysed and there was no evidence of an association between particular recombinant mosaics and CSD. Also, comparisons of CTV population structures indicated that the two most similar CTV populations were those of one of the trees with CSD and the tree without CSD. Conclusion We suggest that if CTV is the causal agent of CSD, it is most likely a subtle feature of population structures within mixed infections and not merely the presence (or absence of a single CTV variant within these populations that triggers the disease.

  10. The First Identified Citrus tristeza virus Isolate of Turkey Contains a Mixture of Mild and Severe Strains

    Directory of Open Access Journals (Sweden)

    Bayram Çevik

    2013-03-01

    Full Text Available The presence of Citrus tristeza virus (CTV has previously been reported in citrus growing regions of Turkey. All serologically and biologically characterized isolates including Iğdır, which was the first identified CTV isolates from Turkey, were considered mild isolates. In this study, molecular characteristics of the Iğdır isolate were determined by different methods. Analysis of the Iğdır isolate by western blot and BD-RT-PCR assays showed the presence of MCA13 epitope, predominantly found in severe isolates, in the Iğdır isolate revealing that it contains a severe component. For further characterization, the coat protein (CP and the RNA-dependent RNA polymerase (RdRp genes representing the 3′ and 5′ half of CTV genome, respectively, were amplified from dsRNA by RT-PCR. Both genes were cloned separately and two clones for each gene were sequenced. Comparisons of nucleotide and deduced amino acid sequences showed that while two CP gene sequences were identical, two RdRp clones showed only 90% and 91% sequence identity in their nucleotide and amino acid sequences, respectively, suggesting a mixed infection with different strains. Phylogenetic analyses of the CP and RdRp genes of Iğdır isolate with previously characterized CTV isolates from different citrus growing regions showed that the CP gene was clustered with NZRB-TH30, a resistance breaking isolate from New Zealand, clearly showing the presence of severe component. Furthermore, two different clones of the RdRp gene were clustered separately with different CTV isolates with a diverse biological activity. While the RdRp-1 was clustered with T30 and T385, two well-characterized mild isolates from Florida and Spain, respectively, the RdRp-2 was most closely related to NZRB-G90 and NZRB-TH30, two well-characterized resistance breaking and stem pitting (SP isolates from New Zealand confirming the mixed infection. These results clearly demonstrated that the Iğdır isolate, which

  11. The conundrum of a unique protein encoded by citrus tristeza virus that is dispensable for infection of most hosts yet shows characteristics of a viral movement protein.

    Science.gov (United States)

    Bak, Aurélie; Folimonova, Svetlana Y

    2015-11-01

    Citrus tristeza virus (CTV), one of the most economically important viruses, produces a unique protein, p33, which is encoded only in the genomes of isolates of CTV. Recently, we demonstrated that membrane association of the p33 protein confers virus ability to extend its host range. In this work we show that p33 shares characteristics of viral movement proteins. Upon expression in a host cell, the protein localizes to plasmodesmata and displays the ability to form extracellular tubules. Furthermore, p33 appears to traffic via the cellular secretory pathway and the actin network to plasmodesmata locations and is likely being recycled through the endocytic pathway. Finally, our study reveals that p33 colocalizes with a putative movement protein of CTV, the p6 protein. These results suggest a potential role of p33 as a noncanonical viral movement protein, which mediates virus translocation in the specific hosts. PMID:26210077

  12. Genetic differentiation and biology of Citrus Tristeza virus populations spreading in California

    Science.gov (United States)

    CTV strains were collected from more than 1500 CTV-infected trees in citrus groves in Tulare, Kern, Ventura, Riverside and San Diego Counties to assess molecular and biological properties of CTV strains currently in California. Tests included serology with MCA13, quantitative (q) real-time Reverse ...

  13. Sequence Analysis of a 282-Kilobase Region Surrounding the Citrus Tristeza Virus Resistance Gene (Ctv) Locus in Poncirus trifoliata L. Raf.1

    Science.gov (United States)

    Yang, Zhong-Nan; Ye, Xin-Rong; Molina, Joe; Roose, Mikeal L.; Mirkov, T. Erik

    2003-01-01

    Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8× coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed. PMID:12586873

  14. Sequence analysis of a 282-kilobase region surrounding the citrus Tristeza virus resistance gene (Ctv) locus in Poncirus trifoliata L. Raf.

    Science.gov (United States)

    Yang, Zhong-Nan; Ye, Xin-Rong; Molina, Joe; Roose, Mikeal L; Mirkov, T Erik

    2003-02-01

    Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8x coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed. PMID:12586873

  15. Booster immunization with a partially purified citrus tristeza virus (CTV) preparation after priming with recombinant CTV coat protein enhances the binding capacity of capture antibodies by ELISA.

    Science.gov (United States)

    Bar-Joseph, M; Filatov, V; Gofman, R; Guang, Y; Hadjinicolis, A; Mawassi, M; Gootwine, E; Weisman, Y; Malkinson, M

    1997-08-01

    Groups of rabbits and young lambs were immunized subcutaneously and intramuscularly with a recombinant citrus tristeza virus (CTV) coat protein (rCTV-CP) antigen. Three weeks after primary immunization the animals were divided into two groups that were boosted either with rCTV-CP or with a partially purified preparation of CTV particles (ppCTV). Twelve and 15 days after the last injection, the animals were bled and the binding capacity of the antisera for CTV detection was examined for capture antibodies by the indirect ELISA. Considerably higher ELISA titers were obtained from animals that were boosted with ppCTV than with rCP. Boosting with partially purified native antigens after priming with recombinant antigens is expected to extend the applicability of the antisera for detecting other structural and non-structural viral antigens by trapping ELISA. PMID:9274814

  16. Refinement of the Citrus tristeza virus resistance gene (Ctv) positional map in Poncirus trifoliata and generation of transgenic grapefruit (Citrus paradisi) plant lines with candidate resistance genes in this region.

    Science.gov (United States)

    Rai, Mamta

    2006-06-01

    Citrus tristeza virus (CTV) is a major pathogen of Citrus. A single dominant gene Ctv present in the trifoliate relative of Citrus, Poncirus trifoliata confers broad spectrum resistance against CTV. Refinement of genetic maps has delimited this gene to a 121 kb region, comprising of ten candidate Ctv resistance genes. The ten candidate genes were individually cloned in Agrobacterium based binary vector and transformed into three CTV susceptible grapefruit varieties. Two of the candidate R-genes, R-2 and R-3 are exclusively expressed in transgenic plants and in Poncirus trifoliata, while five other genes are also expressed in non-transformed Citrus controls. Northern blotting with a CTV derived probe for assessment of infection in virus inoculated plants over a span of three growth periods, each comprising of six to eight weeks, indicates either an absence of initiation of infection or it's slow spread in R-2 plant lines or an initial appearance of infection and it's subsequent obliteration in some R-1 and R-4 plant lines. Limited genome walk up- and downstream form R-1 gene, based on it's 100% sequence identity between Poncirus and Citrus, indicates promoter identity of 92% between the two varieties. Further upstream and downstream sequencing indicates the presence of an O-methyl transferase and a Copia like gene respectively in Citrus instead of the amino acid transporter like gene upstream and a sugar transporter like gene downstream in Poncirus. The possibility of recombinations in the resistance locus of Citrus and the need for consistent monitoring for virus infection and gene expression in the transgenic Citrus trees is discussed. PMID:16830176

  17. Evidence of Recombinant Citrus tristeza virus Isolate Occurring in Acid Lime cv. Pant Lemon Orchard in Uttarakhand Terai Region of Northern Himalaya in India.

    Science.gov (United States)

    Singh, Jaywant Kumar; Tarafdar, Avijit; Sharma, Susheel Kumar; Biswas, Kajal Kumar

    2013-06-01

    The present study for the first time describes biological and molecular characterization of Citrus tristeza virus (CTV) occurring in the Terai area of Uttarakhand State in Northern Himalaya region of India. Direct antigen coated-ELISA and reverse transcriptase-polymerase chain reaction (RT-PCR) detected the CTV infection in Acid lime cv. Pant lemon (Citrus aurantifolia) orchards of Pantnagar with an estimated disease incidence of 16.6-20.5 %. To know the biological and genetic properties, an isolate, CTV Pant 4 was characterized. Isolate Pant 4 could be graft transmitted to Kinnow, Nagpur and Darjeeling mandarins, Mosambi sweet orange, Kagzi lime, Sweet lime, Sour orange but not to Rough lemon. The sequence analyses of the 5'ORF1a (3038 nucleotides) of LPro domain and 3'end (2058 nt) covering ORF7-ORF10 regions of the CTV genome revealed that Pant 4 was closely related to the previously reported Indian CTV isolate, Kpg3 from Northeastern Himalaya region with 97 and 98 % sequence identity, respectively. Whereas, it differed from the previously reported CTV isolate B165 from Southern India with 79 and 92 % identity, respectively for 5'ORF1a and 3' end regions. Recombination and SplitsTree decomposition analyses indicated that CTV isolate Pant 4 was a recombinant isolate originating from Kpg3 as a major and B165 as a minor donor. PMID:24426255

  18. Genetic Marker Analysis of a Global Collection of Isolates of Citrus tristeza virus: Characterization and Distribution of CTV Genotypes and Association with Symptoms.

    Science.gov (United States)

    Hilf, Mark E; Mavrodieva, Vessela A; Garnsey, Stephen M

    2005-08-01

    ABSTRACT Genetic markers amplified from three noncontiguous regions by sequence specific primers designed from the partial or complete genome sequences of Citrus tristeza virus (CTV) isolates T3, T30, T36, and VT were used to assess genetic relatedness of 372 isolates in an international collection. Eighty-five isolates were judged similar to the T3 isolate, 81 to T30, 11 to T36, and 89 to VT. Fifty-one isolates were mixed infections by two or more identifiable viral genotypes, and 55 isolates could not be assigned unequivocally to a group defined by marker patterns. Maximum parsimony analysis of aligned marker sequences supported the grouping of isolates on the basis of marker patterns only. Specific disease symptoms induced in select citrus host plants were shared across molecular groups, although symptoms were least severe among isolates grouped by markers with the T30 isolate and were most severe among isolates grouped by markers with the T3 isolate. Isolates assigned the same genotype showed variable symptoms and symptom severity. A classification strategy for CTV isolates is proposed that combines genetic marker patterns and nucleotide sequence data. PMID:18944413

  19. Polymorphism of the 5' terminal region of Citrus tristeza virus (CTV) RNA: incidence of three sequence types in isolates of different origin and pathogenicity.

    Science.gov (United States)

    Ayllón, M A; López, C; Navas-Castillo, J; Garnsey, S M; Guerri, J; Flores, R; Moreno, P

    2001-01-01

    Sequences of the 5' terminal region of the genomic RNA from eight isolates of Citrus tristeza virus (CTV) were previously classified into three types (I, II and III), with intragroup sequence identity higher than 88% and intergroup sequence identity as low as 44%. Sequencing of an additional 58 cDNA clones from 15 virus isolates showed that all sequences could be unequivocally assigned to one of the three types previously established. The relative frequency of each sequence type was assessed in 57 CTV isolates of different geographic origin and pathogenic characteristics by RT-PCR with sets of type-specific primers using CTV dsRNA as template. None of the isolates yielded amplification of the type I or II sequences alone, but in 19 of them type III sequences were the only amplification product detected. Within isolates containing more than one sequence type, eight had type II and III sequences, 11 had type I and III sequences, and 19 had sequences of the three types. Isolates containing only type III sequences caused only mild to moderate symptoms in Mexican lime, an indicator species for most CTV isolates, whereas isolates causing stem pitting in sweet orange an/or grapefruit, generally contained sequences type II. None of the sequence types could be traced to a precise geographic area, as all types were detected in isolates from at least nine of the 12 countries from which samples were taken. PMID:11266215

  20. The genetics of tolerance to tristeza disease in citrus rootstocks

    Directory of Open Access Journals (Sweden)

    Rita Bordignon

    2004-01-01

    Full Text Available Controlled pollinations between four elite citrus rootstocks, Citrus limonia - 'Limeira' rangpur lime (Cravo, C. sunki - 'Sunki' mandarin (Sunki, C. aurantium - 'São Paulo' sour orange (Azeda and Poncirus trifoliata - 'Davis A' trifoliate orange (Trifoliata, resulted in 1614 nucelar and 1938 hybrid plants identified by the isozyme loci Pgi-1, Pgm-1, Got-1, Got-2, Aps-1, Me-1, Prxa-1 and or by the morphological markers broadness of leaf petiole wing or trifoliolate leaves. Tolerance to the citrus tristeza virus (CTV was evaluated under nursery and field conditions for several years by the reaction of Valencia orange infected with a severe strain of CTV and grafted onto the hybrids and nucellar clones. Genetic analyses indicated that tolerance was controlled by at least two loci designated here as Az and t interacting in dominant-recessive epistasis. Genotypes Az__ __ __ and __ __ tt were tolerant while azaz T__ was intolerant. The intolerant Azeda was azaz TT, the tolerant rootstocks Sunki and Cravo were Azaz tt and the Trifoliata was Azaz TT. The different degrees of intolerance seen in some hybrids may reflect the inability of segregating modifiers from parental clones to overcome the epistatic interaction that controls the major tolerance reaction.

  1. Characterization of Citrus tristeza virus isolates from grapefruit (Citrus paradisi Macf. accessions of Citrus Active Germplasm Bank Caracterização de isolados do vírus da tristeza dos citros de acessos de pomelos (Citrus paradisi Macf. do Banco Ativo de Germoplasma de Citros

    Directory of Open Access Journals (Sweden)

    Maria Júlia Corazza-Nunes

    2006-09-01

    Full Text Available Citrus tristeza virus (CTV isolates from 35 grapefruit accessions belonging to Citrus Active Germplasm Bank of the "Instituto Agronômico de Campinas" located at the "Centro APTA Citros Sylvio Moreira", Cordeirópolis, São Paulo state, Brazil, were characterized and evaluated through symptoms in the trees, biological indexing, immunological diagnosis with different monoclonal antibodies and SSCP analysis (single-strand conformation polymorphism of the coat protein gene. Symptomatology indicated that, in general, the group of plants with smaller canopy volume and severe stem pitting differed significantly from the group that presented greater vegetative development and mild to moderate stem pitting. However, the isolates from most of the accessions induced mild reaction on Mexican lime. The serological evaluation through the DAS-ELISA using monoclonal antibodies did not reveal any association between virus titer in the plant tissue and symptoms. The reaction with different monoclonal antibodies and the distinct electrophoresis patterns obtained through SSCP showed that there is a high degree of diversity among the isolates that infect these grapefruit accessions. High complexity within the same isolate was also observed in the SSCP profiles. This finding indicates that the CTV isolates from these plants are a complex mixture of CTV haplotypes. Similar SSCP banding patterns were observed among some plants with strong stem pitting symptoms, and among some plants with weak or moderate stem pitting symptoms.Isolados do vírus da tristeza dos citros (CTV de 35 acessos de pomelos que fazem parte do Banco Ativo de Germoplasma de Citros, localizado no Centro APTA Citros Sylvio Moreira, Cordeirópolis, São Paulo, Brasil, pertencente ao Instituto Agronômico de Campinas (IAC, foram caracterizados através dos sintomas observados nas árvores, indexação biológica, diagnóstico imunológico e análise SSCP (polimorfismo de conformação de fita simples

  2. Transmisibilidad de aislamiento del Citrus Tristeza Virus (CTV) por áfidos y evaluación de la resistencia en cítricos tranformados con genes del CTV

    OpenAIRE

    Loeza Kuk, Emiliano

    2012-01-01

    La sintomatología en árboles infectados por el Citrus Tristeza Virus (CTV) es influenciada por factores como la población de variantes de secuencia presentes. Esta población es modificada en la transmisión por áfidos y la evidencia sugiere que la interacción del CTV con Toxoptera citricida, incrementa la frecuencia de los aislamientos severos. Se estudió una huerta en Yucatán con una incidencia inicial de 11 árboles positivos a CTV y con tres haplotipos de aislamientos no ...

  3. Frameshift mutations in infectious cDNA clones of Citrus tristeza virus: a strategy to minimize the toxicity of viral sequences to Escherichia coli

    International Nuclear Information System (INIS)

    The advent of reverse genetics revolutionized the study of positive-stranded RNA viruses that were amenable for cloning as cDNAs into high-copy-number plasmids of Escherichia coli. However, some viruses are inherently refractory to cloning in high-copy-number plasmids due to toxicity of viral sequences to E. coli. We report a strategy that is a compromise between infectivity of the RNA transcripts and toxicity to E. coli effected by introducing frameshift mutations into 'slippery sequences' near the viral 'toxicity sequences' in the viral cDNA. Citrus tristeza virus (CTV) has cDNA sequences that are toxic to E. coli. The original full-length infectious cDNA of CTV and a derivative replicon, CTV-ΔCla, cloned into pUC119, resulted in unusually limited E. coli growth. However, upon sequencing of these cDNAs, an additional uridinylate (U) was found in a stretch of U's between nts 3726 and 3731 that resulted in a change to a reading frame with a stop codon at nt 3734. Yet, in vitro produced RNA transcripts from these clones infected protoplasts, and the resulting progeny virus was repaired. Correction of the frameshift mutation in the CTV cDNA constructs resulted in increased infectivity of in vitro produced RNA transcripts, but also caused a substantial increase of toxicity to E. coli, now requiring 3 days to develop visible colonies. Frameshift mutations created in sequences not suspected to facilitate reading frame shifting and silent mutations introduced into oligo(U) regions resulted in complete loss of infectivity, suggesting that the oligo(U) region facilitated the repair of the frameshift mutation. Additional frameshift mutations introduced into other oligo(U) regions also resulted in transcripts with reduced infectivity similarly to the original clones with the +1 insertion. However, only the frameshift mutations introduced into oligo(U) regions that were near and before the toxicity region improved growth and stability in E. coli. These data demonstrate that

  4. Molecular characterization of Cirus tristeza virus isolates associated with stem pitting CTV cross-protection in Peru

    Science.gov (United States)

    During the 1970s and early 1980s, the Peruvian citrus industry was destroyed by severe Citrus tristeza virus (CTV) strains spread by the brown citrus aphid. The Topara Nursery, located 180 km south of Lima Peru, selected and identified CTV isolates that confer cross-protection against virulent stem...

  5. cis-acting elements at opposite ends of the Citrus tristeza virus genome differ in initiation and termination of subgenomic RNAs

    International Nuclear Information System (INIS)

    Citrus tristeza virus (CTV), a member of the Closteroviridae with a plus-stranded genomic RNA of approximately 20 kb, produces 10 3'-coterminal subgenomic (sg) RNAs that serve as messenger (m)RNAs for its internal genes. In addition, a population of 5'-terminal sgRNAs of approximately 700 nts are highly abundant in infected cells. Previous analysis demonstrated that the controller elements (CE) are responsible for the 3'-terminal mRNAs and the small 5'-terminal sgRNAs differ in the number of additional sgRNAs produced. A feature of both types of CE is production of 5'- and 3'-terminal positive-stranded sgRNAs, but the 3' CEs additionally produce a negative-stranded complement of the 3'-terminal mRNAs. Here, we found that the termination (for 5'-terminal sgRNAs) and initiation (for 3'-terminal sgRNAs) sites of the 5' vs. the 3' CEs occur at opposite ends of the respective minimal active CEs. The initiation site for the 3' CE of the major coat protein gene, and probably those of the p20 and p23 genes, was outside (3' in terms of the genomic RNA) the minimal unit, whereas the termination sites were located within the minimal CE, 30-50 nts upstream of the initiation site (referring to the positive-strand sequence). In contrast, the initiation site for the 5' CE was in the 5' region of the minimal unit, with the termination sites 20-35 nts downstream (referring to the positive-strand sequence). Furthermore, the CEs differ in initiation nucleotide and response to mutagenesis of that nucleotide. The 3' CE initiates sgRNA synthesis from a uridylate, whereas the 5' CE initiates from a cytidylate. We previously found that the 3' CEs were unusually tolerant to mutagenesis of the initiation sites, with initiation proceeding from alternative sites. Mutagenesis of the initiation site of the 5' CE prevented synthesis of either the 5'- or 3'-terminal sgRNAs. Thus, the cis-acting elements at opposite ends of the genome are remarkably different, perhaps having arisen from different

  6. Comportamiento de la producción de lima Tahití (Citrus latifolia Tanaka, injertada sobre el patrón de Mandarina Cleopatra (Citrus reticulata Blanco y la influencia del virus de la tristeza (CTV en condiciones del piedemonte del Meta, 1997-2008

    Directory of Open Access Journals (Sweden)

    Julio Quiroga - Cardona

    2010-06-01

    Full Text Available Tahiti limes (Citrus latifolia T is in third place among the citrus species cultivated in Colombia. Its fruits are consumed in the domestic market and has a growing export market. Among the viral diseases affecting citrus crops Virus Citrus Tristeza (CTV is one of the most limiting for production and longevity of plantsespecially in Tahiti lime. This study was carried out under the ecological conditions of the Research Center Corpoica La Libertad, in the foothills of the department of Meta. The plants used in the nursery in 1996 grafted with buds from crops used as standard Cleopatra mandarin (Citrus reticulata Blanco. The crop fieldwas established in 1997, occupying an area of one hectare, with a density of 490 plants ha-1. To determine crop production took annual records, and the incidence and severity of the (CTV were two readings in plants, during the seventh and eleventh year after transplantation (addt. In 2008 (11 addt A description of thesymptoms of the damage caused by citrus tristeza in the plant and the photographic record was made. The Tahiti lime production started three years after transplantation with 4 t/ ha and increased annually to present the peak of production in the eighth year with 62 t/ ha, then decreased until 2 t/ ha in year 11.The incidence of CTV in 2003 (6 addt was 16.5 % for a total of 80 affected plants and in 2008 (11 addt 100 % of plants were affected (490 plants. The severity of CTV, in the 2003 was 29.4 %, while the reading of 2008 was 84 %.

  7. Biological characterization of Citrus tristeza virus strains in lemon in Tucumán, Argentina Caracterización biológica de aislamientos del virus de la tristeza de los cítricos de limoneros en Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    Julia Figueroa

    Full Text Available Tucumán province is the largest lemon producer in the world, with a production of 1.3 million tons. Unfotunality, tristeza disease has been present in Argentina since 1930 and is endemic. Citrus tristeza virus isolates from the main lemon varieties in Tucumán province were biologically characterized on the basis of vein clearing, vein corking, leaf cupping, stunting, stem pitting and other symptoms using standard indicator plants. The lemon varieties were: Frost Eureka, Frost Lisbon, Limoneira 8A and Genoa EEAT. The indicator plants used were Mexican lime, Eureka lemon, Duncan grapefruit, Pineapple sweet orange and sour orange seedlings, plus Ruby Blood sweet orange budded on sour orange rootstock. Symptoms on each of the indicator plants were rated from 0 (no reaction to 5 (most severe. A total rating for each isolate was obtained by summing the ratings on each indicator plant. Differences among lemon isolates were observed. Genoa isolate induced least growth while Limoneira isolate induced the most severe stem pitting. Little difference was observed between Eureka and Lisbon isolate.La Argentina es el primer país productor de limón en el mundo y la provincia de Tucumán lidera esta producción con 1,3 millones de toneladas. Desafortunadamente la tristeza de los cítricos es una enfermedad endémica en la Argentina desde 1930. En el presente trabajo se informa sobre la caracterización biológica realizada a distintos aislamientos del virus de la tristeza de los cítricos de las principales variedades comerciales de limoneros. Las variedades de limoneros estudiadas fueron: Eureka Frost, Lisboa Frost, Lisboa Limoneira 8 A y Génova EEAT. La caracterización se realizó en las plantas indicadoras estándares para este tipo de pruebas y fueron: plantines de lima mexicana, limón Eureka, pomelo Duncan, naranjo dulce Pineapple y naranjo agrio; y plantas injertadas de naranjo dulce Ruby Blood en naranjo agrio. Los principales síntomas evaluados

  8. Transcriptomic Responses of Poncirus trifoliata to Citrus tristeza virus (CTV) Infection%枳感染柑橘衰退病病毒后的应答基因分析

    Institute of Scientific and Technical Information of China (English)

    程春振; 钟云; 吴波; 阳佳位; 贝学军; 姜波; 朱世平; 闫树堂; 张永艳

    2013-01-01

    枳(Poncirus trifoliataL.)高抗柑橘衰退病病毒(Citrus tristeza virus,CTV),但相关抗性机理仍不为人所知.以嫁接健康枝条的无毒枳作为对照,用Affymetrix柑橘基因芯片分析了感染CTV后枳叶片中基因的表达变化情况.结果共检测到表达量差异倍数≥2的基因295个,其中216个表达上调,79个表达下调.BLAST2GO分析发现,差异表达的基因中与抗逆反应相关的基因最多,乙烯、茉莉酸、赤霉素、脱落酸、生长素、水杨酸等植物激素代谢和调节相关基因为数不少,一些编码细胞壁形成或组分相关蛋白的基因差异表达明显.本研究可为揭示枳抗CTV的机理提供了转录组学线索.

  9. Distributional analysis of SSRs in genomes of citrus tristeza virus%柑橘衰退病毒基因组的简单重复序列分布分析

    Institute of Scientific and Technical Information of China (English)

    赵哲; 谭钟扬; 李世访; 王红清

    2013-01-01

    柑橘衰退病毒(Citrus tristeza virus,CTV)属于长线性病毒科(Closteroviridae),是目前已知植物病毒中基因组最大的病毒,其引起的柑橘衰退病对全世界的柑橘产业造成着严重影响.本文以在GenBank登录的32条全长CTV基因组序列为材料,分析简单重复序列(Simple Sequence Repeats,SSRs)在其基因组序列中的分布情况.研究结果显示,在所有的CTV基因组中均有SSRs的分布,SSRs重复次数较少,二型SSRs占主导地位,未在CTV基因组序列中发现五型和六型SSRs.在32条基因组全长序列中仅在5条序列中发现四型SSRs.这是首次以柑橘病毒为材料进行的SSRs分析研究.

  10. Métodos para identificação e controle da tristeza dos citros Methods of identification and control of tristeza disease of citrus

    Directory of Open Access Journals (Sweden)

    S. Moreira

    1954-01-01

    transmission tests for field surveys of the disease in areas where tristeza is already known to be present. Transmission tests are usually carried out by methods of tissue union or by means of the vectors. Young plants of non-tolerant combinations (such as sweet orange on sour orange rootstock or seedlings of West Indian limes may be used as test plants in these tests. A knowledge of the predominance of the various strains of the tristeza virus complex in the invaded areas is very important in regard to the application of control measures. Also the determination of the aphid vector or vectors in the areas concerned will permit forecasting the rate of spread of tristeza because efficiency varies considerably according to the vector species. Control of tristeza in citrus orchards is obtained by indirect methods. In new plantings made in invaded areas, non-tolerant stock-scion combinations should be avoided. Only tolerant rootstocks such as sweet oranges, mandarins, rangpur lime, and rough lemons should be used for most commercial tops. In some instances it may be possible to use unbudded trees originated from nucellar embryos. In established orchards, where a non-tolerant rootstock was employed, individual affected trees may be replaced or the whole planting may be interplanted with trees of a tolerant stock-scion combination. The first method is used in areas where the disease is disseminated by a poor vector, whereas the second method is more advisable in areas where spread of the disease is very rapid. Inarching or rooting the scion (by mounding the soil around its base are used to control tristeza under some conditions. Top working with lemon may also be used. Quarantine barriers may prevent the introduction of tristeza in uninvaded areas. It is highly desirable to inform travellers about the risk represented by the introduction of citrus budwood material or cuttings from areas where the disease is known to be present.

  11. CARACTERIZACIÓN MOLECULAR DE RAZAS SEVERAS Y DÉBILES DEL VIRUS DE LA TRISTEZA DE LOS CÍTRICOS

    OpenAIRE

    Mendoza, Alberto; Salazar, César; ALVARADO, OMAR; CRUZ, MA. ANTONIA; Barrera Saldaña, Hugo A

    2005-01-01

    La tristeza de los cítricos es la enfermedad viral más importante de éstos a nivel mundial; debido a que en los últimos 20 años ha causado la muerte a más de 100 millones de árboles en América del Sur, California, Florida (EE.UU.), Israel y España. El Citrus tristeza closterovirus (Virus de la tristeza de los cítricos o VTC) se transmite principalmente por el áfido Toxoptera citricida y por material vegetativo infectado (injertos). El áfido T. citricida ha sido recient...

  12. Investigações sôbre a tristeza dos Citrus: II - Conceitos e dados sôbre a reação das plantas cítricas à tristeza

    Directory of Open Access Journals (Sweden)

    A. S. Costa

    1949-01-01

    Full Text Available The writers review previous concepts concerning the reaction of citrus plants to the tristeza disease. It is recognized that environmental factors such as temperature, humidity and light can influence plant reaction, but these are considered of relatively minor importance. Characteristics of the plant itself govern its reaction to the disease and among those, resistance to infection, ability to permit virus increase and tolerance or non-tolerance of tissues are considered most important. Tests using viruliferous oriental citrus aphids for inoculation of various citrus types budded over sour orange rootstocks (table 1 and 2 showed a correlation between susceptibility to infection and severity of symptoms. The sweet oranges proved to be the most susceptible to infection and showed severe disease symptoms. The Barão sweet orange appeared to be more susceptible than Valencia. The mandarins tended to show some resistance to infection, but when infected, severe symptoms developed. The tolerant tangelos (7 behaved similarly to sweet oranges : They were very susceptible to infection and showed severe symptoms. The non-tolerant tangelos, susceptible citranges (7 and grapefruits behaved more or less alike, and showed medium susceptibility to infection and moderately severe disease symptoms. Among the grapefruits, Leonardy was. observed to be relatively more susceptible and showed more severe symptoms than Duncan. The pummelos, shaddocks and sour oranges were comparatively very resistant to infection and showed only moderate symptoms when infected. It has been found that the sour oranges can be more easily infected by tissue union than by the aphid vector. Poncirus trifoliata, citrumelos and resistant citranges showed no symptoms and no virus could be recovered from the inoculated plants even after three inoculations. The nature of injury caused by tristeza in the non-tolerant graft and intergraft combinations is discussed. The observation of symptoms

  13. Diferenciación molecular de razas severas y débiles de aislamientos del virus de la tristeza de los cítricos en México

    OpenAIRE

    Alberto Mendoza; César Salazar; Omar Alvarado; Ma. Antonia Cruz; Hugo Barrera

    2003-01-01

    La tristeza de los cítricos es la enfermedad viral más importante de los cítricos a nivel mundial, debido a que en los últimos 20 años ha causado la muerte de más de 100 millones de árboles en América del Sur, Estados Unidos, Israel y España. El Citrus Tristeza Closterovirus (Virus de la Tristeza de los Cítricos, VTC) se transmite principalmente por el áfido Toxoptera citricida y por material vegetativo infectado (injertos). El áfido T. citricida ha sido recientemente detectado en el sureste ...

  14. 不同来源的柑橘衰退病毒分离物基因组5'端A、F变异区序列克隆及分析%Cloning and analyzing of 5' A and F variation sequences of Citrus tristeza virus genomic RNA of isolates from different regions

    Institute of Scientific and Technical Information of China (English)

    丁芳; 洪霓; 钟云; 易干军; 王国平

    2008-01-01

    柑橘衰退病毒(Citrus tristeza virus,CTV)组群自然条件下存在株系分化现象.本研究利用RT-PCR技术扩增、克隆了来自我国不同地区的21个柑橘衰退病毒分离物的5'端A、F变异区.通过分析发现,不同来源的各分离物在5'端A、F区存在较大的变异.21个分离物A区序列相似性最低为85.8%,最高可达99.8%,平均为95.9%;与GenBank中9个代表性株系的平均相似性为84.2%.F区序列相似性较A区高,为98.0%;相似性最低为94.3%,最高达99.1%.结果显示不同来源的CTV分离物5'端序列A、F区变异较大.

  15. A stable RNA virus-based vector for citrus trees

    International Nuclear Information System (INIS)

    Virus-based vectors are important tools in plant molecular biology and plant genomics. A number of vectors based on viruses that infect herbaceous plants are in use for expression or silencing of genes in plants as well as screening unknown sequences for function. Yet there is a need for useful virus-based vectors for woody plants, which demand much greater stability because of the longer time required for systemic infection and analysis. We examined several strategies to develop a Citrus tristeza virus (CTV)-based vector for transient expression of foreign genes in citrus trees using a green fluorescent protein (GFP) as a reporter. These strategies included substitution of the p13 open reading frame (ORF) by the ORF of GFP, construction of a self-processing fusion of GFP in-frame with the major coat protein (CP), or expression of the GFP ORF as an extra gene from a subgenomic (sg) mRNA controlled either by a duplicated CTV CP sgRNA controller element (CE) or an introduced heterologous CE of Beet yellows virus. Engineered vector constructs were examined for replication, encapsidation, GFP expression during multiple passages in protoplasts, and for their ability to infect, move, express GFP, and be maintained in citrus plants. The most successful vectors based on the 'add-a-gene' strategy have been unusually stable, continuing to produce GFP fluorescence after more than 4 years in citrus trees

  16. Mild strain cross protection of tristeza: A review of research to protect against decline on sour orange in Florida

    OpenAIRE

    Richard F. Lee; Manjunath eKeremane

    2013-01-01

    Tristeza, caused by Citrus tristeza virus (CTV), has long been present in Florida but outbreaks of decline on sour orange rootstock were occasional events until the late 1970s. Sour orange rootstock was valued for the high quality of fruit produced and was widely used because of its tolerance of citrus blight, a disease of unknown etiology. Research was directed towards the selection and screening of mild strains of CTV which could protect against sour orange decline strains. Following the...

  17. Mild strain cross protection of tristeza: a review of research to protect against decline on sour orange in Florida

    OpenAIRE

    Richard F. Lee; Keremane, Manjunath L.

    2013-01-01

    Tristeza, caused by Citrus tristeza virus (CTV), has long been present in Florida but outbreaks of decline on sour orange rootstock were occasional events until the late 1970s. Sour orange rootstock was valued for the high quality of fruit produced and was widely used because of its tolerance of citrus blight, a disease of unknown etiology. Research was directed towards the selection and screening of mild strains of CTV which could protect against sour orange decline strains. Following the in...

  18. Identification of differentially expressed proteins in sweet oranges induced by Citrus Tristeza Virus using 2D-DIGE%应用2D-DIGE技术分析柑橘衰退病毒诱导的甜橙差异表达蛋白

    Institute of Scientific and Technical Information of China (English)

    杨方云; 李中安; 周常勇; 周彦

    2013-01-01

    [Objective]To determine the probability of 2D -DIGE technology to identify the differentially expressed proteins in sweet oranges induced by Citrus tristeza virus, CTV. [Method] The same weight leaf samples of each plant were mixed from CTV -inoculated sweet orange plants and healthy plants, respectively. Total proteins were extracted from above mixed samples with three replications. Each protein sample was labeled with three different CyDyes Cy2, Cy3 and Cy5, and Cy2-labeled sample was used as an internal standard pooled from all the samples. Labeled protein samples were separated with 2-D DIGE and differential protein spots were picked out. MALDI-TOF-MS and bioinformatics were adopted to identify and interpret the significance of differentially expressed proteins. [Result]Total 91 Differential protein spots were detected with statistical variance of two groups (relative average volume ratio ≥ 1.5; t-test, P< 0.05). Among these proteins, 56 protein volumes of CTV group were higher than that of healthy group, and 35 proteins lower. PMFs of 37 proteins were obtained by MAIDI-TOF-MS analysis. Through searching NCBI, 19 protein functions were clear, 16 proteins predicted or putative, and 2 proteins unknown. The i-dentified proteins were involved mainly in metabolism (including 2-Phospho-D-glycerate hydrolase, NADP-isocitrate dehydrogenase, Xyloglucan endotransglycosylase, Adenylate kinase), antioxidant activity (including Thioredoxin H-type 5, Ferredoxin-NADP reductase, L-ascorbate peroxidase T, Iron su-peroxide dismutase), photosynthesis (including Ribulose 1,5-bisphosphate carboxylase/oxygenase large or small subunit, Oxygen-evolving enhancer protein 1 and 2, Chlorophyll a/b-binding protein precursor)and molecular chaperone (such as Heat shock protein). [Conclusion] 2D-DIGE can be used to identify the differentially expressed proteins in sweet oranges induced by different pathologic CTV strains in order to clarify the mechanism of CTV pathogenesis.%[目的]为了研究柑橘衰退病毒(Citrus

  19. 纽荷尔脐橙对建阳橘柚上柑橘衰退病毒分离株构成的影响%Influence of Newhall Navel Orange on Composition of Citrus tristeza virus Isolates Collected from Jianyang Tangelo

    Institute of Scientific and Technical Information of China (English)

    易龙; 卢占军; 赖晓桦; 马冠华

    2012-01-01

    In order to find the potential influence of Citrus tristeza virus (CTV) isolates in Jianyang Tangelo on Gannan navel orange, the CTV isolates were characterized at the molecular level. Jianyang Tangelo (Citrus paradisi x C. Reticulata) is a new citrus hybrid cultivar with excellent quality. CTV isolate JY-5 was inoculated in Newhall navel orange (C. Sinensis) and the Hinf I restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism (SSCP) of its coat protein (cp) gene was comparatively analyzed. The results of RFLP analysis revealed that the single group of the CTV isolate in Jianyang Tangelo changed into mixed groups when it inoculated in Newhall navel orange. DNA bands of cp/SSCP of CTV isolates increased when the CTV isolate was graft inoculated from Jianyang Tangelo to Newhall navel orange. The results of Hinf I RFLP and SSCP showed that the replication of some composition of CTV isolate was inhibited in Jianyang Tangelo but enhanced in Newhall navel orange. By analyzing and comparing the nucleotide and amino acid sequences of cp,p23 and k17 of isolate JY-5 in Jianyang Tangelo and isolate JY-5R from inoculated Newhall navel orange, the identity of genomic regions were 92.5%, 90.3% and 82.3%, respectively, and of their amion acid sequences were 95.9%, 90,9% and 77.9%, respectively. Phylogenetic analysis revealed that the isolate JY-5 in Jianyang Tangelo and JY-5R in inoculated Newhall classified into different clusters in phylogenetic trees of cp, p23 and k17. Sequence comparisons and phyiogenetic analysis indicated that no high homology and closer relationships between the isolates JY-5 and JY-5R, the isolate JY-5R was inhibited in Jianyang Tangelo but enhanced in Newhall navel orange. The results suggest that if the CTV isolate from Jianyang Tangelo infects Gannan's Newhall navel orange and spreads in Ganzhou, maybe cause some damage to Gannan's navel oranges. Therefore, it is necessary to take a survey on the CTV occurrence

  20. Investigações sôbre a tristeza dos Citrus: VI - Alguns estudos fisiológicos sôbre a moléstia

    Directory of Open Access Journals (Sweden)

    T. J. Grant

    1950-02-01

    Full Text Available The present paper reports the results of general studies undertaken to determine the relative importance of soil moisture and light on symptom expression of the tristeza disease. It also includes data on the effects of the disease on transpiration and chemical composition of infected plants and records the results of attempts to inactivate the tristeza virus in budwood by means of hot water and chemical treatments. In the present tests, using potted plants, tristeza disease symptoms were observed to occur eight to ten weeks after inoculation on plants maintained in standing water and on those having a daily application of 200cc of water. In contrast to this relatively rapid and positive symptom expression, it required 28 weeks before definite advanced tristeza disease symptoms were recognized on the inoculated plants given only 50cc of water daily. Under continuous heavy shade conditions the healthy and inoculated plants showed practically no growth and no tristeza disease symptoms. The growth of the healthy plants increased with the increase in periods (6, 10, and 14 hrs of exposure to daylight while the inoculated plants grew as well as the healthy plants for the first month they subsequently practically ceased growth. The results of the tests on the influence of light and soil moisture show that conditions favorable for rapid plant growth also favor early symptom expression of the disease and that stunting of the plant is one the principal characteristics of the tristeza disease. The data obtained from the transpiration studies show that under the controlled test conditions the transpiration of the healthy plants was two and a half times greater than that of the tristeza diseased plants. The study of chemical composition of the plants indicated that there were some differences in the percentages of CaO and Na(20 in the leaves and stems of diseased and healthy plants. The data also indicate that, although the differences in the amount of

  1. Recent advances in Citrus psorosis virus

    OpenAIRE

    Achachi, Asmae; Ait Barka, Essaïd; Ibriz, Mohammed

    2014-01-01

    Psorosis is a globally devastating disease of citrus caused by an infectious filamentous ophiovirus, Citrus psorosis virus (CPsV), which causes annual losses of about 5 % and a progressive decline of trees by affecting the conductive tissues. The disease can be harboured asymptomatically in many citrus species. In the field, the most characteristic symptoms of the disease in adult trees are bark scaling in the trunk and main branches and also internal staining in the underlying wood. The viru...

  2. Obtaining a citric tristeza virus p65 protein antibody and preliminary results of p65 in vivo expression

    Directory of Open Access Journals (Sweden)

    Yanneth Torres

    2007-04-01

    Full Text Available The citric tristeza virus (CTV belongs to the Closteroviridae family which indudes the only vegetal viruses possessing genes homologous to HSP70 thermal cellular shock proteins in their genome. Such is the case of the gene encoding for the CTV p65 protein which presents high homology with the HSP70 protein family. It has been shown recently that HSP70h viral proteins (such as CTV p65 are involved both in viral assembly, as a microtubule binding protein, and in cell-cell movement. Since CTV is the most deleterious citrus pathogen, understanding this protein's role in the pathogenesis process is important. Rabbits were immunised with four synthetic peptides (corresponding to CTV p65 thermal shock protein's carboxyl-terminal region to obtain polyclonal antibodies. All the peptides used were immunogenic, even though two of them showed greater response. Whilst none of the antibodies obtained reacted to non-infected plant extract, the p65 proteins was detected in extracts taken from citric plants infected with CTV Based on the antibody's reaction to two Colombian isolates having different serological characteristics, the p65 antibody's immunological behaviour appeared to be independent of the symptomatic severity of the CTV isolates. It was shown that the ORF encoded for the HSP70 homologue in CTV was expressed in vivo, even though the p65 antibody was only detected in concentrated protein extracts taken from infected plants, supporting reports from other studies that the concentration of this protein in plants infected with CTV is low. This is the first time that a polyclonal CTV antibody has been obtained in Colombia against p65 (a protein intervening in viral assembly and movement. Adapting a technique for obtaining p65 antibodies by using synthetic peptides as immunogens could be useful in the future for detecting or diagnosing p65 proteins present in different Colombian CTV isolates, especially in developing studies contributing towards greater

  3. First report of citrus leprosis virus nuclear type in Colombia

    Science.gov (United States)

    Citrus leprosis is a difficult viral disease causing significant damage to citrus fruit in South America and Central America. The disease is marked by dramatic lesions on fruit, leaves and stems resulting in unmarketable product. Citrus leprosis virus cytoplasmic types (CiLV-C and CiLV-C2) wer edete...

  4. Portable Chemical Sensors for Monitoring Infection-Specific Volatiles in Asymptomatic Citrus

    OpenAIRE

    Fink, R.L.; A. A. Aksenov; Thuesen, L.H.; Pasamontes, A.; Cheung, W.H.K.; Peirano, D.J.; Davis, C.E.

    2014-01-01

    Volatile organic compounds (VOCs) are emitted from all plants, and there is mounting evidence these VOCs reflect internal health status and change in response to pathogen infection and other cues. Our group has developed a portable chemical sensing platform that can monitor for VOC emission changes that result from citrus bacterial and viral infections. To date, our VOC library includes putative signal fingerprints for Huanglongbing (HLB), citrus tristeza virus (CTV) and citrus variegated chl...

  5. Reação da laranjeira azêda à tristeza Reaction of the sour orange plant to tristeza

    Directory of Open Access Journals (Sweden)

    A. S. Costa

    1954-01-01

    plantas sadias se desenvolvem mais ou menos satisfatòriamente quando sôbre-enxertadas em galhos de laranjeira doce sobre laranjeira azêda, já em avançado estado de declínio. Uma copa mista de laranjeiras azêda e doce sôbre cavalo de azêda pode causar alguns benefícios à planta afetada pela tristeza sob determinadas condições, mas êsse benefício não é duradouro e o método não oferece possibilidades práticas. A laranjeira azêda em viveiro tem sido utilizada com vantagem na determinação da presença do vírus da tristeza em borbulhas de vários tipos de Citrus, pela observação do crescimento feito a partir dessas borbulhas em comparação com aquêle de borbulhas da mesma variedade garantidamente sadias. Para a determinação da presença de estirpes fracas do vírus o método é mais demorado. Interenxertos de laranjeira azêda entre copas e raízes de laranjeira doce são suficientes para que haja manifestação de sintomas da moléstia. Há aparentemente alguma translocação através do interenxêrto, pois o desenvolvimento do cavalo abaixo e acima dele é aproximadamente igual.Young sour orange seedlings are more easily infected with the tristeza virus by approach-grafts than by means of the aphid vector. Under natural conditions adult plants in the field are highly resistant to infection by the aphid vector. Recovery of the tristeza virus from infected sour orange plants is also more easily accomplished by tissue union than by means of the aphid vector. Sour orange seedlings show yellowing of young leaves followed by stunting and shedding of leaves when infected with the ordinary strain of the tristeza virus in Brazil. These symptoms do not differ from those described for seedling yellows. The symptoms of leaf yellowing are less evident in plants infected with mild strains of the tristeza virus and there is subsequent recovery. New flushes of young leaves may show occasional vein dashes. Sour orange tissues below the bud union of the sweet

  6. Detección del virus de la tristeza de los cítricos por serología, microscopía e hibridación in situ

    Directory of Open Access Journals (Sweden)

    Patricia Rodríguez

    2009-08-01

    Full Text Available In situ serological, microscopy and hybridization detection of CTV Resumen: El virus de la tristeza de los cítricos (CTV es perjudicial para la citricultura y causa la enfermedad llamada tristeza de los cítricos. Infecta las especies del género Citrus ocasionando la muerte de millones de árboles. Los síntomas son decaimiento rápido (QD y acanalamiento de tallo (SP. En el trabajo se diagnosticó molecular y serológicamente al CTV en aislados provenientes de Citrus aurantifolia o Lima Tahití (LT y Citrus madurensis (Lour o Calamondino (Ca, y se realizaron estudios preliminares de detección viral por medio de microscopía óptica e hibridación in situ. Se utilizó IC-RT-PCR e inmunoimpresión de tejido (IMI expuesto a los anticuerpos monoclonales 3DF1+3CA5, y con el anticuerpo discriminante MCA 13 con técnica de Enzyme Linked Inmunossorbent Assay Doble Sándwich (Elisa-DAS. La detección por microscopía se realizó sobre secciones de pecíolo de LT y C que se tiñeron con Azure A, y con acetato de uranilo y citrato de plomo. Para la hibridación in situ se empleó una sonda marcada con digoxigenina dirigida hacia el gen de la proteína mayor de la cápside. Los resultados de IC-RT-PCR, IMI y Elisa fueron positivos para LT y C, indicando la presencia de variantes virales de tipo severo. Con microscopía de luz se detectaron inclusiones citoplasmáticas en las células acompañantes y del floema, confirmado con IMI y por hibridación in situ. Se visualizaron inclusiones de partículas virales en el tejido vegetal con microscopía electrónica con cambios en la ultraestructura celular como presencia de grandes vacuolas propias de la infección viral. Este trabajo integra distintas técnicas diagnósticas sobre dos especies cítricas exóticas.Palabras clave: inmunoimpresión; Elisa;  hibridación; microscopía; CTV;  IC-RT-PCR. Abstract: Citrus tristeza virus (CTV is deleterious for citriculture and causes citrus tristeza disease. CTV

  7. Genome Assembly of Citrus Leprosis Virus Nuclear Type Reveals a Close Association with Orchid Fleck Virus

    OpenAIRE

    Roy, Avijit; Stone, Andrew; Otero-Colina, Gabriel; Wei, Gang; Choudhary, Nandlal; Achor, Diann; Shao, Jonathan; Levy, Laurene; Nakhla, Mark K.; Hollingsworth, Charla R.; Hartung, John S.; Schneider, William L.; Brlansky, Ronald H.

    2013-01-01

    The complete genome of citrus leprosis virus nuclear type (CiLV-N) was identified by small RNA sequencing utilizing leprosis-affected citrus samples collected from the state of Querétaro, Mexico. The nucleotide identity and phylogenetic analysis indicate that CiLV-N is very closely related to orchid fleck virus, which typically infects Cymbidium species.

  8. Evidence of Recombinant Citrus tristezavirus Isolate Occurring in Acid Lime cv. Pant Lemon Orchard in Uttarakhand Terai Region of Northern Himalaya in India

    OpenAIRE

    Singh, Jaywant Kumar; Tarafdar, Avijit; Sharma, Susheel Kumar; Biswas, Kajal Kumar

    2012-01-01

    The present study for the first time describes biological and molecular characterization of Citrus tristeza virus (CTV) occurring in the Terai area of Uttarakhand State in Northern Himalaya region of India. Direct antigen coated-ELISA and reverse transcriptase-polymerase chain reaction (RT-PCR) detected the CTV infection in Acid lime cv. Pant lemon (Citrus aurantifolia) orchards of Pantnagar with an estimated disease incidence of 16.6–20.5 %. To know the biological and genetic properties, an ...

  9. Mild strain cross protection of tristeza: A review of research to protect against decline on sour orange in Florida

    Directory of Open Access Journals (Sweden)

    Richard F Lee

    2013-09-01

    Full Text Available Tristeza, caused by Citrus tristeza virus (CTV, has long been present in Florida but outbreaks of decline on sour orange rootstock were occasional events until the late 1970s. Sour orange rootstock was valued for the high quality of fruit produced and was widely used because of its tolerance of citrus blight, a disease of unknown etiology. Research was directed towards the selection and screening of mild strains of CTV which could protect against sour orange decline strains. Following the introduction of Toxoptera citricida (also known as the brown citrus aphid [BrCA] in 1995 there was a greater concern for maintaining production of existing blocks of citrus on sour orange rootstock. Availability of the CTV genome sequence around the same time as well as molecular characterization of in planta CTV populations led to the selection of mild CTV isolates which when inoculated into existing field trees, extended the productive life of the groves and enabled a more graduate replanting of trees on CTV-tolerant rootstocks. The history of CTV in Florida and the methods developed to select mild isolates for use for mild strain cross protection will be reviewed.

  10. Role Bending: Complex Relationships Between Viruses, Hosts, and Vectors Related to Citrus Leprosis, an Emerging Disease.

    Science.gov (United States)

    Roy, Avijit; Hartung, John S; Schneider, William L; Shao, Jonathan; Leon, Guillermo; Melzer, Michael J; Beard, Jennifer J; Otero-Colina, Gabriel; Bauchan, Gary R; Ochoa, Ronald; Brlansky, Ronald H

    2015-07-01

    Citrus leprosis complex is an emerging disease in the Americas, associated with two unrelated taxa of viruses distributed in South, Central, and North America. The cytoplasmic viruses are Citrus leprosis virus C (CiLV-C), Citrus leprosis virus C2 (CiLV-C2), and Hibiscus green spot virus 2, and the nuclear viruses are Citrus leprosis virus N (CiLV-N) and Citrus necrotic spot virus. These viruses cause local lesion infections in all known hosts, with no natural systemic host identified to date. All leprosis viruses were believed to be transmitted by one species of mite, Brevipalpus phoenicis. However, mites collected from CiLV-C and CiLV-N infected citrus groves in Mexico were identified as B. yothersi and B. californicus sensu lato, respectively, and only B. yothersi was detected from CiLV-C2 and CiLV-N mixed infections in the Orinoco regions of Colombia. Phylogenetic analysis of the helicase, RNA-dependent RNA polymerase 2 domains and p24 gene amino acid sequences of cytoplasmic leprosis viruses showed a close relationship with recently deposited mosquito-borne negevirus sequences. Here, we present evidence that both cytoplasmic and nuclear viruses seem to replicate in viruliferous Brevipalpus species. The possible replication in the mite vector and the close relationship with mosquito borne negeviruses are consistent with the concept that members of the genus Cilevirus and Higrevirus originated in mites and citrus may play the role of mite virus vector. PMID:25775106

  11. Filodinâmica do vírus da tristeza dos citrinos: epidemiologia molecular e biologia evolutiva

    OpenAIRE

    Silva, Gonçalo

    2011-01-01

    O Citrus tristeza virus (CTV), responsável por várias doenças em citrinos, é um dos maiores condicionantes da citricultura a nível mundial. Existem diversos isolados de CTV com diferentes características biológicas e moleculares, sendo que os sintomas causados pelo vírus dependem essencialmente do isolado viral e da combinação variedade/porta-enxerto. A implementação de medidas de controlo da doença depende, em grande parte, do tipo de isolados presentes numa dada região. No Capítulo 2, efetu...

  12. Distribución del virus de la tristeza en tres plantaciones comerciales de cítricos del estado de Nuevo León, México

    OpenAIRE

    Sergio Silva Vara; María de los Angeles Peña del Río; Rebeca Peña Martínez; Nancy Villegas Jiménez; Keir F. Byerly Murphy; Mario A. Rocha Peña

    2001-01-01

    Se llevó a cabo un estudio para determinar la ocurrencia del virus de la tristeza (CTV) en plantaciones comerciales de cítricos en el Estado de Nuevo León, México. La detección del CTV se realizó mediante la prueba de ELISA utilizando anticuerpos policlonales anti-CTV, y mediante el anticuerpo monoclonal MCA13 de reacción específica. El estudio se llevó a cabo en tres huertas en los municipios de Montemorelos, Hualahuises y Linares, con ocurrencias iniciales en porcentajes de 4.34 (34 de 783)...

  13. History and Diversity of Citrus leprosis virus Recorded in Herbarium Specimens.

    Science.gov (United States)

    Hartung, John S; Roy, Avijit; Fu, Shimin; Shao, Jonathan; Schneider, William L; Brlansky, Ronald H

    2015-09-01

    Leprosis refers to two diseases of citrus that present similar necrotic local lesions, often surrounded by chlorotic haloes on citrus. Two distinct viruses are associated with this disease, one that produces particles primarily in the nucleus of infected plant cells (Citrus leprosis virus nuclear type [CiLV-N]; Dichorhavirus) and another type that produces particles in the cytoplasm of infected plant cells (Citrus leprosis virus cytoplasmic type [CiLV-C]; Cilevirus). Both forms are transmitted by Brevipalpid mites and have bipartite, single-stranded, RNA genomes. CiLV-C and CiLV-N are present in South and Central America and as far north as parts of Mexico. Although leprosis disease was originally described from Florida, it disappeared from there in the 1960s. The United States Department of Agriculture-Agricultural Research Service maintains preserved citrus specimens identified at inspection stations 50 or more years ago with symptoms of citrus leprosis. We isolated RNA from these samples and performed degradome sequencing. We obtained nearly full-length genome sequences of both a typical CiLV-C isolate intercepted from Argentina in 1967 and a distinct CiLV-N isolate obtained in Florida in 1948. The latter is a novel form of CiLV-N, not known to exist anywhere in the world today. We have also documented the previously unreported presence of CiLV-N in Mexico in the mid-20th century. PMID:25961338

  14. Global Analyses of Small Interfering RNAs from Sour Orange seedlings Infected with Different Citrus tristeza virus Genotypes

    Science.gov (United States)

    RNA silencing is a sequence-specific regulatory mechanism in development and maintenance of genome integrity and functions in plant antiviral defense mechanisms. Small interfering RNAs (siRNAs) are key mediators of RNA silencing. To study CTV-host interactions and disease expression, profiles of v...

  15. Complete genome sequence analysis of two Citrus tatter leaf virus (CTLV) isolates from China

    Institute of Scientific and Technical Information of China (English)

    SONG Zhen; LI Zhong-an; LIU Ke-hong; ZHOU Chang-yong

    2015-01-01

    In order to understand molecular characterization of Citrus tatter leaf virus (CTLV) isolated from China, ful-length cDNAs of CTLV-MTH and CTLV-XHC from Citrus reticulata and Citrus sinensis were cloned and sequenced based on whole-genome ampliifcation by RT-PCR. The complete nucleotide sequences of CTLV-MTH and CTLV-XHC were determined to be 6 497 nucleotides in length and shared 79.9–91.0%and 78.8–98.0%nucleotide sequence identity, respectively, with other Apple stem grooving virus (ASGV) or CTLV strains available in GenBank. Unexpectedly, CTLV-MTH showed the highest nucleo-tide sequence identity (91%) with an apple isolate of ASGV, fol owed by 86.5%with ASGV-HH and 85.7%with ASGV-CHN. Furthermore, CTLV-MTH and three ASGV strains were grouped to a separate cluster in the phylogenetic tree, suggesting it has a closer relationship to ASGV than to CTLV. Therefore, it can be concluded roughly that CTLV may be not a distinct strains of ASGV. We proposed that Citrus tatter leaf virus should be renamed Apple stem grooving virus.

  16. Rootstock-scion interaction affecting citrus response to CTV infection: a proteomic view.

    Science.gov (United States)

    Laino, Paolo; Russo, Maria P; Guardo, Maria; Reforgiato-Recupero, Giuseppe; Valè, Giampiero; Cattivelli, Luigi; Moliterni, Vita M C

    2016-04-01

    Citrus tristeza virus (CTV) is the causal agent of various diseases with dramatic effects on citrus crops worldwide. Most Citrus species, grown on their own roots, are symptomless hosts for many CTV isolates. However, depending on different scion-rootstock combination, CTV infection should result in distinct syndromes, being 'tristeza' the more severe one, leading to a complete decline of the susceptible plants in a few weeks. Transcriptomic analyses revealed several genes involved either in defense response, or systemic acquired resistance, as well as transcription factors and components of the phosphorylation cascades, to be differentially regulated during CTV infection in Citrus aurantifolia species. To date little is known about the molecular mechanism of this host-pathogen interaction, and about the rootstock effect on citrus response to CTV infection. In this work, the response to CTV infection has been investigated in tolerant and susceptible scion-rootstock combinations by two-dimensional gel electrophoresis (2DE). A total of 125 protein spots have been found to be differently accumulated and/or phosphorylated between the two rootstock combinations. Downregulation in tolerant plants upon CTV infection was detected for proteins involved in reactive oxygen species (ROS) scavenging and defense response, suggesting a probable acclimation response able to minimize the systemic effects of virus infection. Some of these proteins resulted to be modulated also in absence of virus infection, revealing a rootstock effect on scion proteome modulation. Moreover, the phospho-modulation of proteins involved in ROS scavenging and defense response, further supports their involvement either in scion-rootstock crosstalk or in the establishment of tolerance/susceptibility to CTV infection. PMID:26459956

  17. Phylogenetic and Molecular Variability Studies Reveal a New Genetic Clade of Citrus leprosis virus C

    Science.gov (United States)

    Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Breton, Michèle Claire; Arena, Gabriella Dias; Nunes, Maria Andreia; Kitajima, Elliot Watanabe; Machado, Marcos Antonio; Freitas-Astúa, Juliana

    2016-01-01

    Citrus leprosis virus C (CiLV-C) causes a severe disease affecting citrus orchards in the Western hemisphere. This study reveals the molecular variability of the virus by analyzing four genomic regions (p29, p15, MP and RNA2-intergenic region) distributed over its two RNAs. Nucleotide diversity (π) values were relatively low but statistically different over the analyzed genes and subpopulations, indicating their distinct evolutionary history. Values of πp29 and πMP were higher than those of πp15 and πRNA2–IR, whereas πMP was increased due to novel discovered isolates phylogenetically clustered in a divergent clade that we called SJP. Isolate BR_SP_SJP_01 RNA1 and RNA2 sequences, clade SJP, showed an identity of 85.6% and 88.4%, respectively, with those corresponding to CiLV-C, the type member of the genus Cilevirus, and its RNA2 5′-proximal region was revealed as a minor donor in a putative inter-clade recombination event. In addition to citrus, BR_SP_SJP_01 naturally infects the weed Commelina benghalensis and is efficiently transmitted by Brevipalpus yothersi mites. Our data demonstrated that negative selection was the major force operating in the evaluated viral coding regions and defined amino acids putatively relevant for the biological function of cilevirus proteins. This work provides molecular tools and sets up a framework for further epidemiological studies. PMID:27275832

  18. Complete Genome Sequence of Diaphorina citri-associated C virus, a Novel Putative RNA Virus of the Asian Citrus Psyllid, Diaphorina citri

    Science.gov (United States)

    Nouri, Shahideh; Salem, Nidà

    2016-01-01

    We present here the complete nucleotide sequence and genome organization of a novel putative RNA virus identified in field populations of the Asian citrus psyllid, Diaphorina citri, through sequencing of the transcriptome followed by reverse transcription-PCR (RT-PCR). We tentatively named this virus Diaphorina citri-associated C virus (DcACV). DcACV is an unclassified positive-sense RNA virus. PMID:27445370

  19. Complete Genome Sequence of Diaphorina citri-associated C virus, a Novel Putative RNA Virus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Nouri, Shahideh; Salem, Nidà; Falk, Bryce W

    2016-01-01

    We present here the complete nucleotide sequence and genome organization of a novel putative RNA virus identified in field populations of the Asian citrus psyllid, Diaphorina citri, through sequencing of the transcriptome followed by reverse transcription-PCR (RT-PCR). We tentatively named this virus Diaphorina citri-associated C virus (DcACV). DcACV is an unclassified positive-sense RNA virus. PMID:27445370

  20. Molecular characterization of a citrus yellow vein clearing virus strain from China.

    Science.gov (United States)

    Zhen, Song; Kurth, Elizabeth G; Peremyslov, Valera V; Changyong, Zhou; Dolja, Valerian V

    2015-07-01

    The complete nucleotide sequence of an isolate of citrus yellow vein clearing virus from Yunnan, China (CYVCV-RL), was determined following whole-genome amplification by RT-PCR. The CYVCV-RL genome was 7529 nt in length, excluding the 3' poly (A) tail, and contained six open reading frames (ORFs), resembling that of viruses belonging to the genus Mandarivirus in the family Alphaflexiviridae. Sequence analysis showed that the CYVCV-RL shared the greatest nucleotide sequence identity with the CYVCV-Y1 (JX040635) isolate from Turkey for the whole genome (97.1%), 5' UTR (98.7%), 3' UTR (100.0%), and each of six ORFs (96.5% to 97.8%), suggesting that there is apparent genetic stability among CYVCV isolates of different geographic origin. PMID:25913691

  1. Comparative morpho-anatomical studies of the lesions caused by citrus leprosis virus on sweet orange

    Directory of Open Access Journals (Sweden)

    João P.R. Marques

    2010-06-01

    Full Text Available The leprosis disease shows a viral etiology and the citrus leprosis virus is considered its etiologic agent. The disease may show two types of cytopatologic symptom caused by two virus: nuclear (CiLV-N and cytoplasmic (CiLV-C types. The aim of this study was to compare the morpho-anatomical differences in the lesions caused by leprosis virus-cytoplasmic and nuclear types in Citrus sinensis (L. Osbeck 'Pêra'. Leaf and fruit lesions were collected in Piracicaba/São Paulo (cytoplasmic type and Monte Alegre do Sul/São Paulo and Amparo/São Paulo (nuclear type. The lesions were photographed and then fixed in Karnovsky solution, dehydrated in a graded ethylic series, embedded in hydroxy-ethyl methacrylate resin (Leica Historesin, sectioned (5 μm thick, stained and mounted in synthetic resin. The digital images were acquired in a microscope with digital video camera. Leaf and fruit lesions caused by the two viruses were morphologically distinct. Only the lesion caused by CiLV-N virus presented three well-defined regions. In both lesions there was the accumulation of lipidic substances in necrotic areas that were surrounded by cells with amorphous or droplets protein. Only leaf and fruit lesions caused by CiLV-N virus exhibited traumatic gum ducts in the vascular bundles.A doença leprose dos citros tem etiologia viral sendo o citrus leprosis virus seu agente etiológico. Demonstrou-se que há dois vírus distintos que causam sintomas de leprose em ci-tros: citoplasmático (CiLV-C e o nuclear (CiLV-N. O objetivo desse estudo foi comparar as diferenças morfo-anatômicas nas lesões causadas por CiLV-C e por CiLV-N em laranjeira doce (Citrus sinensis (L. Osbeck 'Pêra'. As lesões foliares e dos frutos foram coletadas em Piracicaba/SP (tipo citoplas-mático e em Monte Alegre do Sul/SP e Amparo/SP (tipo nuclear. As lesões foram fotografadas e em seguida fixadas em solução Karnovsky, desidratadas em série etílica, incluídas em historesina e

  2. Identification and Molecular Characterization of Nuclear Citrus leprosis virus, a Member of the Proposed Dichorhavirus Genus Infecting Multiple Citrus Species in Mexico.

    Science.gov (United States)

    Roy, Avijit; Stone, Andrew L; Shao, Jonathan; Otero-Colina, Gabriel; Wei, Gang; Choudhary, Nandlal; Achor, Diann; Levy, Laurene; Nakhla, Mark K; Hartung, John S; Schneider, William L; Brlansky, Ronald H

    2015-04-01

    Citrus leprosis is one of the most destructive diseases of Citrus spp. and is associated with two unrelated virus groups that produce particles primarily in either the cytoplasm or nucleus of infected plant cells. Symptoms of leprosis, including chlorotic spots surrounded by yellow haloes on leaves and necrotic spots on twigs and fruit, were observed on leprosis-affected mandarin and navel sweet orange trees in the state of Querétaro, Mexico. Serological and molecular assays showed that the cytoplasmic types of Citrus leprosis virus (CiLV-C) often associated with leprosis symptomatic tissues were absent. However, using transmission electron microscopy, bullet-shaped rhabdovirus-like virions were observed in the nuclei and cytoplasm of the citrus leprosis-infected leaf tissues. An analysis of small RNA populations from symptomatic tissue was carried out to determine the genome sequence of the rhabdovirus-like particles observed in the citrus leprosis samples. The complete genome sequence showed that the nuclear type of CiLV (CiLV-N) present in the samples consisted of two negative-sense RNAs: 6,268-nucleotide (nt)-long RNA1 and 5,847-nt-long RNA2, excluding the poly(A) tails. CiLV-N had a genome organization identical to that of Orchid fleck virus (OFV), with the exception of shorter 5' untranslated regions in RNA1 (53 versus 205 nt) and RNA2 (34 versus 182 nt). Phylogenetic trees constructed with the amino acid sequences of the nucleocapsid (N) and glycoproteins (G) and the RNA polymerase (L protein) showed that CiLV-N clusters with OFV. Furthermore, phylogenetic analyses of N protein established CiLV-N as a member of the proposed genus Dichorhavirus. Reverse-transcription polymerase chain reaction primers for the detection of CiLV-N were designed based on the sequence of the N gene and the assay was optimized and tested to detect the presence of CiLV-N in both diseased and symptom-free plants. PMID:25423071

  3. The Genome Sequence of an Isolate of Indian Citrus Ringspot Virus Infecting the Sweet Orange in India

    OpenAIRE

    K, Prabha; Baranwal, V.K.

    2012-01-01

    Whole-genome sequencing of an isolate of Mandarivirus infecting the sweet orange [Citrus sinensis (L) Blanco] in the western part of India (Pune) was done. The single-stranded positive-sense RNA genome of Indian citrus ringspot virus (ICRSV) Pune has 7,560 nucleotides (nt), excluding a poly(A) tail, comprised of 27.98% (2,115 nt) A, 32.12% (2,428 nt) C, 19.68% (1,488 nt) G, and 20.22% (1,529 nt) T residues. The genome, organized into six open reading frames (ORFs), shares 97.7% sequence ident...

  4. Somatic hybridization between Citrus sinensis (L. Osbeck and C. grandis (L. Osbeck Hibridação somática entre Citrus sinensis (L. Osbeck e C. grandis (L. Osbeck

    Directory of Open Access Journals (Sweden)

    Marcia Cristina Calixto

    2004-07-01

    Full Text Available This work had as objective to produce citrus somatic hybrids between sweet oranges and pummelos. After chemical fusion of sweet orange embryogenic protoplasts with pummelo mesophyll-derived protoplasts, plants were regenerated by somatic embryogenesis and acclimatized in a greenhouse. The hybrids of 'Hamlin' sweet orange + 'Indian Red' pummelo and 'Hamlin' sweet orange + 'Singapura' pummelo were confirmed by leaf morphology, chromosome counting and molecular analysis. These hybrids have potential to be used directly as rootstocks aiming blight, citrus tristeza virus, and Phytophthora-induced disease tolerance, as well as for rootstocks improvement programs.O objetivo deste trabalho foi produzir híbridos somáticos entre laranjas doces e toranjas. Após fusão de protoplastos embriogênicos de laranja doce com protoplastos derivados de mesófilo foliar de toranjas, plantas foram regeneradas por embriogênese somática e aclimatizadas em casa de vegetação. Os híbridos laranja 'Hamlin' + toranja 'Indian Red' e laranja 'Hamlin' + toranja 'Singapura' foram confirmados pela morfologia foliar, contagem do número de cromossomos e análise molecular. Esses híbridos apresentam potencial para serem testados como porta-enxertos tolerantes a declínio, tristeza e doenças causadas por Phytophthora, bem como em programas de melhoramento de porta-enxertos.

  5. The complete genome sequence of Citrus vein enation virus from China

    Institute of Scientific and Technical Information of China (English)

    HUANG Ai-jun; SONG Zhen; CAO Meng-ji; CHEN Hong-ming; LI Zhong-an; ZHOU Chang-yong

    2015-01-01

    The complete nucleotide sequence of an isolate of Citrus vein enation virus (CVEV-XZG) from China has been determined for the ifrst time. The genome consisted of 5 983 nucleotides, coding for ifve open reading frames (ORFs), had a similar genomic organization features with Pea enation mosaic virus (PEMV). Nucleotide and deduced amino acid sequence identity of the ifve ORFs compared to isolate CVEV VE-1 range from 97.1 to 99.0% and 97.4 to 100.0%, these values compared to isolate PEMV-1 range from 45.2 to 51.6%and 31.1 to 45.2%. Phylogenetic analysis based on the complete genome sequence showed that the isolate CVEV-XZG had close relationship with Pea enation mosaic virus. The results supports CVEV may be a new member of genus Enamovirus. The ful sequence of CVEV-XZG presented here may serve as a basis for future study of CVEV in China.

  6. Advances in the genomics of Citrus tristeza virus%柑桔衰退病毒基因组学研究进展

    Institute of Scientific and Technical Information of China (English)

    姜波; 钟云

    2008-01-01

    柑桔衰退病毒(CTV)是柑桔普遍存在的一种重要病毒病害,因其自身基因变异和寄主的不同而产生不同的症状,给防治CTV带来一定困难.为防治柑桔衰退病,需要研究CTV本身的相关特征.从CTV的基因组学上的特征综述了国内外在CTV基因组学最新的科研进展.

  7. The Citrus Sanitation Center of Estación Experimental Agroindustrial Obispo Colombres, Tucumán, Argentina El Centro de Saneamiento de Citrus de la Estación Experimental Agroindustrial Obispo Colombres de Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    Beatriz E. Stein

    Full Text Available In October 2004, the Estación Experimental Agroindustrial Obispo Colombres (Tucumán, Argentina founded its Citrus Sanitation Center. The goal of this center is to establish and keep a group of the most important citrus varieties and rootstocks true to type and free of graft-transmissible pathogens. These will be used as primary sources of propagating material for citrus growers and researchers in northwestern Argentina. Mother trees of the main commercial citrus varieties were selected from the germplasm bank of the experiment station and were recovered through the standard procedure of shoot tip grafting (STG. Healthy plants are carefully and periodically indexed by biological, serological and molecular methods for tristeza, psorosis, exocortis, cachexia, citrus variegated chlorosis, citrus canker and huanglongbing. The Citrus Sanitation Center will maintain a supply of healthy propagation material and will continue a program initiated in 1966, consting in introducing, producing and releasing nucellar clones.La Estación Experimental Agroindustrial Obispo Colombres (EEAOC creó en el año 2004 el Centro de Saneamiento de Citrus (CSC para la ejecución de tareas de limpieza y diagnóstico de virus en cítricos. El objetivo de este centro es establecer y mantener un plantel de plantas madres cítricas, de variedades copa y portainjertos, de alta calidad genética y libre de plagas y enfermedades transmisibles por injerto. Este grupo de plantas se constituye como fuente primaria de material de propagación para productores, viveristas e investigadores del noroeste argentino. Las plantas madres de las principales variedades comerciales de cítricos se seleccionaron del banco de germoplasma de la EEAOC y se recuperaron por la técnica de microinjerto de ápices caulinares, procedimiento estándar utilizado en la limpieza de plantas cítricas. Periódicamente se verifica su sanidad por métodos biológicos, serológicos y moleculares para las

  8. Variabilidade biológica de isolados do Citrus leprosis virus (CiLV oriundos de cultivares de laranjeira Biological variability of Citrus leprosis virus (CiLV isolates from sweet orange cultivars

    Directory of Open Access Journals (Sweden)

    Jadier de Oliveira Cunha Junior

    2007-09-01

    Full Text Available A leprose, causada pelo Citrus leprosis virus (CiLV, é uma das principais doenças presentes em pomares cítricos fluminenses. O objetivo deste trabalho foi comparar o quadro sintomatológico desenvolvido por isolados de CiLV obtidos de cultivares comerciais de laranjeira (Lima, Pêra e Seleta, inoculados mecanicamente em Chenopodium amaranticolor, em três diluições. Após cinco a sete dias da inoculação foram observadas lesões necróticas, com pequeno halo clorótico quando observadas contra a luz. O maior número de lesões, nas três diluições, foi obtido do isolado de 'Seleta', seguido por 'Pêra' e 'Lima'. A melhor diluição utilizada para a observação das lesões foi de 1:10. Os resultados demonstram uma possível variabilidade biológica entre os isolados virais e/ou uma menor ou maior replicação viral, dependendo da cultivar, indicando um possível mecanismo de resistência da planta ao vírus.Citrus leprosis, caused by Citrus leprosis virus (CiLV is one of the major diseases in citrus orchards in the State of Rio de Janeiro. The objective of this study was to compare the development of symptoms on Chenopodium amaranticolor inoculated with CiLV isolates from 'Lima', 'Pera' and 'Seleta' sweet oranges using three different dilutions. Five to seven-days after inoculation, necrotic lesions exhibiting a small chlorotic halo when exposed to the light, were observed. The highest number of lesions developed using the three dilutions was obtained from 'Seleta', an intermediate value from 'Pêra' and the lowest number from 'Lima'. The best dilution for lesions development was 1:10. The results demonstrate a possible biological variability among the virus isolates and/or a lower or higher viral replication, dependent on the cultivar. This indicates a putative mechanism of Citrus resistance to the virus.

  9. Detection of a new medium for budwood culture in vitro of citrus

    OpenAIRE

    SERTKAYA, Gülşen ŞAŞ; ÇINAR, Ahmet

    1998-01-01

    The transfer of new and quality citrus species and cultivars from one country or growing area to another may lead to the introduction of new pests and diseases. Therefore the import and direct production of citrus budwood without adequate control measures has a high risk. The citrus virus and virus-like disease agents can be successfully eliminated using the shoot-tip grafting (STG) technique which is routinely used to obtain virus-free plants in citrus improvement programs in major citrus...

  10. Ontogênese de caneluras em pedúnculo de flores de laranjeira doce infectados pelo vírus da tristeza dos citros estirpe "Capão Bonito"

    Directory of Open Access Journals (Sweden)

    Francisco André Ossamu Tanaka

    2009-12-01

    Full Text Available Um estudo da ontogênese das caneluras induzidas em ramos de laranjeiras doces suscetíveis por isolados severos do vírus da tristeza dos citros (Citrus tristeza vírus - CTV foi feito usando-se como modelo pedúnculos florais e de frutos. O menor calibre destes órgãos permite um melhor acompanhamento do processo. As observações foram feitas em laranjeira cv. Pêra infetada pelo isolado severo Capão Bonito do CTV. Cinco fases do processo de formação de caneluras puderam ser deduzidas pelas análises anatômicas. As primeiras alterações são representadas pelo aparecimento de células adensadas, hipertrofia e hiperplasia no parênquima e câmbio do floema e uma desorganização generalizada desta área. Segue-se uma atividade intensa do câmbio do floema adjacente e sua expansão em direção ao xilema. Esta invasão do xilema resulta na ruptura do anel do xilema pela massa celular do floema constituída de células recém formadas de parede celular delgada. Esta invasão do floema em direção ao xilema inicia um processo de degeneração dos vasos e parênquima do xilema. Finalmente há um colapso completo da região do xilema invadida, que é substituída pela massa do floema, resultando na canelura, notada ao se remover a casca.An ontogenetic study of the stem pitting was carried out, using as a model system the peduncle of flowers and fruits of sweet orange cv. Pêra infected by a very severe isolate, Capão Bonito, of Citrus tristeza virus (CTV. Anatomical and ultrastructural analysis revealed five phases of this process. It starts with the localized appearance of chromatic cells in the phloem parenchyma, hypertrophy of companion and cambial cells and overall disorganization of the phloem and deposition of a dense material. The next step is characterized by the invasion of the xylem by an abnormal mass of phloem parenchymal cells formed by the disorganized proliferation. These changes lead to the third phase, where xylem ring is

  11. Complete Genome Sequence of the Largest Known Flavi-Like Virus, Diaphorina citri flavi-like virus, a Novel Virus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Matsumura, Emilyn E; Nerva, Luca; Nigg, Jared C; Falk, Bryce W; Nouri, Shahideh

    2016-01-01

    A novel flavi-like virus tentatively named Diaphorina citri flavi-like virus (DcFLV) was identified in field populations of Diaphorina citri through small RNA and transcriptome sequencing followed by reverse transcription (RT)-PCR. We report here the complete nucleotide sequence and genome organization of DcFLV, the largest flavi-like virus identified to date. PMID:27609921

  12. CALOGÊNESE EM ÓVULOS DE ESPÉCIES E VARIEDADES DE CITRUS CALLUS INDUCTION FROM CITRUS SPECIES AND VARIETIES

    Directory of Open Access Journals (Sweden)

    ROBERTO PEDROSO DE OLIVEIRA

    2001-08-01

    Full Text Available A Embrapa Mandioca e Fruticultura vem realizando ações de pesquisa visando à obtenção de híbridos somáticos de citros, particularmente porta-enxertos, melhor adaptados às condições tropicais de cultivo brasileiras que as variedades atualmente em uso. Como objetivo principal, busca-se a seleção de genótipos tolerantes à seca e ao alumínio, tolerantes/resistentes a gomose de Phytophthora e tristeza dos citros, além de adaptados a altas densidades populacionais. Como fontes de protoplastos, vêm sendo utilizadas as tangerinas-'Cleópatra', 'Sunki' e 'Swatow', limões-'Cravo Santa Cruz' e 'Santa Bárbara', 'Volkameriano' e 'Rugoso Mazoe', laranja 'Hamlin CNPMF 04' e 'CNPMF 20', laranjas-azedas 'Comum' e 'Narrow Leaf', citrange-'Troyer', Citrus amblycarpa e Microcitrus papuana. O estudo concentrou-se na etapa de obtenção e cultivo de calos embriogênicos. Foram utilizados óvulos extraídos de frutos imaturos, empregando-se como meio de cultura o MT, adicionando-se 50 g.L-1 de sacarose e 500 mg.L-1de extrato de malte e solidificando com 7 g.L-1 1de ágar. Em geral, a indução de calos nas variedades estudadas ocorreu entre a 6ª e a 8ª semana de cultivo, com maior precocidade na laranja-‘Hamlin’, sendo que, em limão-‘Cravo’, laranja-‘Hamlin’ , tangerinas-‘Cleópatra’ e ‘Swatow’ e citrange-‘Troyer’, a porcentagem de formação de calos foi igual ou superior a 50%, destacando-se a tangerina-‘Cleópatra’ com um porcentual próximo a 70% de calogênese.Embrapa Cassava & Fruits Research with citrus aim at obtaining somatic hybrids, particularly rootstocks, better adapted to the Brazilian tropical cultivation conditions than the varieties currently in use. The main objectives are the selection of genotypes tolerant to drought and aluminum toxicity, tolerant/resistant to Phytophthora foot rot and citrus tristeza virus, besides being well adapted to high planting densities. The following varieties have being

  13. Dinâmica Populacional de Pulgão Preto dos Citros (Sternorrhyncha em Cultivo Orgânico de Tangerina (Citrus reticulata Blanco em Seropédica-RJ

    Directory of Open Access Journals (Sweden)

    William Rodrigues

    2010-07-01

    Abstract. The aphid Toxoptera citricida (Kyrkaldy (Sternorrhyncha is a potential vector of citrus virus tristeza, consider an important pest of the orchard. Was realized bimonthly monitoring between October 2002 and October 2003, with aim of study the populational dynamic this aphid, included predators ant ant-tending, in organic cropping of tangerine cv Ponkan, Fazendinha Agroecológica, Seropédica, RJ. The faunistic analysis of the ant-tending and predators, were realized across Shanon-Wiener (H' and Simpson (D diversity index's, Berger-Parker dominance (d and equitability J (e. The predators considered efficient in the populational reduction of brown citrus aphid (BCA, was Cycloneda sanguinea (L., Azya luteipes Mulsant and Pseudodorus clavatus (Fabr., although has been registered eight predators attacking BCA colonies. Verified that C. sangiunea obtained the biggest populational peak, following P. clavatus and A. luteipes. The predators diversity and equitability was considered high (H'= 0.7979; D =0.9638; e= 0.8836. Tending BCA, was registered Brachymyrmex sp., Camponotus rufipes (Fabricius Camponotus atriceps (Fabricius, Camponotus crassus (Mayr, Camponotus clypeatus (Mayr; Crematogaster sp., Solenospis sp., Ectatomma brunneum (Fabricius and Pseudomyrmex termitarius (Fr. Smith. Ant-tending was considered medium to H' value (0.6585 and high to D value (0.9012. The equitability was considered medium too (e =0.69. T. citricida populational dynamic is influenced to foliar shoot following predation and ant-tending. These two end factors are antagonist due to protection offer to ants at BCA.

  14. Citrus Genomics

    OpenAIRE

    Talon, Manuel; Gmitter, Fred G.Jr.

    2008-01-01

    Citrus is one of the most widespread fruit crops globally, with great economic and health value. It is among the most difficult plants to improve through traditional breeding approaches. Currently, there is risk of devastation by diseases threatening to limit production and future availability to the human population. As technologies rapidly advance in genomic science, they are quickly adapted to address the biological challenges of the citrus plant system and the world's industries. The hist...

  15. Como vencer a tristeza? =How to overcome the sadness?

    Directory of Open Access Journals (Sweden)

    Zanetti, Thiago

    2014-01-01

    Full Text Available Este texto tem por objetivo abordar a superação do sentimento tristeza à luz das Sagradas Escrituras. Tal sentimento é inerente à condição humana; no entanto, permanecer mergulhado no sentimento de tristeza pode ser um perigo. À luz das Sagradas Escritoras, recorremos ao livro dos Salmos, à Carta de São Paulo aos Filipenses e ao Cântico de Maria escrito pelo evangelista S. Lucas, para dizer ao homem (o fiel, o crente, abuscar a alegria, e seu encontro só é possível encontrando-se com Deus. Outro passo importante é recorrer a Maria, a Rainha das Alegrias.

  16. Discovery of a viral pathogen in the Asian citrus psyllid

    Science.gov (United States)

    We used a Metagenomics approach and discovered an insect-infecting virus in adult Asian citrus psyllids in Florida. Though wide spread in nature, this is the first report of a Fijivirus in North America. The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is a small insect tha...

  17. Spatial and temporal analyses of citrus sudden death as a tool to generate hypotheses concerning its etiology.

    Science.gov (United States)

    Bassanezi, Renato B; Bergamin Filho, Armando; Amorim, Lilian; Gimenes-Fernandes, Nelson; Gottwald, Tim R; Bové, Joseph M

    2003-04-01

    ABSTRACT Citrus sudden death (CSD), a new disease of unknown etiology that affects sweet orange grafted on Rangpur lime, was visually monitored for 14 months in 41 groves in Brazil. Ordinary runs analysis of CSD-symptomatic trees indicated a departure from randomness of symptomatic trees status among immediately adjacent trees mainly within rows. The binomial index of dispersion (D) and the intraclass correlation (k) for various quadrat sizes suggested aggregation of CSD-symptomatic trees for almost all plots within the quadrat sizes tested. Estimated parameters of the binary form of Taylor's power law provided an overall measure of aggregation of CSD-symptomatic trees for all quadrat sizes tested. Aggregation in each plot was dependent on disease incidence. Spatial autocorrelation analysis of proximity patterns suggested that aggregation often existed among quadrats of various sizes up to three lag distances; however, significant lag positions discontinuous from main proximity patterns were rare, indicating a lack of spatial association among discrete foci. Some asymmetry was also detected for some spatial autocorrelation proximity patterns, indicating that within-row versus across-row distributions are not necessarily equivalent. These results were interpreted to mean that the cause of the disease was most likely biotic and its dissemination was common within a local area of influence that extended to approximately six trees in all directions, including adjacent trees. Where asymmetry was indicated, this area of influence was somewhat elliptical. Longer-distance patterns were not detected within the confines of the plot sizes tested. Annual rates of CSD progress based on the Gompertz model ranged from 0.37 to 2.02. Numerous similarities were found between the spatial patterns of CSD and Citrus tristeza virus (CTV) described in the literature, both in the presence of the aphid vector, Toxoptera citricida. CSD differs from CTV in that symptoms occur in sweet orange

  18. The psorosis disease of citrus: a pale light at the end of the tunnel

    OpenAIRE

    Moreno, Pedro; Guerri, José; García, María Laura

    2015-01-01

    Abstract First reported in 1896, psorosis was the first citrus disease proven to be graft transmissible and also the first for which eradication and budwood certification programs were launched to prevent its economic damage. For many years psorosis etiology remained elusive and only in 1986 it was associated with the presence of virus-like particles in infected plants. However, in the last two decades a virus with unusual morphology (Citrus psorosis virus, CPsV) was characterized and closely...

  19. Citrus Waste Biomass Program

    Energy Technology Data Exchange (ETDEWEB)

    Karel Grohman; Scott Stevenson

    2007-01-30

    Renewable Spirits is developing an innovative pilot plant bio-refinery to establish the commercial viability of ehtanol production utilizing a processing waste from citrus juice production. A novel process based on enzymatic hydrolysis of citrus processing waste and fermentation of resulting sugars to ethanol by yeasts was successfully developed in collaboration with a CRADA partner, USDA/ARS Citrus and Subtropical Products Laboratory. The process was also successfully scaled up from laboratory scale to 10,000 gal fermentor level.

  20. Genome assembly of citurs leprosis virus nuclear type reveals a close association with orchid fleck virus

    Science.gov (United States)

    Citrus leprosis is a difficult viral disease causing significant damage to citrus fruit in South America and Central America. The disease is marked by dramatic lesions on fruit, leaves and stems resulting in unmarketable product. Citrus leprosis virus cytoplasmic type (CiLV-C) was detected in states...

  1. Commercial risk-based survey for HLB and implications for efficacy of Citrus Health Management Areas (CHMAs)

    OpenAIRE

    Gottwald, T.; Luo, W.; Riley, T; Parnell, S.

    2014-01-01

    The USDA, APHIS, PPQ has been conducting a risk-based multi-pest survey (MPS) for the past two years.  The initial 6 statewide survey cycles were conducted on a 6 week basis, whereas the subsequent 20 cycles have been conducted on a 3-week basis.  HLB and ACP are the two main pests addressed by the MPS but other citrus pests and diseases, i.e., Asiatic Citrus Canker (ACC), Citrus Leprosis Virus (CLiV), Citrus Black Spot (CBS) and Citrus Variegated Chlorosis (CVC) were also given lesser emphas...

  2. Characterization of a Proposed Dichorhavirus Associated with the Citrus Leprosis Disease and Analysis of the Host Response

    Directory of Open Access Journals (Sweden)

    José Luis Cruz-Jaramillo

    2014-07-01

    Full Text Available The causal agents of Citrus leprosis are viruses; however, extant diagnostic methods to identify them have failed to detect known viruses in orange, mandarin, lime and bitter orange trees with severe leprosis symptoms in Mexico, an important citrus producer. Using high throughput sequencing, a virus associated with citrus leprosis was identified, belonging to the proposed Dichorhavirus genus. The virus was termed Citrus Necrotic Spot Virus (CNSV and contains two negative-strand RNA components; virions accumulate in the cytoplasm and are associated with plasmodesmata—channels interconnecting neighboring cells—suggesting a mode of spread within the plant. The present study provides insights into the nature of this pathogen and the corresponding plant response, which is likely similar to other pathogens that do not spread systemically in plants.

  3. PHARMACOLOGICAL IMPORTANCE OF CITRUS FRUITS

    Directory of Open Access Journals (Sweden)

    Amita Tomar *, Mridula Mall and Pragya Rai

    2013-01-01

    Full Text Available This paper reviews the pharmacological importance of citrus fruits. Citrus fruits are used for various pharmacological importance. According to literature the citrus fruit possess anti-cancer, antimicrobial, antioxidant, antiulcer, anti-inflammatory, and hypolipidemic and hepatoprotective properties.

  4. Características da laranjeira 'Valência' sobre clones e híbridos de porta-enxertos tolerantes à tristeza Characteristics of 'Valencia' sweet orange onto clones and hybrid rootstocks tolerant to the tristeza disease

    Directory of Open Access Journals (Sweden)

    Rita Bordignon

    2003-01-01

    Full Text Available Estudou-se a variabilidade e o potencial de seleção de 396 híbridos entre os porta-enxertos limão Cravo 'Limeira' (Citrus limonia (C, tangerina Sunki (C. sunki (S, laranja Azeda 'São Paulo' (C. aurantium (A e Trifoliata 'Davis A' (Poncirus trifoliata (T tolerantes à tristeza, comparativamente aos genitores Cravo, Sunki e Trifoliata. Foram investigados os híbridos T x A, T x S, S x T, C x S, S x C, C x A e S x A quanto à produção das três primeiras colheitas, produtividade e várias características vegetativas e industriais da laranjeira 'Valência' neles enxertada. Cravo, Trifoliata e os híbridos T x S, S x T, T x A e C x A iniciaram a produção precocemente comparado à Sunki, S x C, C x S e S x A, denotando a dominância da produção precoce do Trifoliata, mesmo nos híbridos com Sunki, e a tendência dos híbridos de Sunki em induzir produção tardia, exceto na combinação com o Trifoliata. A produtividade por área de projeção da copa do Trifoliata foi baixa, ao contrário do Cravo, Sunki e híbridos T x S e S x T. Observou-se boa associação entre os diâmetros dos enxertos e também dos porta-enxertos logo após o plantio no campo e nos quatro anos subseqüentes. Altura, diâmetro da copa, dos troncos do enxerto e porta-enxertos são altamente relacionados e úteis para compor um índice caracterizando o vigor. Trifoliata e Sunki foram os mais divergentes quanto ao vigor e os híbridos entre eles, os que apresentaram maior variabilidade para essa característica. Em 2000, vigor e produção correlacionaram-se com o diâmetro do enxerto em 1996, mostrando ser acertada a prática corrente de se escolherem as mudas mais vigorosas para o plantio comercial, indicando sua utilidade na pré-seleção de mudas de híbridos para o plantio de campos de seleção. A incompatibilidade parcial enxerto/porta-enxerto, observada em 'Valência'/Trifoliata, manifestou-se em seus híbridos, mas não se correlacionou com os atributos produ

  5. Experiências de cavalos para citrus II

    Directory of Open Access Journals (Sweden)

    F. G. Brieger

    1945-01-01

    Full Text Available The English resumé is given in a different form from the Portuguese "conclusões". In the former we gave mainly the results which may be of general interest, explaining the tables (quadros and the procedure of statistical analysis, while in the other the properties of the different rootstocks are discussed in detail since they are of immediate local interest. 1. In a previous publication, Moreira (19 explained the layout and the first results of an experiment, under way since 1936 in the Limeira Exp. Sta., on the influence of twelve different types of Citrus rootstocks on three scion varieties : the oranges "Baianinha" and "Pera" and the grape-fruit "Marsh Seedless". We report here three main results obtained during the first six years of the experiment: a all plants budded on sour and bitter-sweet oranges (C. aurantium, showed definite signs of the new disease "tristeza" ; b other rootstocks such as citron (C. medica, ponderosa lemon (C. lemon had such disadvantageous effect that they could be eliminated as suitable stocks ; c the data of the first four crops permit to determine certain particularities of some rootstocks varieties used in the experiment. The present paper deals with the complete

  6. 78 FR 63369 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2013-10-24

    ... Animal and Plant Health Inspection Service 7 CFR Part 301 RIN 0579-AD29 Citrus Canker, Citrus Greening... published an interim rule \\1\\ in the Federal Register (76 FR 23449-23459, Docket No. APHIS-2010-0048) that....usda.gov/plant_health/plant_pest_info/citrus/index.shtml and on Regulations.gov (see footnote 1...

  7. 75 FR 17289 - Citrus Seed Imports; Citrus Greening and Citrus Variegated Chlorosis

    Science.gov (United States)

    2010-04-06

    ... Animal and Plant Health Inspection Service 7 CFR Part 319 RIN 0579-AD07 Citrus Seed Imports; Citrus... of nursery stock to prohibit the importation of propagative seed of several Rutaceae (citrus family... are also requiring propagative seed of these genera imported from all other countries to...

  8. Tristeza, Depresión y Estrategias de Autorregulación en Niños

    OpenAIRE

    Angela Cuervo Martínez; Romina Izzedin Bouquet

    2007-01-01

    Este artículo presenta una revisión de los estudios sobre la tristeza en niños, su vínculo con la depresión infantil y la autorregulación emocional, así como las diferencias de género en la expresión de esta emoción primaria. Se pretende brindar una descripción de los factores asociados a la tristeza y a la depresión y se destaca la importancia de conocer la autorregulación emocional de la tristeza por géneros para prevenir e intervenir oportunamente en la depresión infantil....

  9. Antioxidant activity of Citrus fruits.

    Science.gov (United States)

    Zou, Zhuo; Xi, Wanpeng; Hu, Yan; Nie, Chao; Zhou, Zhiqin

    2016-04-01

    Citrus is well-known for its nutrition and health-promotion values. This reputation is derived from the studies on the biological functions of phytochemicals in Citrus fruits and their derived products in the past decades. In recent years, the antioxidant activity of Citrus fruits and their roles in the prevention and treatment of various human chronic and degenerative diseases have attracted more and more attention. Citrus fruits are suggested to be a good source of dietary antioxidants. To have a better understanding of the mechanism underlying the antioxidant activity of Citrus fruits, we reviewed a study on the antioxidant activity of the phytochemicals in Citrus fruits, introduced methods for antioxidant activity evaluation, discussed the factors which influence the antioxidant activity of Citrus fruits, and summarized the underlying mechanism of action. Some suggestions for future study were also presented. PMID:26593569

  10. Identification and in silico analysis of the Citrus HSP70 molecular chaperone gene family

    Directory of Open Access Journals (Sweden)

    Luciano G. Fietto

    2007-01-01

    Full Text Available The completion of the genome sequencing of the Arabidopsis thaliana model system provided a powerful molecular tool for comparative analysis of gene families present in the genome of economically relevant plant species. In this investigation, we used the sequences of the Arabidopsis Hsp70 gene family to identify and annotate the Citrus Hsp70 genes represented in the CitEST database. Based on sequence comparison analysis, we identified 18 clusters that were further divided into 5 subgroups encoding four mitochondrial mtHsp70s, three plastid csHsp70s, one ER luminal Hsp70 BiP, two HSP110/SSE-related proteins and eight cytosolic Hsp/Hsc70s. We also analyzed the expression profile by digital Northern of each Hsp70 transcript in different organs and in response to stress conditions. The EST database revealed a distinct population distribution of Hsp70 ESTs among isoforms and across the organs surveyed. The Hsp70-5 isoform was highly expressed in seeds, whereas BiP, mitochondrial and plastid HSp70 mRNAs displayed a similar expression profile in the organs analyzed, and were predominantly represented in flowers. Distinct Hsp70 mRNAs were also differentially expressed during Xylella infection and Citrus tristeza viral infection as well as during water deficit. This in silico study sets the groundwork for future investigations to fully characterize functionally the Citrus Hsp70 family and underscores the relevance of Hsp70s in response to abiotic and biotic stresses in Citrus.

  11. Sequence analysis of three citrus viroids infecting a single Tunisian citrus tree (Citrus, reticulata, Clementine

    Directory of Open Access Journals (Sweden)

    Amine Elleuch

    2006-01-01

    Full Text Available We report the nucleotide sequences of three citrus viroids belonging to three different genera: Citrus exocortis viroid (CEVd, Hop stunt viroid (HSVd and Citrus viroid-III (CVd-III isolated from a single natural infected Citrus reticulata var. Clementine tree growing in a tree nursery in Manouba (near Tunis Capital. We describe the sequence variability of these viroids from their natural host without using an alternative passage by an indicator host or an artificial inoculation. This work confirms that naturally occurring viroid infections contain a mixture of sequence variants. These are the first sequences of citrus viroids from Africa.

  12. Duelo, tristeza y rechazo del inconsciente // Mourning, sadness and rejection of the subconscious

    Directory of Open Access Journals (Sweden)

    David Vargas Castro

    2011-06-01

    Full Text Available En el presente texto se articulan desarrollos realizados por Freud y Lacan a propósito del duelo con el fin de responder a la relación entre éste y lo que Lacan propone en Televisión sobre la tristeza y el rechazo del inconsciente. Para tales fines, se parte de las preguntas e intentos de respuestas dadas por Freud en el plano de la economía libidinal a propósito del duelo, para pasar a los desarrollos de orden ético y moral que Lacan plantea a propósito de la tristeza. De esta forma, el rechazo del inconsciente presente en las psicosis se distingue del que tiene lugar en el duelo, al considerar la tristeza un afecto que dará cuenta del rechazo del deseo del Otro. // This text articulates developments made by Freud and Lacan about mourning to attempt a response on how this relates to Lacan‟s proposal in Television about sadness and rejection of the unconscious. To do this, the text departs from the questions and answers given by Freud in the field of the economy of the libido referring to mourning and then moves on to the ethical and moral aspects that Lacan refers about sadness. Consequently, from this perspective the rejection of the unconscious in the psychosis is different from the one that takes place in mourning, considering sadness as an affection that will evidence the rejection of the desire of the Other.

  13. Citrus stubborn disease (CSD)

    Science.gov (United States)

    CSD is caused by Spiroplasma citri, a phloem-limited, cell-wall-less bacterium. S. citri is transmitted in a propagative, circulative manner by several leafhoppers including Circulifer tenellus and Scaphytopius nitridus in citrus-growing regions of California and Arizona and by C. haematoceps (syn....

  14. Potential Nutritional Benefits of Current Citrus Consumption

    OpenAIRE

    Tami Turner; Burri, Betty J.

    2013-01-01

    Citrus contains nutrients and phytochemicals that may be beneficial for health. We collected citrus production and consumption data and estimated the amount of these compounds that are consumed. We then compared the amounts of citrus and citrus-derived compounds used in studies that suggest a health benefit to the amounts typically found in citrus. Data is scarce, but suggests that citrus consumption might improve indices of antioxidant status, and possibly cardiovascular health and insulin s...

  15. Potential Nutritional Benefits of Current Citrus Consumption

    Directory of Open Access Journals (Sweden)

    Tami Turner

    2013-03-01

    Full Text Available Citrus contains nutrients and phytochemicals that may be beneficial for health. We collected citrus production and consumption data and estimated the amount of these compounds that are consumed. We then compared the amounts of citrus and citrus-derived compounds used in studies that suggest a health benefit to the amounts typically found in citrus. Data is scarce, but suggests that citrus consumption might improve indices of antioxidant status, and possibly cardiovascular health and insulin sensitivity.

  16. Phytochemical analysis and radical scavenging profile of juices of Citrus sinensis, Citrus anrantifolia, and Citrus limonum

    OpenAIRE

    Rauf, Abdur; Uddin, Ghias; Ali, Jawad

    2014-01-01

    Background The aim of the current investigation was to identify bioactive secondary metabolites including phenols, tannins, flavonoids, terpinedes, and steroids and compare the phytochemical analysis and antioxidant profile of the juice extracted from the fruits of Citrus sinensis, Citrus anrantifolia, and Citrus limonum. Results Phytochemical screening is important for the isolation of new, novel, and rare secondary metabolites before bulk extraction. Phytochemical analysis of the desired pl...

  17. Valuing Catastrophic Citrus Losses

    OpenAIRE

    Adams, Damian C.; Kilmer, Richard L.; Moss, Charles B.; Schmitz, Andrew

    2004-01-01

    Courts are often required to estimate changes in welfare to agricultural operations from catastrophic events. For example, courts must assign damages in lawsuits, such as with pesticide drift cases, or determine "just compensation" when the government takes private land for public use, as with the removal of dairy farms from environmentally sensitive land or destruction of canker-contaminated citrus trees. In economics, the traditional method of quantifying producer losses is estimating chang...

  18. Induced mutations in citrus

    International Nuclear Information System (INIS)

    Full text: Parthenocarpic tendency is an important prerequisite for successful induction of seedlessness in breeding and especially in mutation breeding. A gene for asynapsis and accompanying seedless fruit has been found by us in inbred progeny of cv. 'Wilking'. Using budwood irradiation by gamma rays, seedless mutants of 'Eureka' and 'Villafranca' lemon (original clone of the latter has 25 seeds) and 'Minneola' tangelo have been obtained. Ovule sterility of the three mutants is nearly complete, with some pollen fertility still remaining. A semi-compact mutant of Shamouti orange has been obtained by irradiation. A programme for inducing seedlessness in easy peeling citrus varieties and selections has been initiated. (author)

  19. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    OpenAIRE

    Neelam Mallick; Rafeeq Alam Khan

    2016-01-01

    Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypo...

  20. Citrus Canker and Citrus Huanglongbing, Two Exotic Bacterial Diseases Threatening the Citrus Industries of the Western Hemisphere

    Science.gov (United States)

    Two exotic Asian bacterial diseases of citrus are currently plaguing citrus industries in the Western Hemisphere. The two largest citrus producing areas in the Americas, located in Florida and the state of São Paulo Brazil, are presently battling these devastating diseases. The presence of these d...

  1. CITRUS CANKER: PLANT PATHOLOGY VERSUS PUBLIC POLICY

    Science.gov (United States)

    Increasing international travel and trade has resulted in an unprecedented number of plant pathogen introductions, including Xanthomonas axonopodis pv citri, (Xac), the bacterium that causes citrus canker. The disease affects commercial and dooryard citrus, and has far-reaching politi...

  2. Complete Genome Sequence of a Putative Densovirus of the Asian Citrus Psyllid, Diaphorina citri.

    Science.gov (United States)

    Nigg, Jared C; Nouri, Shahideh; Falk, Bryce W

    2016-01-01

    Here, we report the complete genome sequence of a putative densovirus of the Asian citrus psyllid, Diaphorina citri Diaphorina citri densovirus (DcDNV) was originally identified through metagenomics, and here, we obtained the complete nucleotide sequence using PCR-based approaches. Phylogenetic analysis places DcDNV between viruses of the Ambidensovirus and Iteradensovirus genera. PMID:27469948

  3. CIBMAN: Database exploring Citrus biodiversity of Manipur

    OpenAIRE

    Sanabam, Rakesh; Somkuwar, Bharat Gopalrao; Thingnam, Gourshyam; Moirangthem, Sila; Handique, Pratap Jyoti; Huidrom, Sunitibala

    2012-01-01

    The rich wealth of Citrus genetic resources makes India to enjoy a remarkable position in the “Citrus belt of the world”. We have developed CIBMAN, a unique database on Citrus biodiversity of Manipur which comprises 33 accessions collected through extensive survey for more than three years. CIBMAN provides integrated access to Citrus species through sophisticated web interface which has following capabilities a) morphological details, b) socio-economic details, c) taxonomic details and d) geo...

  4. Citrus breeding, genetics and genomics in Japan

    OpenAIRE

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional br...

  5. THE GROWTH PERFORMANCE OF CITRUS DERIVED FROM SOMATIC EMBRYOGENESIS PLANTLET AND SCION STOCK

    Directory of Open Access Journals (Sweden)

    Nirmala Friyanti Devy

    2014-10-01

    Full Text Available Somatic embryogenesis (SE of callus culture in vitro is one of citrus propagation ways for producing free virus and genetically true-to-type plantlets. To induce growing of plantlets derived from this technology, they should be grafted ex vitro onto a citrus rootstock. The research aimed to evaluate the growth performance of citrus plants cv. Siam Kintamani (Citrus nobilis L. that used both plantlets and scions as their stocks. The research was conducted at Tlekung Research Station, Indonesian Citrus and Subtropical Fruit Research Institute from June 2011 to December 2012. The treatments were done at nursery house by grafting a plantlet and budding a scion onto an eight-month-old Japanese Citroon (JC rootstock plant. The grafted and budded plants of one-year old were maintained at nursery house then transplanted into the field. In the field, the research was arranged in a randomized block design with three replications and used 15 plants as unit samples. The results showed that the vegetative growth of Siam Kintamani seedling derived from SE or grafted plant was faster than that of budded plant started from 10 to 12 months after treatment in the nersery house. In the field, the growth of SE grafted plant was only significantly different up to 6 months after transplanting. Plantlets produced from SE in vitro propagation can be used as a good alternative stock material for producing healthy citrus plants. Therefore, a further research is required especially on varieties used, reproductive growth and massive planlets production.

  6. Soil Micronutrients and Citrus Growth

    Institute of Scientific and Technical Information of China (English)

    OUYANGTAO

    1993-01-01

    By using nutritional diagnosis of citrus leaves and determining soil micronutrients,the relationship between soil micronutrients and citrus growth in southern China has been studied.Studies showed that there was a significant positive correlation between available micronutrients (such as Zn,Mo,Cu)in the soil and the corresponding nutrients in citrus leaves.Thus,one can roughly learn of the sufficiency or deficiency of certain nutrients in soils by analyzing citrus leaves.Rational spray of Zn B or Mo fertilizer not only improved citrus yields but also increased the total sugar of Satsuma mandarin and of Xinhui orange by 2.9 and 17.2% respectively compared with the control.Spraying Mo fertilizer increased the vitamin C content of Satsuma mandarin juice by 4.7%-8.4%,maturated fruits 7-10 days earlier and gave the peel a brighter color.The ultramicroscopic characteristics of Zn-deficient citrus leaves were investigated under an electron microscope.Results showed that the Zn-deficient leaf cell was characterized mainly by poor cytoplasm,endoplasmic reticula and ribosomes and by big starch grains in the chloroplast.As a result of spraying Zn fertilizer the structure of the cell returned to normal,the cytoplasm became rich and the amount of chloroplast increased.There also appeared a great deal of multiform endoplasmic reticula,thus promoting the photosynthesis of Zn-deficient plants.This provides a cytologico-theoretical basis for fertilization of high-yielding citrus trees.

  7. Citrus Limonoids: Analysis, Bioactivity, and Biomedical Prospects

    Science.gov (United States)

    This publication is a review of the chemistry, biochemistry and bioactivity of limonoids occurring in citrus. The review chronologically relates the evolution of research in citrus limonoids beginning with their association with bitterness development in citrus juices. The chemical and biochemical...

  8. Identificação colorimétrica em citrus

    Directory of Open Access Journals (Sweden)

    Osvaldo Bacchi

    1943-07-01

    Full Text Available In order to study the susceptibility of the various stocks with regard to the new disease "tristeza" ("sadness", a quick and acurate identification of the stock is required. In orchards this cannot be done in most cases as stocks do not always exhibit sprouts and on account of erroneus information frequently given by owners. We have tested the colorimetric identification, already employed in other countries. This identification is based on the differences of color obtained in the watery extract cf the bark taken from the trunk or from the root, when treated by special reagents. The results obtained are somewhat different from those described by the authors of the method. This is perhaps due to variation in environmental conditions. Only the Almen and ferric chloride tests gave satisfactory results, making it possible to arrange the species and varieties examined into four groups : (1 C. aurantium L. ; (2 C. sinensis Osbeck; (3 C. limonia Osbeck ("gigante" variety and (4 all the others. Although deficient in certain respects the test is valuable, permiting us to identify the stocks of orange trees, azeda as well as caipira the most employed in the citrus orchards of the State of S. Paulo.

  9. Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates

    OpenAIRE

    Oikeh, Ehigbai I.; Omoregie, Ehimwenma S; Oviasogie, Faith E.; Oriakhi, Kelly

    2015-01-01

    Abstract The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Citrus aurantifolia (lime) were evaluated. Antimicrobial activities against five bacterial an...

  10. Effectivity of Kaffir lime (Citrus hystrix, Nasnaran Mandarin (Citrus amblycarpa, and Pomelo (Citrus maxima Leaf Extract Against Aedes aegypti Larvae

    Directory of Open Access Journals (Sweden)

    Hebert Adrianto

    2014-03-01

    Full Text Available The used of chemicals as larvicidal may causing resistance, health problem, and environment problem. Leaf extracts of Citrus as biolarvicidal against Aedes aegypti larvae can be used as an alternative larvicidal. The aims of this study is to find out the species of Citrus in the study sample, which is the most effective as biolarvicidal. This study was conducted using nested experiment design, with six treatments and five replicates. Larvae mortality was observed after 24 and 48 hours. Then, data were analyzed by probit. The results of this study show that (1 the LC95 value after 24 hours of exposure of leaf extracts of Citrus hystrix, Citrus amblycarpa, and Citrus maxima, were each 3,176 ppm; 4,174 ppm; and 6,369 ppm. (2 the LC95 value after 48 hours of exposure of leaf extracts of Citrus hystrix, Citrus amblycarpa, and Citrus maxima, were each 2,499 ppm; 3,256 ppm; and 4,886 ppm. (3 leaf extract of Citrus hystrix is the most effective among others as biolarvicidal against Aedes aegypti larvae. Leaf extract of Citrus hystrix can be used as alternative biolarvicidal.

  11. 78 FR 8435 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids and Fortunella

    Science.gov (United States)

    2013-02-06

    ... Animal and Plant Health Inspection Service 7 CFR Part 319 RIN 0579-AD59 Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids and Fortunella spp., Into the Continental United States AGENCY.... australis. \\2\\...

  12. 76 FR 23449 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2011-04-27

    ... 22, 2007 and effective on March 16, 2007 (72 FR 13423-13428, Docket No. APHIS-2007-0032) that....aphis.usda.gov/plant_health/plant_pest_info/citrus/index.shtml . We believe that the procedures set... effective on June 17, 2010 (75 FR 34322-34336, Docket No. APHIS- 2008-0015).\\4\\ Several commenters on...

  13. 75 FR 34322 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

    Science.gov (United States)

    2010-06-17

    ... Animal and Plant Health Inspection Service 7 CFR Parts 301 and 305 RIN 0579-AC85 Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations AGENCY: Animal and Plant Health... African citrus psyllid is not present in the United States. The Animal and Plant Health Inspection...

  14. Quantitative Distribution of Candidatus Liberibacter asiaticus in Citrus Plants and Fruits Infected by Citrus Huanglongbing

    Science.gov (United States)

    Citrus huanglongbing (HLB), or greening disease, is caused by any of three non culturable Gram-negative bacteria belonging to Candidatus Liberibacter spp. The pathogens are transmitted by citrus psyllids to all commercial varieties of citrus. The diseases are lethal and have recently become widespr...

  15. Signaling pathways in a Citrus EST database

    OpenAIRE

    Angela Mehta; Marilia Santos Silva; Simone Guidetti-Gonzalez; Helaine Carrer; Marco Aurélio Takita; Natália F. Martins

    2007-01-01

    Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis) was launched in order to sequence Citrus ESTs (expressed sequence tags) from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under differe...

  16. Antimicrobial Compounds to Combat Citrus Huanglongbing

    OpenAIRE

    Zhang, Muqing; Guo, Ying; Powell, Charles A.; Duan, Yongping

    2014-01-01

    Citrus Huanglongbing (HLB) is associated with the fastidious bacterium,Candidatus Liberibacter, (Las) that is transmitted by a phloem-feeding insect (Citrus Psyllid). An ideal solution to combat citrus HLB is to completely eliminate the bacteria after a single course of the chemotherapy, either active directly on the bacteria or indirectly through induction of host defense compounds. Twenty-seven antimicrobial compounds were screened to test for in vivo activities against HLB bacterium while ...

  17. The aconitate hydratase family from Citrus

    OpenAIRE

    Cercos Manuel; Talon Manuel; Soler Guillermo; Terol Javier

    2010-01-01

    Abstract Background Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrat...

  18. Green synthesis of gold nanoparticles using Citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) aqueous extract and its characterization

    Science.gov (United States)

    Sujitha, Mohanan V.; Kannan, Soundarapandian

    2013-02-01

    This study reports the biological synthesis of gold nanoparticles by the reduction of HAuCl4 by using citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) juice extract as the reducing and stabilizing agent. A various shape and size of gold nanoparticles were formed when the ratio of the reactants were altered with respect to 1.0 mM chloroauric acid solution. The gold nanoparticles obtained were characterized by UV-visible spectra, transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM studies showed the particles to be of various shapes and sizes and particle size ranges from 15 to 80 nm. Selected-area electron diffraction (SAED) pattern confirmed fcc phase and crystallinity of the particles. The X-ray diffraction analysis revealed the distinctive facets (1 1 1, 2 0 0, 2 2 0 and 2 2 2 planes) of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size for colloid gp3 of C. limon, C. reticulata and C. sinensis are 32.2 nm, 43.4 nm and 56.7 nm respectively. The DLS graph showed that the particles size was larger and more polydispersed compared to the one observed by TEM due to the fact that the measured size also includes the bio-organic compounds enveloping the core of the Au NPs. Zeta potential value for gold nanoparticles obtained from colloid gp3 of C. limon, C. reticulata and C. sinensis are -45.9, -37.9 and -31.4 respectively indicating the stability of the synthesized nanoparticles. Herein we propose a novel, previously unexploited method for the biological syntheses of polymorphic gold nanoparticles with potent biological applications.

  19. 7 CFR 319.56-38 - Citrus from Chile.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata Blanco), and tangerines (Citrus reticulata Blanco) may be imported into the United States from Chile,...

  20. Cryopreservation and Cryotherapy of Citrus Cultivars

    Science.gov (United States)

    Long-term conservation of Citrus clones can be accomplished by cryopreservation. Shoot tips will survive liquid nitrogen exposure and storage when appropriately desiccated and treated with cryoprotectant solutions. In our research, vegetative Citrus budwood is shipped from Riverside to Fort Collin...

  1. Comparative Studies of Various Phytonutrients in Citrus Fruits

    Directory of Open Access Journals (Sweden)

    S. Ali

    2014-06-01

    Full Text Available The current piece of research was undertaken to investigate the phytochemicals constituents such as carbohydrates, proteins, alkaloids, anthraquinone, glycosides, Saponin, glycosides, steroid, cyanogenetic glycosides, tannins, phlobotannins, saponins, terpenoids, cardiac glycosides, etc in the species of citrus genus (Citrus sinensis, Citrus reticulate Blanco, Citrus aurantium L. All these plants were collected locally. Qualitative analysis of these phytochemicals was performed. All three types of citrus are rich with phytochemicals. Quantitative screenings is in progress in our lab.

  2. Tentativa de crianças em lidar com as emoções de raiva e tristeza Children trying to deal with emotions of anger and sadness

    Directory of Open Access Journals (Sweden)

    Maria da Graça Bompastor Borges Dias

    2000-06-01

    Full Text Available O presente estudo focaliza respostas de crianças sobre como parar o sentimento de tristeza e raiva, o que implica explorar estratégias de alterações de humor, i.e., pensamentos sobre como regular as emoções. Foi perguntado a crianças brasileiras e norueguesas de 5, 7 e 9 anos de idade como a tristeza e a raiva podiam cessar em 4 diferentes contextos para cada emoção. Os resultados mostram que as estratégias de regulação das emoções (RE variavam em função do contexto e da idade; que as crianças brasileiras usaram mais a interação social e as crianças norueguesas recorreram mais às estratégias cognitivas para raiva, mas não para tristeza. Não foi observada uma diferença clara na estratégia de RE para tristeza e raiva.The present study focus on children's cognitions of how to stop feeling sad and angry, which implies an exploration of their meta mood strategies, i.e. thoughts about how to regulate emotions. It was asking 5, 7, and 9-year-old Brazilian and Norwegian children how sadness and anger could be stopped in 4 different contexts for each emotion. The results showed that ER strategies varied with context and age, that Brazilian children used more social interaction and Norwegian children more cognitive strategies for anger, but not for sadness, and that even three year old children could state different strategies in different emotion contexts. There was not observed a clear difference in ER strategy for sadness and anger.

  3. Accumulation of the sesquiterpenes nootkatone and valencene by callus cultures of Citrus paradisi, Citrus limonia and Citrus aurantium.

    Science.gov (United States)

    Del Río, J A; Ortuño, A; Puig, D G; Iborra, J L; Sabater, F

    1991-10-01

    The production of the sesquiterpenes nootkatone and valencene by callus cultures of Citrus species is described. The levels of these compounds were examined by gas chromatography-mass spectrometry and their yields were compared with the amounts found in mature fruits. A simultaneous increase and decrease in the levels of nootkatone and valencene, respectively, were observed with the aging of callus cultures of Citrus paradisi. These results suggest that valencene might be a possible precursor of nootkatone in this species. The high level of nootkatone detected in 9-month-old callus cultures of Citrus paradisi might be associated with the corresponding cell morphological changes observed. PMID:24221735

  4. Citrus Improvement Using Mutation Techniques

    International Nuclear Information System (INIS)

    Citrus cultivar improvement is hampered by several biological factors inherent to most citrus species. Facultative apomixis, self and cross-incompatibility, long juvenility period, and high heterozygosis are some of the vast arrays of impediments faced by citrus breeders in conventional hybridization. Since oranges and grapefruits are highly polyembryonic, the production of enough numbers of zygotic offspring for selection of superior genotypes of these species is basically impossible; hence, most commercially important cultivars of these species have originated through natural or induced mutation. Star Ruby, a deep-red-fleshed grapefruit, was developed by irradiation of Hudson grapefruit seeds with thermal neutrons. Unlike Hudson, which contains over 50 seeds per fruit, Star Ruby is nearly seedless. Hensz irradiated buds of Ruby Red grapefruit with thermal neutrons and a tree that originated from one of the buds produced fruits three times redder than Ruby Red. It was named A and I-1-48. Ten trees were propagated from A and I -1-48, and out of one of the trees, a budsport mutation was found producing fruits five times redder than Ruby Red. Called Rio Red, it is currently the variety of choice for Texas and is known worldwide for its sweetness, red flesh and beautiful blush. Currently, 37 years after A and I -1-48 was first propagated, the trees are still producing several budsport mutations. So far, in the 2007/2008 season, more than 100 new mutations were obtained from a 100-tree block. In the mandarin group, the existence of several monoembryonic cultivars facilitates conventional breeding, but still, induced mutation is part of most mandarin breeding programmes, and proprietary, new seedless cultivars have been produced in the US, Italy, Israel and elsewhere. Seedless mandarins produced by the University of California Riverside include Dayse, Fairchild, Encore, and Nova. The USDA-ARS, U.S. Horticultural Research Laboratory in Florida released a seedless

  5. Signaling pathways in a Citrus EST database

    Directory of Open Access Journals (Sweden)

    Angela Mehta

    2007-01-01

    Full Text Available Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis was launched in order to sequence Citrus ESTs (expressed sequence tags from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under different development stages (adult vs. juvenile. Several cDNA libraries were constructed and the sequences obtained formed the Citrus ESTs database with almost 200,000 sequences. Searches were performed in the Citrus database to investigate the presence of different signaling pathway components. Several of the genes involved in the signaling of sugar, calcium, cytokinin, plant hormones, inositol phosphate, MAPKinase and COP9 were found in the citrus genome and are discussed in this paper. The results obtained may indicate that similar mechanisms described in other plants, such as Arabidopsis, occur in citrus. Further experimental studies must be conducted in order to understand the different signaling pathways present.

  6. Citrus breeding, genetics and genomics in Japan.

    Science.gov (United States)

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering. PMID:27069387

  7. Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers*

    OpenAIRE

    Wang, Rui; Shi, Xue-gen; Wei, You-zhang; Yang, Xiao-e; Uoti, Juhani

    2006-01-01

    Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P, K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg...

  8. Microbial Production of Pectin from Citrus Peel

    OpenAIRE

    Sakai, Takuo; Okushima, Minoru

    1980-01-01

    A new method for the production of pectin from citrus peel was developed. For this purpose, a microorganism which produces a protopectin-solubilizing enzyme was isolated and identified as a variety of Trichosporon penicillatum. The most suitable conditions for the pectin production were determined as follows. Citrus (Citrus unshiu) peel was suspended in water (1:2, wt/vol), the organism was added, and fermentation proceeded over 15 to 20 h at 30°C. During the fermentation, the pectin in the p...

  9. Green Synthesis and Biological Activities of Gold Nanoparticles Functionalized with Citrus reticulata, Citrus aurantium, Citrus sinensis and Citrus grandis

    International Nuclear Information System (INIS)

    In the present study, gold nanoparticles (GNPs) were prepared at boiling temperature (90-95 degree C) by treating gold ions with Citrus fruit extracts. The effect of mixing ratios of the reactants and concentration of gold hydrochloride was studied. In the standardization process, 10/sup -3/ M solution of HAuCl/sub 4/.3H/sub 2/O was reacted with fruit extracts for half an hour at 90-95 degree C in different ratios. GNPs were characterized by UV-Vis spectroscopy (UV-Vis) and atomic force microscopy (AFM). Their stability was evaluated against varying pH solutions and volumes of sodium chloride along with metals and antibiotics sensing ability. The gold nanoparticles were tested for antibacterial and antifungal activities against various pathogenic strains. The UV-Vis spectra of gold nanoparticles gave surface plasmon resonance at about 540 nm while the AFM images revealed the particle size within the range of 70-100 nm. GNPs showed remarkable stability in varying pH solutions and salt volumes as well as high detection ability towards cobalt, copper, ceftriaxone and penicillin. Moreover, the GNPs possessed moderate antibacterial and good antifungal activity. These results concluded that the Citrus fruit extracts can be utilized for large scale synthesis of cost-effective nanoparticles which may have compatibility for biomedical and pharmaceutical applications. (author)

  10. Effectivity of Kaffir lime (Citrus hystrix), Nasnaran Mandarin (Citrus amblycarpa), and Pomelo (Citrus maxima) Leaf Extract Against Aedes aegypti Larvae

    OpenAIRE

    Hebert Adrianto; Subagyo Yotopranoto; Hamidah

    2014-01-01

    The used of chemicals as larvicidal may causing resistance, health problem, and environment problem. Leaf extracts of Citrus as biolarvicidal against Aedes aegypti larvae can be used as an alternative larvicidal. The aims of this study is to find out the species of Citrus in the study sample, which is the most effective as biolarvicidal. This study was conducted using nested experiment design, with six treatments and five replicates. Larvae mortality was observed after 24 and 48 hours. Then, ...

  11. 2004 SWFWMD Citrus County Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata record describes the ortho & LIDAR mapping of Citrus County, FL. The mapping consists of LIDAR data collection, contour generation, and production...

  12. The aconitate hydratase family from Citrus

    Directory of Open Access Journals (Sweden)

    Cercos Manuel

    2010-10-01

    Full Text Available Abstract Background Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrate, is the first step of citric acid catabolism and a major component of the citrate utilization machinery. In this work, the citrus aconitase gene family was first characterized and a phylogenetic analysis was then carried out in order to understand the evolutionary history of this family in plants. Gene expression analyses of the citrus aconitase family were subsequently performed in several acidic and acidless genotypes to elucidate their involvement in acid homeostasis. Results Analysis of 460,000 citrus ESTs, followed by sequencing of complete cDNA clones, identified in citrus 3 transcription units coding for putatively active aconitate hydratase proteins, named as CcAco1, CcAco2 and CcAco3. A phylogenetic study carried on the Aco family in 14 plant species, shows the presence of 5 Aco subfamilies, and that the ancestor of monocot and dicot species shared at least one Aco gene. Real-time RT-PCR expression analyses of the three aconitase citrus genes were performed in pulp tissues along fruit development in acidic and acidless citrus varieties such as mandarins, oranges and lemons. While CcAco3 expression was always low, CcAco1 and CcAco2 genes were generally induced during the rapid phase of fruit growth along with the maximum in acidity and the beginning of the acid reduction. Two exceptions to this general pattern were found: 1 Clemenules mandarin failed inducing CcAco2 although acid levels were rapidly reduced; and 2 the acidless "Sucreña" orange

  13. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    Directory of Open Access Journals (Sweden)

    Neelam Mallick

    2016-01-01

    Full Text Available Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypolipidemic effects of C. sinensis and C. paradisi in rats receiving diet rich in cholesterol. Materials and Methods: All rats were divided into 11 groups each comprising 10 animals: Normal control group and hyperlipidemic control. C. sinensis treated three groups, C. paradisi treated three groups, C. sinensis and C. paradisi combination treated two groups, and group treated atorvastatin. All rats in the respective groups were treated orally with sterile water, juices, and standard drug for 8 weeks and lipid profile was estimated at the end of dosing. Results: Cholesterol, triglycerides (TGs, and low-density lipoprotein (LDL were decreased at all the three doses of C. sinensis and C. paradisi but rise in high-density lipoprotein (HDL was only significant at 8 ml/kg, and 0.3 ml/kg, respectively. Animals received the combination doses of C. sinensis and C. paradisi also showed a highly significant fall in cholesterol, LDL, and TGs, however HDL level was significantly elevated by SPJ-2 combination. Conclusion: Results suggest that C. sinensis and C. paradisi possess antihyperlipidemic activity due to phytochemicals and other essential nutrients, hence may serve as cardioprotective by preventing thrombosis.

  14. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    Science.gov (United States)

    Mallick, Neelam; Khan, Rafeeq Alam

    2016-01-01

    Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypolipidemic effects of C. sinensis and C. paradisi in rats receiving diet rich in cholesterol. Materials and Methods: All rats were divided into 11 groups each comprising 10 animals: Normal control group and hyperlipidemic control. C. sinensis treated three groups, C. paradisi treated three groups, C. sinensis and C. paradisi combination treated two groups, and group treated atorvastatin. All rats in the respective groups were treated orally with sterile water, juices, and standard drug for 8 weeks and lipid profile was estimated at the end of dosing. Results: Cholesterol, triglycerides (TGs), and low-density lipoprotein (LDL) were decreased at all the three doses of C. sinensis and C. paradisi but rise in high-density lipoprotein (HDL) was only significant at 8 ml/kg, and 0.3 ml/kg, respectively. Animals received the combination doses of C. sinensis and C. paradisi also showed a highly significant fall in cholesterol, LDL, and TGs, however HDL level was significantly elevated by SPJ-2 combination. Conclusion: Results suggest that C. sinensis and C. paradisi possess antihyperlipidemic activity due to phytochemicals and other essential nutrients, hence may serve as cardioprotective by preventing thrombosis. PMID:27134462

  15. Characterization of the Asian Citrus Psyllid Transcriptome

    OpenAIRE

    Reese, Justin; Christenson, Matthew K.; Leng, Nan; Saha, Surya; Cantarel, Brandi; Lindeberg, Magdalen; Tamborindeguy, Cecilia; MacCarthy, Justin; Weaver, Daniel; Trease, Andrew J.; Ready, Steven V.; Davis, Vincent M.; McCormick, Courtney; Haudenschild, Christian; Han, Shunsheng

    2014-01-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is a vector for the causative agents of Huanglongbing, which threatens citrus production worldwide. This study reports and discusses the first D. citri transcriptomes, encompassing the three main life stages of D. citri, egg, nymph and adult. The transcriptomes were annotated using Gene Ontology (GO) and insecticide-related genes within each life stage were identified to aid the development of future D. citri insectici...

  16. La Alegría del Amor: Alegrías, Tristezas y Esperanzas

    Directory of Open Access Journals (Sweden)

    Josef Seifert

    2016-07-01

    Full Text Available La primera parte de este ensayo comienza con una mención de la riqueza de pensamientos preciosos expresados en AL, y con el centro de su mensaje: el amor misericordioso de Dios por cada ser humano. En seguida se refiere a una pequeña parte de sus declaraciones, que acaecedero tendrán el efecto más extendido, pero dan origen a perplejidad, preocupación y tristeza.La segunda parte se dedica a la pregunta si la admisión de parejas en ‘situaciones irregulares’ a los sacramentos, sugerida en AL, está compatible con la doctrina de la Iglesia. Para responder, se debe plantearse la pregunta anterior de quienes son las parejas en ‘situaciones irregulares’, es decir en situaciones objetivamente gravemente pecaminosas, a quienes AL quiere conceder acceso a los sacramentos. Se discuten críticamente cuatro respuestas fundamentalmente diferentes que dominan el debate actual acerca de AL, para mostrar que en la confusión general creada por esta ambigüedad se necesita exasperadamente una declaración clara acerca de cuáles de ellas son verdaderas y cuales son descaradamente falsas: ¿Ninguna pareja irregular? ¿Todas los ‘parejas irregulares?’ ¿Algunas parejas en situaciones irregulares, cuidadosamente examinadas? ¿’Parejas irregulares’ que parecen haber contraído válidos ‘matrimonios de conciencia’ fuera de las reglas del derecho canónico y que AL reconoce por primera vez? La segunda respuesta permite todo tipo de sacrilegio y por lo tanto, si aplicada a la pastoral, transforma el Santo Templo de Dios en un templo de Satanás y luego no puede ser la respuesta del Papa. Pero como esta respuesta a nuestra pregunta fue propuesta por altos dignatarios de la Iglesia, exige urgentemente un rechazo radical.La tercera respuesta es la de Papa Francisco. Ella se somete a una exhaustiva investigación y se proporciona una serie de preguntas sobre ella para mostrar que cada clasificación por ‘buena gente en situaciones irregulares

  17. Phyllosticta citriasiana sp nov., the cause of Citrus tan spot of Citrus maxima in Asia

    NARCIS (Netherlands)

    Wulandari, N.F.; To-anun, C.; Hyde, K.D.; Duong, L.M.; de Gruyter, J.; Meffert, J.P.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    Guignardia citricarpa, the causal agent of Citrus Black Spot, is subject to phytosanitary legislation in the European Union and the U.S.A. This species is frequently confused with G. mangiferae, which is a non-pathogenic, and is commonly isolated as an endophyte from citrus fruits and a wide range o

  18. Phyllosticta citriasiana sp. nov., the cause of Citrus tan spot of Citrus maxima in Asia

    NARCIS (Netherlands)

    Wulandari, N.F.; To-anun, C.; Hyde, K.D.; Duong, L.M.; Gruyter, de J.; Meffert, J.P.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    Guignardia citricarpa, the causal agent of Citrus Black Spot, is subject to phytosanitary legislation in the European Union and the U.S.A. This species is frequently confused with G. mangiferae, which is a non-pathogenic, and is commonly isolated as an endophyte from citrus fruits and a wide range o

  19. Detection of non-typhoid Salmonella infection by citrus and citrus extracts in Lao PDR

    Institute of Scientific and Technical Information of China (English)

    Yutaka Midorikawa; Satoshi Nakamura; Rattanaphone Phetsouvanh; Manivanh Vongsouvaht; Kaoru Midorikawa

    2010-01-01

    Objective: To know the current state of non-typhoid Salmonella infection in Laos. To examine the usefulness of new screening methods for Salmonella using citrus. Methods: Non-typhoidSalmonella infection of person in Lao PDR was studied in this research (2004-2009). The site was Vientiane capital city in 2004. Research from rural villages locating suburb of Vientiane during 2005-2008 was carried out. Rural villages in Attapu province where ethnic minorities were living was searched for this study in 2009. During this research, to detect Salmonella strain, a new method using citrus and citrus extract named MY phenomenon that observing black ring (MIDO ring) on DHL agar was tried. The slice lemon and lime were used for this trial in 2004. After 2005, disk of ascorbic acid and citric acid were used for the device instead of citrus fruits itself. Results: During this research, 65 of 272 human samples (23.9%) were infected with non-typhoid Salmonella. Conclusions: During this study, the method using citrus and citrus extracts was accepted for the detection of Salmonella. This study shows that with citrus and citrus extract, detection of Salmonella is possible using only DHL media. Results suggest that infectious rate of non-typhoid Salmonella was high.

  20. Evaluation of natural colorants and their application on citrus fruit as alternatives to citrus red II

    Science.gov (United States)

    The poor peel color of some varieties of oranges and the hybrids, especially for early season fruits, is caused by the subtropical climate of Florida, and has resulted in the use of a red dye on the peel to improve fruit appearance and marketability. Citrus Red II (CR2), the commercial citrus color ...

  1. Dietary citrus pulp reduces lipid oxidation in lamb meat

    OpenAIRE

    Inserra, L.; Priolo, A.; L. Biondi; Lanza, M.; Bognanno, M.; Gravador, R.; Luciano, G.

    2014-01-01

    This study investigated the effect of replacing cereal concentrateswith high levels of dried citrus pulp in the diet on lamb meat oxidative stability. Over 56 days, lambs were fed a barley-based concentrate (Control) or concentrates inwhich 24% and 35% dried citrus pulpwere included to partially replace barley (Citrus 24% and Citrus 35%, respectively). Meat was aged under vacuum for 4 days and subsequently stored aerobically at 4 °C. The Control diet increased the redness, yellowness and satu...

  2. Whitefly Pest Species (Homoptera: Aleyrodidae) on Citrus Trees

    OpenAIRE

    Katja Žanić; Sonja Kačić; Miro Katalinić

    2000-01-01

    Today, the Citrus whitefly, Dialeurodes citri (Ashmead), is a very important pest on all Citrus species throughout the citrus growing areas in Croatia. It causes direct damage by sucking the plant juice from the leaves. Furthermore, immatures excrete honeydew that stimulates sooy mold. The presence of sooty mold on contaminated leaves interferes with the photosynthesis of plants. Citrus fruits coated by sooty mold lose its market value. Because Dialeurodes citri is poorly known in Croatia, th...

  3. 防治果园周边柑橘木虱控制黄龙病效果研究%Study on control effectiveness of Huanglongbing based on eradication of Asian Citrus Psyllid Diaphorina citri Kuwayama surrounding citrus orchard

    Institute of Scientific and Technical Information of China (English)

    毛润乾; 吴东; 何勇; 陈世伟; 贤家旭; 郑基焕

    2013-01-01

    In new citrus orchards,virus-free citrus seedling were planted,the Asian citrus psyllid Diaphorina citri was regularly monitored and controlled during the new shoot sprouting period,especially in the early summer shoot period and early autumn shoot period.Meanwhile,the host plants of citrus psyllid surrounding the citrus orchard were surveyed,and the citrus psyllid on these host plants were eradicated by regularly sprayed chemical pesticides in late February,early May,late August and late November each year.The results show that,the psyllid and Huanglongbing in citrus orchard were effectively controlled.The Asian citrus psyllid populations in citrus orchard were very low,the largest number of adults was 2.25 per ha,and Huanglongbing was decreased gradually as well after the practice of this management,from 8‰ in 2008 to 0.1‰ in 2012.%在新种柑橘园中栽种柑橘无毒苗,定期监测和防治果园内柑橘木虱Diaphorina citri Kuwayama,防治时期为各新梢萌芽期,重点防治期为早夏梢期和早秋梢期;与此同时,调查柑橘园周围柑橘木虱寄主植物,每年2月下旬、5月上旬、8月下旬和11月下旬定期喷药,清除柑橘园周围寄主植物上的柑橘木虱.结果表明,果园内柑橘木虱和黄龙病均得到有效的控制,果园内柑橘木虱种群数量控制在很低的水平,最高为2.25头/公顷,最低为θ;黄龙病发病率也很低,2008年为8‰,实施该技术后,发病率逐年下降,2012年降低到0.1‰.

  4. Current Situation of Citrus Huanglongbing in Guangdong, P. R. China

    Science.gov (United States)

    Guangdong Province is an important citrus production region in China. Citrus Huanglongbing (HLB, yellow shoot disease) was observed in Guangdong probably in the late 1800’s and the disease was first studied there. Since the 1990’s, citrus production in Guangdong has gradually shifted from the coasta...

  5. Intercropping of citrus and guava trees for management of Huanglongbing

    Science.gov (United States)

    Recent studies conducted in Viet Nam by Vietnamese, Japanese and Australian scientists indicate that interplanting citrus with guava negated infestations of Asian citrus psyllid and consequently huanglongbing, a serious disease caused by a bacterium vectored by the psyllid. Young citrus interplanted...

  6. Trailers transporting oranges to processing plants move Asian citrus psyllids

    Science.gov (United States)

    Huanglongbing (citrus greening) is one of the most serious of citrus diseases. Movement of the disease occurs as a result of natural vector-borne infection and by movement of plant material. We demonstrate here that Diaphorina citri Kuwayama (vector of citrus greening pathogens) can be transported i...

  7. Characterizing the citrus variety Carrizo genome through 454 shotgun sequencing

    Science.gov (United States)

    Citrus production is of global importance both in economic impact and significance to nutrition. The number of natural citrus species appears extremely limited. The genome size is small (haploid approximately 367 Mb), arranged on 18 chromosomes. The citrus variety Carrizo, generated by a ‘Washingt...

  8. Evaluation of natural colorants and their application on citrus fruit

    Science.gov (United States)

    Warm temperatures can often result in poor peel color of some citrus varieties, especially early in the harvest season. Under these conditions, Florida oranges, temples, tangelos, and K-Early citrus fruit are allowed to be treated with Citrus Red No.2 (CR2) to help produce a more acceptable peel col...

  9. Three distinct suppressors of RNA silencing encoded by a 20-kb viral RNA genome

    OpenAIRE

    R. Lu; Folimonov, A; Shintaku, M; Li, W. X.; Falk, B W; Dawson, W O; Ding, S W

    2004-01-01

    Viral infection in both plant and invertebrate hosts requires a virus-encoded function to block the RNA silencing antiviral defense. Here, we report the identification and characterization of three distinct suppressors of RNA silencing encoded by the approximate to20-kb plus-strand RNA genome of citrus tristeza virus (CTV). When introduced by genetic crosses into plants carrying a silencing transgene, both p20 and p23, but not coat protein (CP), restored expression of the transgene. Although ...

  10. INDAGINE GEOGRAFICA A CAMPIONE PER LO STUDIO DEI MUTAMENTI TERRITORIALI CAUSATI DALLA DIFFUSIONE DEL CTV IN UN’AREA AGRUMICOLA SICILIANA ATTRAVERSO LA GEO-LOCALIZZAZIONE DEI FOCOLAI D'INFEZIONE

    OpenAIRE

    De Cristofaro, Bernardina; Incognito, Antonella; Petino, Gianni

    2012-01-01

    Il virus della “tristeza” (Citrus Tristeza Virus CTV) ha già arrecato ingenti danni e continua a diffondersi in tutto l’areale agrumicolo italiano, in particolare in Sicilia e Calabria. Per poter tentare di arginare questa epidemia e limitarne le conseguenze è importante avere dei validi strumenti d’indagine, anche dal punto di vista geografico-economico. Tra questi, possiamo annoverare l’elaborazione di cartografie sufficientemente dettagliate di micro areali agrumicoli che ev...

  11. Does citrus leaf miner impair hydraulics and fitness of citrus host plants?

    Science.gov (United States)

    Raimondo, Fabio; Trifilò, Patrizia; Gullo, Maria A Lo

    2013-12-01

    Gas exchange and hydraulic features were measured in leaves of three different Citrus species (Citrus aurantium L., Citrus limon L., Citrus  ×  paradisii Macfad) infested by Phyllocnistis citrella Staiton, with the aim to quantify the impact of this pest on leaf hydraulics and, ultimately, on plant fitness. Infested leaves were characterized by the presence on the leaf blade of typical snake-shaped mines and, in some cases, of a crumpled leaf blade. Light microscopy showed that leaf crumpling was induced by damage to the cuticular layer. In all three Citrus species examined: (a) the degree of infestation did not exceed 10% of the total surface area of infested plants; (b) control and infested leaves showed similar values of minimum diurnal leaf water potential, leaf hydraulic conductance and functional vein density; and (c) maximum diurnal values of stomatal conductance to water vapour, transpiration rate and photosynthetic rate (An) were similar in both control leaves and the green areas of infested leaves. A strong reduction of An was recorded only in mined leaf areas. Our data suggest that infestation with P. citrella does not cause conspicuous plant productivity reductions in young Citrus plants, at least not in the three Citrus species studied here. PMID:24319027

  12. Evaluation of natural colorants and their application on citrus fruit as alternatives to Citrus Red No. 2

    Science.gov (United States)

    Warm field temperatures can often result in poor peel color of some citrus varieties, especially early in the harvest season. Under these conditions, Florida oranges, temples, tangelos, and K-Early citrus fruit are allowed to be treated with Citrus Red No.2 (CR2) to help produce a more acceptable pe...

  13. 果树病毒载体研究进展%Progresses in Study of Virus-Based Vectors of Fruit Trees

    Institute of Scientific and Technical Information of China (English)

    周彦

    2014-01-01

    Virus-based vectors are commonplace tools for the production of proteins or induction of RNA silencing in plants. But even if the existing vectors from herbaceous plant viruses could infect fruit trees, the time for systemic infection and analysis of the expressed genes in trees generally exceeds the stability of known virus-based vectors. Now this problem has been solved by using virus-based vectors from fruit trees. Progress in studies on virus-based vectors from fruit trees was summarized. The results obtained in recent years are as following: (1) The transmission, host range, differentiation of pathogenicity, genome organization and regulation of gene expression of Citrus tristeza virus (CTV), Citrus leaf blotch virus (CLBV), Apple latent spherical virus (ALSV), Plum pox virus (PPV), Grapevine virus A (GVA) and Grapevine leafroll-associated virus (GLRaV) have been elucidated. Construction of Agrobacterium-mediated infectious cDNA clones or infectious RNA transcripts derived from the full-length cDNA clones of these fruit crops viruses. And then, a foreign open reading frame (ORF) such as green fluorescence protein (GFP) gene,β-glucuronidase gene (GUS) was inserted between coat protein (CP) gene and the adjacent gene as a reporter. The expression of the foreign gene was driven by a duplicated native CP subgenomic (sg) RNA controller element (CE) or an introduced heterologous CE of other virus. (2) Virus-based vectors from fruit trees have been used to elucidate cell-to-cell as well as long-distance movement, spatial separation, localization within the host cells, the processes of stem pitting induced by CTV in Citrus macrophylla and the mechanism of CTV superinfection exclusion. These vectors also can be used as virus induced gene silencing (VIGS) vectors to elucidate gene function. Furthermore, CTV-RNAi vector has been demonstrated to silence the endogenous genes of Diaphorina citri and Candidatus Liberibacter asiaticus. (3) From the environmental safety

  14. Progresses in Study of Virus-Based Vectors of Fruit Trees%果树病毒载体研究进展

    Institute of Scientific and Technical Information of China (English)

    周彦

    2014-01-01

    Virus-based vectors are commonplace tools for the production of proteins or induction of RNA silencing in plants. But even if the existing vectors from herbaceous plant viruses could infect fruit trees, the time for systemic infection and analysis of the expressed genes in trees generally exceeds the stability of known virus-based vectors. Now this problem has been solved by using virus-based vectors from fruit trees. Progress in studies on virus-based vectors from fruit trees was summarized. The results obtained in recent years are as following: (1) The transmission, host range, differentiation of pathogenicity, genome organization and regulation of gene expression of Citrus tristeza virus (CTV), Citrus leaf blotch virus (CLBV), Apple latent spherical virus (ALSV), Plum pox virus (PPV), Grapevine virus A (GVA) and Grapevine leafroll-associated virus (GLRaV) have been elucidated. Construction of Agrobacterium-mediated infectious cDNA clones or infectious RNA transcripts derived from the full-length cDNA clones of these fruit crops viruses. And then, a foreign open reading frame (ORF) such as green fluorescence protein (GFP) gene,β-glucuronidase gene (GUS) was inserted between coat protein (CP) gene and the adjacent gene as a reporter. The expression of the foreign gene was driven by a duplicated native CP subgenomic (sg) RNA controller element (CE) or an introduced heterologous CE of other virus. (2) Virus-based vectors from fruit trees have been used to elucidate cell-to-cell as well as long-distance movement, spatial separation, localization within the host cells, the processes of stem pitting induced by CTV in Citrus macrophylla and the mechanism of CTV superinfection exclusion. These vectors also can be used as virus induced gene silencing (VIGS) vectors to elucidate gene function. Furthermore, CTV-RNAi vector has been demonstrated to silence the endogenous genes of Diaphorina citri and Candidatus Liberibacter asiaticus. (3) From the environmental safety

  15. Differential expression of genes identified from Poncirus trifoliata tissue inoculated with CTV through EST analysis and in silico hybridization

    Directory of Open Access Journals (Sweden)

    Mariângela Cristofani-Yaly

    2007-01-01

    Full Text Available Citrus is the most important fruit crop in Brazil and Citrus tristeza virus (CTV is considered one of the most important pathogens of citrus. Most citrus species and varieties are susceptible to CTV infection. However, Poncirus trifoliata, a close relative of citrus, is resistant to the virus. In order to better understand the responses of citrus plants to the infection of CTV, we constructed expressed sequence tag (EST libraries with tissues collected from Poncirus trifoliata plants, inoculated or not with Citrus tristeza virus at 90 days after inoculation, grafted on Rangpur lime rootstocks. We generated 17,867 sequence tags from Poncirus trifoliata inoculated (8,926 reads and not (8,941 reads with a severe CTV isolate. A total of 2,782 TCs (Tentative Consensi sequences were obtained using both cDNA libraries in a single clusterization procedure. By the in silico hybridization approach, 289 TCs were identified as differentially expressed in the two libraries. A total of 121 TCs were found to be overexpressed in plants infected with CTV and were grouped in 12 primary functional categories. The majority of them were associated with metabolism and defense response. Some others were related to lignin, ethylene biosynthesis and PR proteins. In general, the differentially expressed transcripts seem to be somehow involved in secondary plant response to CTV infection.

  16. Detection of citrus canker and Huanglongbing using fluorescence imaging spectroscopy and support vector machine technique.

    Science.gov (United States)

    Wetterich, Caio Bruno; Felipe de Oliveira Neves, Ruan; Belasque, José; Marcassa, Luis Gustavo

    2016-01-10

    Citrus canker and Huanglongbing (HLB) are citrus diseases that represent a serious threat to the citrus production worldwide and may cause large economic losses. In this work, we combined fluorescence imaging spectroscopy (FIS) and a machine learning technique to discriminate between these diseases and other ordinary citrus conditions that may be present at citrus orchards, such as citrus scab and zinc deficiency. Our classification results are highly accurate when discriminating citrus canker from citrus scab (97.8%), and HLB from zinc deficiency (95%). These results show that it is possible to accurately identify citrus diseases that present similar symptoms. PMID:26835778

  17. Noninvasive maturity detection of citrus with machine vision

    Science.gov (United States)

    Ying, Yibin; Xu, Zhenggang; Fu, Xiaping; Liu, Yande

    2004-03-01

    A computer vision system was established to explore a method for citrus maturity detection. The surface color information and the ratio of total soluble solid to titratable acid (TSS/TA) were used as maturity indexes of citrus. The spectral reflectance properties with different color were measured by UV-240 ultraviolet and visible spectrophotometer. The biggest discrepancy of gray levels between citrus pixels and background pixels was in blue component image by image background segmentation. Dynamic threshold method for background segmentation had best result in blue component image. Methods for citrus image color description were studied. The citrus spectral reflectance experiments showed that green surface and saffron surface of citrus were of highest spectral reflectance at the wavelength of 700nm, the difference between them reached to maximum, about 53%, and the image acquired at this wavelength was of more color information for maturity detection. A triple-layer feed forward network was established to map citrus maturity from the hue frequency sequence by the mean of artificial neural network. After training, the network mapper was used to detect the maturity of the test sample set, which was composed of 252 Weizhang citrus with different maturity. The identification accuracy of mature citrus reached 79.1%, that of immature citrus was 63.6%, and the mean identification accuracy was 77.8%. This study suggested that it is feasible to detect citrus maturity non-invasively by using the computer vision system and hue frequency sequence method.

  18. Next generation haplotyping to decipher nuclear genomic interspecific admixture in Citrus species: analysis of chromosome 2

    OpenAIRE

    Curk, Franck; Ancillo, Gema; Garcia-Lor, Andres; Luro, François; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Navarro, Luis; Ollitrault, Patrick

    2014-01-01

    Background The most economically important Citrus species originated by natural interspecific hybridization between four ancestral taxa (Citrus reticulata, Citrus maxima, Citrus medica, and Citrus micrantha) and from limited subsequent interspecific recombination as a result of apomixis and vegetative propagation. Such reticulate evolution coupled with vegetative propagation results in mosaic genomes with large chromosome fragments from the basic taxa in frequent interspecific heterozygosity....

  19. 7 CFR 457.107 - Florida citrus fruit crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... of the following: (1) Citrus I—Early and mid-season oranges; (2) Citrus II—Late oranges juice; (3) Citrus III—Grapefruit for which freeze damage will be adjusted on a juice basis; (4) Citrus IV—Tangelos...; or (2) The following juice content, if acceptable records are not furnished: (i) Citrus I—52...

  20. Biogenic emissions from Citrus species in California

    Science.gov (United States)

    Fares, Silvano; Gentner, Drew R.; Park, Jeong-Hoo; Ormeno, Elena; Karlik, John; Goldstein, Allen H.

    2011-09-01

    Biogenic Volatile Organic Compounds (BVOC) emitted from plants are the dominant source of reduced carbon chemicals to the atmosphere and are important precursors to the photochemical production of ozone and secondary organic aerosols. Considering the extensive land used for agriculture, cultivated Citrus plantations may play an important role in the chemistry of the atmosphere especially in regions such as the Central Valley of California. Moreover, the BVOC emissions from Citrus species have not been characterized in detail and more species-specific inputs for regional models of BVOC emissions are needed. In this study, we measured the physiological parameters and emissions of the most relevant BVOC (oxygenated compounds, monoterpenes, and sesquiterpenes) for four predominant Citrus species planted in California ( Citrus sinensis var. 'Parent Navel', Citrus limon var. 'Meyer', Citrus reticulata var. 'W. Murcott' and 'Clementine'). We used two analytical techniques to measure a full range of BVOC emitted: Proton Transfer Reaction Mass Spectrometry (PTR-MS) and gas chromatography with mass spectrometry. Methanol, followed by acetone and acetaldehyde, were the dominant BVOC emitted from lemon and mandarin trees (basal emission rates up to 300 ng(C) g(DW) -1 h -1), while oxygenated monoterpenes, monoterpenes, and sesquiterpenes were the main BVOC emitted from orange trees (basal emission rates up to = 2500 ng(C) g(DW) -1 h -1). Light and temperature-dependent algorithms were better predictors of methanol, acetaldehyde, acetone, isoprene and monoterpenes for all the Citrus species. Whereas, temperature-dependent algorithms were better predictors of oxygenated monoterpenes, and sesquiterpenes. We observed that flowering increased emissions from orange trees by an order of magnitude with the bulk of BVOC emissions being comprised of monoterpenes, sesquiterpenes, and oxygenated monoterpenes. Chemical speciation of BVOC emissions show that the various classes of terpene

  1. Antimycotic Activity and Genotoxic Evaluation of Citrus sinensis and Citrus latifolia Essential Oils

    OpenAIRE

    Ruiz-Pérez, Nancy J.; González-Ávila, Marisela; Sánchez-Navarrete, Jaime; Toscano-Garibay, Julia D.; Moreno-Eutimio, Mario A.; Sandoval-Hernández, Teresa; Arriaga-Alba, Myriam

    2016-01-01

    The aim of this study was to evaluate the antifungal activity of essential oils (EOs) of Citrus sinensis (C. sinensis) and Citrus latifolia (C. latifolia) against five Candida species: Candida albicans, Candida tropicalis, Candida glabrata, Candida lusitaniae and Candida guilliermondii; and perform its genotoxic evaluation. The EOs of C. sinensis and C. latifolia were obtained from the peel by hydro-distillation. The major components determined by GC-MS were in C. sinensis, d-limonene (96%) a...

  2. Complete nucleotide sequence of an Olive latent virus 1 isolate from olive trees

    OpenAIRE

    Félix, M. Rosário; Cardoso, Joana M. S.; Varanda, Carla M.R.; Oliveira, Solange; Clara, M. Ivone E.

    2005-01-01

    Olive latent virus 1 (OLV-1) is a necrovirus belonging to the familyTombusviridae. It is a small icosahedral plant virus, which encapsidates a single stranded positivesense RNA. This virus was first isolated from symptomless olive trees in Italy [7] and afterwards in Jordan and Portugal [10, 4]. OLV-1 was also isolated from symptomatic hosts, such as citrus trees in Turkey [11] and tulips in Japan [9]. Up to now, only one complete genome sequence of an OLV-1 citrus isolate has ...

  3. Alegrias e tristezas no cotidiano de trabalho do agente comunitário de saúde: cenários de paixões e afetamentos

    Directory of Open Access Journals (Sweden)

    Heletícia Scabelo Galavote

    2013-09-01

    Full Text Available O estudo busca desvendar o processo de trabalho do agente comunitário de saúde (ACS com base na teoria das afecções de Espinosa. Considera o encontro como uma unidade de análise, e pretende compreendê-lo na sua dinâmica de produção do cuidado, analisando as afecções que se expressam por alegrias e tristezas e os seus efeitos no trabalho do ACS. Trata-se de estudo exploratório-descritivo, de caráter qualitativo, realizado na Unidade Jardim Catarina, São Gonçalo, Rio de Janeiro, Brasil. Os dados foram coletados em entrevista com dez ACS's, por meio de roteiro semiestruturado e observação etnográfica. O estudo revela um ACS múltiplo, exposto às afecções das relações que mantém, variando entre o reconhecimento e a submissão às lógicas instituídas, resultando em alegria e tristeza, aumento e redução da sua potência de agir, respectivamente.

  4. Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; SHI Xue-gen; WEI You-zhang; YANG Xiao-e; UOTI Juhani

    2006-01-01

    Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to studythe effects of compound fertilizers on their yieldsand quality. In the citrus experiment, application of compound fertilizers increased available P,K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51, 0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea.Optimal rates of compound fertilizers were recommended for both crops.

  5. Chemical composition, antioxidant and antimicrobial activities of citrus jambhiri lush and citrus reticulata blanco essential oils

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the time interval in which we can get maximum concentration of essential oil from the peels of Citrus jambhiri Lush and Citrus reticulata Blanco, to determine the composition of peel oils and to evaluate the antioxidant and antimicrobial activity of extracted oils. It was observed that in case of Citrus jambhiri Lush maximum oil yield (I %) was obtained when fruits were immature (during October). As the fruit samples got matured, the oil yield decreased. In December the oil yield decreased to 0.2 %. In case of Citrus reticulata Blanco maximum oil yield (0.189 %) was obtained during the last week of January. Chemical analysis of essential oils showed that limonene was the most abundant compound (86 %-93 %) followed by alpha terpinene (2 %-4.5 %), beta-pinene(1 0/0-2 %) and nerol (0.5 %-1.5 %). The radical scavenging and antioxidant activities of essential oils were determined by DPPH and linoleic acid test. The essential oil of Citrus jambhiri Lush inhibited the oxidation of linoleic acid by 54.98 % and that of Citrus reticulata Blanco inhibited by 49.98 %. Moreover, the essential oils also showed antimicrobial activities against the tested microorganisms. (author)

  6. Huanglongbing resistance and tolerance in citrus

    Science.gov (United States)

    Huanglongbing (HLB) is severely impacting Florida citrus. Productivity declines in many HLB-affected genotypes, often with greatly thinned canopies. Fruit size and quality are often adversely affected as the disease advances. HLB was assessed in diverse cultivars in commercial groves with high HLB-i...

  7. Assessment of Stubborn Disease Incidence in Citrus

    Science.gov (United States)

    Citrus stubborn disease, caused by Spiroplasma Citri, has occured in California for more than 90 years, however, detection methods for estimating disease incidence have not been well developed. Two 8 ha plots in Kern Co. CA were established and sampled in July and August, 2006. Different tissues o...

  8. Asian citrus psyllid - biology and seasonal ecology

    Science.gov (United States)

    The seasonal ecology of Diaphorina citri was investigated in a non-irrigated citrus grove of mature orange trees beginning January 2005 in east central Florida. No insecticides were applied during the study. Predators including lady beetles, lacewings and syrphid flies were observed during the stud...

  9. Digital PCR for detection of citrus pathogens

    Science.gov (United States)

    Citrus trees are often infected with multiple pathogens of economic importance, especially those with insect or mite vectors. Real-time/quantitative PCR (qPCR) has been used for high-throughput detection and relative quantification of pathogens; however, target reference or standards are required. I...

  10. Founder lines for improved citrus biotechnology

    Science.gov (United States)

    This article discusses the research needed to develop the RMCE strategy and molecular assays for site-specific recombinases as tools for genome manipulation. Explanation of genetic engineering used to generate transgenic citrus plants to exhibit a novel phenotype, but not to contain the recombinase...

  11. Assessment of Stubborn Disease Incidence in Citrus

    Science.gov (United States)

    Citrus stubborn disease (CSD) has been a problem in California for over 90 years, yet, methods for rapidly detecting its causal agent, Spiroplasma citri, for use in estimating disease incidence have not been optimized. Two 8 ha blocks within two commercial groves were sampled in July and August, 20...

  12. Slight Fermentation with Lactobacillus fermentium Improves the Taste (Sugar:Acid Ratio) of Citrus (Citrus reticulata cv. chachiensis) Juice.

    Science.gov (United States)

    Yu, Yuanshan; Xiao, Gengsheng; Xu, Yujuan; Wu, Jijun; Fu, Manqin; Wen, Jing

    2015-11-01

    The aim of this study was to evaluate the hypothesis that fermentation with Lactobacillus fermentium, which can metabolize citric acid, could be applied in improving the taste (sugar:acid ratio) of citrus juice. During fermentation, the strain of L. fermentium can preferentially utilize citric acid of citrus (Citrus reticulata cv. Chachiensis) juice to support the growth without the consumption of sugar. After 6 h of fermentation with L. fermentium at 30 °C, the sugar:acid ratio of citrus juice increased to 22:1 from 12:1, which resulted in that the hedonic scores of sweetness, acidity and overall acceptability of fermented-pasteurized citrus juice were higher than the unfermented-pasteurized citrus juice. Compared with unfermented-pasteurized citrus juice, the ORAC value and total amino acid showed a reduction, and no significant change (P > 0.05) in the L*, a*, b*, total soluble phenolics and ascorbic acid (Vc) content in the fermented-pasteurized citrus juice was observed as compared with unfermented-pasteurized citrus juice. Hence, slight fermentation with L. fermentium can be used for improving the taste (sugar:acid ratio) of citrus juice with the well retaining of quality. PMID:26447635

  13. Confirmation of the presence of citrus viroids in citrus orchards in Northwestern Argentina Confirmación de la presencia de viroides de citrus en quintas cítricas en el Noroeste Argentino

    Directory of Open Access Journals (Sweden)

    Julia Figueroa

    Full Text Available Citrus viroids cause two well known diseases: exocortis and cachexia. In the citrus area of Northwestern Argentina, the presence of viroids was reported in the 1960's and diagnosis was based only on visual symptoms on susceptible rootstocks. From 2004 onwards, budwood samples from citrus trees showing viroid symptoms have been collected in Tucumán, Salta and Jujuy provinces. Biological indexing has been performed using Etrog citron Arizona 861-S1 grafted on rough lemon seedlings as the indicator plant. Since 2006, molecular diagnosis has also been performed using sequential polyacrylamide gel electrophoresis (sPAGE. The presence of viroids has been confirmed for the first time in northwestern region, using both techniques. Symptoms obtained in inoculated Etrog citron vary from mild to very severe. sPAGE utilization showed that most infections consisted of mixtures of two or more viroids. All viroid isolates are kept in the virus bank at the Citrus Sanitation Center of EEAOC in Tucumán. Currently, 22 isolates from Northwestern Argentina are stored and further characterization of these viroids will be done using PCR.Los viroides de los citrus causan dos enfermedades bien conocidas en las regiones citrícolas del mundo: exocortis y caquexia. Las citas de viroides en fincas cítricas del Noroeste Argentino (NOA se remontan a 1960 y el correspondiente diagnóstico se basaba sólo en observaciones de síntomas en portainjertos susceptibles. En 2004, se comenzó con la recolección de muestras de árboles con síntomas de viroides en las provincias de Tucumán, Salta y Jujuy. Se realizó el diagnóstico biológico, usando como planta indicadora el cidro Etrog Arizona 861- S1 inoculado sobre limón rugoso. En 2006 se comenzó también con el diagnóstico molecular usando la técnica de electroforesis secuencial en geles de poliacrilamida (sPAGE, siendo esta la primera vez que se confirmó la presencia de viroides en el NOA utilizando ambas t

  14. In vitro xanthine oxidase inhibitory activity of leaves, fruits and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon

    Directory of Open Access Journals (Sweden)

    Muthiah PL

    2012-07-01

    Full Text Available Aim of the study: To evaluate the in vitro xanthine oxidase inhibitory activity of the extract of leaves, fruits and peel of Citrus aurantium, Citrus limetta and Citrus limon.   Materials and Methods: Xanthine oxidase inhibitory activity was assayed spectrophotometrically under aerobic conditions and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295nm associated with uric acid formation.   Results: Among the extracts tested, the C.limetta peel extract exhibited highest potency of xanthine oxidase inhibition (IC50 40.16±0.88μg/ml. This was followed by C.aurantium peel (IC50 51.50±2.05μg/ml, C.limon peel (IC50 64.90±1.24μg/ml, C.aurantium leaf (IC5073.50±1.26μg/ml, C.limetta leaf (IC50 74.83±2.42μg/ml, C.limon leaf (IC50 76.83±2.02μg/ml, C.limetta fruit (IC50 95.16±0.60μg/ml extracts compared with the IC50 value of standard allopurinol was 6.6μg/ml.   Conclusion: Recent findings show that the occurrence of gout is increasing worldwide, possibly due to the changes in dietary habits like intake of food rich in nucleic acids, such as meat, sea foods, etc. Xanthine oxidase inhibitors such as allopurinol is the drug of choice, however it has been observed more side effects.  An alternative to allopurinol is the use of medicinal plants, We thus began our program to look for xanthine oxidase inhibitors of phytochemical origin. In conclusion, the study suggests that the leaves and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon possess xanthine oxidase inhibitory activity that might be helpful in preventing or slowing the progress of gout and related disorders.

  15. INFLUENCE OF SALINITY ON CITRUS: A REVIEW PAPER

    Directory of Open Access Journals (Sweden)

    ADNAN Al-Yassin

    2005-04-01

    Full Text Available Due to the rapid expansion of irrigated agriculture, effi cient use of the limited water resources in arid and semi-arid regions is becoming more and more vital. However, water salinity is a major problem due to its negative infl uence on the yields of many crops. It reduces citrus trees’ growth and causes physiological disorders. Primarily salt-stress lowers net CO2 assimilation, stomatal conductance, and water potential of citrus tree leaves, in addition to accumulation of excessive concentration of Chloride or Sodium in leaves. A great deal of research indicates that citrus have the genetic potential to be salt-sensitive; however inheritance studies in citrus are scarce. In this paper the adverse of effects of salinity on physiological aspects of citrus are reviewed. The review summarizes the prevailing state of knowledge about the responses and tolerance of citrus trees to salinity.

  16. Progress on Dissecting and Controlling the Citrus Huanglongbing Complex

    OpenAIRE

    Duan, Yongping; Zhou, Lijuan; Zhang, Muqing; Benyon, Lesley; Armstrong-Vahling, Cheryl; Hoffman, Michele; Hao, Guixia; Zou, Huasong; Doud, Melissa; Ding, Fang; Morgan, Kent

    2014-01-01

    Citrus huanglongbing (HLB) is a century-old and emerging disease that impedes citrus production worldwide. ‘Candidatus Liberibacter asiaticus’ (Las) is the globally prevalent species of HLB bacteria. Here we describe our molecular characterizations of Las, and our newly-developed control methods for citrus HLB. From a genomics standpoint, we revealed Las has a significantly reduced genome (1.26Mb) and unique features adapted to its intracellular life style.  Although the genome is small, Las ...

  17. Citrus Genetic Resources Grown on the Ryukyu Islands, Japan

    OpenAIRE

    Yamamoto, Masashi; ヤマモト, マサシ; 山本, 雅史

    2014-01-01

    The Ryukyu Islands are located southwest part of Japan. Various local citrus are grown in this subtropical region. Since there are large geographical and climatic differences between the Ryukyu Islands and the main islands (Honshu, Kyushu, and Shikoku) of Japan, there are unique local citrus genetic resources on the Ryukyu Islands. Shiikuwasha (Citrus depressa) is an indigenous mandarin species in this region. This species is clearly distinguished from the mandarin grown in China and India ba...

  18. Synergy and Other Interactions between Polymethoxyflavones from Citrus Byproducts

    OpenAIRE

    Benito F. García; Ascensión Torres; Francisco A. Macías

    2015-01-01

    The citrus by-products released from citrus processing plants may contain high levels of potentially bioactive compounds such as flavonoids, which are a widely distributed group of polyphenolic compounds with health-related properties based on their antioxidant activity. In the study reported here, the potential bioactivities and antioxidant activities of extracts, fractions and compounds from citrus by-products were evaluated along with the chemical interactions of binary mixtures of compoun...

  19. Mechanisms of sexual polyploidization and inheritance in triploid citrus populations

    OpenAIRE

    CUENCA IBÁÑEZ, JOSÉ

    2013-01-01

    Citrus is the main fruit crop in the world and Spain is the 6th producer and the major exporter for the fresh fruit market. Seedlessness is one of the most important fruit quality traits for this market since consumers do not accept seedy fruits. Recovery of triploid hybrids has become an important breeding strategy to develop new seedless citrus varieties and several of them have been already released from citrus breeding programs worldwide. Despite the undisputable importance of polyploidy ...

  20. Resistance to Gas Diffusion in Internal Tissues of Citrus Fruit

    OpenAIRE

    Dirpan, Andi

    2015-01-01

    Japan is a major citrus fruit-producing country, and Ehime Prefecture is one of the main citrus fruit producing regions in Japan. As many as 20 major citrus varieties are cultivated in Ehime. To further develop postharvest technology for quality preservation such as modified atmosphere packaging (MAP) and controlled atmosphere (CA) storage, creating an optimum gas concentration around fruit and vegetables have to be precisely achieved. However, the external atmosphere of fresh products in MAP...

  1. Citrus blackfly in Florida: Eradication or bio-control?

    OpenAIRE

    Tefertiller, Kenneth R.; McKee, Vernon C.; Perry, Vernon G.

    1991-01-01

    The citrus blackfly (CBF) invaded south Florida in January 1976. It was considered by scientists to be a major threat to the Florida citrus industry located in the central part of the state. The CBF was successfully contained in a 1000 square mile tri-county quarantined area surrounding Ft. Lauderdale for several months before breaking out to an area near the commercial citrus production area. During this time federal and state research agencies were evaluating a bio-control approach involvin...

  2. Discrimination of Citrus reticulata Blanco and Citrus reticulata 'Chachi' by gas chromatograph-mass spectrometry based metabolomics approach.

    Science.gov (United States)

    Duan, Li; Guo, Long; Dou, Li-Li; Zhou, Chang-Lin; Xu, Feng-Guo; Zheng, Guo-Dong; Li, Ping; Liu, E-Hu

    2016-12-01

    Citri Reticulatae Pericarpium, mainly including the pericarp of Citrus reticulata Blanco and the pericarp of Citrus reticulata 'Chachi', has been consumed daily as food and dietary supplement for centuries. In this study, GC-MS based metabolomics was employed to compare comprehensively the volatile constituents in Citrus reticulata Blanco and Citrus reticulata 'Chachi'. Principal component analysis and orthogonal partial least squares discrimination analysis indicated that samples could be distinguished effectively from one another. Fifteen metabolites were finally identified for use as chemical markers in discrimination of Citri Reticulatae Pericarpium samples. The antimicrobial activity against Gram-negative and Gram-positive bacteria of the volatile oil from Citrus reticulata Blanco and Citrus reticulata 'Chachi' was investigated preliminarily. PMID:27374515

  3. Study of Thermotherapy against Citrus Huanglongbing in Fujian Province, China

    OpenAIRE

    Fan, Guocheng; Liu, Bo; Lie, Xiongjie; Cai, Zijian; Hu, Hanqing; Wang, Xianda; Ruan, Chuanqing; Lu, Lianming; Sequeira, Ronald; Xia, Yulu

    2014-01-01

    Huanglongbing (HLB) is a major threat to world citrus production. In this study, we investigated using a heat treatment technique for managing HLB-affected citrus trees in the field. A total of 72 5-to-8-year old mandarin citrus, Citrus reticulata Blanco, trees were used for the study. Nine trees were regarded as a replicate or a block with four replicates per treatment. A randomized complete block design was used for field experimental design. The treated trees were covered by using plastic ...

  4. Citrus Flavonoids as Regulators of Lipoprotein Metabolism and Atherosclerosis.

    Science.gov (United States)

    Mulvihill, Erin E; Burke, Amy C; Huff, Murray W

    2016-07-17

    Citrus flavonoids are polyphenolic compounds with significant biological properties. This review summarizes recent advances in understanding the ability of citrus flavonoids to modulate lipid metabolism, other metabolic parameters related to the metabolic syndrome, and atherosclerosis. Citrus flavonoids, including naringenin, hesperitin, nobiletin, and tangeretin, have emerged as potential therapeutics for the treatment of metabolic dysregulation. Epidemiological studies reveal an association between the intake of citrus flavonoid-containing foods and a decreased incidence of cardiovascular disease. Studies in cell culture and animal models, as well as a limited number of clinical studies, reveal the lipid-lowering, insulin-sensitizing, antihypertensive, and anti-inflammatory properties of citrus flavonoids. In animal models, supplementation of rodent diets with citrus flavonoids prevents hepatic steatosis, dyslipidemia, and insulin resistance primarily through inhibition of hepatic fatty acid synthesis and increased fatty acid oxidation. Citrus flavonoids blunt the inflammatory response in metabolically important tissues including liver, adipose, kidney, and the aorta. The mechanisms underlying flavonoid-induced metabolic regulation have not been completely established, although several potential targets have been identified. In mouse models, citrus flavonoids show marked suppression of atherogenesis through improved metabolic parameters as well as through direct impact on the vessel wall. Recent studies support a role for citrus flavonoids in the treatment of dyslipidemia, insulin resistance, hepatic steatosis, obesity, and atherosclerosis. Larger human studies examining dose, bioavailability, efficacy, and safety are required to promote the development of these promising therapeutic agents. PMID:27146015

  5. Physicochemical Characteristics of Citrus Seed Oils from Kerman, Iran

    OpenAIRE

    Mohammad Reazai; Issa Mohammadpourfard; Shahrokh Nazmara; Mahdi Jahanbakhsh; Leila Shiri

    2014-01-01

    Recently, there has been a great deal of attention on usage, byproducts, and wastes of the food industry. There have been many studies on the properties of citrus seeds and extracted oil from citrus grown in Kerman, Iran. The rate of oil content of citrus seeds varies between 33.4% and 41.9%. Linoleic acid (33.2% to 36.3%) is the key fatty acid found in citrus seeds oil and oleic (24.8% to 29.3%) and palmitic acids (23.5% to 29.4%) are the next main fatty acids, respectively. There are also o...

  6. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing

    OpenAIRE

    Yang, Chuanyu; Powell, Charles A.; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The res...

  7. Pseudocercospora leaf and fruit spot disease of citrus: Achievements and challenges in the citrus industry: A review

    OpenAIRE

    Mohammed Yesuf

    2013-01-01

    Citruses are the worlds’ second fruit crops by volume next to banana. It is one of the most important commodity in tropical Africa as source of foreign currency, raw material for agro-industries and source of employment. The production and productivity of citrus in tropical Africa including Ethiopia are critically threatened by a number of diseases. Among others, pseudocercospora leaf and fruit spot of citrus caused by a fungus Pseudocercospora angolensis is the most destructive disease of c...

  8. Citrus phytophthora diseases: Management challenges and successes

    OpenAIRE

    Graham, J; Feichtenberger, E.

    2015-01-01

    Phytophthora spp. are present in nearly all citrus groves in Florida and Brazil and phytophthora-induced diseases, especially foot and root rot, have the potential to cause economically important crop losses. Disease-related losses due to root rot are difficult to estimate because fibrous root damage and yield loss are not always directly proportional. Challenges from phytophthora diseases have been addressed in both countries by enacting phytosanitary requirements for production of pathogen-...

  9. Chemistry and Pharmacology of Citrus sinensis

    OpenAIRE

    Juan Manuel J. Favela-Hernández; Omar González-Santiago; Mónica A. Ramírez-Cabrera; Patricia C. Esquivel-Ferriño; María del Rayo Camacho-Corona

    2016-01-01

    Presently the search for new drugs from natural resources is of growing interest to the pharmaceutical industry. Natural products have been the source of new drugs since ancient times. Plants are a good source of secondary metabolites which have been found to have beneficial properties. The present study is a review of the chemistry and pharmacology of Citrus sinensis. This review reveals the therapeutic potential of C. sinensis as a source of natural compounds with important activities that ...

  10. Huanglongbing Resistance and Tolerance in Citrus

    OpenAIRE

    Stover, E; McCollum, G.; Driggers, R.; Duan, Y.; Shatters, Jr., R. G.; Ritenour, M.; Hall, D.G.; J. Chaparro

    2014-01-01

    Huanglongbing (HLB) is severely impacting Florida citrus. Productivity declines in many HLB-affected genotypes, often with greatly thinned canopies. Fruit size and quality are often adversely affected as the disease advances. HLB was assessed in diverse cultivars in commercial groves with high HLB-incidence. ‘Temple’ had the lowest HLB symptoms and Liberibacter (Las) titer, while ‘Murcott’ and ‘Minneola’ had the highest. The USDA Ft. Pierce, FL farm is managed to reveal genotype responses to ...

  11. Comparison of evapotranspiration rates for flatwoods and ridge citrus

    Science.gov (United States)

    Jia, X.; Swancar, A.; Jacobs, J.M.; Dukes, M.D.; Morgan, K.

    2007-01-01

    Florida citrus groves are typically grown in two regions of the state: flatwoods and ridge. The southern flatwoods citrus area has poorly drained fine textured sands with low organic matter in the shallow root zone. Ridge citrus is located in the northern ridge citrus zone and has fine to coarse textured sands with low water-holding capacity. Two commercial citrus groves, selected from each region, were studied from 15 July 2004 to 14 July 2005. The flatwoods citrus (FC) grove had a grass cover and used drainage ditches to remove excess water from the root zone. The ridge citrus (RC) grove had a bare soil surface with weeds periodically eliminated by tillage. Citrus crop evapotranspiration (ETc) rates at the two citrus groves were measured by the eddy correlation method, and components in the energy balance were also examined and compared. The study period had higher than average rainfall, and as a result, the two locations had similar annual ETc rates (1069 and 1044 mm for RC and FC, respectively). The ETc rates were 59% (RC) and 47% (FC) of the rainfall amounts during the study period. The annual reference crop evapotranspiration (ETo) rates were 1180 mm for RC and 1419 mm for FC, estimated using the standardized reference evapotranspiration equation. The citrus crop coefficients (Kc, ratio of ETc to ET o) were different between the two locations because of differences in latitude, ground cover, and rainfall amounts. The Kc values ranged from 0.70 between December and March to 1.05 between July and November for RC, and from 0.65 between November and May to 0.85 between June and October for FC. The results are consistent with other Kc values reported from field studies on citrus in both Florida and elsewhere using these and alternate methods.

  12. Essential oils of flowers of Citrus sinensis and Citrus clementina cultivated in Algarve, Portugal

    OpenAIRE

    Miguel, Maria Graça; Dandlen, S.; Figueiredo, A. C.; Barroso, J. G.; Pedro, L. G.; Duarte, Amílcar; Faísca, J

    2008-01-01

    The essential oils, isolated by hydrodistillation, from the flowers of different cultivars of Citrus sinensis (L.) Osbeck (Cs) and Citrus clementina Hort. Ex Tan. (Cc) collected at different harvesting times, were analyzed by GC and GC-MS. All the samples studied afforded yellowish oil which yields ranged from 0.05 to 0.08 % (v/w). The monoterpene fraction dominated both oils (66-91%), being the monoterpene hydrocarbons the main components of this fraction (45-69%). Sabinene (31-48%), linaloo...

  13. Movement of Diaphorina citri Kuwayama (Hemiptera: Liviidae) adults between huanglongbing-affected and healthy citrus

    Science.gov (United States)

    Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a vector transmitting the pathogen of citrus huanglongbing (HLB, also called yellow shoot disease or citrus greening disease). A typical symptom of citrus HLB is leaf yellowing. ACP adults behaved differently on HLB-affe...

  14. 21 CFR 74.302 - Citrus Red No. 2.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color...

  15. 21 CFR 172.210 - Coatings on fresh citrus fruit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Coatings on fresh citrus fruit. 172.210 Section 172.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... CONSUMPTION Coatings, Films and Related Substances § 172.210 Coatings on fresh citrus fruit. Coatings may...

  16. First steps towards rescuing Las-infected citrus germplasm

    Science.gov (United States)

    Huanglongbing (HLB) disease is having significant impact on the USDA citrus breeding program as it has shown up in a number of trees which exist only in a virtually irreplaceable collection of diverse citrus types. It is critical that we rescue HLB-free budwood from elite germplasm that is HLB-patho...

  17. Developing cryotherapy to eliminate graft-transmissible pathogens in citrus

    Science.gov (United States)

    This article summarizes research being conducted as part of a project funded by the California Citrus Research Board to develop cryotherapy (freezing buds in liquid nitrogen, and then recovering them) as a viable method for elimination of graft transmissible pathogens from Citrus. There are current...

  18. Utilization of founder lines for improved Citrus biotechnology via RMCE

    Science.gov (United States)

    On October 1st 2011 the CRB chose to fund a unique research project, the development of citrus cultivars specifically for genetic engineering (GE). The objective of this research was to develop GE citrus ‘Founder Lines’ containing DNA sequences that will allow the precise insertion of genes for de...

  19. 7 CFR 319.56-41 - Citrus from Peru.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Peru. 319.56-41 Section 319.56-41... from Peru. Grapefruit (Citrus paradisi), limes (C. aurantiifolia), mandarins or tangerines (C... States from Peru under the following conditions: (a) The fruit must be accompanied by a permit issued...

  20. Insights regarding sensory evaluation of bitterness development in citrus juice

    Science.gov (United States)

    Delayed bitterness is a well-known phenomenon in citrus juice and has a negative impact on juice quality. Bitterness results when the tasteless limonoic acid A-ring lactone (LARL) in juice is converted to the bitter compound limonin after juicing. Citrus varieties that produce juice that becomes bit...

  1. Microwave extraction of citrus peel to release pectin

    Science.gov (United States)

    After removal of soluble sugars and other compounds by washing, citrus peel is largely composed of pectin, cellulose and hemicellulose. In order to utilize the greatest amount of citrus peel product, it would appear reasonable that one or all three of these polysaccharides be converted to a useful m...

  2. Heartland Virus

    Science.gov (United States)

    ... Vector-Borne Diseases (DVBD) NCEZID Share Compartir Heartland virus On this Page What is Heartland virus? How ... Do I Need to Know? What is Heartland virus? Heartland virus belongs to a family of viruses ...

  3. Coccinellid predators do not track populations of the Asian citrus phyllid (Diaphorina citri) in citrus in Puerto Rico

    Science.gov (United States)

    Yellow sticky cards were used to survey populations of Diaphorina citri, the vector of Huanglongbing, the most devastating bacterial disease of citrus worldwide. The numbers of coccinellids, potential predators of Diaphorina citri, were also surveyed. Citrus surveyed included a variety of species (V...

  4. Metabolic Interplay between the Asian citrus psyllid and its Profftella symbiont: An Achilles’ heel of the citrus greening insect vector

    Science.gov (United States)

    ‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including ‘Candidatus Profftella armatura’, are likely to impact tra...

  5. A comparison of traps and stem tap sampling for monitoring adult Asian citrus psyllid (Hemiptera: Psyllidae), in citrus

    Science.gov (United States)

    Studies were conducted at two different field sites to compare yellow sticky card traps, blue sticky card traps, Multi-Lure traps, and CC traps (red, blue, black, white, yellow, and green) for monitoring adult Asian citrus psyllid, Diaphorina citri Kuwayama,in citrus. The Multi-Lure trap is useful f...

  6. Incidence of the Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae) and its parasitoid Tamarixia radiata (Hymenoptera: Eulophidae) in Florida citrus

    Science.gov (United States)

    Diaphorina citri Kuwayama, vectors the bacterium Candidatus Liberibacter asiaticus, one of the causal organisms of the devastating citrus disease “huanglongbing” or citrus greening. In the United States, D. citri was first discovered in Florida, in 1998. Tamarixia radiata Waterston, was imported fro...

  7. Seasonal Movement Patterns and Long-Range Dispersal of Asian Citrus Psyllid in Florida Citrus.

    Science.gov (United States)

    Lewis-Rosenblum, Hannah; Martini, Xavier; Tiwari, Siddharth; Stelinski, Lukasz L

    2015-02-01

    The Asian citrus psyllid, Diaphorina citri Kuwayama, is the vector of the bacterial pathogen, Candidatus Liberibacter asiaticus, which is the causal agent of huanglongbing (HLB) in the United States. Both short-range and long-range dispersal of D. citri adults affect the spread of HLB; however, little is known about the long-range dispersal capabilities of D. citri in the field or the seasonality of flight behavior. In the present study, an in situ protein marking technique was used to determine the dispersal of D. citri by trapping marked adults under natural field conditions. D. citri movement from abandoned citrus groves to adjacent managed citrus groves was greatest during the spring and summer months and decreased significantly during the colder months (September-March). D. citri were able to traverse potential geographic barriers such as roads and fallow fields. In an experiment conducted to determine long-range dispersal capacity in the absence of severe weather events, D. citri were able to disperse at least 2 km within 12 d. Wind direction was not correlated with the number of marked psyllids captured, indicating substantial flight capability by D. citri. Finally, the number of marked psyllids captured increased with the density of emerging young leaves on surrounding trees. The results confirm that abandoned citrus groves in Florida serve as reservoirs for D. citri, which can disperse across long distances despite geographical barriers. PMID:26470097

  8. Comparison of FTIR spectra between huanglongbing (citrus greening) and other citrus maladies

    Science.gov (United States)

    Fourier Transform Infrared Spectroscopy has the ability to quickly identify the presence of specific carbohydrates in plant materials. The presence of the disease Huanglongbing(HLB) in the leaves of infected citrus plants has a distinctive spectrum that can be used to distinguish an infected plant ...

  9. Screening of citrus and its close relatives for tolerance to huanglongbing

    OpenAIRE

    Ramadugu, C.; Keremane, M.; Stover, E; Halbert, S.; Duan, Y. P.; Lee, R. F.

    2014-01-01

    Huanglongbing (HLB), a devastating disease of citrus, has become a serious problem for the citrus industries in Brazil and Florida, and both the disease and its psyllid vector, Diaphorina citri continue to spread to other citrus growing regions. Host resistance or tolerance to the pathogen would be extremely valuable to the citrus industry. A field trial was established in Fort Pierce, Florida where HLB has become endemic to assess the HLB tolerance level of different cultivars of citrus and ...

  10. Targeting excessive free radicals with peels and juices of citrus fruits: grapefruit, lemon, lime and orange

    OpenAIRE

    Guimarães, Rafaela; Barros, Lillian; João C. M. Barreira; Sousa, Maria João; Carvalho, Ana Maria; Ferreira, Isabel C. F. R.

    2010-01-01

    A comparative study between the antioxidant properties of peel (flavedo and albedo) and juice of some commercially grown citrus fruit (Rutaceae), grapefruit (Citrus paradisi), lemon (Citrus limon), lime (Citrus aurantiifolia) and sweet orange (Citrus sinensis) was performed. Different in vitro assays were applied to the volatile and polar fractions of peels and to crude and polar fraction of juices: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power...

  11. Chemical control of the Asian citrus psyllid and of huanglongbing disease in citrus.

    Science.gov (United States)

    Boina, Dhana Raj; Bloomquist, Jeffrey R

    2015-06-01

    By 2014, huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus-growing regions of the world, including the United States, with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus-growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB-free seedlings and early detection and removal of symptomatic and asymptomatic trees, has been very effective in managing ACP. Area-wide management of ACP by application of insecticides at low volume in large areas of citrus cultivation has been shown to be effective in managing HLB and reducing management costs. As insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB-infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area-wide management programs with due consideration to the insecticide resistance problem. PMID:25491482

  12. Chemistry and Pharmacology of Citrus sinensis.

    Science.gov (United States)

    Favela-Hernández, Juan Manuel J; González-Santiago, Omar; Ramírez-Cabrera, Mónica A; Esquivel-Ferriño, Patricia C; Camacho-Corona, María del Rayo

    2016-01-01

    Presently the search for new drugs from natural resources is of growing interest to the pharmaceutical industry. Natural products have been the source of new drugs since ancient times. Plants are a good source of secondary metabolites which have been found to have beneficial properties. The present study is a review of the chemistry and pharmacology of Citrus sinensis. This review reveals the therapeutic potential of C. sinensis as a source of natural compounds with important activities that are beneficial for human health that could be used to develop new drugs. PMID:27072414

  13. Dicty_cDB: SHA505 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available AXSIERLSPLTFVKQXXAXPLSVISGGDKTNNXLKP Translated Amino Acid sequence (All Frames) Frame A: iiyyiiiffsin*yffvf...e RPCI-11-73P16, genomic survey sequence. 46 0.91 1 AF506028 |AF506028.1 Poncirus trifoliata citrus tristeza virus resista...adoxa starch phospho... 94 4e-18 CR954204_212( CR954204 |pid:none) Ostreococcus tauri ...strain OTTH05... 91 4e-17 AY098895_1( AY098895 |pid:none) Citrus hybrid cultivar star...icylww**nqqxfkt Frame B: lfiillffsq*inislyfflyyslkkkk*kknqxkkk--- ---EVNKVKKIIHDGKFTPDTXWARVLTAIKEDTFGPHEQFQ

  14. Dicty_cDB: SHL257 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available SPLTFVKQTFXFPLSVIXG GDKTNNXLKPKQ Translated Amino Acid sequence (All Frames) Frame A: iyyiiiffsin*yffvflfilf.... 597 e-166 1 AF506028 |AF506028.1 Poncirus trifoliata citrus tristeza virus resistance gene locus, complete...8895_1( AY098895 |pid:none) Citrus hybrid cultivar starch phos... 63 3e-09 CR954204_212( CR954204 |pid:none) Ostreococcus tauri...*xmextrssssfk*xxxxfissxxiwfxk*yqxyfn*kiixfnfc*tnfxfsiicylw w**nqqxfktktn Frame B: fiillffsq*inislyfflyyslkkk...icant alignments: (bits) Value EU165056_1( EU165056 |pid:none) Cyanophora paradoxa starch phospho.

  15. Antimutagenicity and Anticancer Effects of Citrus Medica Fruit Juice

    Directory of Open Access Journals (Sweden)

    Majd Ahmad

    2009-10-01

    Full Text Available Currently cancer is considered as one of the main factors of mortality globally. Many chemicals in our environment can cause genetic mutations and are potentially responsible for millions of cancer-related deaths. Nowadays the scientists are looking for food materials which can potenthially prevent the cancer occurrence. The purpose of this research is to examine antimutagenicity and anticancer effect of Citrus Medica fruit juice.In present study human astrocytoma cancer cells were cultured in DMEM (Gibco,supplemented with 10% fetal calf serum,peniciline-streptomycin,L-glutamine and incubated at 37 ºC for 2 days.In addition cancer cell line were treated by half-ripe and ripe Citrus Medica fruit juice and cellular vital capacity was determined by MTT. The Citrus Medica fruit juice was subsequenthy evaluated in terms of antimutagenicity and anticancer properties by a standard reverse mutation assay (Ames Test. This was performed with histidine auxotroph strain of Salmonella typhimurium (TA100 .Thus, it requires histidine from a foreign supply to ensure its growth.The aforementioned strain gives rise to reverted colonies when expose to carcinogen substance (Sodium Azide. During MTT, human astrocytoma cell line revealed to have a meaningful cell death when compared with controls (P<0.01. In Ames Test the fruit juice prevented the reverted mutations and the hindrance percent of half-ripe Citrus Medica was 71.7% and ripe Citrus Medica was 34.4% in antimutagenicity test and this value in anticancer test was 83.3% and 50% in half-ripe Citrus Medica and ripe Citrus Medica respectively.This is the first study that have revealed antimutagenicity and anticancer effect of Citrus Medica fruit juice and the effects were higher in half-ripe Citrus Medica in comparison to the riprned one.

  16. The Asian Citrus Psyllid Genome (Diaphorina citri, Hemiptera)

    OpenAIRE

    Hunter, Wayne B.; Reese, Justin; International Psyllid Genome Consortium, The

    2014-01-01

    The Asian citrus psyllid, Diaphorina citri (Hemiptera), is an important pest of citrus because it vectors bacteria responsible for huanglongbing, which is one of the most serious diseases of citrus worldwide.  The first genome draft of D. citri (DIACI_1.0) was completed in 2011 (ARS, Ft. Pierce, FL), however, gaps in the assembly prompted additional sequencing using the long run PacBio system at the Los Alamos National Lab, NM.  The revised draft genome (DIACI_1.1) was assembled using the new...

  17. Penicillium digitatum metabolites on synthetic media and citrus fruits

    DEFF Research Database (Denmark)

    Ariza, M.R.; Larsen, Thomas Ostenfeld; Petersen, Bent O.; Duus, Jens Øllgaard; Barrero, A.F.

    2002-01-01

    Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YES).Cultivation of fungal cultures on solid medium allowed the isolation of two novel tryptoquivaline-like metabolites, tryptoquialanine A (1) and tryptoquialanine B (2), also biosynthesized on citrus...... fruits.Their structural elucidation is described on the basis of their spectroscopic data, including those from 2D NMR experiments. The analysis of the biomass sterols led to the identification of 8-12. Fungal infection on the natural substrates induced the release of citrus monoterpenes together with...

  18. Genome-wide comparative analysis reveals possible common ancestors of nucleotide-binding sites domain containing genes in hybrid Citrus sinensis genome and original Citrus clementina genome

    Science.gov (United States)

    We identified and re-annotated candidate disease resistance (R) genes with nucleotide-binding sites (NBS) domain from a Citrus clementina genome and two complete Citrus sinensis genome sequences (one from the USA and one from China). We found similar numbers of NBS genes from three citrus genomes, r...

  19. Phenology of Asian citrus psyllid (Hemiptera: Liviidae) and associated parasitoids on two species of Citrus, kinnow mandarin and sweet orange, in Punjab Pakistan.

    Science.gov (United States)

    Khan, Shouket Zaman; Arif, Muhammad Jalal; Hoddle, Christina D; Hoddle, Mark S

    2014-10-01

    The population phenology of Asian citrus psyllid, Diaphorina citri Kuwayama, was monitored weekly for 110 wk on two species of Citrus, kinnow mandarin and sweet orange, at two different research sites in Faisalabad, Punjab Pakistan. Citrus flush growth patterns were monitored and natural enemy surveys were conducted weekly. Flush patterns were similar for kinnow and sweet orange. However, flush on sweet orange was consistently more heavily infested with Asian citrus psyllid than kinnow flush; densities of Asian citrus psyllid eggs, nymphs, and adults were higher on sweet orange when compared with kinnow. When measured in terms of mean cumulative insect or Asian citrus psyllid days, eggs, nymphs, and adults were significantly higher on sweet orange than kinnow. Two parasitoids were recorded attacking Asian citrus psyllid nymphs, Tamarixia radiata (Waterston) and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal). The dominant parasitoid species attacking Asian citrus psyllid nymphs on kinnow and sweet orange was T. radiata, with parasitism averaging 26%. D. aligarhensis parasitism averaged 17%. Generalist predators such as coccinellids and chrysopids were collected infrequently and were likely not important natural enemies at these study sites. Immature spiders, in particular, salticids and yellow sac spiders, were common and may be important predators of all Asian citrus psyllid life stages. Low year round Asian citrus psyllid densities on kinnow and possibly high summer temperatures, may, in part, contribute to the success of this cultivar in Punjab where Candidatus Liberibacter asiaticus, the putative causative agent of huanglongbing, a debilitating citrus disease, is widespread and vectored by Asian citrus psyllid. PMID:25198345

  20. The genetic diversity of Citrus dwarfing viroid populations is mainly dependent on the infected host species.

    Science.gov (United States)

    Tessitori, Matilde; Rizza, Serena; Reina, Antonella; Causarano, Giovanni; Di Serio, Francesco

    2013-03-01

    As with viruses, viroids infect their hosts as polymorphic populations of variants. Identifying possible sources of genetic variability is significant in the case of the species Citrus dwarfing viroid (CDVd) which has been proposed as a dwarfing agent for high-density citrus plantings. Here, a natural CDVd isolate (CMC) was used as an inoculum source for long-term (25 years) and short-term (1 year) bioassays in different citrus host species. Characterization of progenies indicated that the genetic stability of CDVd populations was high in certain hosts (trifoliate orange, Troyer citrange, Etrog citron, Navelina sweet orange), which preserve viroid populations similar to the original CMC isolate even after 25 years. By contrast, CDVd variant populations in Interdonato lemon and Volkamer lemon were completely different to those in the inoculated sources, highlighting how influential the host is on the genetic variability of CDVd populations. Implications for risk assessment of CDVd as a dwarfing agent are discussed. The GenBank/EMBL/DDBJ accession numbers for the complete sequences of the Citrus dwarfing viroid variants are JF970266.1 forH2-2, JF970267.1 for H2-7, EU938647.1 for H6-2, EU938651.1 forH6-10, JF970268.1 for H10-7, EU938652.1 for H14-13, EU938653.1for H14-14, JF970269.1 for H14-16, EU938648.1 for H15-9,EU938649.1 for H16-2, JF970265.1 for H16-9, EU938654.1 forH16-13, EU938650.1 for H20-3, JF970270.1 for H20-7, EU938641.1for PR-1, EU938642.1 for PR-3, EU938643.1 for PR-7, EU938644.1for CR-1, EU938639.1 for VR-4, JF12070.1 for VR-15, JF812069.1LS-4, EU938640.1 for LS-10 and JF970264.1 for LS-11. PMID:23152366

  1. Effect of beneficial bacterial isolates from citrus roots in Florida on citrus Huanglongbing disease development

    OpenAIRE

    Li, J.; Trivedi, P.; Wang, N.

    2014-01-01

    Huanglongbing (HLB) is the most devastating disease of citrus in Florida. HLB is caused by the phloem-inhabiting bacterium ‘Candidatus Liberibacter asiaticus’ (Las), which is transmitted by psyllid vector Diaphorina citri. The current management strategies of HLB are to control psyllids and eradicate infected plants. However, these management practices have not been able to stop the spreading of HLB (Duan et al. 2009). Alternative approaches are needed to control HLB. In previous studies we i...

  2. Soil Applied Systemic Insecticides for Control of Asian citrus psyllid in Newly Planted Citrus Trees

    OpenAIRE

    Stansly, Phil; Kostyk, Barry

    2014-01-01

    Orchard renewal is a special challenge where HLB is endemic.  Young trees are especially susceptible to the disease and continuously attractive to the psyllid vector due to frequent flushing.  Heavy reliance is placed on systemic insecticides to protect young trees.  However, all presently labeled for citrus are neonicotinoids (IRAC Group 4a) making resistance likely and the long term viability of this strategy questionable.  Rotation partners are needed to forestall selection for resistance....

  3. Anti-inflammatory effects of Citrus sinensis L., Citrus paradisi L. and their combinations.

    Science.gov (United States)

    Khan, Rafeeq Alam; Mallick, Neelam; Feroz, Zeeshan

    2016-05-01

    Citrus bioflavonoids embrace a wide group of phenolic compounds effecting the production and scavenging of reactive oxygen species and the processes relating free radical-mediated injury. Keeping in view of the antioxidant and anti-inflammatory properties of Citrus sinensis and Citrus paradisi, present study was undertaken to explore the effects of C. sinensis (orange juice) and C. paradisi (grapefruit juice) at three different doses alone and their two combinations with the objective to examine the effects of these compounds in an experimental model of rat colitis induced by trinitrobenzenesulphonic acid (TNBS). Hence biochemical parameters e.g. myeloperoxidase, alkaline phosphatase, C-reactive protein (CRP) and glutathione were assessed. Data entry and analysis was accomplished by Statistical Package for the Social Sciences version 17 and was presented as mean ± S.E.M with 95% confidence interval. Present result shows that these juices, mainly C. paradisi, may be efficacious for the management of inflammatory bowel disease. In acute colitis model, C. paradise encouraged a decrease in the extension of the lesion escorted by a decrease in the occurrence of diarrhea and reinstatement of the glutathione content. Related effects were produced by the administration of C. sinensis, which also prevented the myeloperoxidase and alkaline phosphatase actions in acute intestinal inflammatory process. The effect of the citrus juices on the inflammatory process may be associated to their antioxidant and anti-inflammatory properties, as revealed in present investigation. The favorable effects exerted were demonstrated both by histological and biochemical changes and were related with a progress in the colonic oxidative status. PMID:27166529

  4. The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms.

    Science.gov (United States)

    Oliveira, Sarah Almeida Coelho; Zambrana, Jéssica Rabelo Mina; Iorio, Fernanda Bispo Reis Di; Pereira, Cristiane Aparecida; Jorge, Antonio Olavo Cardoso

    2014-01-01

    The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs) compared to 0.2% chlorhexidine (CHX) and 1% sodium hypochlorite (NaOCl) on multispecies biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL) and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10): C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride NaCl)]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. , the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05). C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7%) was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases. PMID:25000605

  5. The antimicrobial effects of Citrus limonum and Citrus aurantium essential oils on multi-species biofilms

    Directory of Open Access Journals (Sweden)

    Sarah Almeida Coelho Oliveira

    2014-01-01

    Full Text Available The aim of this study was to evaluate the effects of Citrus limonum and Citrus aurantium essential oils (EOs compared to 0.2% chlorhexidine (CHX and 1% sodium hypochlorite (NaOCl on multi-species biofilms formed by Candida albicans, Enterococcus faecalis and Escherichia coli. The biofilms were grown in acrylic disks immersed in broth, inoculated with microbial suspension (106 cells/mL and incubated at 37°C / 48 h. After the biofilms were formed, they were exposed for 5 minutes to the solutions (n = 10: C. aurantium EO, C. limonum EO, 0.2% CHX, 1% NaOCl or sterile saline solution [0.9% sodium chloride (NaCl]. Next, the discs were placed in sterile 0.9% NaCl and sonicated to disperse the biofilms. Tenfold serial dilutions were performed and the aliquots were seeded onto selective agar and incubated at 37°C / 48 h. Next, the number of colony-forming units per milliliter was counted and analyzed statistically (Tukey test, p ≤ 0.05. C. aurantium EO and NaOCl inhibited the growth of all microorganisms in multi-species biofilms. C. limonum EO promoted a 100% reduction of C. albicans and E. coli, and 49.3% of E. faecalis. CHX was less effective against C. albicans and E. coli, yielding a reduction of 68.8% and 86.7%, respectively. However, the reduction of E. faecalis using CHX (81.7% was greater than that obtained using C. limonum EO. Both Citrus limonum and Citrus aurantium EOs are effective in controlling multi-species biofilms; the microbial reductions achieved by EOs were not only similar to those of NaOCl, but even higher than those achieved by CHX, in some cases.

  6. Ulcer protective potential of standardized hesperidin, a citrus flavonoid isolated from Citrus sinensis

    OpenAIRE

    Papiya Bigoniya; Kailash Singh

    2014-01-01

    Free radicals play an important role in stomach ulcer formation. The present investigation validates the anti ulcer activity of hesperidin, isolated from Citrus sinensis (L.) Osbeck, Rutaceae, through the assessment of its antioxidant potential over stomach mucosal tissue by histological examination. Hesperidin was isolated from the dried peel of C. sinensis, and authenticated by TLC, IR and HPLC. The anti-ulcerogenic potential of this fruit was assessed using indomethacin and hypothermic res...

  7. Penicillium digitatum metabolites on synthetic media and citrus fruits

    DEFF Research Database (Denmark)

    Ariza, M.R.; Larsen, Thomas Ostenfeld; Petersen, Bent O.;

    2002-01-01

    fruits.Their structural elucidation is described on the basis of their spectroscopic data, including those from 2D NMR experiments. The analysis of the biomass sterols led to the identification of 8-12. Fungal infection on the natural substrates induced the release of citrus monoterpenes together with......Penicillium digitatum has been cultured on citrus fruits and yeast extract sucrose agar media (YES).Cultivation of fungal cultures on solid medium allowed the isolation of two novel tryptoquivaline-like metabolites, tryptoquialanine A (1) and tryptoquialanine B (2), also biosynthesized on citrus...... fungal volatiles. The host-pathogen interaction in nature and the possible biological role of citrus volatiles are also discussed...

  8. Effect of NaCl on citrus cultivars

    OpenAIRE

    Cámara-Zapata, José; García-Sánchez, F.; Martinez, V.; Nieves, M. (Marcos); Cerdá, A.

    2004-01-01

    We investigated the effects of salinity stress-relief on the growth and mineral composition (leaf and root) of one-year-old seedlings of Cleopatra mandarin (Citrus reticulata Blanco) and Sour orange (Citrus aurantium [L]). Salinization reduced plant dry weight more in Sour orange than in Cleopatra mandarin plants, although there was no correlation between Cl and Na concentration in leaves and shoot fresh weight reduction. We observed that regulation of Na+ and Cl- uptake and transport from ro...

  9. Breeding, genetic and genomic of citrus for disease resistance

    OpenAIRE

    Machado, Marcos A; Mariângela Cristofani-Yaly; Marinês Bastianel

    2011-01-01

    Although the citriculture is one of the most important economic activities in Brazil, it is based on a small number of varieties. This fact has contributed for the vulnerability of the culture regarding the phytosanitary problems. A higher number of varieties/genotypes with potential for commercial growing, either for the industry or fresh market, has been one of the main objectives of citrus breeding programs. The genetic breeding of citrus has improved, in the last decades, due to the possi...

  10. Larvicidal Activity of Citrus Limonoids against Aedes Albopictus Larvae

    OpenAIRE

    Hazrat Bilal; Waseem Akram; Soaib Ali-Hassan

    2012-01-01

    Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecti­cides therefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to sup­press mosquito larval population.Methods: World Health Organization recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars test...

  11. Citrus bergamia essential oil: from basic research to clinical application

    OpenAIRE

    Michele eNavarra; Carmen eMannucci; Marisa eDelbò; Gioacchino eCalapai

    2015-01-01

    Citrus bergamia Risso et Poiteau, also known as Bergamot, is a plant belonging to the Rutaceae family, defined as a hybrid of bitter orange and lemon. It is an endemic plant of the Calabria region (Italy). Bergamot fruit is primarily used for the extraction of its essential oil (bergamot essential oil: BEO), employed in perfume, cosmetics, food and confections.The aim of this review was to collect recent data from the literature on Citrus bergamia essential oil and, through a critical analysi...

  12. Citrus Fruit Intake Substantially Reduces the Risk of Esophageal Cancer

    OpenAIRE

    Wang, Anqiang; Zhu, Chengpei; Fu, Lilan; Wan, Xueshuai; Yang, Xiaobo; Zhang, Haohai; Miao, Ruoyu; He, Lian; Sang, Xinting; ZHAO, HAITAO

    2015-01-01

    Abstract Many epidemiologic studies indicate a potential association between fruit and vegetable intake and various cancers. The purpose of this meta-analysis is to investigate the association between citrus fruit intake and esophageal cancer risk. The authors conducted a comprehensive search on PubMed, EMBASE, and the Cochrane Library from inception until July 2014. Studies presenting information about citrus intake and esophageal cancer were analyzed. The authors extracted the categories of...

  13. Phenolic Compounds Characterization and Biological Activities of Citrus aurantium Bloom

    OpenAIRE

    Armin Oskoueian; Jaafar, Hawa Z. E.; Rudi Hendra; Ehsan Oskoueian; Ehsan Karimi

    2012-01-01

    Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and fla...

  14. Micro-irrigation systems, automation and fertigation in citrus

    OpenAIRE

    Parameshwar Sidramappa Shirgure

    2012-01-01

    Citrus is number one group of fruits grown in more than 140 countries in the world. Micro-irrigation systems and fertigation management is one of the main concerns of the modem citrus fruit production irrespective of availability of soil, water and fertilizer resources. A variety of recommendations have emerged world over on irrigation systems and fertigation based on soil and leaf analysis of the nutrients, evapo-transpiration and water use pattern. The research review of literature has reve...

  15. Evaluation of Thermotherapy against Huanglongbing (Citrus Greening) under Laboratory Conditions

    OpenAIRE

    Fan, Guocheng; Xia, Yulu; Lin, Xiongjie; Cai, Zijian; Hu, Hanqing; Wang, Xianda; Ruan, Chuanqing; Lu, Lianming; Sequeira, Ronald; Liu, Bo

    2014-01-01

    Huanglongbing (HLB, citrus greening) is the most destructive disease of citrus. The disease is associated with “Candidatus Liberibacter asiaticus”. Few management options are available, besides preventive measures such as the removal of affected plants, planting disease-free stock and maintaining vector-free production in quarantine areas. In this study, we assessed the efficacy of thermotherapy against the disease under controled laboratory conditions. A total of sixty, 2-year old graft-infe...

  16. Effects of Citrus sinensis juice on blood pressure

    OpenAIRE

    Asgary, Sedigheh; keshvari, Mahtab

    2013-01-01

    BACKGROUND Citrus sinensis juice (CSJ) is a rich source of dietary flavonoids which reduce the risk of adverse cardiovascular events. This study aimed to examine the effects of four-week intake of natural and commercial orange (Citrus sinensis) juice on blood pressure in healthy volunteers. METHODS In this single-blind randomized crossover study, 22 healthy subjects (age: 18-59 years old) were included and randomly divided into two groups of 11. Group A consumed commercial CSJ during the firs...

  17. Essential Oils from the Malaysian Citrus (Rutaceae) Medicinal Plants

    OpenAIRE

    Siti Nur Atiqah Md Othman; Muhammad Aizam Hassan; Lutfun Nahar; Norazah Basar; Shajarahtunnur Jamil; Satyajit D. Sarker

    2016-01-01

    This review article appraises the extraction methods, compositions, and bioactivities of the essential oils from the Citrus species (family: Rutaceae) endemic to Malaysia including C. aurantifolia, C. grandis, C. hystrix, and C. microcarpa. Generally, the fresh peels and leaves of the Citrus species were extracted using different methods such as steam and water distillation, Likens-Nikerson extraction, solvent extraction, and headspace solid-phase micro-extraction (HS-SPME). Most of the Citru...

  18. Characterization of Citrus Rootstock Responses to Tylenchulus semipenetrans (Cobb)

    OpenAIRE

    Kaplan, David T.

    1981-01-01

    Citrus rootstocks which significantly limited the reproduction of Tylenchulus semipenetrans (Cobb) "Citrus" and "Poncirus" biotypes responded to infection by producing a hypersensitive-type response in the root hypodermis, wound periderm and/or cavities in the root cortex, and/or abnormal vacuoles in nurse cell cytoplasm. Rootstocks which limited nematode reproduction also had significantly fewer nematodes in the rhizoplane within 8 d of inoculation than did rootstocks which did not limit rep...

  19. Study Antimicrobial Activity of Lemon (Citrus lemon L.) Peel Extract

    OpenAIRE

    Maruti J. Dhanavade; Chidamber B. Jalkute; Jai S. Ghosh; Kailash D. Sonawane

    2011-01-01

    The main objective of the study is extraction, identification of antimicrobial compounds and demonstration of antimicrobial activity of lemon (Citrus lemon L.) peel against bacteria. As microorganism are becoming resistant to present day antibiotics, our study focuses on antimicrobial activity and future prophylactic potential of the lemon peel. Biologically active compounds present in the medicinal plants have always been of great interest to scientists. The peel of citrus fruits is a rich s...

  20. The Lebanese Citrus Aurantium: A Promising Future in Medicinal Phytochemistry

    OpenAIRE

    Salim Makhoul; Youssef Bakkour; Hanna El-Nakat; Fawaz El Omar

    2012-01-01

    The West Bekaa region of Lebanon is mostly an agricultural land where traditional herbal medicine is a common practice. Many medicinal applications are especially attributed to the Citrus aurantium plant mainly used in the food and drink industry. In this work, the essential oil of Citrus aurantium is studied in an attempt to find an explanation for the different medical applications of this plant extract which is widely known among locals. Using Gas Chromatography coupled to Mass Spectrometr...

  1. Citrus growers vary in their adoption of biological control

    OpenAIRE

    Grogan, Kelly A.; Goodhue, Rachael E

    2012-01-01

    In a spring 2010 survey, we investigated the characteristics that influenced whether California growers controlled major citrus pests with beneficial insects. We also performed statistical analysis of growers' reliance on Aphytus melinus, a predatory wasp, to control California red scale. The survey results suggest that growers with greater citrus acreage and more education are more likely to use biological control. Marketing outlets, ethnicity and primary information sources also influenced ...

  2. Can Florida’s citrus industry be saved while preserving the environment? An economic analysis for the bio-control of the Asian Citrus Psyllid

    OpenAIRE

    Alvarez, Sergio; Solis, Daniel; Thomas, Michael

    2015-01-01

    The Asian citrus psyllid (ACP) is the insect vector of a fatal disease for citrus known as Huanglongbing (HLB) or citrus greening disease. HLB has been responsible for significant economic losses in Asia and Africa with crop losses between 30 to 100% in many production areas. In 1998, HLB was first detected in Florida and by 2005 this pest had spread to most commercial citrus groves in the State, threatening the sustainability of Florida’s Citrus industry. Since no cure for this disease is ye...

  3. In vitro organogenesis in some citrus species

    Directory of Open Access Journals (Sweden)

    Evandro Henrique Schinor

    2011-06-01

    Full Text Available In vitro organogenesis of Citrus was studied for the genotypes Citrus sinensis cv. 'Natal', C. limonia, C. volkameriana, and C. aurantium, with the use of epicotyl segments-derived explants, cultured in MT salts and vitamins medium supplemented with different concentrations of 6-benzylaminopurine (BAP - 0.0; 0.5; 1.0; 1.5 or 2.0 mg L-1. For the recalcitrant genotypes C. limonia and C. aurantium the in vitro organogenesis was also studied with internodal segments-derived explants, cultured in MT salts and vitamins medium supplemented with 0; 0.5; 1.0; 2.0, or 4.0 mg L-1 of BAP. The efficiency of culture medium supplementation with the combination of BAP (0.0; 1.0, or 2.0 mg L-1 and NAA (1-naphthaleneacetic acid - 0.0; 0.3, or 0.5 mg L-1 in the development of adventitious shoots was evaluated for C. aurantium. Culture medium supplementation with BAP is not essential for the adventitious shoots development in the four genotypes studied when epicotyl segments-derived explants are used. In general, culture media supplementation with BAP decreased the percentage of responsive explants excepted for C. sinensis cv. 'Natal' and C. limonia when the concentrations of 1.5 and 2.0 mg/L were used. The presence of cytokinin, in concentrations up to 2 mg/L, stimulated the in vitro organogenesis when internodal segments-derived explants were used for C. limonia and C. aurantium. For C. aurantium no adventitious shoots developed in explants (internodal segments cultured in basal culture medium, without BAP supplementation. Although no statistic differences could be detected, culture media supplementation with the combination of BAP and NAA favored the development of adventitious shoots in C. aurantium. The best concentration of NAA varied according to BAP concentration. The results presented herein, show that Citrus in vitro organogenesis depends on the interaction of culture medium composition, explant differentiation level, and genotype.

  4. Physicochemical Characteristics of Citrus Seed Oils from Kerman, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Reazai

    2014-01-01

    Full Text Available Recently, there has been a great deal of attention on usage, byproducts, and wastes of the food industry. There have been many studies on the properties of citrus seeds and extracted oil from citrus grown in Kerman, Iran. The rate of oil content of citrus seeds varies between 33.4% and 41.9%. Linoleic acid (33.2% to 36.3% is the key fatty acid found in citrus seeds oil and oleic (24.8% to 29.3% and palmitic acids (23.5% to 29.4% are the next main fatty acids, respectively. There are also other acids found at trivial rates such as stearic, palmitoleic, and linolenic. With variation between 0.54 meg/kg and 0.77 mgq/kg in peroxide values of citrus seed oils, acidity value of the oil varies between 0.44% and 0.72%. The results of the study showed that citrus seeds under study (orange and sour lemon grown in Kerman province and the extracted oil have the potential of being used as the source of edible oil.

  5. Pathogen infection drives patterns of nutrient resorption in citrus plants.

    Science.gov (United States)

    Cao, Jirong; Cheng, Chunzhen; Yang, Junjie; Wang, Qibing

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen 'Candidatus Liberibacter asiaticus' grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of 'Ca. L. asiaticus' infection on nitrogen (N) and phosphorus (P) concentrations and resorption in different citrus species (i.e. Citrus reticulata, Citrus limon and Citrus maxima). HLB-pathogen infection had distinctive impacts on nutrient resorption in different species. P resorption efficiency substantially decreased in infected C. reticulata plants relative to the healthy plants in summer, which may account for the marked decrease in the average fruit yield. P resorption was more efficient in infected C. limon plants than in the healthy plants. However, for C. maxima plants, HLB had no significant effects on N:P ratio in live leaves and resorption efficiency as well as on fruit yield. Keeping efficient internal nutrient cycling can be a strategy of citrus species being tolerant to HLB. PMID:26419510

  6. Physicochemical characteristics of citrus seed oils from kerman, iran.

    Science.gov (United States)

    Reazai, Mohammad; Mohammadpourfard, Issa; Nazmara, Shahrokh; Jahanbakhsh, Mahdi; Shiri, Leila

    2014-01-01

    Recently, there has been a great deal of attention on usage, byproducts, and wastes of the food industry. There have been many studies on the properties of citrus seeds and extracted oil from citrus grown in Kerman, Iran. The rate of oil content of citrus seeds varies between 33.4% and 41.9%. Linoleic acid (33.2% to 36.3%) is the key fatty acid found in citrus seeds oil and oleic (24.8% to 29.3%) and palmitic acids (23.5% to 29.4%) are the next main fatty acids, respectively. There are also other acids found at trivial rates such as stearic, palmitoleic, and linolenic. With variation between 0.54 meg/kg and 0.77 mgq/kg in peroxide values of citrus seed oils, acidity value of the oil varies between 0.44% and 0.72%. The results of the study showed that citrus seeds under study (orange and sour lemon grown in Kerman province) and the extracted oil have the potential of being used as the source of edible oil. PMID:25136460

  7. Embryogenic calli induction from nucellar tissue of Citrus cultivars

    Directory of Open Access Journals (Sweden)

    Mendes-da-Glória Fernanda Januzzi

    1999-01-01

    Full Text Available Nucellar tissues of seven Citrus varieties were introduced onto three growth media to produce embryogenic callus. The media tested were: EME [MT, modified, with the addition of malt extract (500 mg.L-1]; 1/2-EME [half concentration of MT macronutrients + half concentration of BH3 macronutrients + 500 mg.L-1 malt extract + 1.55 g.L-1 of glutamine]; and EBA [EME + 0.44 muM 6-benzyladenine + 0.04 muM 2,4 D]. Soft friable calli were obtained from 'Cravo' and 'Ponkan' mandarins (Citrus reticulata, Blanco, 'Murcott' tangor (Citrus reticulata Blanco x Citrus sinensis L. Osbeck, 'Serra d'água' and 'Valencia' sweet oranges (Citrus sinensis, L. Osbeck 120 days after callus induction. 'Natal' and 'Pera' sweet oranges (Citrus sinensis, L. Osbeck produced hard non-friable calli in this period. EME and 1/2-EME media had the best results for 'Cravo' mandarin, 'Ponkan' mandarin and 'Serra d'água' sweet orange, whereas EBA was the best media composition to induce soft friable calli on 'Murcott' tangor and 'Valencia' sweet orange. Friable callus cultures of 'Cravo' and 'Ponkan' mandarins, and 'Murcott' tangor yielded high quality protoplasts after isolation. Abbreviations: a.c. - activated charcoal; BA - 6-benzyladenine; IAA - indole-acetic acid; 2,4-D - 2,4-diclorophenoxyacetic acid; MT - Murashige & Tucker basal medium.

  8. An RNA-Seq-based reference transcriptome for Citrus.

    Science.gov (United States)

    Terol, Javier; Tadeo, Francisco; Ventimilla, Daniel; Talon, Manuel

    2016-03-01

    Previous RNA-Seq studies in citrus have been focused on physiological processes relevant to fruit quality and productivity of the major species, especially sweet orange. Less attention has been paid to vegetative or reproductive tissues, while most Citrus species have never been analysed. In this work, we characterized the transcriptome of vegetative and reproductive tissues from 12 Citrus species from all main phylogenetic groups. Our aims were to acquire a complete view of the citrus transcriptome landscape, to improve previous functional annotations and to obtain genetic markers associated with genes of agronomic interest. 28 samples were used for RNA-Seq analysis, obtained from 12 Citrus species: C. medica, C. aurantifolia, C. limon, C. bergamia, C. clementina, C. deliciosa, C. reshni, C. maxima, C. paradisi, C. aurantium, C. sinensis and Poncirus trifoliata. Four different organs were analysed: root, phloem, leaf and flower. A total of 3421 million Illumina reads were produced and mapped against the reference C. clementina genome sequence. Transcript discovery pipeline revealed 3326 new genes, the number of genes with alternative splicing was increased to 19,739, and a total of 73,797 transcripts were identified. Differential expression studies between the four tissues showed that gene expression is overall related to the physiological function of the specific organs above any other variable. Variants discovery analysis revealed the presence of indels and SNPs in genes associated with fruit quality and productivity. Pivotal pathways in citrus such as those of flavonoids, flavonols, ethylene and auxin were also analysed in detail. PMID:26261026

  9. Preliminary evaluation on citrus demostrative plantation of health management in Fujian province%对福建省柑桔健康栽培示范园的初步评估

    Institute of Scientific and Technical Information of China (English)

    柯冲

    2001-01-01

    In 1980's, citrus demonstrative plantations of health management(called virus-free mother tree plantations ) were established in five counties in Fujian province. From the point of view of health management, the following requirements were carried out strictly: new citrus plantation was settled in isolated area far from the diseased one; the free-virus nursery seedling was used for planting material; Huanglongbing, virus diseases and their vectors were examined periodically by monitoring technique; elimination of diseased plants and prevention of insect vectors were carried out in time and management of soil, fertilizer and water was kept in good manner. The comparison of citrus demonstrative plantation of health management with control plantation in general management show that the citrus plants in former plantation grow strong and their shoots push in time, the quality of citrus fruit was superfine and quantity was great, and the economic effect of the production has prolonged for more than 5 years. The observation and survey made through out the years of 1982-1999 show that the occurrence of citrus Huanglongbing and virus diseases were completely dependent to the invasion of their insect vectors to citrus demonstrative plantations.%80年代,福建省在5个地区建立柑桔示范园(曾称为无病母本园)。按照健康栽培的观点严格实施,在隔离的地区建园,种植无病毒的苗木,对黄龙病、病毒病及其虫媒定期检测,及时铲除病株和防治虫媒,加强土壤、肥、水的管理措施。这样的柑桔健康栽培示范园,与对照柑桔园相比,前者的植株生长强壮而抽梢整齐,结果优质而高产,经济效益延长5a以上。在1982~1999年间,对示范园的观察与调研中发现,黄龙病和病毒病的发生,完全取决于能否阻止其虫媒的侵入。

  10. Generating Asian citrus Psyllid Diaphorina citri Kuwayama (Homoptera: Psyllidae) with twisting wings to prevent the spread of citrus greening disease

    OpenAIRE

    El-Shesheny, I.; Harjeri, S.; Gowda, S.; Killiny, N.

    2014-01-01

    Huanglongbing (HLB) is seriously threatening and causing considerable economic losses to the citrus groves. Its Management depends critically on the control of the Asian citrus Psyllid (ACP), the vector of the cause of HLB, Candidatus Liberibacter asiaticus bacteria (CLas). Silencing genes by RNA interference (RNAi) is a promising technique to control pests. In this study, the abnormal disk wing (awd) has been selected from the available psyllid annotated genome. It has been known that awd ge...

  11. Molecular Interactions between the Citrus Bacterial Pathogen Candidatus Liberbacter asiaticus and Its Insect Vector the Asian Citrus Psyllid Diaphorina citri

    OpenAIRE

    Wang, Linling; Killiny, Nabil

    2014-01-01

    Huanglongbing (HLB), the most serious disease of citrus, is attributed in the United States to Candidatus Liberibacter asiaticus (CLas), a gram-negative, phloem-restricted α-proteobacterium transmitted by the Asian citrus psyllid (Diaphorina citri). Despite the fact that the psyllid is well recognized as the vector of CLas, to the best of our knowledge, little research has so far been conducted on molecular interactions between CLas and the psyllid. Many gram-negative bacterial pathogens have...

  12. Morphological, molecular and virulence characterization of three Lencanicillium species infecting Asian citrus psyllids in Huangyan citrus groves.

    Science.gov (United States)

    Lu, Lianming; Cheng, Baoping; Du, Danchao; Hu, Xiurong; Peng, Aitian; Pu, Zhanxu; Zhang, Xiaoya; Huang, Zhendong; Chen, Guoqing

    2015-02-01

    Citrus greening or Huanglongbing (HLB) is caused by the infection of Candidatus Liberibacter spp. in citrus plants. Since Asian citrus psyllid is the primary vector of this bacterial pathogen, the spread of HLB can be mitigated by suppressing Asian citrus psyllid populations in citrus groves using entomopathogens. To expand the current data on entomopathogens infecting Asian citrus psyllids, we isolated and characterized three different entomopathogens. Strains ZJLSP07, ZJLA08, and ZJLP09 infected the Asian citrus psyllid, Diaphorina citri Kuwayama, in Huangyan citrus groves. Based on molecular and morphological analyses, two were identified as Lecanicillium attenuatum and Lecanicillium psalliotae, and the third was recognized as an unidentified species of the genus, Lecanicillium. The corrected mortalities caused by strains ZJLSP07, ZJLA08 were 100% at 7days post-inoculation, while by ZJLP09 complete mortality occurred at 6days after inoculation, with 1.0×10(8)conidia/ml at 25°C and a relative humidity of 90% in the laboratory. Under the same condition, the corrected mortalities caused by strains ZJLSP07, ZJLA08 and ZJLP09 were 100%, 92.55% and 100%, respectively at 9days post-inoculation in the greenhouse. Our findings also revealed that these fungal strains infected D. citri using hyphae that penetrated deep into the insect tissues. Further, all three strains secreted the enzymes proteinases, chitinases and lipases with a potential to destroy insect tissues. Interestingly, strain ZJLP09 had an earlier invasion time and the highest levels of enzyme activities when compared to the other two strains. These findings have expanded the existing pool of entomopathogenic fungi that infect D. citri and can be potentially used for the management of D. citri populations. PMID:25593036

  13. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing

    Science.gov (United States)

    Yang, Chuanyu; Powell, Charles A.; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

  14. The Distribution of Coumarins and Furanocoumarins in Citrus Species Closely Matches Citrus Phylogeny and Reflects the Organization of Biosynthetic Pathways

    Science.gov (United States)

    Dugrand-Judek, Audray; Olry, Alexandre; Hehn, Alain; Costantino, Gilles; Ollitrault, Patrick; Froelicher, Yann; Bourgaud, Frédéric

    2015-01-01

    Citrus plants are able to produce defense compounds such as coumarins and furanocoumarins to cope with herbivorous insects and pathogens. In humans, these chemical compounds are strong photosensitizers and can interact with medications, leading to the “grapefruit juice effect”. Removing coumarins and furanocoumarins from food and cosmetics imply additional costs and might alter product quality. Thus, the selection of Citrus cultivars displaying low coumarin and furanocoumarin contents constitutes a valuable alternative. In this study, we performed ultra-performance liquid chromatography coupled with mass spectrometry analyses to determine the contents of these compounds within the peel and the pulp of 61 Citrus species representative of the genetic diversity all Citrus. Generally, Citrus peel contains larger diversity and higher concentrations of coumarin/furanocoumarin than the pulp of the same fruits. According to the chemotypes found in the peel, Citrus species can be separated into 4 groups that correspond to the 4 ancestral taxa (pummelos, mandarins, citrons and papedas) and extended with their respective secondary species descendants. Three of the 4 ancestral taxa (pummelos, citrons and papedas) synthesize high amounts of these compounds, whereas mandarins appear practically devoid of them. Additionally, all ancestral taxa and their hybrids are logically organized according to the coumarin and furanocoumarin pathways described in the literature. This organization allows hypotheses to be drawn regarding the biosynthetic origin of compounds for which the biogenesis remains unresolved. Determining coumarin and furanocoumarin contents is also helpful for hypothesizing the origin of Citrus species for which the phylogeny is presently not firmly established. Finally, this work also notes favorable hybridization schemes that will lead to low coumarin and furanocoumarin contents, and we propose to select mandarins and Ichang papeda as Citrus varieties for use in

  15. Living on the Edges: Spatial Niche Occupation of Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), in Citrus Groves

    OpenAIRE

    Sétamou, Mamoudou; Bartels, David W.

    2015-01-01

    The spatial niche occupation of the Asian citrus psyllid, Diaphorina citri Kuwayama, 1908, was evaluated to determine its field colonization and food resource exploitation strategies in citrus groves. Mature grapefruit and sweet orange groves were surveyed as part of an area-wide program in 2009–2010 to determine D. citri population densities and between-tree distribution. In both cultivars, significantly more psyllids were found on perimeter trees throughout the study period suggesting a str...

  16. Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles’ Heel of the Citrus Greening Insect Vector

    OpenAIRE

    Ramsey, John S; Johnson, Richard S.; Hoki, Jason S.; Kruse, Angela; Mahoney, Jaclyn; Hilf, Mark E.; Hunter, Wayne B.; Hall, David G.; Schroeder, Frank C.; MacCoss, Michael J.; Cilia, Michelle

    2015-01-01

    ‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including ‘Candidatus Profftella armatura’, are likely to impact transmission of CLas. We used quantitative mass spectrometry to compare the proteomes of CLas(+) and CLas(-) populations of D. citri, and found that proteins involved in polyketide biosynthesis by the ...

  17. The Distribution of Coumarins and Furanocoumarins in Citrus Species Closely Matches Citrus Phylogeny and Reflects the Organization of Biosynthetic Pathways

    OpenAIRE

    Dugrand-Judek, Audray; Olry, Alexandre; Hehn, Alain; Costantino, Gilles; Ollitrault, Patrick; Froelicher, Yann; Bourgaud, Frederic

    2015-01-01

    Citrus plants are able to produce defense compounds such as coumarins and furanocoumarins to cope with herbivorous insects and pathogens. In humans, these chemical compounds are strong photosensitizers and can interact with medications, leading to the "grapefruit juice effect". Removing coumarins and furanocoumarins from food and cosmetics imply additional costs and might alter product quality. Thus, the selection of Citrus cultivars displaying low coumarin and furanocoumarin contents constit...

  18. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing.

    Directory of Open Access Journals (Sweden)

    Chuanyu Yang

    Full Text Available Huanglongbing (HLB is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las, resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm compared to those of Brij 35 (4.34 mm and Amp solution (2.83 mm alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB.

  19. Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing.

    Science.gov (United States)

    Yang, Chuanyu; Powell, Charles A; Duan, Yongping; Shatters, Robert; Zhang, Muqing

    2015-01-01

    Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

  20. Pharmacognostical evaluation of Citrus jambhiri Lush. fruit

    Directory of Open Access Journals (Sweden)

    Swapnil Y Chaudhari

    2014-01-01

    Full Text Available Background: Citrus jambhiri Lush., commonly known as Jambīra Nimbū in Sanskrit is medium to large indigenous tree with spreading habit, less spiny than lemon and belonging to the family Rutaceae. In Ayurveda, it is used in many pharmaceutical procedures of purification (Śodhana, calcination (Māraṇa etc., Though it is an important plant, till date, no pharmacognostical reports have been available on its fruit. Materials and Methods: Study of fruit and its powder, histochemical tests and preliminary physicochemical investigations were done. Results and Conclusion: Results showed prismatic crystals of calcium oxalate, aerenchyma cells, oil globules, pitted vessels, scalariform vessels, juicy sac, etc., Preliminary physicochemical analysis revealed loss on drying (1.1%, ash value (1.4%, alcohol soluble extract (28.6%, and water soluble extract (53.3%. These observations can be of use in future studies.

  1. Isolation, characterization and modification of citrus pectins

    Directory of Open Access Journals (Sweden)

    MARIA KRATCHANOVA

    2012-01-01

    Full Text Available Orange and lemon peels were used for obtaining pectic polysaccharides. Citrus peels were previously treated with 96% ethanol, and the obtained alcohol-insoluble solids (AIS were subjected to a sequential extraction with hot distilled water and hot 0.5% HCl. Water- and acid-extracted orange (WEOP and AEOP and lemon (WELP and AELP pectins were obtained. Acid extraction gave higher yields of pectin than water extraction and lemon peels were richer in pectin. Comparative investigations were carried out with chromatographically purified commercial citrus pectin (CPCP. Chemical and physicochemical characterization of all pectins was accomplished. It was found that pectins were similar in anhydrouronic acid content (AUАC, 69-81%, but differed in their degree of methylesterification (DM, 55-81%. Generally water-extracted pectins were with higher DM. Both orange pectins were with higher DM and degree of acetylation (DA, 2%, in comparison with the corresponding lemon pectins. Water-extracted pectins were with higher degree of feruloylation (DF, 0.12-0.34%. To our knowledge this is the first report on the estimation of ester-linked ferulic acid in orange and lemon peel pectins. Pectic polysaccharides differed in molecular weight and homogeneity. WELP was with the highest molecular weight and homogeneity. The pectins contained D-galacturonic and D-glucuronic acids, L-arabinose, D-galactose, L-fucose, L-rhamnose and D-xylose. All investigated pectins showed immunostimulating activity by complement activation in the classical pathway at 1.25 and 2.5 mg/mL. Pectic polysaccharides were modified with endopolygalacturonase. Enzyme-modified CPCP and WEOP had higher anti-complementary activity than the corresponding initial pectins.

  2. Citrus peel extract incorporated ice cubes to protect the quality of common pandora: Fish storage in ice with citrus.

    Science.gov (United States)

    Yerlikaya, Pinar; Ucak, Ilknur; Gumus, Bahar; Gokoglu, Nalan

    2015-12-01

    The objective of this study was to investigate the effects of ice with albedo and flavedo fragments of Citrus (Grapefruit (Citrus paradisi) and Bitter orange (Citrus aurantium L.)) extracts on the quality of common pandora (Pagellus erythrinus). Concentrated citrus extracts were diluted with distilled water (1/100 w/v) before making of ice. The ice cubes were spread on each layer of fishes and stored at 0 °C for 15 days. The pH value showed a regular increase in all samples. TVB-N levels of bitter orange treatment groups were recorded lower than the other groups reaching to 25.11 ± 0.02 mg/100 g at the end of the storage. The TMA-N values of bitter orange treatment groups were lower than that of control and grapefruit treatment groups. In terms of TBARS value, alteration was observed in the control samples and this value significantly (p citrus extracts treatment groups at the end of storage since their antioxidant capacity. The oxidation was suppressed in citrus extracts treatment groups, especially in bitter orange flavedo treatment. The results showed the bitter orange albedo and bitter orange flavedo extracts in combination with ice storage have more effectiveness in controlling the biochemical indices in common pandora. PMID:26604414

  3. Young citrus leaves decrease dispersal distance of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

    Science.gov (United States)

    To manage citrus Huanglongbing, understanding factors that affect dispersal behavior of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is required to answer questions related to disease epidemiology and to improve management tactics. Currently, little is known about cues medi...

  4. Characterization of an ATP/ADP translocase in the citrus huanglongbing bacterium, Candidatus Liberibacter

    Science.gov (United States)

    Citrus huanglongbing (HLB), a disease currently threatening the citrus industry worldwide, has been associated with three different species of Alphaproteobacteria known as Candidatus Liberibacter. A complete genome sequence was recently obtained via metagenomics for Ca. L. asiaticus (Las), the prom...

  5. Antimicrobial Activity and Phytochemical Analysis of Citrus Fruit Peels -Utilization of Fruit Waste

    Directory of Open Access Journals (Sweden)

    K. Ashok kumar

    2011-06-01

    Full Text Available Antibacterial activity of five different solvent extracts(ethyl acetate, acetone, ethanol, petroleum ether and water prepared by soxhlet extractor from two citrus fruit peel (Citrus sinensis and Citrus limon were screened against five pathogenic bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli , Klebsiella pneumonia and Salmonella typhi. The highest antibacterial potentiality was exhibited by the acetone peel extract of Citrus sinensis followed by the ethyl acetate peel extract of Citrus limon. The peel extract of Citrus sinensis and Citrus limon can be considered to be as equally potent as the antibiotics, such as metacillin and penicillin. MICs were tested at concentrations ranging from 50-6.25 mg/ml as wells as their MBCs. The phytochemical analysis of the citrus peel extracts showed the presence of flavonoids, saponins, steroids, terpenoids, tannins and alkaloids

  6. Conceptualización, factores asociados y estrategias de autorregulación de la tristeza en niños y niñas de 10 años

    Directory of Open Access Journals (Sweden)

    Romina Izzedin Bouquet

    2009-01-01

    Full Text Available El objetivo de la presente investigación fue establecer las diferencias o semejanzas en el concepto de tristeza, los factores asociados que la producen y las estrategias de autorregulación de esta emoción en niños y niñas de 10 años. Se utilizó una metodología cualitativa a partir de una entrevista estructurada y de entrevistas de grupo focal, para lo cual se procedió con una muestra de 40 niños y niñas de instituciones educativas públicas y privadas seleccionados mediante muestreo intencional. No se identificaron diferencias en el concepto de tristeza en niños y niñas ya que ambos dan cuenta de la emoción, el sentimiento y el dolor para conceptualizar esta emoción. Sin embargo, se pudo ver que las conceptualizaciones de la tristeza que los participantes reproducen provienen del sentido común, lo cual demuestra que las representaciones que estos niños y niñas han construido sobre esta emoción tendrían un componente social muy marcado. Con respecto a los factores asociados, se destacan los contextos familiar y escolar, principalmente los malos tratos, peleas y muertes en la familia, los problemas de bullying y el bajo rendimiento académico. Finalmente, con relación a las estrategias de autorregulación, se encontraron diferencias en las estrategias conductuales: los niños utilizan más el aislamiento y las niñas la búsqueda de apoyo.

  7. Sequencing of diverse mandarin, pummelo and orange genomes reveals complex history of admixture during citrus domestication

    OpenAIRE

    Wu, G. Albert; Prochnik, Simon; Jenkins, Jerry; Salse, Jerome; Hellsten, Uffe; Murat, Florent; Perrier, Xavier; Ruiz, Manuel; Scalabrin, Simone; Terol, Javier; Takita, Marco Aurelio; Labadie, Karine; Poulain, Julie; Couloux, Arnaud; Jabbari, Kamel

    2014-01-01

    Cultivated citrus are selections from, or hybrids of, wild progenitor species whose identities and contributions to citrus domestication remain controversial. Here we sequence and compare citrus genomes-a high-quality reference haploid clementine genome and mandarin, pummelo, sweet-orange and sour-orange genomes- and show that cultivated types derive from two progenitor species. Although cultivated pummelos represent selections from one progenitor species, Citrus maxima, cultivated mandarins ...

  8. Genome Similarity Implies that Citrus-Parasitic Burrowing Nematodes do not Represent a Unique Species

    OpenAIRE

    Kaplan, D. T.; Opperman, C. H.

    1997-01-01

    Burrowing nematodes from Central America, Dominican Republic, Florida, Guadeloupe, Hawaii, and Puerto Rico were characterized for their ability to parasitize citrus, but citrus parasites were found only in Florida. Sequence tag sites originally amplified from a citrus-parasitic burrowing nematode were polymorphic among 37 burrowing nematode isolates and were not correlated with citrus parasitism, nematode isolate collection site, or amplification of a 2.4-kb sequence tag site (DK#1). Results ...

  9. Odorants for Surveillance and Control of the Asian Citrus Psyllid (Diaphorina citri)

    OpenAIRE

    Coutinho-Abreu, Iliano V; Forster, Lisa; Guda, Tom; Ray, Anandasankar

    2014-01-01

    Background The Asian Citrus Psyllid (ACP), Diaphorina citri, can transmit the bacterium Candidatus Liberibacter while feeding on citrus flush shoots. This bacterium causes Huanglongbing (HLB), a major disease of citrus cultivation worldwide necessitating the development of new tools for ACP surveillance and control. The olfactory system of ACP is sensitive to variety of odorants released by citrus plants and offers an opportunity to develop new attractants and repellents. Results In this stud...

  10. Effect of limonene on anaerobic digestion of citrus waste and pretreatments for its improvement

    OpenAIRE

    RUIZ FUERTES, BEGOÑA

    2015-01-01

    [EN] Anaerobic digestion is a sustainable and technically sound way to valorise citrus waste if the inhibitory effect of the citrus essential oil (CEO) is controlled. Several strategies have been proposed to overcome these difficulties: keeping the organic loading rate (OLR) in low values to avoid excess dosage of inhibitor, supplementing the citrus waste with nutrient and buffering solutions or pre-treating the citrus waste in order to reduce the CEO concentration, either by recovery or by d...

  11. Integrated pest management in citrus orchards in Antalya (1995-1999)

    OpenAIRE

    Özkan, A.; Akteke, Ş.A.; Kaplan, M.; Gürol, M.; Eray, N.; Dalka, Y.; UYSAL, H.; Aytekin, H.; Akyel, E.; Çelik, G.; ARSLAN, M.; Tuncel, H.

    2008-01-01

    This study relating to integrated pest management citrus orchards consisting Central, Kumluca, Finike and Alanya counties of Antalya has been carried out in 8 orchards in 2124 trees during 1995-1999. The citrus mealybug has been found as the main pest and controlled biologically by releasing Leptomastix dactylopii as parasitoid and Cryptolaemus montrouzieri as predator. Citrus whitefly, Citrus red mite and Carob moth have been found as the secondary pests. Mineral oils and specific aca...

  12. The use of kaolin to control Ceratitis capitata in organic citrus groves.

    OpenAIRE

    LO VERDE, G; Caleca, V; LO VERDE, 
V

    2011-01-01

    The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera Tephritidae), is the key pest in some organically managed citrus orchards in Sicily. The effectiveness of processed kaolin (Surround WP) for control of C. capitata damage was tested in field trials carried out in 2003-2004 on two early ripening citrus species: satsuma (Citrus unshiu Markow.) and clementine (Citrus clementina Hort. ex Tan.). Although the number of males captured in trimedlure baited traps was high in both yea...

  13. Temperature Studies with the Asian Citrus Psyllid, Diaphorina citri: Cold Hardiness and Temperature Thresholds for Oviposition

    OpenAIRE

    Hall, David G.; Wenninger, Erik J.; Hentz, Matthew G.

    2011-01-01

    This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was d...

  14. Characterization of the RNA Interference Response in the Asian Citrus Psyllid

    OpenAIRE

    Shaffer, Lindsay; Shatters, Jr., R. G.; Powell, C.; Cave, R.; Borovsky, D.

    2014-01-01

    The Asian citrus psyllid (ACP), Diaphorina citri, is a major pest of citrus since it is the only known vector of ‘Candidatus Liberibactor’ species, the bacterium associated with citrus greening disease.  Since control of the psyllid is the only effective defense so far against citrus greening, and heavy reliance upon pesticides is not sustainable, an RNA interference (RNAi) strategy for ACP control was investigated. RNA interference is an innate immune response triggered by the cellular uptak...

  15. STUDIES ON ANTIMICROBIAL ACTIVITY AND PHYTOCHEMICAL ANALYSIS OF CITRUS FRUIT JUICES AGAINST SELECTED ENTERIC PATHOGENS

    OpenAIRE

    Bansode.D.S.; Chavan.M.D.

    2012-01-01

    The present study was carried out to find out the antimicrobial activity and phytochemical study of citrus fruit juices viz. Lemon (Citrus limon) and Orange (Citrus ourantium) against medically important selected enteric pathogens. As microorganisms are becoming resistant to present day antibiotics, our study focuses on antimicrobial activity and phytochemical study of Citrus fruit juices against selected enteric pathogens. Biological active compounds present in the medicinal important fruit ...

  16. Appropriate tools of Marketing Information System for Citrus Crop in the Lattakia Region, R. A. SYRIA

    OpenAIRE

    Sulaiman, H.; K. Malec; M. Maitah

    2014-01-01

    Citrus production represents the only livelihood source for many families in Lattakia region. Citrus farmers are not informed about expected prices. This information is crucial to make business decisions. For the farmers is necessary to take into account the spatial and temporal arbitrage of citrus harvest and storage, which may improve citrus farmer’s position in marketing chain and reduce the influence of intermediaries. The aim of the paper is to verify using of SARIMA models as a tool of ...

  17. A generic method to identify plant viruses by high-resolution tandem mass spectrometry of their coat proteins.

    Science.gov (United States)

    Blouin, Arnaud G; Greenwood, David R; Chavan, Ramesh R; Pearson, Michael N; Clover, Gerard R G; MacDiarmid, Robin M; Cohen, Daniel

    2010-01-01

    Although a number of protocols have been developed for detection of viruses at the genus or family level, universal approaches to detect and identify unknown viruses are still required. High-resolution tandem mass spectrometry was used to identify accurately peptide masses and their constituent sequences from partially purified plant virus preparations. Analysis of the peptide fragment masses against a virus database using pattern-matching algorithms identified sequences with homology to known virus peptides and also predicted peptides using de novo sequence analysis. This method provided sufficient information to confirm the identity of two known viruses that were included as controls (Cucumber mosaic virus and Tomato spotted wilt virus) and to identify unknown viruses in six viral isolates. The unknown viruses have been identified as four common viruses (Alfalfa mosaic virus, Tobacco streak virus, Citrus leaf blotch virus and Ribgrass mosaic virus), and two novel viruses (a potexvirus and a vitivirus). The identification of viruses from five distinct families by the tandem mass spectrometric determination of their coat protein demonstrates that this is a useful method for initial virus identification. This method, complemented with molecular or immunological procedures, provides a rapid and convenient way to identify both known and novel plant viruses. PMID:19712699

  18. 7 CFR 301.75-17 - Funds for the replacement of certified citrus nursery stock.

    Science.gov (United States)

    2010-01-01

    ...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Canker Notice of Quarantine and Regulations § 301.75-17 Funds for the replacement of certified citrus... 7 Agriculture 5 2010-01-01 2010-01-01 false Funds for the replacement of certified citrus...

  19. 7 CFR 301.75-15 - Funds for the replacement of commercial citrus trees.

    Science.gov (United States)

    2010-01-01

    ...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Canker Notice of Quarantine and Regulations § 301.75-15 Funds for the replacement of commercial citrus... 7 Agriculture 5 2010-01-01 2010-01-01 false Funds for the replacement of commercial citrus...

  20. Detection of Citrus Huanglongbing by Fourier Transform Infrared-Attenuated Total Reflection (FTIR-ATR) Spectroscopy

    Science.gov (United States)

    Citrus Huanglongbing (HLB, also known as citrus greening disease) was discovered in Florida in 2005 and is spreading rapidly amongst the citrus growing regions of the state. Detection via visual symptoms of the disease is not a long term viable option. New techniques are being developed to test fo...

  1. Bacterial brown leaf spot of citrus, a new disease caused by Burkholderia andropogonis

    Science.gov (United States)

    A new bacterial disease of citrus was recently identified in Florida and named as bacterial brown leaf spot (BBLS) of citrus. BBLS-infected citrus displayed flat, circular and brownish lesions with water-soaked margins surrounded by a chlorotic halo on leaves. Based on Biolog carbon source metabolic...

  2. HLB resistance and tolerance in citrus scion development at the US Horticultural Research Laboratory

    Science.gov (United States)

    Huanglongbing (HLB) is severely impacting Florida citrus and threatening industries in the rest of the US. Productivity declines in many HLB-affected trees. Fruit size and quality often diminish as the disease advances. The USDA citrus scion breeding program is charged with producing improved citrus...

  3. First Report of Dodder Transmission of Huanglongbing from Naturally Infected Murraya paniculata to Citrus

    Science.gov (United States)

    Huanglongbing (HLB) or “greening” disease of citrus is caused by phloem-limited, uncultured bacteria in the genus “Candidatus Liberibacter”. HLB is one of the most destructive diseases of citrus worldwide and is considered so dangerous to a U.S. citrus production that the USDA has listed “Ca. Liberi...

  4. Investigations of the feasibility for managing the Asian citrus pysllid using Isaria fumosorosea

    Science.gov (United States)

    The Asian citrus psyllid (AsCP), Diaphorina citri, transmits one of the most devastating diseases of citrus, the plant pathogenic bacterium Candidatus Liberibacter asiaticus, which is strongly associated with the occurrence of huanglongbing (HLB), also known as citrus greening disease. In Florida, g...

  5. An evaluation of different plant genotypes for rearing Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psylloidea)

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is the vector of bacteria responsible for a serious citrus disease known as huanglongbing (also known as citrus greening disease). Many research endeavors on ACP are dependent on a steady supply of ACP, which can be facilitated using a laboratory or greenhouse colony m...

  6. Complete Genome sequence of citrus huanglongbing bacterium, ‘Candidatus Liberibacter asiaticus’ obtained through metagenomics

    Science.gov (United States)

    Citrus huanglongbing (HLB) is the most destructive disease of citrus worldwide. It is spread by the citrus psyllids (Diaphorina citri and Trioza erytreae), and is associated with low-titer, phloem-limited infections by any of the three uncultured species of a-Proteobacteria: 'Candidatus Liberibact...

  7. Consumer preferences for fresh citrus: Impacts of demographic and behavioral characteristics

    Science.gov (United States)

    From 2000 to 2006, per capita consumption of fresh citrus fruit increased by 11.0%, but the relative shares of types of citrus consumed changed. Per capita consumption of the historically dominant citrus fruit, fresh oranges, experienced a continuous decline from 12.4 pounds to 7.4 pounds from 1990 ...

  8. Sequencing of diverse mandarin, pummelo and orange genomes reveals complex history of admixture during citrus domestication

    Science.gov (United States)

    Cultivated citrus are selections from, or hybrids of, wild progenitor species whose identities and contributions to citrus domestication remain controversial. Here we sequence and compare citrus genomes—a high-quality reference haploid clementine genome and mandarin, pummelo, sweet-orange and sour-o...

  9. Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates.

    Science.gov (United States)

    Oikeh, Ehigbai I; Omoregie, Ehimwenma S; Oviasogie, Faith E; Oriakhi, Kelly

    2016-01-01

    The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Citrus aurantifolia (lime) were evaluated. Antimicrobial activities against five bacterial and three fungal strains were evaluated. The results revealed the presence of alkaloids, flavonoids, steroids, terpenoids, saponins, cardiac glycosides, and reducing sugars in all the juice concentrates. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging capacities varied with tangerine and grape juices having better scavenging capacities than lemon and lime juices. Grape juice was observed to have a significantly higher (P juice concentrates had lower MIC and MBC values with orange and tangerine having the highest values. Minimum fungicidal concentrations ranged from 50 to 200 μg/mL. The results of this study suggest that these juice concentrates may have beneficial antimicrobial roles that can be exploited in controlling unwanted microbial growth. PMID:26788316

  10. Study of the thermal degradation of citrus seeds

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Montoya, V. [Centro de Quimica, Instituto de Ciencias, Universidad Autonoma de Puebla, Apdo. Postal J-55, Puebla 72570, Pue (Mexico); Instituto Nacional del Carbon, CSIC, Apartado 73, E-33080 Oviedo (Spain); Montes-Moran, M.A. [Instituto Nacional del Carbon, CSIC, Apartado 73, E-33080 Oviedo (Spain); Elizalde-Gonzalez, M.P. [Centro de Quimica, Instituto de Ciencias, Universidad Autonoma de Puebla, Apdo. Postal J-55, Puebla 72570, Pue (Mexico)

    2009-09-15

    The citrus seeds are one of the principal residues in the juice industry and their utilization can decrease significantly the problems of their final disposal. In this work the thermal degradation of three Mexican citrus seeds: orange (Citrus sinensis), lemon (Citrus Limon) and grapefruit (Citrus paradisi) was studied in nitrogen atmosphere. The two components (embryo and husk) of the seeds were characterized separately. The results showed that the thermal effects are very similar between the three embryos and the three husks. The embryos show higher degradability, superior content of nitrogen and higher heating value than the husks. The thermal degradation of the components of the three seeds is completed at 600 C and it is considered to be a global process derived from the decomposition of their principal components (cellulose, hemicellulose and lignin). The results suggest that mixing the three entire seeds will not lead to a severe deviation from their individual thermal behavior and that the industry could apply them for carbonization purposes. (author)

  11. Identification of photoperception and light signal transduction pathways in citrus

    Directory of Open Access Journals (Sweden)

    Vera Quecini

    2007-01-01

    Full Text Available Studies employing model species have elucidated several aspects of photoperception and light signal transduction that control plant development. However, the information available for economically important crops is scarce. Citrus genome databases of expressed sequence tags (EST were investigated in order to identify genes coding for functionally characterized proteins responsible for light-regulated developmental control in model plants. Approximately 176,200 EST sequences from 53 libraries were queried and all bona fide and putative photoreceptor gene families were found in citrus species. We have identified 53 orthologs for several families of transcriptional regulators and cytoplasmic proteins mediating photoreceptor-induced responses although some important Arabidopsis phytochrome- and cryptochrome-signaling components are absent from citrus sequence databases. The main gene families responsible for phototropin-mediated signal transduction were present in citrus transcriptome, including general regulatory factors (14-3-3 proteins, scaffolding elements and auxin-responsive transcription factors and transporters. A working model of light perception, signal transduction and response-eliciting in citrus is proposed based on the identified key components. These results demonstrate the power of comparative genomics between model systems and economically important crop species to elucidate several aspects of plant physiology and metabolism.

  12. Cryopreservation of citrus shoot tips using micrografting for recovery.

    Science.gov (United States)

    Volk, Gayle M; Bonnart, Remi; Krueger, Robert; Lee, Richard

    2012-01-01

    The USDA-ARS National Plant Germplasm System (NPGS) and the University of California Citrus Variety Collection maintain more than 888 unique accessions representing 132 taxa of Citrus, Fortunella, and citrus wild species within field, screenhouse, and greenhouse collections. We have identified a cryopreservation method by which Citrus genetic resources that are not maintained in vitro can be successfully conserved. Shoot tips were excised from actively growing vegetative flushes of protected trees. Surface-disinfected shoot tips were precultured overnight in 0.3 M sucrose, loaded with a loading solution for 20 min and treated with PVS2 for 30 or 60 min at 0 degree C, prior to direct immersion in liquid nitrogen. Rewarmed shoot tips post-cultured overnight on survival medium were then micrografted on 'Carrizo' seedling rootstocks to produce whole plants. Micrografted shoot tips recovered quickly and rooted plants could be transferred to the greenhouse within months. Regrowth of whole plants after micrografting averaged 53 percent for cryopreserved shoot tips of cultivars representing eight Citrus and Fortunella species. This method has several advantages: it uses screenhouse or greenhouse plants as source materials, it is not dependent upon cultivar-specific recovery media, and it avoids seedling juvenility. PMID:23250401

  13. Estado de ánimo caracterizado por soledad y tristeza: factores relacionados en personas mayores Characterized mood by loneliness and sadness: factors related elderly

    Directory of Open Access Journals (Sweden)

    Pilar Jürschik

    2013-03-01

    Full Text Available El objetivo de este estudio fue conocer el estado de ánimo y los factores que pueden influir en las personas mayores. Se trata de un estudio epidemiológico y transversal que incluye a personas mayores de 65 años de instituciones atendidos en diferentes niveles asistenciales en la ciudad de Lleida. Las variables incluidas fueron, además del estado de ánimo caracterizado por soledad y tristeza, las características sociodemográficas y diversos parámetros del estado de salud. La depresión es una alteración patológica del estado de ánimo. Es importante detectar este último ya que puede predecir la gravedad de la depresión en las personas de edad avanzada. El personal de enfermería se encuentra en una situación privilegiada por su proximidad con los pacientes.The aim of this study was to determine the prevalence of mood and the factors that can affect older people. Cross-sectional epidemiological study including people aged >ó= 65 years of institutions with different levels of care located in the city of Lleida. The variables included, in addition to depressed mood characterized by loneliness and sadness, the sociodemographic characteristics and various health parameters. Depression is a pathological alteration of mood. It is important to detect because it can predict the severity of depression in elderly. The nursing staff is in a prime location for its proximity to patients.

  14. Na Alegria e na Tristeza: Compartilhamento de Informações, Comparação e Consumo em Comunidades Virtuais de Noivas

    Directory of Open Access Journals (Sweden)

    Rute de Alencar Frota

    2015-06-01

    Full Text Available As comunidades virtuais são compreendidas por pesquisadores da área de marketing como um importante grupo de referência para a tomada de decisão dos consumidores, servindo como fonte ou até mesmo ambiente de consumo. Pouco se conhece sobre os mecanismos de comparação social que ocorrem nestes ambientes e seus consequentes em termos de emoção gerada e consumo. O objetivo deste trabalho é analisar o consumo motivado pela comparação em comunidades virtuais. Para tal, uma pesquisa netnográfica foi empreendida na comunidade “Noivinhas”, presente na rede social Facebook, e formada por noivas de uma capital do Brasil. Entrevistas semiestruturadas junto a participantes também foram conduzidas para alcançar o objetivo do estudo. Foi possível constatar que os depoimentos, fotos e vídeos postados na comunidade virtual estudada não só dão margens para que a comparação ocorra, mas também para que, a partir dela, emoções sejam geradas. As emoções negativas foram as mais lembradas pelas entrevistadas e também eram relatadas pelas participantes da comunidade. Inveja, arrependimento e tristeza podem ser citadas como as mais recorrentes. Já as emoções positivas não são tão marcantes para algumas noivas e a grande maioria só relata a felicidade. Em relação ao consumo, todas as entrevistadas admitiram que a comparação acaba motivando-o, principalmente quando a emoção gerada é negativa.

  15. ECHO virus

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001340.htm ECHO virus To use the sharing features on this page, please enable JavaScript. Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that lead to ...

  16. Changes of Peel Essential Oil Composition of Four Tunisian Citrus during Fruit Maturation

    OpenAIRE

    Soumaya Bourgou; Fatma Zohra Rahali; Iness Ourghemmi; Moufida Saïdani Tounsi

    2012-01-01

    The present work investigates the effect of ripening stage on the chemical composition of essential oil extracted from peel of four citrus: bitter orange (Citrus aurantium), lemon (Citrus limon), orange maltaise (Citrus sinensis), and mandarin (Citrus reticulate) and on their antibacterial activity. Essential oils yields varied during ripening from 0.46 to 2.70%, where mandarin was found to be the richest. Forty volatile compounds were identified. Limonene (67.90–90.95%) and 1,8-cineole (tr-1...

  17. Relationships between mycorrhizas and antioxidant enzymes in citrus (citrus tangerina) seedlings inoculated with glomus mosseae

    International Nuclear Information System (INIS)

    A potted experiment was conducted to evaluate the effects of an arbuscular mycorrhizal fungus (AMF), Glomus mosseae, on growth performance and superoxide dismutase (SOD) and catalase (CAT) activities of citrus (Citrus tangerina) seedlings. After five months of AMF inoculation, mycorrhizal colonization and vesicles, but not arbuscules and entry points, increased with the increase of inoculated mycorrhizal dosages among 5-40 g (32 spores/g dosage). Mycorrhizal inoculation with 10-40 g dosages significantly increased plant growth traits, including plant height, stem diameter, and shoot, root and total fresh weights. Higher leaf chlorophyll content was found in all the mycorrhizal plants, compared with the non-mycorrhizal plants. Inoculation with G. mosseae markedly decreased SOD and CAT activities of leaf and root, except an increase of either root CAT with the 20 g mycorrhizal treatment or root SOD with the 20 and 40 g mycorrhizal treatments. In addition, mycorrhizal colonization and vesicles significantly positively correlated with root SOD and without root CAT. We also discussed the relationships between mycorrhizal effects on antioxidant enzymes and growth environment of host plants. (author)

  18. Volatile constituents of redblush grapefruit (Citrus paradisi) and pummelo (Citrus grandis) peel essential oils from Kenya.

    Science.gov (United States)

    Njoroge, Simon Muhoho; Koaze, Hiroshi; Karanja, Paul Nyota; Sawamura, Masayoshi

    2005-12-14

    The volatile constituents of cold-pressed peel essential oils of redblush grapefruit (Citrus paradisi Macfadyen forma Redblush) and pummelo (Citrus grandis Osbeck) from the same locality in Kenya were determined by GC and GC-MS. A total of 67 and 52 compounds, amounting to 97.9 and 98.8% of the two oils, respectively, were identified. Monoterpene hydrocarbons constituted 93.3 and 97.5% in the oils, respectively, with limonene (91.1 and 94.8%), alpha-terpinene (1.3 and 1.8%), and alpha-pinene (0.5%) as the main compounds. Sesquiterpene hydrocarbons constituted 0.4% in each oil. The notable compounds were beta-caryophyllene, alpha-cubebene, and (E,E)-alpha-farnesene. Oxygenated compounds constituted 4.2 and 2.0% of the redblush grapefruit and pummelo oils, respectively, out of which carbonyl compounds (2.0 and 1.3%), alcohols (1.4 and 0.3%), and esters (0.7 and 0.4%) were the major groups. Heptyl acetate, octanal, decanal, citronellal, and (Z)-carvone were the main constituents (0.1-0.5%). Perillene, (E)-carveol, and perillyl acetate occurred in the redblush grapefruit but were absent from the pummelo oil. Nootkatone, alpha- and beta-sinensal, methyl-N-methylanthranilate, and (Z,E)-farnesol were prominent in both oils. PMID:16332132

  19. Antimycotic Activity and Genotoxic Evaluation of Citrus sinensis and Citrus latifolia Essential Oils.

    Science.gov (United States)

    Ruiz-Pérez, Nancy J; González-Ávila, Marisela; Sánchez-Navarrete, Jaime; Toscano-Garibay, Julia D; Moreno-Eutimio, Mario A; Sandoval-Hernández, Teresa; Arriaga-Alba, Myriam

    2016-01-01

    The aim of this study was to evaluate the antifungal activity of essential oils (EOs) of Citrus sinensis (C. sinensis) and Citrus latifolia (C. latifolia) against five Candida species: Candida albicans, Candida tropicalis, Candida glabrata, Candida lusitaniae and Candida guilliermondii; and perform its genotoxic evaluation. The EOs of C. sinensis and C. latifolia were obtained from the peel by hydro-distillation. The major components determined by GC-MS were in C. sinensis, d-limonene (96%) and α-myrcene (2.79%); and in C. latifolia, d-limonene (51.64%), β-thujene (14.85%), β-pinene (12.79%) and γ-terpinene (12.8%). Antifungal properties were studied by agar diffusion method, where C. sinensis presented low activity and C. latifolia essential oil was effective to inhibit growing of C. lusitaniae and C. guilliermondii with IC50 of 6.90 and 2.92 μg respectively. The minimum inhibitory concentrations (MIC) for C. sinensis were in a range of 0.42-3.71 μg and for C. latifolia of 0.22-1.30 μg. Genotoxic evaluation was done by Ames test where none of the oils induced point mutations. Flow cytometry was used to measure toxicity in human oral epithelial cells, C. sinensis was not cytotoxic and C. latifolia was toxic at 21.8 μg. These properties might bestow different odontological applications to each essential oil. PMID:27137128

  20. Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro

    OpenAIRE

    Zhang, Lancui; Ma, Gang; Kato, Masaya; Yamawaki, Kazuki; Takagi, Toshihiko; Kiriiwa, Yoshikazu; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Nesumi, Hirohisa

    2011-01-01

    In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sac...

  1. The push-pull strategy for citrus psyllid control.

    Science.gov (United States)

    Yan, Huaxue; Zeng, Jiwu; Zhong, Guangyan

    2015-07-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the only natural vector of Candidatus Liberibacter asiaticus that causes citrus huanglongbing (HLB), a most destructive disease of citrus. Currently, no remedial therapy exists for the disease, and so effective control of ACP is very important in curbing the transmission of the disease. The push-pull strategy should be thoroughly explored as an approach to ACP management. This mini-review summarises the current progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull-push strategy are briefly discussed. It is expected that the pull-push strategy will be gradually developed following more extensive research. PMID:25256398

  2. Content evaluation of 4 furanocoumarin monomers in various citrus germplasms.

    Science.gov (United States)

    Xu, Juan; Ma, Lili; Jiang, Dong; Zhu, Shiping; Yan, Fuhua; Xie, Yunxia; Xie, Zongzhou; Guo, Wenwu; Deng, Xiuxin

    2015-11-15

    Due to the furanocoumarin compounds in the fruit, the production and consumption of grapefruit have been affected in the past decades since the 'grapefruit juice effect' was declared. To provide elite germplasm and obtain knowledge for future citrus breeding programs, the contents of 4 furanocoumarin monomers (FCMs) in the juice sacs from 73 citrus germplasms were evaluated using ultra-performance liquid chromatography. 6',7'-Dihydroxybergamottin and bergamottin were dominant in all the tested grapefruits, while there were some pomelos with dominant epoxybergamottin, and some with dominant 6',7'-dihydroxybergamottin and bergamottin. The contents of FCMs were low or below detection in sweet oranges, mandarins, lemons and trifoliate oranges. The results also show that the dominant patterns of FCMs are genotype-related, and crossing and selection are effective approaches to alter FCM profiles in citrus breeding. Furthermore, the contribution of pomelo as a parent to grapefruit regarding their FCM profiles was discussed. PMID:25977000

  3. Insecticidal activity of some citrus oils against culex quinquefasciatus

    International Nuclear Information System (INIS)

    The present study deals with the larvicidal potency of peel oils of grapefruit (Citrus paradise), sweet orange (Citrus sinensis) and lime (Citrus aurantifolia) on 4''th instar larvae of the mosquito, Culex quinquefasciatus. Orange oil was the most effective followed by grapefruit oil and then lime oil. The toxicity of the oils applied to the 4''th instar larval stage was extended to pupal and adult stages. All oils produced deleterious effects on fecundity of survivors of sublethal doses. By the aid of chemical analysis of oils, the active compound was found to be limonene, a monoterpene compound. The percentages limonene were 97.15%, 92.46% and 32.29% for orange, grapefruit and lime respectively.(Author)

  4. In vitro pollen germination of five citrus species

    International Nuclear Information System (INIS)

    The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

  5. Analysis of SSR in Citrus Sequences from EMBL Database

    Institute of Scientific and Technical Information of China (English)

    MENG Hai-jun; CAO Qing-qin; HU Zhi-yong; LIU Gao-ping; CHENG Yun-jiang; DENG Xiu-xin

    2005-01-01

    Abundance of simple sequence repeat (SSR) in Citrus sequences from EMBL database was investigated by using computer program MISA (MIcroSAtellite), which aimed to provide useful information for the development of SSR markers.Among 32 896 sequences of Citrus, 4987 SSRs were found in 4167 sequences and the average distance between SSRs was approximately 3.5 kb. Mononucleotide repeats (50.6%) were the most abundant repeats. And di-, tri-, tetra-, penta- and hexa-nucleotide repeats were 22.8, 25.2, 1, 0.08, and 0.36%, respectively. The most abundant motif was A/T followed in descending order by AG/CT, AC/GT, AT/TA. AAT/ATT, AAG/CTT, AGC/CGT, ACG/CTG and C/G. They comprised about90% of all microsatellites. Ten primer pairs were designed, and three of them produced clear visible bands among Citrus and its related genera.

  6. Technological quality of irradiated Moroccan citrus fruits

    International Nuclear Information System (INIS)

    The effect of irradiation at doses of 125, 250, 375, and 500 Gy, commonly used for quarantine treatment, on the quality of Maroc-late orange, the most common export variety of Morocco was investigated. In the first study fruits were irradiated without any previous cold conditioning treatment as practiced by the export trade for quarantine purposes. In the second study fruits obtained from the normal chain after conditioning was irradiated. Storage of irradiated fruits was studied at room temperature and 10 deg. C at 0 deg. C in case of control fruits. The parameters studied included juice yield, total solids, reducing and total sugars, total acids and volatile acids, dry weight and weight loss. The results showed that irradiation did not affect the technological quality of citrus fruits during four weeks storage. The result thus far points to the possibility for the successful application of irradiation as an alternative quarantine treatment to the classical methods, which result in browning of the peel. The browning phenomenon could be controlled by waxing and will be the subject of a future study. (author)

  7. Radiation preservation of Citrus Unshiu, 3

    International Nuclear Information System (INIS)

    Effects of energy and current of electron-beams and synergistic effect of heat and radiation on a growth of fungi and a browning of peel were investigated to extend shelf-life of Citrus Unshiu (''Satsuma'' orange). The fruits were irradiated with a surface dose of 200krad by various energies of electrons (0.2-1.5MeV), and then stored at 30C for 3 months. Percent of browned fruit in the fruits irradiated by 0.2MeV electrons was almost the same as that in the unirradiated ones. However, if the fruits were irradiated by energies of more than 0.5MeV, the browning of peel increased with increasing energy of electrons. The browning seems to depend on a dose absorbed only in peel, but not to depend on a total dose absorbed in fruit. When the fruits were stored at 30C for 3 months followed by storage at room temperature (16-250C) for one week, the effective growth inhibition of fungi was observed on the fruits irradiated by 0.5MeV electrons. On the fruits irradiated with 0.1-1.0mA of beam current by 0.5MeV electrons, increasing current tended to inhibit the growth of fungi. But the browning of peel was unaffected by beam current. Heat and radiation combination increased the browning of peel and the growth of fungi during storage. (auth.)

  8. In Vitro Propagation of Citrus Rootstocks

    Directory of Open Access Journals (Sweden)

    Suneel SHARMA

    2009-06-01

    Full Text Available Present investigation was conducted to standardize a protocol for in-vitro propagation of citrus rootstocks viz. Rough lemon, Cleopatra mandarin Pectinifera and Troyer citrange. The shoot tip explant was found better for callus induction of these rootstocks than the nodal segment. Maximum callus formation (40.0% and 23.3% of shoot tip explants was obtained in Cleopatra mandarin, Pectinifera, and Rough lemon and Troyer citrange, respectively in treatment MS basal media + 0.5mg/l Kin, 2.0mg/l NAA, and 2.0mg/l 2, 4-D. Furthermore, the maximum number of shoots per explant was obtained through the callus in Pectinifera, Rough lemon and Cleopatra mandarin in MS basal media + BAP 1mg/l. Maximum rooting of shoots (1.11% was noted in rootstock Rough lemon followed by Cleopatra mandarin for the � MS media supplemented with 10mg/l IBA. Although the callus development and bud proliferation was recorded in rootstock Troyer citrange however, shoot and root formation did not occur. The potting media consisting of soil, sand and FYM in the ratio of 1:1:1 by volume was better with maximum survival rate of hardened plants six weeks after transferring to the pots under greenhouse for Rough lemon followed by Pectinifera and Cleopatra mandarin rootstock.

  9. Recovery and characterization of a Citrus clementina Hort. ex Tan. 'Clemenules' haploid plant selected to establish the reference whole Citrus genome sequence

    OpenAIRE

    Navarro Luis; Ollitrault Patrick; Pina José A; Hernández María; Juárez José; Aleza Pablo

    2009-01-01

    Abstract Background In recent years, the development of structural genomics has generated a growing interest in obtaining haploid plants. The use of homozygous lines presents a significant advantage for the accomplishment of sequencing projects. Commercial citrus species are characterized by high heterozygosity, making it difficult to assemble large genome sequences. Thus, the International Citrus Genomic Consortium (ICGC) decided to establish a reference whole citrus genome sequence from a h...

  10. Targeting juvenile hormone metabolic genes in the Asian citrus psyllid (Diaphorina citri Kuwayama) as a strategy to reduce the spread of citrus greening disease

    OpenAIRE

    Van Ekert, Evelien; Borovsky, D.; Powell, C A; Cave, R. D.; Alessandro, R. T.; Shatters, Jr., R. G.

    2014-01-01

    Diaphorina citri Kuwayama, the Asian citrus psyllid (ACP), is a devastating citrus pest due to its transmission of a phloem-limited bacterial pathogen, Candidatus Liberibacter asiaticus, that causes citrus greening. Psyllid control is a major part of effective greening disease management, and our research targets perturbation of insect juvenile hormone metabolism as a new psyllid control strategy.  Previous studies have shown that application of a juvenile hormone (JH) analogue, pyriproxyfen,...

  11. Stylet Morphometrics and Ultrastructure in Relation to Feeding Behavior and Pathogen Transmission by Nymphs and Adults of the Asian Citrus Psyllid Diaphorina citri, Vector of Citrus Huanglongbing Bacterium

    OpenAIRE

    Ammar, E. D.; Shatters, R G; Hall, D.G.

    2014-01-01

    The feeding behavior and stylet morphometrics were studied in nymphs and adults of the Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera, Psyllidae), vector of Candidatus Liberibacter asiaticus (Las) associated with citrus huanglongbing (HLB) disease. The stylet length of first instar nymphs averaged 266 µm (83% of body length) whereas that of 5th instar nymphs was 615 µm (34% of body length). Younger ACP nymphs feed only on young citrus leaves on smaller veins or on the sides of the mi...

  12. RNAi-Based Strategy for Asian Citrus Psyllid (Diaphorina citri) Control: A Method to Reduce the Spread of Citrus Greening Disease

    OpenAIRE

    Hawkings, Chloe; Morgan, K.; Shaffer, L.; Powell, C.; Borovsky, D.; Cave, R.; Dawson, B.; Gowda, S.; Shatters, Jr., R. G.

    2014-01-01

    Citrus greening disease is a serious bacterial disease of citrus worldwide and is vectored by the Asian citrus pysllid (Diaphorina Citri).  The only effective control strategy includes vigorous control of the psyllid, primarily through heavy reliance on pesticides. As a more sustainable and environmentally friendly method of psyllid control, we evaluated a RNA interference (RNAi) approach based on psyllid oral uptake of dsRNA molecules that target specific psyllid genes.  This approach is bas...

  13. Hydrolysates of citrus plants stimulate melanogenesis protecting against UV-induced dermal damage.

    Science.gov (United States)

    Chiang, Hsiu-Mei; Lin, Jen-Wen; Hsiao, Pei-Ling; Tsai, Shang-Yuan; Wen, Kuo-Ching

    2011-04-01

    The sun-tanning process occurs as a spontaneous response to ultraviolet (UV) irradiation. UV will induce tanning and DNA damage, processes that can lead to photoaging and skin disorders such as hyperpigmentation and cancer. The pigment melanin protects skin from UV damage; therefore, an efficient melanin-promoting suntan lotion could be highly beneficial. In this study, a process was developed to increase the content of naringenin in citrus extracts and to determine whether a higher naringenin content of citrus would induce melanogenesis. Melanin content and tyrosinase expression in mouse B16 melanoma cells were assayed after treatment with citrus plant extracts and their hydrolysates. The results indicate that hydrolysis increased the naringenin content in citrus extracts and that citrus preparations stimulated cellular melanogenesis and tyrosinase expression. It is suggested that this method is applicable to the industrial production of melanin-promoting suntan lotions with antiphotocarcinogenic properties derived from citrus rind and citrus products. PMID:20857432

  14. Learning to fight a fly : developing citrus IPM in Bhutan

    OpenAIRE

    Schoubroeck, van, H.J.

    1999-01-01

    The chinese citrus fly is one of the key pests in Bhutanese mandarin orchards that lays eggs in developing fruit that cause pre-mature fruit drop. In this study it is used as a "model subject" to explore the integration of technical, social and administrative domains of knowledge. The confinement of the study to control of the fly leads to the study addressing a broad set of issues that are linked through their relevance to control the pest. Citrus fly control and its consequent doubling of t...

  15. Induced mutations in citrus shoot tip culture in vitro

    International Nuclear Information System (INIS)

    This study was undertaken to determine the efficacy of using induced mutation of the callus of citrus clones as a method in citrus breeding. It was observed that the nuclear clones had a higher ratio of callus cell differentiation than the old clones. The callus cells were exposed to gamma irradiation of 7,000 roentgen at 127 R/min. Callus cells derived from the shoot tip proved to be more appropriate for cytological examination by the smearing technique than the root tip cells. Gamma irradiation of callus cells is quite effective for inducing chromosome aberration and micronucleus inspection

  16. Weed Biomass and Weed Species Diversity of Juvenile Citrus Trees Intercrop with some Arable Crops

    Directory of Open Access Journals (Sweden)

    Patience Mojibade OLORUNMAIYE

    2012-02-01

    Full Text Available A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34% in all the plots except in citrus/maize plot (0.78% at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m-2 respectively than in citrus/groundnut plot (143.00 m-2. Similarly, significantly lower grass weed densities were produced in citrus/Mucuna and citrus/sweet potato (0.33 m-2 each plots than the control plot (11.33 m-2. Whereas citrus/corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m-2 than citrus/Mucuna plot (126.47 g m-2 at 3WAP, citrus/large green plot (16.15 g m-2 and citrus/groundnut plot (123.25 g m-2 followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m-2 in all the plots compared with control plot.

  17. Determination of elements in citrus leaves

    International Nuclear Information System (INIS)

    In many agricultural stations and farms most of the problems encountered generally reduce to questions of diminished yield. This may be due to a number of factors, including soil exhaustion and the application of fertilizers of unsuitable formula. The chemical impoverishment of the soil is due to the leaching-out phenomenon, i- e. the washing out of bases, and to the ''exportation'' of fertilizer elements in the form of crops in years when nothing has been returned to the soil. These losses have a particularly adverse effect if the parent rock does not contain sufficient mineral reserves to compensate for them by a slow alteration process. Such impoverishment is revealed by soil and foliar analyses. The authors have attempted to determine the content in citrus plants of the following elements: Mn, P, Cu, Cl and K (the latter on three samples only). After collection, the samples are treated by Bransolten's method (Rapport de Recherche TRICO № 15/1968), dried for at least 12 hours at 105°C, followed by pulverization of the leaves, after which the determination is carried out. The determination of Mn and Cl is very simple, as is that of Cu. The latter is determined by activation with slow neutrons in order to avoid Zn formation. The phosphorus content is determined by measuring the beta-radiation emitted by the radioactive elements. In this case particular precautions must be taken to ensure that the same layer is used for the samples and the standards, since beta-radiation is absorbed by these layers. For the K and Na determinations thermal neutrons are used for activation and a Ge(Li) detector for measurement of the gamma-spectra. Because of the high resolution of the detector, the two elements can be determined without separation. (author)

  18. In vitro mutant obtainment by irradiation of nucellar tissue of citrus (Citrus Sinensis Osb.)

    International Nuclear Information System (INIS)

    Nucellus of cultivar Valencia (Citrus Sinensis, Osb.) extracted from fruits 12 weeks after fertilization, were gamma irradiated (0.1, 1.0, 2.0, 4.0, 8.0 and 12.0 kR) before inoculation in culture media (pH 5.7) which comprised of macro and micronutrients of medium MS to which were added (in mg/l): mesoinusitol, 100; pyroxidin HCl, 1; nicotinic acid, 1; thiamine HCl, 0.2; malt extract, 500; sacarose, 50,000; agar-agar, 8,000. They were then Kept under 16 h light and 8h dark at a temperature of 270C. (M.A.C.)

  19. Cytological and molecular characterization of three gametoclones of Citrus clementina

    OpenAIRE

    GERMANA, MARIA ANTONIETTA; Aleza, Pablo; Carrera, Esther; Chen, Chunxian; Chiancone, Benedetta; Costantino, Gilles; Dambier, Dominique; Deng, Xiuxin; Federici, Claire T.; Froelicher, Yann; Guo, Wenwu; Ibanez, Victoria; Juarez, Jose; Kwok, Kevin; Luro, François

    2013-01-01

    Abstract Background Three gametoclonal plants of Citrus clementina Hort. ex Tan., cv. Nules, designated ESP, FRA, and ITA (derived from three labs in Spain, France, and Italy, respectively), were selected for cytological and molecular characterization in order to elucidate genomic rearrangements provoked by haploidization. The study included comparisons of their ploidy, homozygosity, genome integrity, and gene dosage, using chromosome counting, flow c...

  20. Larvicidal Activity of Citrus Limonoids against Aedes albopictus Larvae

    Directory of Open Access Journals (Sweden)

    Hazrat Bilal

    2012-12-01

    Full Text Available Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticidestherefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppressmosquito larval population.Methods: WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis wasthe best in terms of LC50 (297 ppm, % mortality (97% and LT50 (18.49 hours then freutrall early (Citrus reticulatewith LC50 (377.4 ppm, % mortality (88% and LT50 (31 hours, While nomilin gave lowest LC50 (121.04 ppm than limonin (382.22 ppm after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml than freutrall early (5.29 μg/ml and 3.89 μg/ml respectively.Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required.

  1. Larvicidal Activity of Citrus Limonoids against Aedes Albopictus Larvae

    Directory of Open Access Journals (Sweden)

    Hazrat Bilal

    2012-12-01

    Full Text Available Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecti­cides therefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to sup­press mosquito larval population.Methods: World Health Organization recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis was the best in terms of LC50 (297 ppm, % mortality (97% and LT50 (18.49 hours then freutrall early (Citrus reticulate with LC50 (377.4 ppm, % mortality (88% and LT50 (31 hours, While nomilin gave lowest LC­­50 (121.04 ppm than limonin (382.22 ppm after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 µg/ml and 21.19 µg/ml than freutrall early (5.29 µg/ml and 3.89 µg/ml respectively.Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required

  2. Energy requirement and economic analysis of citrus production in Turkey

    International Nuclear Information System (INIS)

    The aim of this research was to examine the energy requirements of the inputs and output in citrus production in the Antalya province of Turkey. Data for the production of citrus fruits (orange, lemon and mandarin) were collected from 105 citrus farms by using a face to face questionnaire method. The research results revealed that lemon production was the most energy intensive among the three fruits investigated. The energy input of chemical fertilizer (49.68%), mainly nitrogen, has the biggest share in the total energy inputs followed by Diesel (30.79%). The lemon production consumed a total of 62 977.87 MJ/ha followed by orange and mandarin with 60 949.69 and 48 838.17 MJ/ha, respectively. The energy ratios for orange, mandarin and lemon were estimated to be 1.25, 1.17 and 1.06, respectively. On average, the non-renewable form of energy input was 95.90% of the total energy input used in citrus production compared to only 3.74% for the renewable form. The benefit-cost ratio was the highest in orange production (2.37) followed by lemon. The results indicate that orange production in the research area is most remunerative to growers compared to lemon and mandarin

  3. Energy requirement and economic analysis of citrus production in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ozkan, Burhan E-mail: bozkan@akdeniz.edu.tr; Akcaoz, Handan; Karadeniz, Feyza

    2004-07-01

    The aim of this research was to examine the energy requirements of the inputs and output in citrus production in the Antalya province of Turkey. Data for the production of citrus fruits (orange, lemon and mandarin) were collected from 105 citrus farms by using a face to face questionnaire method. The research results revealed that lemon production was the most energy intensive among the three fruits investigated. The energy input of chemical fertilizer (49.68%), mainly nitrogen, has the biggest share in the total energy inputs followed by Diesel (30.79%). The lemon production consumed a total of 62 977.87 MJ/ha followed by orange and mandarin with 60 949.69 and 48 838.17 MJ/ha, respectively. The energy ratios for orange, mandarin and lemon were estimated to be 1.25, 1.17 and 1.06, respectively. On average, the non-renewable form of energy input was 95.90% of the total energy input used in citrus production compared to only 3.74% for the renewable form. The benefit-cost ratio was the highest in orange production (2.37) followed by lemon. The results indicate that orange production in the research area is most remunerative to growers compared to lemon and mandarin.

  4. Comparative analysis of Asian citrus psyllid and Potato psyllid antennae

    Science.gov (United States)

    The comparative investigation of the morphological basis for olfactory reception in two psyllid species, Diaphorina citri (the Asian citrus psyllid), and Bacterocera cockerelli (the potato/tomato psyllid) (both species Hemiptera:Psyllidae) was performed using scanning electron microscopy to elucidat...

  5. Limettin and furocoumarins in beverages containing citrus juices or extracts.

    Science.gov (United States)

    Gorgus, E; Lohr, C; Raquet, N; Guth, S; Schrenk, D

    2010-01-01

    Phototoxic and photo-genotoxic furocoumarins occur, e.g., in citrus species, parsnip, parsley, celery, and figs. They exhibit phototoxic and photo-genotoxic properties in combination with UV radiation, while less is known about the phototoxicity of the coumarin derivative limettin mainly found in limes and lemons. Risk assessment of dietary furocoumarins is based on a threshold approach and on estimates of 1.2-1.45 mg for the average daily exposure for adults via the diet in several countries. In these estimates, the major contribution to overall daily exposure has been attributed to citrus-flavored non-alcoholic beverages, in spite of a lack of analytical data for those products. Therefore, we analyzed a number of furocoumarins in a variety of citrus-containing beverages and included limettin in the pattern of analyzed constituents. Our findings provide strong evidence that grapefruit juice and not citrus-flavored non-alcoholic beverages is the major source of furocoumarin exposure in a Western diet. Based on these findings it can be assumed that the average dietary exposure to furocoumarins is about 3-fold lower than previously estimated, i.e. in the range of 548 and 2237 microg/day for the average and high consumer, respectively. The coumarin derivative limettin was mainly found in lime products. PMID:19770019

  6. Developments in ethanol production from citrus peel waste

    Science.gov (United States)

    Each year, the Florida citrus juice industry produces about 3.5~5.0 million tons of wet peel waste, which are currently dried and sold as cattle feed, often at a loss, to dispose of the waste residual. Profitability would be greatly improved if the peel waste could be used to produce higher value pr...

  7. Economic analysis of ethanol production from citrus peel waste

    Science.gov (United States)

    The Florida citrus juice industry produces about 3.5 million tons of wet peel waste per year. In current industrial practice, waste peels are dried and sold as cattle feed to offset the waste disposal cost. Profitability would be greatly improved if peels could be used to produce higher value produ...

  8. Characterization of Pectin from Citrus sinensis (Sweet Orange) Juice

    Science.gov (United States)

    Pectin is a structurally diverse polysaccharide synthesized in plants. Its core element is a backbone of a-(1,4)-galacturonic acid residues, which may be interspersed with rhamnose residues, esterified, and decorated with a variety of glycan chains. In citrus juice, pectin comprises the majority o...

  9. Essential Oils from the Malaysian Citrus (Rutaceae Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Siti Nur Atiqah Md Othman

    2016-06-01

    Full Text Available This review article appraises the extraction methods, compositions, and bioactivities of the essential oils from the Citrus species (family: Rutaceae endemic to Malaysia including C. aurantifolia, C. grandis, C. hystrix, and C. microcarpa. Generally, the fresh peels and leaves of the Citrus species were extracted using different methods such as steam and water distillation, Likens-Nikerson extraction, solvent extraction, and headspace solid-phase micro-extraction (HS-SPME. Most of the Citrus oils were found to be rich in monoterpene hydrocarbons with limonene (1 as the major component identified in the peels of C. aurantifolia (39.3%, C. grandis (81.6%–96.9%, and C. microcarpa (94.0%, while sabinene (19 was the major component in the peels of C. hystrix (36.4%–48.5%. In addition, citronellal (20 (61.7%–72.5%, linalool (18 (56.5%, and hedycaryol (23 (19.0% were identified as the major components in the oil of C. hystrix leaves, C. grandis blossom and C. microcarpa leaves, respectively. The C. hystrix essential oil has been experimentally shown to have antimicrobial and antifeedant activities, while no bioactivity study has been reported on the essential oils of other Malaysian Citrus species.

  10. Efficiency of chemotherapy coupled with thermotherapy against citrus HLB

    Science.gov (United States)

    Six independent experiments were carried out to evaluate the effectiveness of the chemotherapy coupled with the thermotherapy on pot-contained HLB-affected plants based on our previous results from graft-based methods. Three-year old potted HLB-affected citrus plants were exposed to 4 thermotherapy ...

  11. Micro-irrigation systems, automation and fertigation in citrus

    Directory of Open Access Journals (Sweden)

    Parameshwar Sidramappa Shirgure

    2012-11-01

    Full Text Available Citrus is number one group of fruits grown in more than 140 countries in the world. Micro-irrigation systems and fertigation management is one of the main concerns of the modem citrus fruit production irrespective of availability of soil, water and fertilizer resources. A variety of recommendations have emerged world over on irrigation systems and fertigation based on soil and leaf analysis of the nutrients, evapo-transpiration and water use pattern. The research review of literature has revealed best promising results on irrigation scheduling based on depletion pattern of soil available water content, irrigation systems and fertigation. Various micro-irrigation systems have established their superiority over traditionally used flood irrigation with micro-jets having little edge over rest of the others. Similarly, fertigation has shown good responses on growth, yield, quality and uniform distribution pattern of applied nutrients within the plant rootzone compared to band placement involving comparatively localized fertilization. Automated fertigation in citrus orchards is a new concept, which would be the only solitary choice amongst many irrigation monitoring methods in near future. The present status of the review on micro-irrigation and fertigation in citrus cultivars is clearly indicated in this article.

  12. Inhibition of acetylcholinesterase activity by essential oil from Citrus paradisi.

    Science.gov (United States)

    Miyazawa, M; Tougo, H; Ishihara, M

    2001-01-01

    Inhibition of acetylcholinesterase (AChE) activity by essential oils of Citrus paradisi (grapefruit pink in USA) was studied. Inhibition of AChE was measured by the colorimetric method. Nootkatone and auraptene were isolated from C. paradisi oil and showed 17-24% inhibition of AChE activity at the concentration of 1.62 microg/mL. PMID:11858553

  13. Reproductive biology and behavior of the Asian citrus psyllid

    Science.gov (United States)

    A review of research conducted during 2006-2008 on the reproductive biology and behavior of the Asian citrus psyllid (Diaphorina citri) will be presented. Information to be discussed will include daily patterns of mating; frequency of mating; pre-mating and pre-oviposition intervals; daily and seaso...

  14. Infection and decontamination of citrus-canker-inoculated leaf surfaces

    Science.gov (United States)

    Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida and continues to spread. Personnel and equipment decontamination is practiced in both disease-endemic and disease-free areas to reduce the risk of bacterial spread by man or machinery. We used grapefruit leaf su...

  15. Learning to fight a fly : developing citrus IPM in Bhutan

    NARCIS (Netherlands)

    Schoubroeck, van H.J.

    1999-01-01

    The chinese citrus fly is one of the key pests in Bhutanese mandarin orchards that lays eggs in developing fruit that cause pre-mature fruit drop. In this study it is used as a "model subject" to explore the integration of technical, social and administrative domains of knowledge. The confinement of

  16. Citrus greening detection using airborne hyperspectral and multispectral imaging techniques

    Science.gov (United States)

    Hyperspectral imaging can provide unique spectral signatures for diseased vegetation. Airborne multispectral and hyperspectral imaging can be used to detect potentially infected trees over a large area for rapid detection of infected zones. This paper proposes a method to detect the citrus greening...

  17. Development of direct somatic embryogenesis and regeneration on citrus sinesis

    International Nuclear Information System (INIS)

    The plant regeneration processes in Citrus sinensis involves direct somatic embryogenesis. Culture medium used was MS basal supplemented with 50 mg/L sucrose, 0.27% agar and 0.1% vitamin at pH 5.8. Sucrose is the major carbon source for the induction of somatic embryo and also the maturation and germination of somatic embryo. (Author)

  18. Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri (Hemiptera: Psyllidae, is the primary vector of the phloem-limited bacterium Candidatus Liberibacter asiaticus (LAS associated with huanglongbing (HLB, citrus greening, considered the world's most serious disease of citrus. Stylet morphometrics of ACP nymphs and adults were studied in relation to citrus vein structure and to their putative (histologically verified feeding sites on Valencia orange leaves. ACP nymphs preferred to settle and feed on the lower (abaxial side of young leaves either on secondary veins or on the sides of the midrib, whereas adults preferred to settle and feed on the upper (adaxial or lower secondary veins of young or old leaves. Early instar nymphs can reach and probe the phloem probably because the distance to the phloem is considerably shorter in younger than in mature leaves, and is shorter from the sides of the midrib compared to that from the center. Additionally, the thick-walled 'fibrous ring' (sclerenchyma around the phloem, which may act as a barrier to ACP stylet penetration into the phloem, is more prominent in older than in younger leaves and in the center than on the sides of the midrib. The majority (80-90% of the salivary sheath termini produced by ACP nymphs and adults that reached a vascular bundle were associated with the phloem, whereas only 10-20% were associated with xylem vessels. Ultrastructural studies on ACP stylets and LAS-infected leaves suggested that the width of the maxillary food canal in first instar nymphs is wide enough for LAS bacteria to traverse during food ingestion (and LAS acquisition. However, the width of the maxillary salivary canal in these nymphs may not be wide enough to accommodate LAS bacteria during salivation (and LAS inoculation into host plants. This may explain the inability of early instar nymphs to transmit LAS/HLB in earlier reports.

  19. Role of imidacloprid in integrated pest management of California citrus.

    Science.gov (United States)

    Grafton-Cardwell, E E; Lee, J E; Robillard, S M; Gorden, J M

    2008-04-01

    Portions of three commercial citrus orchards were treated for 1 yr with foliar imidacloprid or for 2 yr with a systemic formulation in a replicated plot design to determine the impact of this neonicotinoid on the San Joaquin Valley California citrus integrated pest management (IPM) program. Foliar-applied imidacloprid had little effect on California red scale, Aonidiella aurantii (Maskell); cottony cushion scale, Icerya purchasi Maskell; or citrus red mite, Panonychus citri (McGregor), populations. Short-term suppression of the parasitoids Aphytis melinus DeBach and Comperiella bifasciata Howard; vedalia, Rodolia cardinalis (Mulsant); and the predacious mite Euseius tularensis (Congdon) were observed. Suppression of natural enemies allowed scales and mites to maintain higher populations in the treated areas compared with the nontreated areas. Thus, foliar imidacloprid did not exhibit control of these citrus pest species, and it disrupted biological control. Systemically applied imidacloprid suppressed California red scale and citricola scale populations 2-3 mo after treatment. Suppression of parasitoids of the California red scale also was observed. Thus, treatments of systemic imidacloprid applied in areawide management programs for invasive pests would provide a benefit of California red scale and citricola scale suppression. However, this treatment provided only single-season control of citricola scale, it was somewhat disruptive of biological control, and it did not suppress densities of either scale as low as a treatment of the organophosphate chlorpyrifos for citricola scale or the insect growth regulator pyriproxyfen for California red scale. Insecticides with longer periods of efficacy and greater IPM compatibility than imidacloprid should be used for a sustainable IPM approach in California citrus. PMID:18459411

  20. Twelve polymorphic microsatellite loci from the Asian Citrus Psyllid, Diaphorina citri Kuwayama, the vector for citrus greening disease Huanglongbing

    Science.gov (United States)

    Twelve polymorphic microsatellite markers were developed from microsatellite-enriched DNA libraries and mined from an EST library of Diaphorina citri, the vector of the devastating citrus greening disease (Huanglongbing). Analysis of 288 individuals from Florida, Texas, and Brazil showed allelic di...

  1. Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles' Heel of the Citrus Greening Insect Vector.

    Directory of Open Access Journals (Sweden)

    John S Ramsey

    Full Text Available 'Candidatus Liberibacter asiaticus' (CLas, the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including 'Candidatus Profftella armatura', are likely to impact transmission of CLas. We used quantitative mass spectrometry to compare the proteomes of CLas(+ and CLas(- populations of D. citri, and found that proteins involved in polyketide biosynthesis by the endosymbiont Profftella were up-regulated in CLas(+ insects. Mass spectrometry analysis of the Profftella polyketide diaphorin in D. citri metabolite extracts revealed the presence of a novel diaphorin-related polyketide and the ratio of these two polyketides was changed in CLas(+ insects. Insect proteins differentially expressed between CLas(+ and CLas(- D. citri included defense and immunity proteins, proteins involved in energy storage and utilization, and proteins involved in endocytosis, cellular adhesion, and cytoskeletal remodeling which are associated with microbial invasion of host cells. Insight into the metabolic interdependence between the insect vector, its endosymbionts, and the citrus greening pathogen reveals novel opportunities for control of this disease, which is currently having a devastating impact on citrus production worldwide.

  2. Living on the Edges: Spatial Niche Occupation of Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae, in Citrus Groves.

    Directory of Open Access Journals (Sweden)

    Mamoudou Sétamou

    Full Text Available The spatial niche occupation of the Asian citrus psyllid, Diaphorina citri Kuwayama, 1908, was evaluated to determine its field colonization and food resource exploitation strategies in citrus groves. Mature grapefruit and sweet orange groves were surveyed as part of an area-wide program in 2009-2010 to determine D. citri population densities and between-tree distribution. In both cultivars, significantly more psyllids were found on perimeter trees throughout the study period suggesting a strong edge effect in D. citri distribution in the groves. D. citri densities and infestation levels gradually declined from the edge to the center of grove. Higher numbers of D. citri were recorded on trees located on the east and south sides of the groves than those on the west and north sides. Citrus groves located at the outer edge of the study with at least one side non-surrounded to other citrus groves harbored significantly more D. citri than groves located within the block cluster and entirely surrounded by other groves. In detailed field studies during 2012, infestation of D. citri started from border trees in the grove where possibly one generation is completed before inner trees become infested. In addition, psyllid densities decreased significantly with increasing distance from the grove edge. Using the selection index, D citri exhibited a strong niche occupation preference for border trees.

  3. First report of citrus exocortis viroid and two citrus variants of the hop stunt viroid on lemon in Azerbaijan

    Science.gov (United States)

    Budwood received from a lemon tree growing at the Bioresources Institute Nakhichivan, Azerbaijan, produced symptoms corresponding with citrus viroids and cachexia on biological indicators ‘S-1’ citron and ‘Parson’s Special’ (PSM) mandarin, respectively. Sequential poly acrylamide gel electrophoresis...

  4. Dietary citrus pulp improves protein stability in lamb meat stored under aerobic conditions

    DEFF Research Database (Denmark)

    Gravador, Rufielyn Sungcaya; Jongberg, Sisse; Andersen, Mogens Larsen;

    2014-01-01

    The antioxidant effects of dried citrus pulp on proteins in lamb meat, when used as a replacement of concentrate in the feed, was studied using meat from 26 male Comisana lambs. The lambs of age 90. days had been grouped randomly to receive one of the three dietary treatments: (1) commercial...... concentrate with 60% barley (Control, n=8), (2) concentrate with 35% barley and 24% citrus pulp (Cp24, n=9), or (3) concentrate with 23% barley and 35% citrus pulp (Cp35, n=9). Slices from the longissimus thoracis et lomborum muscle were packed aerobically and stored for up to 6. days at 4°C in the dark. The...... citrus pulp groups, Cp24 and Cp35, significantly decreased protein radicals and carbonyls, and preserved more thiols within six days of storage compared to the Control group. The citrus pulp groups significantly slowed down the rate of protein oxidation, indicating that dietary citrus pulp reduced...

  5. The effect of pre spring spray to reduce of citrus important pests.

    Science.gov (United States)

    Hashemi, B; Damavandian, M R; Shoushtaril, R Vafaei; Tafaghodynia, B

    2008-10-01

    The importance of pre spring spray against citrus aphids, Pulvinaria aurantii Cockerell and Panonychus citri McGregor that are the most important pest of citrus during spring was tested. In this research, 150 trees ten years old sweet orange (Thomson navel on Citrus aurantium (root stocks)) in a citrus orchard approximately three hectares sampled. The experiment was laid out in a totally randomized (one-way) design replicated five times. According to the results, the pre spring spray do not effect on population density of citrus aphids and P. aurantii during March, April, May and June. However, the P. citri population decreased. Therefore, it seems the pre spring spray in citrus orchards is not necessary, but if P. citri is observed, the pre spring spray should be recommended. PMID:19137868

  6. Authenticity analysis of citrus essential oils by HPLC-UV-MS on oxygenated heterocyclic components

    Directory of Open Access Journals (Sweden)

    Hao Fan

    2015-03-01

    Full Text Available Citrus essential oils are widely applied in food industry as the backbone of citrus flavors. Unfortunately, due to relatively simple chemical composition and tremendous price differences among citrus species, adulteration has been plaguing the industry since its inception. Skilled blenders are capable of making blends that are almost indistinguishable from authentic oils through conventional gas chromatography analysis. A reversed-phase high performance liquid chromatography (HPLC method was developed for compositional study of nonvolatile constituents in essential oils from major citrus species. The nonvolatile oxygenated heterocyclic components identified in citrus oils were proved to be more effective as markers in adulteration detection than the volatile components. Authors are hoping such an analysis procedure can be served as a routine quality control test for authenticity evaluation in citrus essential oils.

  7. Citrus essential oils and their influence on the anaerobic digestion process: an overview.

    Science.gov (United States)

    Ruiz, B; Flotats, X

    2014-11-01

    Citrus waste accounts for more than half of the whole fruit when processed for juice extraction. Among valorisation possibilities, anaerobic digestion for methane generation appears to be the most technically feasible and environmentally friendly alternative. However, citrus essential oils can inhibit this biological process. In this paper, the characteristics of citrus essential oils, as well as the mechanisms of their antimicrobial effects and potential adaptation mechanisms are reviewed. Previous studies of anaerobic digestion of citrus waste under different conditions are presented; however, some controversy exists regarding the limiting dosage of limonene for a stable process (24-192 mg of citrus essential oil per liter of digester and day). Successful strategies to avoid process inhibition by citrus essential oils are based either on recovery or removal of the limonene, by extraction or fungal pre-treatment respectively. PMID:25081855

  8. Construction and Evaluation of the Theoretical Model of Citrus Cooperative Organization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the general overview of cooperative economic organizations of citrus industry at home and abroad,theoretical model of the modernization,industrialization and marketization of Citrus Cooperative Organization is established.After selecting the indices,such as the scale of production,the scale of management,the rate of encouraged farmers,and the market competitiveness,quantitative evaluation index system for modernization,industrialization and marketization is established.Then,Citrus Cooperative Organization is divided into three stages,such as primary stage,intermediate stage and senior stage.After evaluating the modernization,industrialization and marketization of citrus industry in the United States,Spain and South Africa,it is pointed out that the Citrus Cooperative Organization in China at present is at the primary stage.Finally,policy direction of the development of Citrus Cooperative Organization in China is pointed out.

  9. Comparison of different diagnostic methods for detection of Hop stunt viroid and Citrus exocortis viroid in citrus

    Directory of Open Access Journals (Sweden)

    Cecilia Escobar Ponce de León

    2012-06-01

    Full Text Available Viroids such as Hop stunt viroid (HSVd and Citrus exocortis viroid (CEVd are important pathogens in citrus plants. A comparative assay was performed to evaluate the viroid diagnostic techniques currently available at the Citrus Sanitation Center of Estación Experimental Agroindustrial Obispo Colombres. We compared the results obtained in the diagnosis of HSVd and CEVd in citrus using two molecular techniques: s-PAGE and RT-PCR and biological indexing. Biological indexing was performed in a greenhouse under controlled temperature, using Etrog citron Arizona 861-S1 grafted on rough lemon rootstock as the indicator plant. Tissue samples for s-PAGE were obtained from inoculated citrons used in the biological indexing tests, and DNA extraction was performed following published procedures. HSVd and CEVd specific primers were used for RT-PCR, and samples were taken directly from field plants and inoculated citrons. Two nucleic acid extraction methods were compared. A total of 12 viroid isolates collected from orange, citron, grapefruit, citrumelo and lime trees, mostly from North Western Argentina, were used in these assays. The three diagnostic methods compared gave similar results in 11 of 12 samples assayed. Several viroids were detected by s-PAGE and most of them were found as mixtures. HSVd and CEVd were identified by RT-PCR and no differences were found between the two extraction methods assayed. Sample R-407 was positive for exocortis with biological diagnosis and s-PAGE, but it was negative with RT-PCR. This was probably due to inefficient cDNA synthesis or to the presence of inhibitors that could interfere with the reaction. On the basis of the results obtained, it can be concluded that the three techniques assayed are complementary and useful tools for diagnosis and identification of HSVd and CEVd in citrus.

  10. Mining of haplotype-based expressed sequence tag single nucleotide polymorphisms in citrus

    OpenAIRE

    Chen, Chunxian; Gmitter Jr, Fred G

    2013-01-01

    Background Single nucleotide polymorphisms (SNPs), the most abundant variations in a genome, have been widely used in various studies. Detection and characterization of citrus haplotype-based expressed sequence tag (EST) SNPs will greatly facilitate further utilization of these gene-based resources. Results In this paper, haplotype-based SNPs were mined out of publicly available citrus expressed sequence tags (ESTs) from different citrus cultivars (genotypes) individually and collectively for...

  11. Evaluation of Skin Anti-aging Potential of Citrus reticulata Blanco Peel

    OpenAIRE

    Apraj, Vinita D.; Pandita, Nancy S.

    2016-01-01

    Background: The peel of Citrus reticulata Blanco is traditionally used as tonic, stomachic, astringent, and carminative. It is also useful in skin care. Objective: To study the anti-aging potential of alcoholic extracts of C. reticulata Blanco peel using in vitro antioxidant and anti-enzyme assays. Materials and Methods: Plant extracts were obtained by Soxhlation (CR HAE- Hot Alcoholic Extract of Citrus reticulata) and maceration method (CR CAE- Cold Alcoholic Extract of Citrus reticulata). Q...

  12. Evaluation of skin anti-aging potential of Citrus reticulata blanco peel

    OpenAIRE

    Vinita D Apraj; Nancy S Pandita

    2016-01-01

    Background: The peel of Citrus reticulata Blanco is traditionally used as tonic, stomachic, astringent, and carminative. It is also useful in skin care. Objective: To study the anti-aging potential of alcoholic extracts of C. reticulata Blanco peel using in vitro antioxidant and anti-enzyme assays. Materials and Methods: Plant extracts were obtained by Soxhlation (CR HAE- Hot Alcoholic Extract of Citrus reticulata) and maceration method (CR CAE- Cold Alcoholic Extract of Citrus reticulata). Q...

  13. Characterization and biological properties of Citrus industrial derivatives and waste products for the formulation of nutraceuticals

    OpenAIRE

    Pagano, Francesco

    2015-01-01

    2013 - 2014 Polyphenols are natural chemical compounds, common in higher plants as and particularly known and appreciated for their health properties. We focused attention on Citrus bergamia, Citrus sinensis, Mela annurca and Vitis Vinifera. Citrus is one of larges species among plant; it consists of 40 species which are distributed in all continents and its fruits. We have developed a fast HPLC with ion-trap TOF-MS method for the analysis of flavonoids in these juices. With respect to the...

  14. Metalized Polyethylene Mulch to Reduce Incidence of Huanglongbing and Improve Growth of New Citrus Plantings

    OpenAIRE

    Croxton, S.; Stansly, P.

    2014-01-01

    Polyethylene mulch was evaluated for deterring colonization by Asian citrus psyllid (ACP) Diaphorina citri, reducing incidence of huanglongbing (HLB) or citrus greening disease and accelerating growth of young citrus.  UV reflective low density polyethylene mulch metalized with aluminum, low density whitefaced polyethylene mulch and bare ground all using drip irrigation in a randomized complete block design were tested and compared to the current grower standard using micro-sprinkler irrigati...

  15. Evaluation of antibiotics against the bacteria, Candidatus Liberibacter for control of citrus Huanglongbing

    OpenAIRE

    Zhang, Muqing; Guo, Ying; Powell, Charles A.; Duan, Yongping

    2014-01-01

    Citrus Huanglongbing (HLB) is one of the most serious diseases of citrus worldwide. The present study was undertaken to screen antibiotics against Candidatus Liberibacter asiaticus (Las) while simultaneously assessing phytotoxicity to citrus. Twenty-eight antibiotics from ten classes of medical-antibiotics and three agricultural-antibiotics were tested for in vivo activities against HLB bacterium using the previously optimized graft-based chemotherapy method (Zhang et al., 2012). First, sampl...

  16. Relations between behavior of HLB and Iron application to Citrus trees

    OpenAIRE

    Matsuyama, T.; Muraki, S.; Subandiyah, S.; Joko, T.; Ono, H.; Masaoka, Y

    2014-01-01

    Citrus Greening Disease or Huanglongbing (HLB) is one of the most serious citrus diseases in the world. There are no effective methods to cure this disease, and major countermeasures include detection of initial detection and cutting down  infected trees. Thus, HLB delivers serious impact to the agricultural economy. It is well known that an HLB infected tree shows specific symptoms like micronutrient deficiency. We revealed that iron (Fe) content of citrus leaves showing symptoms f...

  17. Analyses of proteomic expression profiles and nutrient status of citrus plants in response to Huanglongbing

    OpenAIRE

    H. Lin; Nwugo, C. C.; Duan, Y.

    2014-01-01

    Huanglongbing (HLB) is a highly devastating citrus disease and represents a major threat to the citrus industries in US. The etiology of HLB worldwide is associated with three insect-transmissible phloem-limited members of the bacterial group ‘Candidatus Liberibacter spp.’, prevalently ‘Candidatus Liberibacter asiaticus’ (Las). All citrus cultivars are susceptible to HLB. To better understand the physiological and molecular processes involved in host responses to Las, proteomic analyses via 2...

  18. Construction of citrus gene coexpression networks from microarray data using random matrix theory

    OpenAIRE

    Dongliang Du; Nidhi Rawat; Zhanao Deng; Gmitter Jr., Fred G.

    2015-01-01

    After the sequencing of citrus genomes, gene function annotation is becoming a new challenge. Gene coexpression analysis can be employed for function annotation using publicly available microarray data sets. In this study, 230 sweet orange (Citrus sinensis) microarrays were used to construct seven coexpression networks, including one condition-independent and six condition-dependent (Citrus canker, Huanglongbing, leaves, flavedo, albedo, and flesh) networks. In total, these networks contain 3...

  19. Citrus sinensis Annotation Project (CAP): A Comprehensive Database for Sweet Orange Genome

    OpenAIRE

    Wang, Jia; Chen, DiJun; Lei, Yang; Chang, Ji-Wei; Hao, Bao-Hai; Xing, Feng; Li, Sen; Xu, Qiang; Deng, Xiu-Xin; Chen, Ling-ling

    2014-01-01

    Citrus is one of the most important and widely grown fruit crop with global production ranking firstly among all the fruit crops in the world. Sweet orange accounts for more than half of the Citrus production both in fresh fruit and processed juice. We have sequenced the draft genome of a double-haploid sweet orange (C. sinensis cv. Valencia), and constructed the Citrus sinensis annotation project (CAP) to store and visualize the sequenced genomic and transcriptome data. CAP provides GBrowse-...

  20. Citrus pectin as a hydrocolloid emulsifier: Emulsifying and emulsion stabilizing properties

    OpenAIRE

    Schmidt, Ulrike

    2016-01-01

    Citrus pectin is commonly used as a gelling agent and viscosity enhancer in food products. However, it is considered to be less effective in terms of emulsifier. This thesis explores ways to enhance the emulsifying properties of citrus pectin by molecular modification and by a proper choice of recipe parameters. It is shown how stable emulsions can be produced with citrus pectin when the viscosity enhancing effects are properly accounted for.

  1. Measuring the amount of vitamin C in citrus fruits by atwo step oxidation-

    OpenAIRE

    M.A. Ebrahimzadeh; S.J. Hosseinimehr; M Mahmodi; M.R. Gayekhloo; M. Hoseiani

    2005-01-01

    Background and purpose:Epidemiological evidence has suggested that consumption of fruits reduces the risk of chronic diseases such as cancer and cardiovascular disease. These benefits are often attributed to their high antioxidant components such as vitamin C (ascorbic acid). Citrus species are extremely rich sources for this vitamin, therefore we decided to determine the amount of vitamin C in some citrus fruits.Materials and methods : 13 species of commonly used citrus fruits were collected...

  2. Citrus essential oils and their influence on the anaerobic digestion process: An overview

    OpenAIRE

    RUIZ FUERTES, BEGOÑA; Flotats Ripoll, Xavier

    2014-01-01

    Citrus waste accounts for more than half of the whole fruit when processed for juice extraction. Among valorisation possibilities, anaerobic digestion for methane generation appears to be the most technically feasible and environmentally friendly alternative. However, citrus essential oils can inhibit this biological process. In this paper, the characteristics of citrus essential oils, as well as the mechanisms of their antimicrobial effects and potential adaptation mechanisms are reviewed. P...

  3. Spatial Externalities of Pest Control Decisions in the California Citrus Industry

    OpenAIRE

    Grogan, Kelly A.; Goodhue, Rachael E

    2012-01-01

    Predaceous and parasitic insects provide control of important citrus pests. However, many pesticides are toxic to these beneficials. Using California citrus grower survey data, this article tests whether landscape-level use of pesticides affects the presence of and reliance on Aphytis melinus, an important beneficial insect. Results show that landscape-level pesticide use decreases the presence of A. melinus and increases reliance on insecticides. Pesticide use on non-citrus crops has a signi...

  4. Collaborating to compete: the imperative for the South Australian citrus industry

    OpenAIRE

    Coelho, Bruno; Chapman, Paul

    2006-01-01

    This paper arises from a series of economic reports into the South Australian citrus industry undertaken by the Department of Primary Industries and Resources South Australia (PIRSA). The citrus industry faces a number of significant challenges. Future prosperity depends on the response. Principles of Transaction Cost Economics are drawn upon to understand the nature of the investments involved in citrus growing, permitting the identified problems to be viewed in light of inefficiencies and o...

  5. Quality assessment of citrus-processing industry waste compost for organic and conventional farming

    OpenAIRE

    Ciaccia, Dr Corrado; Di Bartolomeo, Dr Emanuela; Calabretta, Dr M.L.; Intrigliolo, Dr Francesco; Tittarelli, Dr. Fabio; Canali, Dr. Stefano

    2008-01-01

    The aim of the work was to verify the potential of citrus by-products for the production of a quality compost to be used in both conventional and organic farming. Two different composts were produced utilizing Pastazzo (mixture of citrus pulp and skins). One of them, to be used in conventional farming, was prepared adding sludges obtained from citrus industry waste water treatment to pastazzo. The other one, whose final destination was organic farming, was produced without the addition of slu...

  6. Observation of Climacteric-Like Behavior of Citrus Leaves Using Fluorescence Spectroscopy

    Directory of Open Access Journals (Sweden)

    Caio B. Wetterich

    2014-01-01

    Full Text Available Observation of climacteric-like behavior in citrus leaves depends on the detection of ethylene. However, such detection requires a gas chromatographer and complex sample preparation procedures. In this work, fluorescence spectroscopy was investigated as a diagnostic technique for climacteric-like behavior in citrus leaves. Our results indicate that the chlorophyll fluorescence presents a time evolution consistent with the ethylene evolution. Therefore, fluorescence spectroscopy may be used to observe the climacteric-like behavior in citrus leaves.

  7. Recommended pesticides persistence for integrated citrus production on ectoparasitoid Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae)

    OpenAIRE

    Beloti, Vitor H.; Zanardi, Odimar Z.; Lira, Aline C. S.; Rugno, Gabriel R.; José R. P. Parra; Pedro T. Yamamoto

    2014-01-01

    Tamarixia radiata (Waterston, 1922) is the main biological control agent of the psyllid Diaphorina citri Kuwayama, vector of bacteria associated with Huanglongbing in citrus. However, indiscriminate use of chemicals affects its control rate. Thus, this study assessed the biological persistence of 22 insecticides, two oils and 16 acaricides recommended for the control of citrus pests, on the parasitoid T. radiata. For this, the parasitoid adults were exposed to waste products sprayed on citrus...

  8. Genomics meets induced mutations in citrus: identification of deleted genes through comparative genomic hybridization

    International Nuclear Information System (INIS)

    We report on the use of genomic approaches to identify pivotal genes in induced citrus mutants. Citrus is the most economically important fruit crop in the world while Spain is the first fresh citrus producer. The survival of the Citrus industry is critically dependent on genetically superior cultivars but improvements in fruit quality traits through traditional techniques are extremely difficult due to the unusual combination of biological characteristics of citrus. Genomic science, however, holds promise of improvements in breeding. In this work, we reported the successful identification of genes included in hemizygous deletions induced by fast neutron irradiation on Citrus clementina. Microarray-based CGH was used to identify underrepresented genes in a citrus mutant that shows color break delay. Subsequent confirmation of gene doses through quantitative PCR and comparison of best hits of putative deleted citrus genes against annotated genomes from other eudicots, specially poplar, enabled the prediction that these genes were clustered into a 700 kb fragment. The availability of Citrus BAC end sequences helped to draw a partial physical map of the deletion. Furthermore, gene content and order in the deleted segment was established by PCR location of gene hits on the physical map. Finally, a lower chlorophyll a/b ratio was found in green tissues from the mutant, an observation that can be related to the hemizygous deletion of a ClpC-like gene, coding a putative subunit of a multifunctional protease complex located into the chloroplast. Analysis of gene content and order inside this Citrus deletion led to the conclusion that microsynteny and local gene colinearity with Populus trichocarpa were higher than with the phylogenetically closer Arabidopsis thaliana genome. In conclusion, a combined strategy including genomics tools and induced citrus mutations has been proved to be a successful approach to identify genes with major roles in citrus fruit development

  9. Genomics Meets Induced Mutations in Citrus: Identification of Deleted Genes Through Comparative Genomic Hybridization

    International Nuclear Information System (INIS)

    We report on the use of genomic approaches to identify pivotal genes in induced citrus mutants. Citrus is the most economically important fruit crop in the world and Spain is the first fresh citrus producer. The survival of the citrus industry is critically dependent on genetically superior cultivars but improvements in fruit quality traits through traditional techniques are extremely difficult due to the unusual combination of biological characteristics of citrus. Genomic science, however, holds promise of improvements in breeding. In this work, we reported the successful identification of genes included in hemizygous deletions induced by fast neutron irradiation on Citrus clementina. Microarray-based CGH was used to identify underrepresented genes in a citrus mutant that shows color break delay. Subsequent confirmation of gene doses through quantitative PCR and comparison of best hits of putative deleted citrus genes against annotated genomes from other eudicots, specially poplar, enabled the prediction that these genes were clustered into a 700 kb fragment. The availability of Citrus BAC end sequences helped to draw a partial physical map of the deletion. Furthermore, gene content and order in the deleted segment was established by PCR location of gene hits on the physical map. Finally, a lower chlorophyll a/b ratio was found in green tissues from the mutant, an observation that can be related to the hemizygous deletion of a ClpC-like gene, coding a putative subunit of a multifunctional protease complex located into the chloroplast. Analysis of gene content and order inside this Citrus deletion led to the conclusion that microsynteny and local gene colinearity with Populus trichocarpa were higher than with the phylogenetically closer Arabidopsis thaliana genome. In conclusion, a combined strategy including genomics tools and induced citrus mutations has been proved to be a successful approach to identify genes with major roles in citrus fruit development

  10. Authenticity analysis of citrus essential oils by HPLC-UV-MS on oxygenated heterocyclic components

    OpenAIRE

    Hao Fan; Qingli Wu; Simon, James E.; Shyi-Neng Lou; Chi-Tang Ho

    2015-01-01

    Citrus essential oils are widely applied in food industry as the backbone of citrus flavors. Unfortunately, due to relatively simple chemical composition and tremendous price differences among citrus species, adulteration has been plaguing the industry since its inception. Skilled blenders are capable of making blends that are almost indistinguishable from authentic oils through conventional gas chromatography analysis. A reversed-phase high performance liquid chromatography (HPLC) method was...

  11. Differential Reaction of Citrus Species in Malaysia to Huanglongbing (HLB Disease using Grafting Method

    Directory of Open Access Journals (Sweden)

    Hajivand Shokrollah

    2009-01-01

    Full Text Available Problem statement: Huanglongbing (HLB is a phloem limited disease in citrus caused by a fastidious bacterium called Candidatus Liberibacter found in Africa, Asia and United States of America (USA. HLB can severely reduce vigor and yield or kill all citrus trees within 5 years. There is a need to screen and identify suitable rootstock for propagation of clean plan materials for citrus in the tropics. This study was conducted to detect the presence of HLB on 18 selected citrus species and to categorize the level of infection and susceptibility of citrus species to HLB. Approach: Eighteen citrus species were assessed for susceptibility to HLB by graft transmission from source infection (Citrus reticulata. Results: HLB was detected in 15 species 6 months after grafting using PCR test. Conclusion: The species could be categorized in five groups: Severe group (72-58% severity which includes C. reticulata, C. sinensis, C. reshni cv. cleopatra, moderate group (50- 41% severity includes Fortunella sp. cv. Kasturi Chinai, C. macrophylla, C. microcarpa, mild group (25-17% severity which included C. medica, C. aurantifolia, Citrus sp. (natural biotype, C. jambhiri. The tolerant group which did not show any HLB symptoms but tested positive by PCR test includes C. aurantium and C. aurantifolia. The resistant groups which include C. grandis cv. Limau Bali, C. hysterix and Citrus sp. cv. Limau Tembikai showed no symptoms and were tested negative for HLB.

  12. Taxonomy and phylogeny of the genus citrus based on the nuclear ribosomal dna its region sequence

    International Nuclear Information System (INIS)

    The genus Citrus (Aurantioideae, Rutaceae) is the sole source of the citrus fruits of commerce showing high economic values. In this study, the taxonomy and phylogeny of Citrus species is evaluated using sequence analysis of the ITS region of nrDNA. This study is based on 26 plants materials belonging to 22 Citrus species having wild, domesticated, and cultivated species. Through DNA alignment of the ITS sequence, ITS1 and ITS2 regions showed relatively high variations of sequence length and nucleotide among these Citrus species. According to previous six-tribe discrimination theory by Swingle and Reece, the grouping in our ITS phylogenetic tree reconstructed by ITS sequences was not related to tribe discrimination but species discrimination. However, the molecular analysis could provide more information on citrus taxonomy. Combined with ITS sequences of other subgenera in then true citrus fruit tree group, the ITS phylogenetic tree indicated subgenera Citrus was monophyletic and nearer to Fortunella, Poncirus, and Clymenia compared to Microcitrus and Eremocitrus. Abundant sequence variations of the ITS region shown in this study would help species identification and tribe differentiation of the genus Citrus. (author)

  13. IN VITRO ANTIOXIDANT ACTIVITIES OF LEAVES, FRUITS AND PEEL EXTRACTS OF CITRUS

    Directory of Open Access Journals (Sweden)

    Muthiah PL

    2012-03-01

    Full Text Available ABSTRACT: Aim: The present study was aimed at investigating the antioxidant activities of the leaves, fruits and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon belonging to the family Rutaceae. Materials and Methods: The antioxidant activities of the hydroethanolic extracts have been evaluated by using different in vitro assays and the results were compared with the standard antioxidants such as butylated hydroxytoluene (BHT, ascorbic acid, curcumin, quercetin, etc. In addition, total phenolic and flavonoid contents in these extracts were determined as pyrocatechol and quercetin equivalents respectively. Among the extracts assayed, 4 extracts (leaf and peel extracts of C.aurantium , peel and fruit extracts of C.limetta had effective H donor ability, reducing power ability, metal chelating activity, superoxide anion radical, nitric oxide radical and hydroxyl radical scavenging activities. The antioxidant activity depends upon concentration and increased with increasing amount of the extracts. The free radical scavenging and antioxidant activities may be attributed to the presence of phenolic and flavonoid compounds present in the extracts. Result: The results obtained in the present study indicate that the leaves, fruits and peel of Citrus aurantium, Citrus limetta and Citrus limon serve as the potential source of natural antioxidants. Keywords: Antioxidant; Citrus aurantium; Citrus limetta; Citrus limon; free radical; Rutaceae.

  14. Analysis of Major Carotenoid Composition and Its Content of Citrus Fruit

    Institute of Scientific and Technical Information of China (English)

    TAO Jun; ZHANG Shang-long; ZHANG Liang-cheng; XU Jian-guo; LIU Chun-rong

    2003-01-01

    a-carotene, β-carotene, lycopene, β-cryptoxanthin, zeaxanthin and lutein content of fruits in53 citrus cultivars were determined using HPLC. In both peel and pulp of citrus fruit, the major carotenoidswere lutein, zeaxanthin and β-cryptoxanthin. β-carotene content was relatively low and extremely low was theamount of or-carotene. Among the 53 cultivars tested, lycopene was detected only in pulp of Cara Cara navelorange. Carotenoid content in both peel and pulp of citrus fruit was the highest in Citrus reticulata Blanco andlowest in Citrus grandis Osbeck. Consequently, as far as the health protection value is considered, fruit ofCitrus reticulata Blanco ranks probably higher than other citrus fruits. In fruit of most Citrus retieulatavarities, β-cryptoxanthin was the main carotenoid component in pulp and its amount approximated that of lu-tein in peel. Content of lutein, zeaxanthin and β-cryptoxanthin in peel was about 2.5 - 15 times that in pulp onthe basis of fresh weight. Thus peel was inferred to be the principal location for the carotenoid stock in citrus fruit.

  15. Chikungunya Virus

    Science.gov (United States)

    ... Gaines, PhD, MPH, MA, CHES Differentiating Chikungunya From Dengue: A Clinical Challenge For Travelers CDC Travelers' Health Chikungunya Virus Home Prevention Transmission Symptoms & Treatment Geographic Distribution Chikungunya virus in ...

  16. Zika Virus

    Science.gov (United States)

    Zika is a virus that is spread mostly by mosquitoes. A pregnant mother can pass it to ... through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, ...

  17. Chikungunya virus

    Science.gov (United States)

    Chikungunya virus infection; Chikungunya ... Where Chikungunya is found Before 2013, the virus was found in Africa, Asia, Europe, and the Indian and Pacific oceans. In late 2013, outbreaks occurred for the first time in the ...

  18. Effects of Olfactory Stimulation from the Fragrance of the Japanese Citrus Fruit Yuzu (Citrus junos Sieb. ex Tanaka) on Mood States and Salivary Chromogranin A as an Endocrinologic Stress Marker

    OpenAIRE

    Matsumoto, Tamaki; Asakura, Hiroyuki; Hayashi, Tatsuya

    2014-01-01

    Objective: This study investigated the soothing effects of fragrance from yuzu, a Japanese citrus fruit (Citrus junos Sieb. ex Tanaka), with salivary chromogranin A (CgA) used as an endocrinologic stress marker reflecting sympathetic nervous system activity.

  19. ECHO virus

    Science.gov (United States)

    Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that lead to gastrointestinal infection and skin rashes. ... Echovirus is one of several families of viruses that affect the ... are common. In the United States, they are most common in ...

  20. Zika Virus

    Science.gov (United States)

    ... Zika Virus | See Q&A —June 21, 2016 Zika Virus Protein Could Be Vaccine Target —May 19, 2016 Research Conducted and Supported by the National Institutes of Health (NIH) in Addressing Zika Virus Disease. Testimony before the House Democratic Steering ...

  1. Advances made in in vitro mutation breeding in citrus

    International Nuclear Information System (INIS)

    Induced calli of citrus cultured in vitro were exposed to gamma rays and ethylmethanesulphonate (EMS). An increased frequency of mutation (300 times higher than that in nature) was observed. Two computerized models were established. A high frequency somatic embryogenesis system was developed using glycerol (1-5%), lactose (3-8%) or glactose (7%) as the sole carbon source in MT medium. The habituated embryogenic calli of four citrus cultivars were selected from nucellar calli. Protoplasts with a viability of 91.2% were isolated from the habituated calli after being treated with 0.3% callulase and 0.3% pectinase for 16 hours. The protoplasts began to regenerate into plantlets after 2-3 months. No chromosome variation was found. Two salt resistant mutants were obtained after exposing the calli to gamma rays (5-8 krad) and EMS (0.3-0.5%) and screening with sodium chloride in vitro. Protoplast fusion is also discussed. (author). 4 figs

  2. Citrus bergamia essential oil: from basic research to clinical application

    Directory of Open Access Journals (Sweden)

    Michele eNavarra

    2015-03-01

    Full Text Available Citrus bergamia Risso et Poiteau, also known as Bergamot, is a plant belonging to the Rutaceae family, defined as a hybrid of bitter orange and lemon. It is an endemic plant of the Calabria region (Italy. Bergamot fruit is primarily used for the extraction of its essential oil (bergamot essential oil: BEO, employed in perfume, cosmetics, food and confections.The aim of this review was to collect recent data from the literature on Citrus bergamia essential oil and, through a critical analysis, focus on safety and the beneficial effects on human health. Clinical studies on the therapeutic applications of BEO exclusively focus on the field of aromatherapy, suggesting that its use can be useful for reducing anxiety and stress.

  3. Antibacterial activity of Citrus limonum fruit juice extract.

    Science.gov (United States)

    Okeke, Malachy Ifeanyi; Okoli, Arinze Stanley; Eze, Edith Nneka; Ekwume, Grace Chinwe; Okosa, Evangelin Uchena; Iroegbu, Christian Ukwuoma

    2015-09-01

    The fruit juice extract of Citrus limonum was investigated for antibacterial activity. The antibacterial activity of the extract on ten strains of bacteria was determined by both agar well diffusion and macro-broth dilution methods. The extract was variously bacteriostatic and bactericidal against Bacillussubtilis ATCC 6051, Staphylococcus aureus ATCC 12600, Escherichia coli ATCC 11775, Pseudomonas aeruginosa ATCC 10145 as well as locally isolated clinical strains of the above bacteria and Salmonella kintambo (Human: 13, 23: mt:-), Salmonella typhi and Proteus sp. The MICs ranged from 0.78 mg/ml to 50mg/ml; MBCs, 25.0mg/ml to >100mg/ml and MBC/MIC ratios 2.0 to >16.0. These results provide scientific justification for the medicinal use of Citrus limonum fruit juice by Nigerian herbalists in the treatment of diseases in which strains of the test organisms have been implicated as etiologic agents. PMID:26408878

  4. Micropropagation of Citrus spp. by organogenesis and somatic embryogenesis.

    Science.gov (United States)

    Chiancone, Benedetta; Germanà, Maria Antonietta

    2013-01-01

    Citrus spp., the largest fruit crops produced worldwide, are usually asexually propagated by cuttings or grafting onto seedling rootstocks. Most of Citrus genotypes are characterized by polyembryony due to the occurrence of adventive nucellar embryos, which lead to the production of true-to-type plants by seed germination. Tissue culture and micropropagation, in particular, are valuable alternatives to traditional propagation to obtain a high number of uniform and healthy plants in a short time and in a small space. Moreover, in vitro propagation provides a rapid system to multiply the progeny obtained by breeding programs, allows the use of monoembryonic and seedless genotypes as rootstocks, and it is very useful also for breeding and germplasm preservation.In this chapter, two protocols regarding organogenesis of a rootstock and somatic embryogenesis of a cultivar have been described. PMID:23179693

  5. Ulcer protective potential of standardized hesperidin, a citrus flavonoid isolated from Citrus sinensis

    Directory of Open Access Journals (Sweden)

    Papiya Bigoniya

    2014-06-01

    Full Text Available Free radicals play an important role in stomach ulcer formation. The present investigation validates the anti ulcer activity of hesperidin, isolated from Citrus sinensis (L. Osbeck, Rutaceae, through the assessment of its antioxidant potential over stomach mucosal tissue by histological examination. Hesperidin was isolated from the dried peel of C. sinensis, and authenticated by TLC, IR and HPLC. The anti-ulcerogenic potential of this fruit was assessed using indomethacin and hypothermic restrain stress-induced ulceration models on rats at 150, 300 and 450 mg/kg dose orally. The parameters measured were gastric pH, volume, free and total acidity, ulcer index, and mucin, glutathione, super oxide dismutase, catalase and protein content. Hesperidin at 300 and 450 mg/kg dose showed significant (p < 0.01-0.001 increase in pH, decrease in acidity and ulcer index against indomethacin and hypothermic restrain stress, along with histological evidence of cytoprotection. Glutathione, super oxide dismutase, catalase and mucin levels increased significantly at 450 mg/kg (p <0.05-0.001 after indomethacin ulceration, whereas hypothermic restrain stress only increased glutathione and mucin levels. Hesperidin prevents oxidative cell injury by significant rise of super oxide dismutase, glutathione and catalase levels in gastric mucosa. Hesperidin allowed the regeneration of ulcerated tissue, and prevented hemorrhagic injury of gastric mucosa. The potential anti-ulcer effect of hesperidin may be due to antioxidant, mucoprotective and cytoprotective activities.

  6. A Phylogenetic Analysis of 34 Chloroplast Genomes Elucidates the Relationships between Wild and Domestic Species within the Genus Citrus

    OpenAIRE

    Carbonell-Caballero, Jose; Alonso, Roberto; Ibañez, Victoria; Terol, Javier; Talon, Manuel; Dopazo, Joaquin

    2015-01-01

    Citrus genus includes some of the most important cultivated fruit trees worldwide. Despite being extensively studied because of its commercial relevance, the origin of cultivated citrus species and the history of its domestication still remain an open question. Here, we present a phylogenetic analysis of the chloroplast genomes of 34 citrus genotypes which constitutes the most comprehensive and detailed study to date on the evolution and variability of the genus Citrus. A statistical model wa...

  7. PR gene families of citrus: their organ specific-biotic and abiotic inducible expression profiles based on ESTs approach

    OpenAIRE

    Magnólia A. Campos; Daniel D. Rosa; Juliana Érika C. Teixeira; Maria Luisa P.N. Targon; De Souza, Alessandra A.; Paiva, Luciano V.; Dagmar R. Stach-Machado; Machado, Marcos A

    2007-01-01

    In silico expression profiles, of the discovered 3,103 citrus ESTs putatively encoding for PR protein families (PR-1 to PR-17), were evaluated using the Brazil citrus genome EST CitEST/database. Hierarchical clustering was displayed to identify similarities in expression patterns among citrus PR-like gene families (PRlgf) in 33 selected cDNA libraries. In this way, PRlgf preferentially expressed by organ and citrus species, and library conditions were highlighted. Changes in expression profil...

  8. Transcriptome analysis of root response to citrus blight based on the newly assembled Swingle citrumelo draft genome

    OpenAIRE

    Zhang, Yunzeng; Barthe, Gary; Grosser, Jude W.; Wang, Nian

    2016-01-01

    Background Citrus blight is a citrus tree overall decline disease and causes serious losses in the citrus industry worldwide. Although it was described more than one hundred years ago, its causal agent remains unknown and its pathophysiology is not well determined, which hampers our understanding of the disease and design of suitable disease management. Results In this study, we sequenced and assembled the draft genome for Swingle citrumelo, one important citrus rootstock. The draft genome is...

  9. RNA Interference Screening Reveals Redox Processes to be Most Responsive to Low dsRNA Doses in Asian Citrus Psyllid

    OpenAIRE

    Ramos, John E.; Shatters, Robert G; Powell, Charles A.; Borovsky, Dov; Jain, Ritesh; Shaffer, Lindsay; Ben-Mahmoud, Sulley K.

    2014-01-01

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is an invasive Homopteran that has crippled citrus production in Florida with the spread of the Huanglongbing (Citrus Greening) disease, which yields small discolored and bitter fruit. The disease is associated with the bacterium ‘Candidatus’ Liberibacter and is rapidly spreading to other citrus producing states. Gene targets were competitively deposited by experts from diverse fields for RNAi screening through an Innocentive challenge fund...

  10. Behavioral, Ultrastructural, and Chemical Studies on the 'Honeydew' Excretions in Nymphs and Adults of the Asian Citrus Psyllid

    OpenAIRE

    Ammar, E. D.; Alessandro, R.; Shatters, R G; Hall, D.G.

    2014-01-01

    The Asian citrus psyllid (ACP) Diaphorina citri (Hemiptera:  Psyllidae) is the main vector of bacteria responsible for citrus huanglongbing (citrus greening), the most serious citrus disease worldwide. Behavioral and ultrastructural studies on ‘honeydew’ excretions by ACP indicated interesting differences between nymphs, males and females. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adults. Video recordings showed ...

  11. Non-enzymatic browning in citrus juice: chemical markers, their detection and ways to improve product quality

    OpenAIRE

    Bharate, Sonali S.; Bharate, Sandip B.

    2012-01-01

    Citrus juices are widely consumed due to their nutritional benefits and variety of pharmacological properties. Non-enzymatic browning (NEB) is one of the most important chemical reactions responsible for quality and color changes during the heating or prolonged storage of citrus products. The present review covers various aspects of NEB in citrus juice viz. chemistry of NEB, identifiable markers of NEB, analytical methods to identify NEB markers and ways to improve the quality of citrus juice...

  12. Identification of photoperception and light signal transduction pathways in citrus

    OpenAIRE

    Vera Quecini

    2007-01-01

    Studies employing model species have elucidated several aspects of photoperception and light signal transduction that control plant development. However, the information available for economically important crops is scarce. Citrus genome databases of expressed sequence tags (EST) were investigated in order to identify genes coding for functionally characterized proteins responsible for light-regulated developmental control in model plants. Approximately 176,200 EST sequences from 53 libraries...

  13. Effectiveness of Phenolic Compounds against Citrus Green Mould

    OpenAIRE

    Sanzani, Simona M.; Leonardo Schena; Antonio Ippolito

    2014-01-01

    Stored citrus fruit suffer huge losses because of the development of green mould caused by Penicillium digitatum. Usually synthetic fungicides are employed to control this disease, but their use is facing some obstacles, such public concern about possible adverse effects on human and environmental health and the development of resistant pathogen populations. In the present study quercetin, scopoletin and scoparone—phenolic compounds present in several agricultural commodities and associated w...

  14. Evaluation of Citrus Fibers as a Tablet Excipient

    OpenAIRE

    Cespi, Marco; Bonacucina, Giulia; Roberts, Matthew; Hanson, Samuel; Jones, Stephen; Makevica, Elina; Casettari, Luca; Palmieri, Giovanni Filippo

    2013-01-01

    The consumption of fibers is associated with many health benefits, such as a reduction of cardiovascular and gastrointestinal diseases, control of body weight, and prevention of diabetes. Despite the widespread use of fiber supplements such as capsules or tablets, there is an almost complete lack of information concerning the technological properties of functional fibers used in nutraceutical formulations. The aim of this work was to characterize the technological properties of citrus fibers ...

  15. Discrimination of Five Citrus Diseased Leaves by FTIR Spectroscopy

    OpenAIRE

    Zhao, Xingxiang; Liu, Gang; Li, Weixing; Wang, Xiaohua; Hao, Jianming; Zhou, Xiangping

    2014-01-01

    In this paper, citrus brown spot, huanglongbing, canker, fuliginous, cercospora sp. and healthy leaves were studied using Fourier transform infrared spectroscopy (FTIR) combined with statistical analysis. The results showed that the spectra of the samples were similar, whereas there were obvious differences in the second derivatives of infrared spectra in the range of 1500-700 cm-1. The correlative analysis were evaluated, results showed that the correlation coefficients were larger than 0.91...

  16. Pathogen infection drives patterns of nutrient resorption in citrus plants

    OpenAIRE

    Jirong Cao; Chunzhen Cheng; Junjie Yang; Qibing Wang

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen ‘Candidatus Liberibacter asiaticus’ grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of ‘Ca. L. asiaticus’ infection on nit...

  17. Influence of Metalaxyl on Three Nematodes of Citrus

    OpenAIRE

    Kaplan, David T.

    1983-01-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability...

  18. Asian Citrus Psyllid Management Strategies for California, 2012 and Beyond

    OpenAIRE

    Grafton-Cardwell, E. E.; Morse, J. G.; Taylor, B J

    2014-01-01

    Asian citrus psyllid (ACP) was first detected in southern California in September 2008 in the urban landscape.  Since that time, the California Department of Food and Agriculture has conducted an eradication program utilizing systemic imidacloprid and foliar cyfluthrin wherever psyllids are detected.  This program was halted in Los Angeles County in 2011 because of the size of the ACP infestation. Psyllids have continued to spread to the east and the south into San Bernardino, Riverside, and ...

  19. Preparation and Characterization of Pectin Hydroxamates from Citrus Unshiu Peels.

    OpenAIRE

    In Young Bae; Hyun Jae Rha; Suyong Lee; Hyeon Gyu Lee

    2011-01-01

    Pectin was extracted from unshiu orange (Citrus unshiu) peels and was subjected to chemical modification using hydroxamic acid. The structural and physical properties of the resulting derivatives were investigated as a function of hydroxamic acid content (4.68-9.58%). The extracted unshiu orange pectin showed 66.8% degree of esterification, 787.5 mg/g galacturonic acid, and 92 mg/g neutral sugars, which were composed of arabinose (53%), galactose (35%), glucose (5%), rhamnose (5%), and fructo...

  20. Enantiomeric distribution of key volatile components in Citrus essential oils

    OpenAIRE

    Ivana Bonaccorsi; Danilo Sciarrone; Antonella Cotroneo; Luigi Mondello; Paola Dugo; Giovanni Dugo

    2011-01-01

    Citrus as many other plants present characteristic distribution of some enantiomers, thus it is often possible to use this parameter for identification, characterization, genuineness, and pharmacological activity assessment. In particular, it is possible to reveal adulteration of different nature, such as addition of synthetic compounds, or natural components of different botanical origin, with drastic changes in the biological and olfactory properties. This study is focused on the evaluation...

  1. Isolation and Characterisation of Flavonoids From Citrus Peels

    OpenAIRE

    Makovšek, Katja

    2013-01-01

    Citrus flavonoids are very interesting for food and pharmaceutical industry since they possess many antioxidant properties and biological activities. Mandarin peels represent an important source of hesperidin and polymethoxy flavones nobiletin and tangeretin. Pommelo peels represent an important source of naringin that can be used as precursor for naringin dihdydro-2,3-chalcone artificial sweetener. Since pommelo peels possess good antioxidant and antimicrobial properties, their extracts are ...

  2. Antimutagenicity and Anticancer Effects of Citrus Medica Fruit Juice

    OpenAIRE

    Majd Ahmad; Falahian Fathollah; Mehrabian Sedigheh; Hashemi Mehrdad; Ardeshiry Lajimi Abdolreza; Entezari Maliheh

    2009-01-01

    Currently cancer is considered as one of the main factors of mortality globally. Many chemicals in our environment can cause genetic mutations and are potentially responsible for millions of cancer-related deaths. Nowadays the scientists are looking for food materials which can potenthially prevent the cancer occurrence. The purpose of this research is to examine antimutagenicity and anticancer effect of Citrus Medica fruit juice.In present study human astrocytoma cancer cells were cultured i...

  3. Antifungal Edible Coatings for Fresh Citrus Fruit: A Review

    OpenAIRE

    Lluís Palou; Valencia-Chamorro, Silvia A.; Pérez-Gago, María B.

    2015-01-01

    According to their origin, major postharvest losses of citrus fruit are caused by weight loss, fungal diseases, physiological disorders, and quarantine pests. Cold storage and postharvest treatments with conventional chemical fungicides, synthetic waxes, or combinations of them are commonly used to minimize postharvest losses. However, the repeated application of these treatments has led to important problems such as health and environmental issues associated with fungicide residues or waxes ...

  4. Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB).

    Science.gov (United States)

    Hao, Guixia; Stover, Ed; Gupta, Goutam

    2016-01-01

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker. PMID:27499757

  5. Study Antimicrobial Activity of Lemon (Citrus lemon L. Peel Extract

    Directory of Open Access Journals (Sweden)

    Maruti J. Dhanavade

    2011-08-01

    Full Text Available The main objective of the study is extraction, identification of antimicrobial compounds and demonstration of antimicrobial activity of lemon (Citrus lemon L. peel against bacteria. As microorganism are becoming resistant to present day antibiotics, our study focuses on antimicrobial activity and future prophylactic potential of the lemon peel. Biologically active compounds present in the medicinal plants have always been of great interest to scientists. The peel of citrus fruits is a rich source of flavanones and many polymethoxylated flavones, which are very rare in other plants. These compounds, not only play an important physiological and ecological role, but are also of commercial interest because of their multitude of applications in the food and pharmaceutical industries. The citrus peel oils show strong antimicrobial activity. The antimicrobial activity has been checked in terms of MIC by using different solvents against microorganisms like Pseudomonas aeruginosa NCIM 2036 for which MIC was 1:20 in presence of methanol, for Salmonella typhimurium NCIM 5021 the observed MIC was 1:20 in presence of acetone. In case of Micrococcus aureus NCIM 5021 the observed MIC was 1:20 when ethanol was used as solvent. The compounds like coumarin and tetrazene were identified by GC/MS of lemon peel extract.

  6. Citrus rootstocks influence the population densities of pest mites

    Directory of Open Access Journals (Sweden)

    Rafael Rocha da Silva

    2016-01-01

    Full Text Available Citrus are attacked by pest mites such as the citrus rust mite Phyllocoptruta oleivora (Ashmead (Acari: Eriophyidae and the spider mite Tetranychus mexicanus (McGregor (Acari: Tetranychidae. However, little is known on citrus rootstocks influencing pest mites. We aimed to evaluate the influence of rootstocks on population densities of pest mites on the sweet oranges 'Pera CNPMF D-6' and 'Valencia Tuxpan' throughout time. Adults of both mite species were monthly counted during 19 months from June 2011 to February 2013. Rootstocks influenced the populations of pest mites, since lower densities of P. oleivora were found on 'Pera CNPMF D-6' sweet orange grafted on the hybrid TSKC × CTTR - 002 and on 'Swingle' citrumelo in comparison with the hybrid LVK × LCR - 010, 'Red' rough lime and 'Santa Cruz' rangpur lime as rootstocks. Similarly, lower densities of T. mexicanus were found on 'Valencia Tuxpan' sweet orange grafted on the hybrid HTR-051 in comparison to 'Indio' citrandarin, 'Sunki Tropical' mandarin and LVK × LCR - 010 as rootstocks. We concluded that densities of the mites P. oleivora and T. mexicanus on the sweet oranges 'Pera CNPMF D-6' and 'Valencia Tuxpan' were affected in some periods of the year by some rootstocks, suggesting influence of some genotypes on these pests.

  7. Synergy and Other Interactions between Polymethoxyflavones from Citrus Byproducts

    Directory of Open Access Journals (Sweden)

    Benito F. García

    2015-11-01

    Full Text Available The citrus by-products released from citrus processing plants may contain high levels of potentially bioactive compounds such as flavonoids, which are a widely distributed group of polyphenolic compounds with health-related properties based on their antioxidant activity. In the study reported here, the potential bioactivities and antioxidant activities of extracts, fractions and compounds from citrus by-products were evaluated along with the chemical interactions of binary mixtures of compounds and complex mixtures. The bioactivities and interactions were evaluated in wheat coleoptile bioassays and the antioxidant activity was evaluated by the al DPPH (2,2-diphenyl-1-picrylhdrazyl radical radical scavenging assay. The extracts, fractions and most of the isolated compounds (mainly polymethoxyflavones showed high activity in the wheat coleoptile bioassay. However, the antioxidant activity was not consistently high, except in the acetone extract fractions. Moreover, a study of the interactions with binary mixtures of polymethoxyflavones showed the occurrence of synergistic effects. The complex mixtures of fractions composed mainly of polymethoxyflavones caused a synergistic effect when it was added to a bioactive compound such as anethole. The results reported here highlight a new application for the wheat coleoptile bioassay as a quick tool to detect potential synergistic effects in compounds or mixtures.

  8. Influence of mitochondria on gene expression in a citrus cybrid.

    Science.gov (United States)

    Bassene, Jean-Baptiste; Froelicher, Yann; Navarro, Luis; Ollitrault, Patrick; Ancillo, Gema

    2011-06-01

    The production of cybrids, combining nucleus of a species with alien cytoplasmic organelles, is a valuable method used for improvement of various crops. Several citrus cybrids have been created by somatic hybridization. These genotypes are interesting models to analyze the impact of cytoplasmic genome change on nuclear genome expression. Herein, we report genome-wide gene expression analysis in leaves of a citrus cybrid between C. reticulata cv 'Willowleaf mandarin' and C. limon cv 'Eureka lemon' compared with its lemon parent, using a Citrus 20K cDNA microarray. Molecular analysis showed that this cybrid possesses nuclear and chloroplast genomes of Eureka lemon plus mitochondria from Willowleaf mandarin and, therefore, can be considered as a lemon bearing foreign mitochondria. Mandarin mitochondria influenced the expression of a large set of lemon nuclear genes causing an over-expression of 480 of them and repression of 39 genes. Quantitative real-time RT-PCR further confirmed the credibility of microarray data. Genes over-expressed in cybrid leaves are predominantly attributed to the functional category "cellular protein metabolism" whereas in the down-regulated none functional category was enriched. Overall, mitochondria replacement affected different nuclear genes including particularly genes predicted to be involved in mitochondrial retrograde signaling. Mitochondria regulate all cell structures even chloroplast status. These results suggest that nuclear gene expression is modulated with respect to new information received from the foreign organelle, with the final objective to suit specific needs to ensure better cell physiological balance. PMID:21308470

  9. Effect of irradiation as quarantine treatment on citrus fruit quality

    Energy Technology Data Exchange (ETDEWEB)

    Betancurt, Pablo; Montalban, Antonio; Arcia, Patricia; Borthagaray, Maria D.; Curutchet, Ana; Pica, Leticia; Soria, Alejandra; Abreu, Anibal V., E-mail: irradiacion@latu.org.u, E-mail: lacam@latu.org.u [Laboratorio Tecnologico del Uruguay (LATU), Montevideo (Uruguay); Ares, M. Ines, E-mail: mares@mgap.gub.u [Ministerio de Ganaderia, Agricultura y Pesca (MGAP), Montevideo (Uruguay). Directoria General de Sanidad Vegetal (DGSV)

    2009-07-01

    Gamma radiations have been used to improve sanitation treatments without significant effects on fresh fruit quality. The objective of this work was to evaluate the fruit quality characteristics of citrus variety Valencia (Valencia Late), main variety produced and exported in Uruguay. All samples were stored at 3-5 deg C, 80% RH, for 20 and 40 days. Irradiation doses used were 0,35 kGy min. and 0,80 kGy max. (doses that also eliminate the fruit fly). Irradiation experiments were conducted using irradiation equipment from Atomic Center (CAE), year 1968, Co60 source, 800.000 Ci. The effects of irradiation on sensory qualities and physical characteristics were studied. The attributes evaluated were visual appearance (1- 4 hedonic scale, expert), overall acceptance (1-9 hedonic scale, consumers), texture (TAB Stevens, speed: 2m/s, distance: 2mm), yield of juice and colour (Hunter values). In general, no significant changes in these parameters were observed after irradiation. Quality was not significantly affected by doses usually applied to decrease the viability of pathogen that cause citrus Scab. This is an important contribution for the protocols that would allow citrus fruit exportation. (author)

  10. Study of VOC distribution in citrus fruits by chromatographic analysis.

    Science.gov (United States)

    Ligor, Magdalena; Buszewski, Bogusław

    2003-07-01

    The contamination of various parts of citrus fruits by toluene (a representative of volatile organic compounds-VOCs) was analyzed. The model of contamination distribution, based on investigations of the sorption and accumulation of toluene in particular parts of citrus fruits was considered. Solvent extraction of components from fruit parts (waxy layer, cuticle, and pulp) was applied. The extracts were analyzed by gas chromatography. The sorption time profiles for such citrus fruits as kumquats and mandarins were determined by plotting the extracted mass, or the relationship C/C(0), versus the sorption time of toluene. After the sorption process the highest concentration of toluene was observed in the flavedo, where the oil glands of kumquats and mandarins are located. The data obtained prove that the high dissolution of aromatic hydrocarbons results from the presence of essential oils in the oil glands. The diffusion coefficients of toluene for the cuticle and pulp of kumquats were also calculated. The results of model investigations were compared with the actual concentration of toluene in kumquats, citrons, mandarins and oranges from outdoor stands and orchards. PMID:12768263

  11. Effect of irradiation as quarantine treatment on citrus fruit quality

    International Nuclear Information System (INIS)

    Gamma radiations have been used to improve sanitation treatments without significant effects on fresh fruit quality. The objective of this work was to evaluate the fruit quality characteristics of citrus variety Valencia (Valencia Late), main variety produced and exported in Uruguay. All samples were stored at 3-5 deg C, 80% RH, for 20 and 40 days. Irradiation doses used were 0,35 kGy min. and 0,80 kGy max. (doses that also eliminate the fruit fly). Irradiation experiments were conducted using irradiation equipment from Atomic Center (CAE), year 1968, Co60 source, 800.000 Ci. The effects of irradiation on sensory qualities and physical characteristics were studied. The attributes evaluated were visual appearance (1- 4 hedonic scale, expert), overall acceptance (1-9 hedonic scale, consumers), texture (TAB Stevens, speed: 2m/s, distance: 2mm), yield of juice and colour (Hunter values). In general, no significant changes in these parameters were observed after irradiation. Quality was not significantly affected by doses usually applied to decrease the viability of pathogen that cause citrus Scab. This is an important contribution for the protocols that would allow citrus fruit exportation. (author)

  12. The Lebanese Citrus Aurantium: A Promising Future in Medicinal Phytochemistry

    Directory of Open Access Journals (Sweden)

    Salim Makhoul

    2012-11-01

    Full Text Available The West Bekaa region of Lebanon is mostly an agricultural land where traditional herbal medicine is a common practice. Many medicinal applications are especially attributed to the Citrus aurantium plant mainly used in the food and drink industry. In this work, the essential oil of Citrus aurantium is studied in an attempt to find an explanation for the different medical applications of this plant extract which is widely known among locals. Using Gas Chromatography coupled to Mass Spectrometry, twenty-six different chemicals were identified and quantified. These include the major constituent, Linalool, (29.99%, Bergamol (14.94%, Farnesol (9.86% and D-Limonene (8.42%. The latter as well as Linalool are known to have anticancer effects, thus representing major components in anticancer treatments. Their proportions in the studied essential oil and the presence of the other components (a-thujene, apinene, Camphene, Sabinene, b-pinene, b-Myrcene, p-Cymene, Ocimene (E, Linalool oxide (Trans, Linalool oxide (Cis, Terpinen-4-ol, Terpineol, Nerol (Or Cis-Geraniol, Neral, Geranial, Neryl acetate, Geranyl acetate, Nerolidol, Farnesal, Eicosane, Tetracosane, Pentacosane have amplified the importance of Citrus aurantium as a scientifically-proven medicinal plant thus justify its diverse medical applications

  13. Evaluation of antioxidant potential of citrus peel extracts

    International Nuclear Information System (INIS)

    The antioxidant potential of different solvent extracts of three different locally grown citrus varieties; grape fruit, lemon and mussambi, was assessed using some antioxidant assays like estimation of total phenolic contents (TPC), total flavonoids contents (TFC), percentage inhibition of linoleic acid oxidation and DPPH free radical scavenging capacity. The yield of extracts was found in the range of 17.92-30.8%. TPC, TFC, percent inhibition of linoleic acid oxidation and DPPH radical scavenging capacity of different citrus peel extracts were found in range of 2.72 - 3.77 g/100g as Gallic Acid Equivalent (GAE), 2.20-2.98 g/100g as Catechine Equivalent (CE), 68.20 - 91.78% and 19.53 - 41.88 mg/mL, respectively. Statistical analysis showed significant (p < 0.05) variations in the yield and antioxidant potentials of the extracts with respect to different species and solvent systems. From the results it is reasonable to say that methanolic extracts of citrus peels have exhibited varying degree of antioxidant potentials. (author)

  14. Antifungal Edible Coatings for Fresh Citrus Fruit: A Review

    Directory of Open Access Journals (Sweden)

    Lluís Palou

    2015-12-01

    Full Text Available According to their origin, major postharvest losses of citrus fruit are caused by weight loss, fungal diseases, physiological disorders, and quarantine pests. Cold storage and postharvest treatments with conventional chemical fungicides, synthetic waxes, or combinations of them are commonly used to minimize postharvest losses. However, the repeated application of these treatments has led to important problems such as health and environmental issues associated with fungicide residues or waxes containing ammoniacal compounds, or the proliferation of resistant pathogenic fungal strains. There is, therefore, an increasing need to find non-polluting alternatives to be used as part of integrated disease management (IDM programs for preservation of fresh citrus fruit. Among them, the development of novel natural edible films and coatings with antimicrobial properties is a technological challenge for the industry and a very active research field worldwide. Chitosan and other edible coatings formulated by adding antifungal agents to composite emulsions based on polysaccharides or proteins and lipids are reviewed in this article. The most important antifungal ingredients are selected for their ability to control major citrus postharvest diseases like green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, and include low-toxicity or natural chemicals such as food additives, generally recognized as safe (GRAS compounds, plant extracts, or essential oils, and biological control agents such as some antagonistic strains of yeasts or bacteria.

  15. Localized autoinoculation and dissemination of Isaria fumosorosea for control of the Asian citrus psyllid in South Texas

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the causal organism of citrus greening disease. Integrated strategies are needed to control D. citri in south Texas. Control approaches involving entomopathogenic fungi may be useful on ornamental and abandoned citrus and other rutaceous...

  16. Expression of Bacillus thuringiensis Cytolytic Toxin (Cyt2Ca1) in citrus roots to control Diaprepes abbreviatus larvae

    Science.gov (United States)

    Diaprepes abbreviatus (L.) is an important pest of citrus in the USA. Currently, no effective management strategies of Diaprepes abbreviatus exist in citriculture. To protect citrus against Diaprepes abbreviatus a transgenic citrus rootstock expressing Bacillus thuringiensis Cyt2Ca1, an insect toxin...

  17. Determination of genomic diversity within mutant lemon (Citrus limon L.) and mandarin (Citrus reticulata) using molecular markers

    International Nuclear Information System (INIS)

    Mutation breeding is considered to be successful in order to obtain new cultivars and expanding the genetic source of new varieties of lemon and mandarin in Citrus. In this study, different doses of gamma radiation (60Co) have been used to generate novel mutants of the common variety Yerli Yuvarlak lemon and Yerli mandarin. The differences within the mutants were examined using simple sequence repeats (SSR) and sequence related amplified polymorphism (SRAP) markers. A total of 26 SSR primers and 28 SRAP primer combinations were screened for linkage to the different traits. Six SSR primers were showed polymorphism and closely linked to shoot tip color in lemon. Whereas, all of SRAP primer combinations were not produce any scorable polymorphic bands in both Yerli Yuvarlak lemon and Yerli mandarin. In this study, SSR and SRAP molecular markers were used together for first time to determination the genetic differences in citrus mutation breeding in the world. (author)

  18. Induction and identification of somatic mutations with particular reference to perennial plants. Part of a coordinated programme on improvement of vegetatively propagated crops and tree crops through radiation-induced mutations

    International Nuclear Information System (INIS)

    An attempt was made to obtain resistance of oranges (Citrus sinensis L. Osbeck) and grapefruit (C. paradisi Macf.) to Tristeza virus by induced mutation breeding. Two methods were used. In one, buds were treated with X or gamma radiation. The detached sprouts were subsequently grafted. In the other, a number of chemical mutagens were used: diethyl sulfate or propylenoxide on buds; diethyl sulfate or nitrosemethylurethane on seeds (2400). The selection and isolation of mutants from treated buds and seeds, respectively, are described. Intermediate results only are given and discussed

  19. Candidatus Liberibacter asiaticus causes damage to citrus fibrous roots before visual decline of Huanglongbing-infected citrus trees

    OpenAIRE

    Graham, J. H.; Johnson, E. G.; Gottwald, T. R.; Irey, M. S.

    2014-01-01

    Huanglongbing (HLB), associated with Candidatus Liberibacter asiaticus (Las), was first detected in Florida in late 2005 and is now widely distributed throughout the commercial citrus-growing regions. In recent seasons, concurrent with freeze and drought episodes, symptomatic HLB-infected trees were much more affected by the extremes of temperature and moisture than trees without HLB. Symptoms exhibited by the stressed trees were excessive leaf loss and premature fruit drop even when HLB-infe...

  20. Citrus Essential Oil of Nigeria Part IV: Volatile Constituents of Leaf Oils of Mandarins (Citrus Reticulata Blanco) From Nigeria

    OpenAIRE

    Adeleke A. Kasali; Oladipupo. A. Lawal; Olatunji T. F. Abanikannda; Abayomi A. Olaniyan; William N. Setzer

    2010-01-01

    The chemical composition of hydrodistilled oils obtained from the leaves of six Citrus reticulata Blanco (mandarin) cultivars grown in Nigeria were examined by GC and GC/MS, the result of their chemical composition were further submitted to cluster analysis. Fifty seven constituents were characterized accounting for 88.2 - 96.7% of the total oils. Sabinene, g -terpinene, P-cymene, d -3-carene and (E)- b -ocimene were observed in great variability in all the oils. Other constituents include li...

  1. Bacteria as growth-promoting agents for citrus rootstocks.

    Science.gov (United States)

    Giassi, Valdionei; Kiritani, Camila; Kupper, Katia Cristina

    2016-09-01

    The microbial community plays an essential role in maintaining the ecological balance of soils. Interactions between microorganisms and plants have a major influence on the nutrition and health of the latter, and growth-promoting rhizobacteria can be used to improve plant development through a wide range of mechanisms. Therefore, the objective of the present study was to evaluate bacteria as growth-promoting agents for citrus rootstocks. A total of 30 bacterial isolates (11 of Bacillus spp., 11 actinobacteria, and 8 lactic acid bacteria) were evaluated in vitro for indoleacetic acid production, phosphate solubilization, and nitrogen (N) fixation. In vivo testing consisted of growth promotion trials of the bacterial isolates that yielded the best results on in vitro tests with three rootstocks: Swingle citrumelo [Citrus×paradisi Macfad cv. Duncan×Poncirus trifoliata (L.) Raf.], Sunki mandarin (Citrus sunki Hort. ex Tan), and rangpur (Citrus×limonia Osbeck). The parameters of interest were height, number of leaves, stem diameter, shoot and root dry mass, and total dry mass at 150days after germination. The results showed that most bacterial isolates were capable of IAA production. Only one lactic acid bacterium isolate (BL06) solubilized phosphate, with a high solubilization index (PSI>3). In the actinobacteria group, isolates ACT01 (PSI=2.09) and ACT07 (PSI=2.01) exhibited moderate phosphate-solubilizing properties. Of the Bacillus spp. isolates, only CPMO6 and BM17 solubilized phosphate. The bacterial isolates that most fixated nitrogen were BM17, ACT11, and BL24. In the present study, some bacteria were able to promote growth of citrus rootstocks; however, this response was dependent on plant genotype and isolate. Bacillus spp. BM16 and CPMO4 were able to promote growth of Swingle citrumelo. In Sunki mandarin plants, the best treatment results were obtained with BM17 (Bacillus sp.) and ACT11 (actinobacteria). For Rangpur lime rootstock, only BM05 (Bacillus sp

  2. Phenolic Compounds Characterization and Biological Activities of Citrus aurantium Bloom

    Directory of Open Access Journals (Sweden)

    Armin Oskoueian

    2012-01-01

    Full Text Available Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and flavonoids compared to ethanolic and boiling water extracts. The obtained total phenolics value for methanolic Citrus aurantium bloom extract was 4.55 ± 0.05 mg gallic acid equivalent (GAE/g dry weight (DW, and for total flavonoids it was 3.83 ± 0.05 mg rutin equivalent/g DW. In addition, the RP-HPLC analyses of phenolics and flavonoids indicated the presence of gallic acid, pyrogallol, syringic acid, caffeic acid, rutin, quercetin and naringin as bioactive compounds. The antioxidant activity of Citrus aurantium bloom were examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH assay and the ferric reducing/antioxidant potential (FRAP. The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of Citrus aurantium bloom at a concentration of 300 μg/mL, with values of 55.3% and 51.7%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. Furthermore, the anti-inflammatory result of methanolic extract showed appreciable reduction in nitric oxide production of stimulated RAW 264.7 cells at the presence of plant extract. Apart from that, the anticancer activity of the methanolic extract was investigated in vitro against human cancer cell lines (MCF-7; MDA-MB-231, human colon adenocarcinoma (HT-29 and Chang cell as a normal human hepatocyte. The obtained result demonstrated the moderate to

  3. Breeding, genetic and genomic of citrus for disease resistance

    Directory of Open Access Journals (Sweden)

    Marcos A. Machado

    2011-10-01

    Full Text Available Although the citriculture is one of the most important economic activities in Brazil, it is based on a small number of varieties. This fact has contributed for the vulnerability of the culture regarding the phytosanitary problems. A higher number of varieties/genotypes with potential for commercial growing, either for the industry or fresh market, has been one of the main objectives of citrus breeding programs. The genetic breeding of citrus has improved, in the last decades, due to the possibility of an association between biotechnological tools and classical methods of breeding. The use of molecular markers for early selection of zygotic seedlings from controlled crosses resulted in the possibility of selection of a high number of new combination and, as a consequence, the establishment of a great number of hybrids in field experiments. The faster new tools are incorporated in the program, the faster is possibility to reach new genotypes that can be tested as a new variety. Good traits should be kept or incorporate, whereas bad traits have to be excluded or minimized in the new genotype. Scion and rootstock can not be considered separately, and graft compatibility, fruit quality and productivity are essential traits to be evaluated in the last stages of the program. The mapping of QTLs has favored breeding programs of several perennial species and in citrus it was possible to map several characteristics with qualitative and quantitative inheritance. The existence of linkage maps and QTLs already mapped, the development of EST and BAC library and the sequencing of the Citrus complete genome altogether make very demanding and urgent the exploration of such data to launch a wider genetic study of citrus. The rising of information on genome of several organisms has opened new approaches looking for integration between breeding, genetic and genome. Genome assisted selection (GAS involves more than gene or complete genome sequencing and is becoming

  4. Digital Gene Expression Analysis of Ponkan Mandarin (Citrus reticulata Blanco in Response to Asia Citrus Psyllid-Vectored Huanglongbing Infection

    Directory of Open Access Journals (Sweden)

    Yun Zhong

    2016-07-01

    Full Text Available Citrus Huanglongbing (HLB, the most destructive citrus disease, can be transmitted by psyllids and diseased budwoods. Although the final symptoms of the two main HLB transmission ways were similar and hard to distinguish, the host responses might be different. In this study, the global gene changes in leaves of ponkan (Citrus reticulata mandarin trees following psyllid-transmission of HLB were analyzed at the early symptomatic stage (13 weeks post inoculation, wpi and late symptomatic stage (26 wpi using digital gene expression (DGE profiling. At 13 wpi, 2452 genes were downregulated while only 604 genes were upregulated in HLB infected ponkan leaves but no pathway enrichment was identified. Gene function analysis showed impairment in defense at the early stage of infection. At late stage of 26 wpi, however, differentially expressed genes (DEGs involved in carbohydrate metabolism, plant defense, hormone signaling, secondary metabolism, transcription regulation were overwhelmingly upregulated, indicating that the defense reactions were eventually activated. The results indicated that HLB bacterial infection significantly influenced ponkan gene expression, and a delayed response of the host to the fast growing bacteria might be responsible for its failure in fighting against the bacteria.

  5. A reference genetic map of C. clementina hort. ex Tan.; citrus evolution inferences from comparative mapping

    OpenAIRE

    Ollitrault Patrick; Terol Javier; Chen Chunxian; Federici Claire T; Lotfy Samia; Hippolyte Isabelle; Ollitrault Frédérique; Bérard Aurélie; Chauveau Aurélie; Cuenca Jose; Costantino Gilles; Kacar Yildiz; Mu Lisa; Garcia-Lor Andres; Froelicher Yann

    2012-01-01

    Abstract Background Most modern citrus cultivars have an interspecific origin. As a foundational step towards deciphering the interspecific genome structures, a reference whole genome sequence was produced by the International Citrus Genome Consortium from a haploid derived from Clementine mandarin. The availability of a saturated genetic map of Clementine was identified as an essential prerequisite to assist the whole genome sequence assembl...

  6. Disease stress detection on citrus using a leaf optical model and field spectroscopy

    Science.gov (United States)

    Badnakhe, Mrunalini R.; Durbha, Surya; Adinarayana, J.

    2015-10-01

    As citrus is progressively contributing to horticultural production, wealth and economy of a country, it is necessary to understand the factors impacting citrus production. Gummosis is one of the most serious diseases causing considerable loss of overall citrus production and yield quality. A qualitative and quantitative analysis of citrus leaf biochemical properties are necessary to monitor the crop health, disease /pest stress and production. Total leaf chlorophyll content (Cab) represents one of the key biochemical factors which contributes in water, carbon, and energy exchange processes. Photosynthesis process in citrus will be disturbed as gummosis disease life cycle progresses. It is important to study Cab to evaluate the photosynthesis rate and disease stress. In this study the potential of Radiative Transfer (RT) PROSPECT model to retrieve Cab in citrus orchards was undertaken at different sites. The main goal is to evaluate the relationship between Cab and gummosis disease stress for citrus at various phenological stages. Inversion of PROSPECT model on measured hyperspectral data is carried out to extract the leaf level parameters influencing the disease. This model was inverted with the ground truth hyperspectral reading. The testing was separately initiated for healthy and infected plant leaves. This can lead to understand the disease stress on citrus leaves. For accuracy, raw spectra are filtered and processed which is an input parameter for Inversion PROSPECT model. Here, retrieved Cab content was correlated with gummosis disease stress in terms of oozing with R2 = 0.6021 and RMSE= 0.481272.

  7. 76 FR 17617 - Changes to Treatments for Citrus Fruit From Australia

    Science.gov (United States)

    2011-03-30

    ... cherries and citrus fruit. We considered those comments and, in a notice dated August 4, 2010 (75 FR 46901...; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service Changes to Treatments for Citrus Fruit..., 2009, we published in the Federal Register (74 FR 53424-53430, Docket No. APHIS-2008-0140) a...

  8. 7 CFR 301.75-5 - Commercial citrus-producing areas.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Commercial citrus-producing areas. 301.75-5 Section 301.75-5 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Citrus Canker Notice of...

  9. Insecticide sprays, natural enemy assemblages and predation on Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae).

    Science.gov (United States)

    Monzo, C; Qureshi, J A; Stansly, P A

    2014-10-01

    The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is considered a key citrus pest due to its role as vector of 'huanglongbing' (HLB) or citrus greening, probably the most economically damaging disease of citrus. Insecticidal control of the vector is still considered a cornerstone of HLB management to prevent infection and to reduce reinoculation of infected trees. The severity of HLB has driven implementation of intensive insecticide programs against ACP with unknown side effects on beneficial arthropod fauna in citrus agroecosystems. We evaluated effects of calendar sprays directed against this pest on natural enemy assemblages and used exclusion to estimate mortality they imposed on ACP populations in citrus groves. Predator exclusion techniques were used on nascent colonies of D. citri in replicated large untreated and sprayed plots of citrus during the four major flushing periods over 2 years. Population of spiders, arboreal ants and ladybeetles were independently assessed. Monthly sprays of recommended insecticides for control of ACP, adversely affected natural enemy populations resulting in reduced predation on ACP immature stages, especially during the critical late winter/early spring flush. Consequently, projected growth rates of the ACP population were greatest where natural enemies had been adversely affected by insecticides. Whereas, this result does not obviate the need for insecticidal control of ACP, it does indicate that even a selective regimen of sprays can impose as yet undetermined costs in terms of reduced biological control of this and probably other citrus pests. PMID:24830653

  10. Amino acids implicated in plant defense are higher in Candidatus Liberibacter asiaticus-tolerant citrus varieties.

    Science.gov (United States)

    Killiny, Nabil; Hijaz, Faraj

    2016-04-01

    Citrus Huanglongbing (HLB), also known as citrus greening, has been threatening the citrus industry since the early 1900's and up to this date there are no effective cures for this disease. Field observations and greenhouse controlled studies demonstrated that some citrus genotypes are more tolerant to Candidatus Liberibacter asiaticus (CLas) pathogen than others. However, the mechanisms underpinning tolerance has not been determined yet. The phloem sap composition of CLas-tolerant and sensitive citrus varieties was studied to identify metabolites that could be responsible for their tolerance to CLas. The citrus phloem sap was collected by centrifugation and was analyzed with gas chromatography-mass spectrometry after methyl chloroformate derivatization. Thirty-three metabolites were detected in the phloem sap of the studied varieties: twenty 20 amino acids, eight 8 organic acids, and five 5 fatty acids. Interestingly, the levels of most amino acids, especially those implicated in plantdefense to pathogens such as phenylalanine, tyrosine, tryptophan, lysine, and asparagine were higher in tolerant varieties. Although the level of organic acids varied between cultivars, this variation was not correlated with citrus resistance to CLas and could be cultivar specific. The fatty acids were found in trace amounts and in most cases their levels were not significantly different among varieties. Better understanding of the mechanisms underpinning citrus tolerance to CLas will help in developing economically tolerant varieties. PMID:27057814

  11. Evaluation of low-volume sprayers used in asian citrus Psyllid control applications

    Science.gov (United States)

    The Asian citrus psyllid (Diaphorina citri Kumayama, Sternorrhyncha: Psyllidae) is a detrimental pest to citrus crops when it serves as a vector of the pathogen that causes greening (huanglongbing, or HLB). Transmission of this disease causes mottling, chlorosis, dieback and reductions in both frui...

  12. Evaluation of Quantitative Real-Time PCR Assays for Detection of Citrus Greening

    Science.gov (United States)

    Citrus huanglongbing (HLB), or citrus greening, is a serious and industry-limiting disease. Preliminary diagnoses can be made through visual symptoms, and greater certainty can be achieved through quantitative real-time PCR (qPCR). Several qPCR procedures are available including those by designed by...

  13. The scion/rootstock genotypes and habitats affect arbuscular mycorrhizal fungal community in citrus

    NARCIS (Netherlands)

    Song, Fang; Pan, Zhiyong; Bai, Fuxi; An, Jianyong; Liu, Jihong; Guo, Wenwu; Bisseling, Ton; Deng, Xiuxin; Xiao, Shunyuan

    2015-01-01

    Citrus roots have rare root hairs and thus heavily depend on arbuscular mycorrhizal fungi (AMF) for mineral nutrient uptake. However, the AMF community structure of citrus is largely unknown. By using 454-pyrosequencing of 18S rRNA gene fragment, we investigated the genetic diversity of AMF colon

  14. Systemic translocation and metabolism of 14C-metalaxyl in citrus

    International Nuclear Information System (INIS)

    Systemic uptake and translocation of 14C-metalaxyl to citrus seedlings from soils (Humic Gley and Yellow Red Latosol) with different physical - chemical properties are studied. Seedlings of Citrus limonia are treated with 14C-metalaxyl. (M.A.C.)

  15. Acoustic signals in the courtship of male and female Asian citrus psyllids

    Science.gov (United States)

    The Asian citrus psyllid, Diaphorina citri Kuwayama, was discovered in Broward County, Florida in 1998, and has since spread through most of the state. It is an important vector of Huanglongbing, an economically devastating disease of citrus; consequently, researchers and regulators are trying to d...

  16. A comparison of sticky traps for monitoring Asian citrus psyllid (Diaphorina citri Kuwayama)

    Science.gov (United States)

    Six types of sticky card traps differing in color and trapping adhesive were evaluated for monitoring Asian citrus psyllid in citrus in the United States (Florida and Texas). Spectral reflectance measurements were taken to categorize the color (wavelength) spectrum of each trap. Three of the traps (...

  17. Viability of ‘Candidatus Liberibacter asiaticus’ prolonged by addition of citrus juice to culture medium

    Science.gov (United States)

    Huanglongbing, or citrus greening disease, is associated with infection by the phloem-limited bacterium ‘Candidatus Liberibacter asiaticus’ (LAS). Infection with LAS, vectored by the Asian citrus psyllid (Diaphorina citri), is incurable; therefore, knowledge regarding LAS biology and pathogenesis is...

  18. 78 FR 4305 - Common Crop Insurance Regulations; Florida Citrus Fruit Crop Insurance Provisions; Correction

    Science.gov (United States)

    2013-01-22

    ... Friday, December 21, 2012 (74 FR 75509-75521). The regulation pertains to the insurance of Florida Citrus..., 2012, (74 FR 75509-75521). Need for Correction As published, the final regulation contained errors that... in the final rule because all citrus fruit insured as fresh will have a default juice...

  19. Transmission and Propagation of ‘Candidatus Liberibacter asiaticus’ by Grafting with Individual Citrus Leaves

    Science.gov (United States)

    Huanglongbing (HLB) is a chronic, progressive decline disease in citrus associated with systemic infection by the bacterium Candidatus Liberibacter asiaticus (CLas). Transmission in the field is by the Asian citrus psyllid (ACP), Diaphorina citri, Kuwayama. Experimental propagation of CLas is done c...

  20. Accelerated extraction of pectin from orange citrus albedo using focused microwaves

    Science.gov (United States)

    After removal of soluble sugars and other compounds by washing, citrus peel is largely composed of pectin, cellulose and hemicellulose. In order to utilize the greatest amount of citrus peel product, it would appear reasonable that one or all three of these polysaccharides be converted to a useful p...

  1. The community structure of endophytic bacteria in different parts of Huanglongbing-affected citrus plants

    Science.gov (United States)

    The analyses methods of Pearson correlation coefficient (PCC), hierarchical cluster analysis and diversity index were used to study the relevance between citrus huanglongbing (HLB) and the endophytic bacteria in different branches and leaves as well as roots of huanglongbing (HLB)-affected citrus tr...

  2. Comparative carotenoid compositions during maturation and their antioxidative capacities of three citrus varieties.

    Science.gov (United States)

    Yoo, Kyung-Mi; Moon, BoKyung

    2016-04-01

    This study investigated total carotenoid content, comparative carotenoid composition, vitamin C content, and total antioxidant capacity of three citrus varieties which are Yuza (Citrus junos Sieb ex Tabaka), Kjool (Citrus unshiu Marcow), and Dangyooja (Citrus grandis Osbeck). Seven carotenoids were identified, with β-cryptoxanthin, astaxanthin, and zeaxanthin being predominant in citrus varieties. Ripening increased the total carotenoid in three citrus varieties. Individual carotenoid of canthaxanthin, astaxanthin, and α-carotene in citrus varieties decreased with maturation, whereas the others increased with ripening. Yuza exhibited the highest total antioxidant capacity in 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, with VCEAC values of 582.9 mg/100 g and 451.5 mg/100g, respectively. The relative VCEAC values were vitamin C (1.00)>lycopene (0.375), α-carotene (0.304), β-carotene (0.289), β-cryptoxanthin (0.242), and zeaxanthin (0.099). These results indicate that Yuza contains higher amounts of total carotenoids, individual carotenoids, and vitamin C than other Korean citrus varieties. PMID:26593526

  3. Citrus (Rutaceae): a review of recent advances in etymology, systematics and medical applications

    OpenAIRE

    Mabberley, D.J.

    2004-01-01

    The naming, introduction and classification of citrus crops and their allies is outlined. Traditional medicinal use and ‘Western’ applications in the treatment of scurvy and obesity, the prevention of AIDS, and in contraception is reviewed. Names for the commercially significant citrangequat (Citrus × georgiana) and the ‘sunrise lime’ or ‘faustrimedin’ (C. × oliveri) are provided.

  4. Cryopreservation of Citrus seeds via dehydration and direct immersion in liquid nitrogen

    Science.gov (United States)

    Citrus germplasm is conventionally conserved in clonal orchards and greenhouses, where it is subjected to potential losses due to pests, diseases and climatic hazards. In recent years, many studies reported preservation of germplasm in the genus Citrus. As a result, effective freezing protocols have...

  5. Molecular Detection of Spiroplasma Citri Associated with Stubborn Disease in Citrus Orchards in Syria

    Science.gov (United States)

    Spiroplasma citri, a phloem-limited pathogen, causes citrus stubborn disease (CSD) and can be transmitted from plant to plant by several species of phloem-feeding leafhoppers. CSD is an important disorder in certain warm and arid citrus-growing areas, and its agent has been recorded from several Med...

  6. HLB/ACP Resistance or Tolerance in Non-transgenic Citrus Scion Varieties: Potential Commercial Significance

    Science.gov (United States)

    Poncirus trifoliata hybrids grown in the USHRL variety block on Sun Chu Sha (a unifoliate mandarin rootstock similar to Cleopatra) were tested for CLas 16S rDNA and Citrus dehydrin (as an internal standard to permit expression of data in CLas genomes/citrus genomes) by qPCR, assessing random quadran...

  7. Huanglongbing: An overview of a complex pathosystem ravaging the world's citrus.

    Science.gov (United States)

    da Graça, John V; Douhan, Greg W; Halbert, Susan E; Keremane, Manjunath L; Lee, Richard F; Vidalakis, Georgios; Zhao, Hongwei

    2016-04-01

    Citrus huanglongbing (HLB) has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed. PMID:26466921

  8. Construction of citrus gene coexpression networks from microarray data using random matrix theory.

    Science.gov (United States)

    Du, Dongliang; Rawat, Nidhi; Deng, Zhanao; Gmitter, Fred G

    2015-01-01

    After the sequencing of citrus genomes, gene function annotation is becoming a new challenge. Gene coexpression analysis can be employed for function annotation using publicly available microarray data sets. In this study, 230 sweet orange (Citrus sinensis) microarrays were used to construct seven coexpression networks, including one condition-independent and six condition-dependent (Citrus canker, Huanglongbing, leaves, flavedo, albedo, and flesh) networks. In total, these networks contain 37 633 edges among 6256 nodes (genes), which accounts for 52.11% measurable genes of the citrus microarray. Then, these networks were partitioned into functional modules using the Markov Cluster Algorithm. Significantly enriched Gene Ontology biological process terms and KEGG pathway terms were detected for 343 and 60 modules, respectively. Finally, independent verification of these networks was performed using another expression data of 371 genes. This study provides new targets for further functional analyses in citrus. PMID:26504573

  9. Characterisation of free and bound volatile compounds from six different varieties of citrus fruits.

    Science.gov (United States)

    Ren, Jing-Nan; Tai, Ya-Nan; Dong, Man; Shao, Jin-Hui; Yang, Shu-Zhen; Pan, Si-Yi; Fan, Gang

    2015-10-15

    Free volatile compounds in six varieties of citrus juices were analyzed by solid-phase microextraction-gas chromatography-mass spectrometry. Bound fractions were isolated and extracted with methanol and Amberlite XAD-2 resin and then hydrolyzed by almond β-glucosidase. A total of 43 free and 17 bound volatile compounds were identified in citrus. Free volatile contents in sweet orange were the most abundant, followed by those in grapefruits and mandarins. Among free volatiles, terpenes were the most abundant in citrus juice. Sensory analysis results showed that the flavor of the same citrus cultivars was similar, but the flavor of different cultivars varied. Among bound volatiles, benzenic compounds were the most abundant in these citrus juices. Bound volatiles also significantly differed among cultivars. In addition, only p-vinylguaiacol were detected in all of the samples. PMID:25952837

  10. Induction of apoptosis by Citrus paradisi essential oil in human leukemic (HL-60) cells.

    Science.gov (United States)

    Hata, Tomona; Sakaguchi, Ikuyo; Mori, Masahiro; Ikeda, Norikazu; Kato, Yoshiko; Minamino, Miki; Watabe, Kazuhito

    2003-01-01

    Limonene is a primary component of citrus essential oils (EOs) and has been reported to induce apoptosis on tumor cells. Little is known about induction of apoptosis by citrus EOs. In this study, we examined induction of apoptosis by Citrus aurantium var. dulcis (sweet orange) EO, Citrus paradisi (grapefruit) EO and Citrus limon (lemon) EO. These EOs induced apoptosis in HL-60 cells and the apoptosis activities were related to the limonene content of the EOs. Moreover, sweet orange EO and grapefruit EO may contain components besides limonene that have apoptotic activity. To identify the components with apoptotic activity, grapefruit EO was fractionated using silica gel columns, and the components were analyzed by GC-MS. The n-hexane fraction contained limonene, and the dichloromethane fraction (DF) contained aldehyde compounds and nootkatone. Decanal, octanal and citral in the DF showed strong apoptotic activity, suggesting that the aldehyde compounds induced apoptosis strongly in HL-60 cells. PMID:14758720

  11. Huanglongbing:An overview of a complex pathosystem ravaging the world’s citrus

    Institute of Scientific and Technical Information of China (English)

    John V da Graa; Greg W Douhan; Susan E Halbert; Manjunath L Keremane; Richard F Lee; Georgios Vidalakis; Hongwei Zhao

    2016-01-01

    Citrus huanglongbing (HLB) has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed.

  12. Citrus paradisi: An Effective bio-adsorbent for Arsenic (V Remediation

    Directory of Open Access Journals (Sweden)

    Mazhar I. Khaskheli

    2014-06-01

    Full Text Available In the present study As (V was removed by citrus paradisi (grape fruit peel. Kinetics of the adsorption reaction was analyzed by the Pseudo second order and Morris-weber equations. Freundlich and Langmuir isotherm models were utilized for understanding of the relationship between the arsenic ions and citrus paradisi peel adsorbent. The maximum measured uptake capacity of citrus paradisi was 37.76 mg.g-1 at pH 4. FT-IR characterization of unloaded and As (V loaded citrus paradisi peel adsorbent showed the participation of carbonyl (CO and hydroxyl (OH groups in adsorption process. The proposed citrus paradisi peel adsorbent with optimized parameters was used for the removal of arsenic from arsenic contaminated real water samples.

  13. Citrus paradisi: an effective bio-adsorbent for arsenic (v) remediation

    International Nuclear Information System (INIS)

    In the present study As(V) was removed by citrus paradise (grape fruit) peel. Kinetics of the adsorption reaction was analyzed by the Pseudo second order and Morris-weber equations. Freundlich and Langmuir isotherm models were utilized for understanding of the relationship between the arsenic ions and citrus paradise peel adsorbent. The maximum measured uptake capacity of citrus paradise was 37.76 mg.g/sup -1/ at pH 4. FT-IR characterization of unloaded and As (V) loaded citrus paradisi peel adsorbent showed the participation of carbonyl (CO) and hydroxyl (OH) groups in adsorption process. The proposed citrus paradis peel adsorbent with optimized parameters was used for the removal of arsenic from arsenic contaminated real water samples. (author)

  14. Multiplexed lateral flow microarray assay for detection of citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis pv citri

    Science.gov (United States)

    Cary; R. Bruce; Stubben, Christopher J.

    2011-03-22

    The invention provides highly sensitive and specific assays for the major citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis, including a field deployable multiplexed assay capable of rapidly assaying for both pathogens simultaneously. The assays are directed at particular gene targets derived from pathogenic strains that specifically cause the major citrus diseases of citrus variegated chlorosis (Xylella fastidiosa 9a5c) and citrus canker (Xanthomonas axonopodis pv citri). The citrus pathogen assays of the invention offer femtomole sensitivity, excellent linear dynamic range, and rapid and specific detection.

  15. Computer Virus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Computer viruses are small software programs that are designed to spread from one computerto another and to interfere with computer operation.A virus might delete data on your computer,use your e-mail program to spread itself to othercomputers,or even erase everything on your hard disk.Viruses are most easily spread by attach-ments in e-mail messages or instant messaging messages.That is why it is essential that you never

  16. Detection of Liberibacter asiaticus in a single infected Asian citrus psyllid adult or nymph: Impact of dilution with clean Asian citrus psyllids (Diaphorina citri) during extraction

    OpenAIRE

    LeVesque, Cynthia; Kumagai, Lucita; Bloomquist, Cheryl; Keremane, Manjunath; Lee, Richard; Kunta, Madhurababu; da Graça, John V.; Vidalakis, Georgious; Lin, Hong; Morgan, John; Hall, David G.; Polek, MaryLou

    2014-01-01

    Now that the presence of Huanglongbing (HLB) has been confirmed in California, protecting the state’s citrus industry through early detection of disease is essential in curtailing its spread. Because ‘Candidatus Liberibacter asiaticus’ (Las), the putative causal agent of HLB, accumulates in its vector, the Asian citrus psyllid (ACP), Diaphorina citri, Kuwayama, accurate testing of the insect is vital. Due to the fact that insect secondary metabolites interfere with downstream applications (1,...

  17. Transferability of the EST-SSRs developed on Nules clementine (Citrus clementina Hort ex Tan) to other Citrus species and their effectiveness for genetic mapping

    OpenAIRE

    Ollitrault Patrick; Talon Manuel; Wincker Patrick; Allario Thierry; Argout Xavier; Terol Javier; Costantino Gilles; Luro François L; Morillon Raphael

    2008-01-01

    Abstract Background During the last decade, numerous microsatellite markers were developed for genotyping and to identify closely related plant genotypes. In citrus, previously developed microsatellite markers were arisen from genomic libraries and more often located in non coding DNA sequences. To optimize the use of these EST-SSRs as genetic markers in genome mapping programs and citrus systematic analysis, we have investigated their polymorphism related to the type (di or trinucleotide) or...

  18. Transcriptome profiling of citrus fruit response to huanglongbing disease.

    Directory of Open Access Journals (Sweden)

    Federico Martinelli

    Full Text Available Huanglongbing (HLB or "citrus greening" is the most destructive citrus disease worldwide. In this work, we studied host responses of citrus to infection with Candidatus Liberibacter asiaticus (CaLas using next-generation sequencing technologies. A deep mRNA profile was obtained from peel of healthy and HLB-affected fruit. It was followed by pathway and protein-protein network analysis and quantitative real time PCR analysis of highly regulated genes. We identified differentially regulated pathways and constructed networks that provide a deep insight into the metabolism of affected fruit. Data mining revealed that HLB enhanced transcription of genes involved in the light reactions of photosynthesis and in ATP synthesis. Activation of protein degradation and misfolding processes were observed at the transcriptomic level. Transcripts for heat shock proteins were down-regulated at all disease stages, resulting in further protein misfolding. HLB strongly affected pathways involved in source-sink communication, including sucrose and starch metabolism and hormone synthesis and signaling. Transcription of several genes involved in the synthesis and signal transduction of cytokinins and gibberellins was repressed while that of genes involved in ethylene pathways was induced. CaLas infection triggered a response via both the salicylic acid and jasmonic acid pathways and increased the transcript abundance of several members of the WRKY family of transcription factors. Findings focused on the fruit provide valuable insight to understanding the mechanisms of the HLB-induced fruit disorder and eventually developing methods based on small molecule applications to mitigate its devastating effects on fruit production.

  19. Anthelmintic effects of citrus peels ethanolic extracts against Ascaridia galli.

    Science.gov (United States)

    Abdelqader, Anas; Qarallah, Bassam; Al-Ramamneh, Diya; Daş, Gürbüz

    2012-08-13

    The use of phytogenic bioactive compounds to control poultry helminthes is increasing in different production systems. In vitro and in vivo anthelmintic activity of citrus peels against Ascaridia galli was investigated. Ethanolic extracts of three citrus peels species were suspended in 0.5% dimethyl sulfoxide (DMSO) to form an experimental composition (EC). EC was mainly composed of Limonene (96%), followed by β-Pinene (1.5%), α-Pinene (0.5%), and Sabinene (0.3%). For in vitro investigation, adult A. galli worms (n=225) were collected from naturally infected chickens and distributed to 3 equal groups. Groups 1, 2, and 3 were exposed to Fenbendazole (0.5mg/ml), EC (50mg/ml), and 0.5% DMSO, respectively. For in vivo investigation, 200 Lohmann Selected Leghorns chicks were infected at 1-day old with 250 embryonated A. galli eggs. At 6 weeks of age, 150 A. galli infected birds were randomly allocated into 5 equal groups. Groups 1, 2, and 3 were treated with 300, 600, and 1200 mg EC kg(-1) body weight, respectively. Group 4 was treated with Fenbendazole (50 mg kg(-1)). Group 5 was left as control. Birds were euthanized 2-weeks post-treatment, and all worms were collected from their intestines. EC possessed significant (P0.05) difference was quantified between number of motile worms exposed either to EC or Fenbendazole 7h post-exposure. A significant (Pgalli burden (Efficacy=97%) followed by 1200 mg EC kg(-1) (68%), 600 mg EC kg(-1) (66%), and 300 mg EC kg(-1) (5%). It is concluded that citrus peels extracts have potential anthelmintic properties against A. galli. PMID:22463876

  20. Soil organic matter on citrus plantation in Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; Pereira, Paulo; Novara, Agata; Prosdocimi, Massimo

    2015-04-01

    Citrus plantations in Eastern Spain are the main crop and Valencia region is the largest world exporter. The traditional plantation are located on flood irrigated areas and the new plantation are located on slopes were drip irrigation is the source of the wetting. It has been demonstrate that the citrus plantations contribute to high erosion rates on slopes (Cerdà et al., 2009b) as it is usual on agriculture land (Cerdà et al., 2009a), but when organic farming is present the soil erosion is much lower (Cerdà and Jurgensen, 2008; Cerdà et al., 2009; Cerdà and Jurgensen, 2011). This is a worldwide phenomenon (Wu et al., 2007; Wu et al., 2011; Xu et al., 2010; Xu et al., 2012a; Xu et al., 2012b), which are a key factor of the high erosion rates in rural areas (García Orenes et al., 2009: García Orenes et al., 20010; García Orenes et al., 2012; Haregewyn et al., 2013; Zhao et al., 2013). The key factor of the contrasted response of soils to the rain in citrus is the organic matter cover. This is why the Soil Erosion and Degradation Research Team developed a survey to determine the soil erosion rates on citrus orchards under different managements. A hundred of samples were collected in a citrus plantation on slope under conventional management (Chemical management), one on organic farming, one on traditional flood irrigated organic farming and one on traditional chemical flooding farm. The organic farming soils were treated with 10000 Kg ha-1 of manure yearly. The results show that the mean soil organic matter content was 1.24 %, 3.54%, 5,43% and 2.1% respectively, which show a clear impact of organic farming in the recovery of the soil organic matter. meanwhile the on the slopes and the flood-irrigated soils are Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7- ENV-2013- supported this research. References Cerdà, A., Flanagan, D.C., le Bissonnais