Socio-economic determinants of the awareness and adoption of citrus production practices in Pakistan

Directory of Open Access Journals (Sweden)

Saleem Ashraf

2015-09-01

Full Text Available Citrus is the leading fruit of Pakistan and famous worldwide especially kinnow cultivar because of its pleasant taste and remarkable quality. The yield of citrus per hectare in Pakistan is almost half of potential due to non-adoption of recommended horticultural practices by citrus growers. Adopting a decision regarding the improvement of practices is usually influenced by various factors including farmers' socio-economic attributes. In order to determine the relationship between socio-economic aspects and the awareness and adoption of recommended citrus production practices the present study was carried out in Sargodha district from central Punjab, Pakistan. The Study was based upon cross sectional survey research design due to availability of sampling frame, probability (random sampling was applied for sample selection. Through random sampling, 120 citrus growers were selected as sample. Structured questionnaire administered through interview was used as a research instrument. Analysis of the data collected from the targeted citrus growers revealed a highly significant influence of education on awareness and adoption. Moreover, significant association was found between citrus cultivation area and awareness and adoption of improved practices. Age also showed significant association with awareness and adoption. Moreover, dominancy of middle aged farmers and illiteracyin the study area strongly point the need of provision of formal and non-formal education and training program for farmers. Young generation needs to be focused and reorientation of youth clubs may help in better way to gain the utmost outcome.

ENERGY USE IN CITRUS PRODUCTION OF MAZANDARAN ...

African Journals Online (AJOL)

Prof. Adipala Ekwamu

The aim of this study was to evaluate energy use in citrus production in the Mazandaran Province in Iran. Data used in this study were obtained from 155 farmers using a face-to-face interview method. The total energy .... control mainly were mechanised and a few of them ... fertilisers was manual; while manure application.

Utilization of citrus crops processing by-products in the preparation of tarhana

Directory of Open Access Journals (Sweden)

Michal Magala

2015-05-01

Full Text Available After processing of citrus fruits (e.g. lemon, orange, grapefruit, mandarin for juice and essential oils production, approximately 50% of the original fruit mass is left as waste material. Citrus crops processing by-products are valuable components as they contain nutrients such as pectins, saccharides, carotenoids, some vitamins, minerals, polyphenols and substances with antioxidant activity. Utilisation of these kind of side products in the recipe of various cereal product led to enhancement of final product nutritional value and better sensory attributes as well as improvement of product functional properties. In this work was studied the effect of orange and mandarin dietary fibre application at level 5 and 10% (w/w in tarhana preparation and the influence on tarhana fermentation process. Chemical analysis showed, that dietary fibre preparations reached higher concentration of ash, fat and total dietary fibre compared to wheat flour. Wheat flour exhibited higher moisture content and protein concentration than citrus dietary fibre preparations. Orange and mandarin dietary fibre preparations showed higher values of water and oil absorption capacity, swelling capacity and least gellation concentration compared to wheat flour. Application of fruit dietary fibre preparations to tarhana recipe caused a rapid decrease in pH from 4.70 - 5.02 to values 4.31 - 4.51 during fermentation process. Reducing saccharides served as an available source of energy for fermenting microbiota and their concentration decreased from 24.5 - 32.8 to 2.2 - 0.2 g/kg after 144 h incubation. Fermentation also led to lactic acid (1.67 - 2.09 g/kg and acetic acid (1.91 - 2.53 g/kg production as a consequence of present microorganisms metabolic activity. Sensory evaluation of samples showed, that higher proportion of citrus dietary fibre preparations (10% negatively affected taste, odour, consistency and sourness. Among all prepared tarhana samples with proportion of citrus

A Climatic Classification for Citrus Winter Survival in China.

Science.gov (United States)

Shou, Bo Huang

1991-05-01

The citrus tree is susceptible to frost damage. Winter injury to citrus from freezing weather is the major meteorological problem in the northern pail of citrus growing regions in China. Based on meteorological data collected at 120 stations in southern China and on the extent of citrus freezing injury, five climatic regions for citrus winter survival in China were developed. They were: 1) no citrus tree injury. 2) light injury to mandarins (citrus reticulate) or moderate injury to oranges (citrus sinensis), 3) moderate injury to mandarins or heavy injury to oranges, 4) heavy injury to mandarins, and 5) impossible citrus tree growth. This citrus climatic classification was an attempt to provide guidelines for regulation of citrus production, to effectively utilize land and climatic resources, to chose suitable citrus varieties, and to develop methods to prevent injury by freezing.

Exploring the potential of biobeds for the depuration of pesticide-contaminated wastewaters from the citrus production chain: Laboratory, column and field studies

International Nuclear Information System (INIS)

Omirou, M.; Dalias, P.; Costa, C.; Papastefanou, C.; Dados, A.; Ehaliotis, C.; Karpouzas, D.G.

2012-01-01

The high wastewater volumes produced during citrus production at pre- and post-harvest level presents serious pesticide point-source pollution for groundwater bodies. Biobeds are used for preventing such point-source pollution occurring at farm level. We explored the potential of biobeds for the depuration of wastewaters produced through the citrus production chain following a lab-to-field experimentation. The dissipation of pesticides used pre- or post-harvest was studied in compost-based biomixtures, soil, and a straw-soil mixture. A biomixture of composted grape seeds and skins (GSS-1) showed the highest dissipation capacity. In subsequent column studies, GSS-1 restricted pesticides leaching even at the highest water load (462 L m −3 ). Ortho-phenylphenol was the most mobile compound. Studies in an on-farm biobed filled with GSS-1 showed that pesticides were fully retained and partially or fully dissipated. Overall biobeds could be a valuable solution for the depuration of wastewaters produced at pre- and post-harvest level by citrus fruit industries. - Highlights: ► High pesticide amounts are used for pre- and post-harvest treatments of citrus fruits. ► Pesticide-containing wastewaters from citrus production activities require depuration. ► Biobeds is a possible means for the depuration of wastewaters from the citrus industry. ► Biomixture and water management of biobeds were optimized via lab and column studies. ► On-farm offset biobed showed a high dissipation capacity against citrus pesticides. - Biobeds provide an effective solution for the depuration of wastewaters produced by the citrus production industry at both on-farm and post-harvest level.

Exploring the potential of biobeds for the depuration of pesticide-contaminated wastewaters from the citrus production chain: Laboratory, column and field studies

Energy Technology Data Exchange (ETDEWEB)

Omirou, M [Agricultural Research Institute, Nicosia (Cyprus); Dalias, P; Costa, C [Agricultural Research Institute, Nicosia (Cyprus); Papastefanou, C; Dados, A [cp FOODLAB LTD, Lefkosia (Cyprus); Ehaliotis, C [Agricultural University of Athens, Department of Natural Resources and Agricultural Engineering, Laboratory of Soils and Agricultural Chemistry, Athens (Greece); Karpouzas, D.G., E-mail: dkarpouzas@bio.uth.gr [University of Thessaly, Department of Biochemistry and Biotechnology, Larisa 41221 (Greece)

2012-07-15

The high wastewater volumes produced during citrus production at pre- and post-harvest level presents serious pesticide point-source pollution for groundwater bodies. Biobeds are used for preventing such point-source pollution occurring at farm level. We explored the potential of biobeds for the depuration of wastewaters produced through the citrus production chain following a lab-to-field experimentation. The dissipation of pesticides used pre- or post-harvest was studied in compost-based biomixtures, soil, and a straw-soil mixture. A biomixture of composted grape seeds and skins (GSS-1) showed the highest dissipation capacity. In subsequent column studies, GSS-1 restricted pesticides leaching even at the highest water load (462 L m{sup -3}). Ortho-phenylphenol was the most mobile compound. Studies in an on-farm biobed filled with GSS-1 showed that pesticides were fully retained and partially or fully dissipated. Overall biobeds could be a valuable solution for the depuration of wastewaters produced at pre- and post-harvest level by citrus fruit industries. - Highlights: Black-Right-Pointing-Pointer High pesticide amounts are used for pre- and post-harvest treatments of citrus fruits. Black-Right-Pointing-Pointer Pesticide-containing wastewaters from citrus production activities require depuration. Black-Right-Pointing-Pointer Biobeds is a possible means for the depuration of wastewaters from the citrus industry. Black-Right-Pointing-Pointer Biomixture and water management of biobeds were optimized via lab and column studies. Black-Right-Pointing-Pointer On-farm offset biobed showed a high dissipation capacity against citrus pesticides. - Biobeds provide an effective solution for the depuration of wastewaters produced by the citrus production industry at both on-farm and post-harvest level.

Evaluation of the Tolerance of Some Citrus Rootstocks to Citrus Nematode in Greenhouse (Tylenchulus semipenetrans

Directory of Open Access Journals (Sweden)

Y. Mohammad Alian

2018-02-01

Full Text Available Introduction: Citrus nematode is one of the most important damaging nematodes of citrus trees, spreading widely in most areas under citrus planting causing dieback, the gradual decline of trees and crop decrease in citrus orchards. Eighty citrus cultivars and species are sensitive to this nematode. From other nematode hosts, we can refer to olive, fig, medlar, persimmon, pear and grapevine. Surveys Full filled in Mazandaran province is indicative of the widespread of this nematode in citrus horticulture and the level of infection in some samples is so high, thus it is necessary to use different ways of controlling this parasite. Materials and Methods: This research was carried out for 2 successive years and the reaction of sin citrus rootstocks including Citromelo, Poncirus, Sour Orange, Bakraee, Rough lemon and Off-type to citrus nematode under controlled conditions in the greenhouse was evaluated. Three months years old plants of this rootstock Were planted in completely random design with 5 replications in pots containing the population of 40 larvae per cubic centimeter of soil and after six months, the level of infection of roots was investigated and then the most tolerable rootstock for nematode was introduced on the basis of the least population of young females and adult females injected in one gram of root volume. Results and Discussion: Experiment results on the basis of LSD test in two successive years indicated that there is a meaningful statistical difference between Citrumelo and poncirus Poncirus with the least population of nematode of adult female on the root and other treatments the results show that sour orange and off-type rootstocks are the most sensitive to citrus nematode, poncirus Poncirus and Citrumelo are the most tolerable to nematode Bakraee and Rough lemon are in the biotype group with average tolerance (relatively sensitive to citrus nematode. Purpose of this research is to assess the sensitivity level of six citrus

(JASR) VOL. 10, No. 2, 2010 69 CITRUS FARMERS PRODUCTION

African Journals Online (AJOL)

oma

TRAINING ON IMPROVED TECHNIQUES OF CITRUS PRODUCTION. OYEDELE,. 1. O. O. AND ..... 56pp. Adetola, A (2008) Ekiti Kete: The value, the virtue and the vision. ... water resources, and biodiversity in the United States. Centre for ...

A stable RNA virus-based vector for citrus trees

International Nuclear Information System (INIS)

Folimonov, Alexey S.; Folimonova, Svetlana Y.; Bar-Joseph, Moshe; Dawson, William O.

2007-01-01

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

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. Copyright © 2014. Published by Elsevier B.V.

Citrus allergy from pollen to clinical symptoms.

Directory of Open Access Journals (Sweden)

Rosa Anna Iorio

Full Text Available Allergy to citrus fruits is often associated with pollinosis and sensitization to other plants due to a phenomenon of cross-reactivity. The aims of the present study were to highlight the cross-reactivity among citrus and the major allergenic pollens/fruits, throughout clinical and molecular investigations, and to evaluate the sensitization frequency to citrus fruits in a population of children and adults with pollinosis. We found a relevant percentage of sensitisation (39% to citrus fruits in the patients recruited and in all of them the IgE-mediated mechanism has been confirmed by the positive response to the prick-to-prick test. RT-PCR experiments showed the expression of Cit s 1, Cit s 3 and a profilin isoform, already described in apple, also in Citrus clementine pollen. Data of multiple sequence alignments demonstrated that Citrus allergens shared high percentage identity values with other clinically relevant species (i.e. Triticum aestivum, Malus domestica, confirming the possible cross-allergenicity citrus/grasses and citrus/apple. Finally, a novelty of the present work has been the expression of two phospholipaseA2 isoforms (PLA2 α and β in Citrus as well as in Triticum pollens; being PLA2 able to generate pro-inflammatory factors, this enzyme could participate in the activation of the allergenic inflammatory cascade.

Comparative analysis of juice volatiles in selected mandarins, mandarin relatives and other citrus genotypes.

Science.gov (United States)

Yu, Yuan; Bai, Jinhe; Chen, Chunxian; Plotto, Anne; Baldwin, Elizabeth A; Gmitter, Frederick G

2018-02-01

Citrus fruit flavor is an important attribute prioritized in variety improvement. The present study compared juice volatiles compositions from 13 selected citrus genotypes, including six mandarins (Citrus reticulata), three sour oranges (Citrus aurantium), one blood orange (Citrus sinensis), one lime (Citrus limonia), one Clementine (Citrus clementina) and one satsuma (Citrus unshiu). Large differences were observed with respect to volatile compositions among the citrus genotypes. 'Goutou' sour orange contained the greatest number of volatile compounds and the largest volatile production level. 'Ponkan' mandarin had the smallest number of volatiles and 'Owari' satsuma yielded the lowest volatile production level. 'Goutou' sour orange and 'Moro' blood orange were clearly distinguished from other citrus genotypes based on the analysis of volatile compositions, even though they were assigned into one single group with two other sour oranges by the molecular marker profiles. The clustering analysis based on the aroma volatile compositions was able to differentiate mandarin varieties and natural sub-groups, and was also supported by the molecular marker study. The gas chromatography-mass spectrometry analysis of citrus juice aroma volatiles can be used as a tool to distinguish citrus genotypes and assist in the assessment of future citrus breeding programs. The aroma volatile profiles of the different citrus genotypes and inter-relationships detected among volatile compounds and among citrus genotypes will provide fundamental information on the development of marker-assisted selection in citrus breeding. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

IDENTIFICATION AND QUANTIFICATION OF DIFFERENTIALLY EXPRESSED GENES ASSOCIATED WITH CITRUS BLIGHT (Citrus spp.

Directory of Open Access Journals (Sweden)

José Renato de Abreu

2015-02-01

Full Text Available Brazil is the largest citrus producer in the world, being responsible for more than 20% of its production, which is, however still low due to phytosanitary issues such as citrus blight. Citrus blight is an anomaly whose causes still have not yet been determined, therefore there are no efficient control measures to minimize the production losses with the use of resistant varieties being considered the most appropriate method. However, little is known about the genes involved in the defense response of the plants to this anomaly. Considering that many physiological alterations associated with plant stress responses are controlled at a transcriptional level, in this study we sought the identification and characterization of the gene expression products differentially expressed in the response to the citrus blight. Through the suppressive subtractive hybridization technique, expressed cDNA libraries were built using mRNAs isolated from "Cravo" lemon tree roots (Citrus limonia L. Osbeck under "Pera" orange (Citrus sinensis L. Osbeck of healthy and sick plants. 129 clones were obtained by subtraction and their sequences were compared in databases. 34 of them linked to proteins associated to stress processes, while the others were similar to sequences of unknown functions or did not present similarity with sequences deposited in the databases. 3 genes were selected and their expressions were studied by RT - qPCR in real-time. Plants with citrus blight presented an increase of the expression level in two of those genes, suggesting that these can be directly involved with this anomaly.

Development of a Tandem Repeat-Based Polymerase Chain Displacement Reaction Method for Highly Sensitive Detection of 'Candidatus Liberibacter asiaticus'.

Science.gov (United States)

Lou, Binghai; Song, Yaqin; RoyChowdhury, Moytri; Deng, Chongling; Niu, Ying; Fan, Qijun; Tang, Yan; Zhou, Changyong

2018-02-01

Huanglongbing (HLB) is one of the most destructive diseases in citrus production worldwide. Early detection of HLB pathogens can facilitate timely removal of infected citrus trees in the field. However, low titer and uneven distribution of HLB pathogens in host plants make reliable detection challenging. Therefore, the development of effective detection methods with high sensitivity is imperative. This study reports the development of a novel method, tandem repeat-based polymerase chain displacement reaction (TR-PCDR), for the detection of 'Candidatus Liberibacter asiaticus', a widely distributed HLB-associated bacterium. A uniquely designed primer set (TR2-PCDR-F/TR2-PCDR-1R) and a thermostable Taq DNA polymerase mutant with strand displacement activity were used for TR-PCDR amplification. Performed in a regular thermal cycler, TR-PCDR could produce more than two amplicons after each amplification cycle. Sensitivity of the developed TR-PCDR was 10 copies of target DNA fragment. The sensitive level was proven to be 100× higher than conventional PCR and similar to real-time PCR. Data from the detection of 'Ca. L. asiaticus' with filed samples using the above three methods also showed similar results. No false-positive TR-PCDR amplification was observed from healthy citrus samples and water controls. These results thereby illustrated that the developed TR-PCDR method can be applied to the reliable, highly sensitive, and cost-effective detection of 'Ca. L. asiaticus'.

Male Gametophytic Screening of Citrus Genotypes for Salt Stress Tolerance

Directory of Open Access Journals (Sweden)

A. Barandan

2016-07-01

Full Text Available Citrus species are classified as a sensitive group of trees to salt stress, but the levels of their sensitivity or tolerance to salt are different among cultivars. In order to evaluate the effects of salinity stress on pollen germination of some citrus cultivars, an experiment was performed in factorial, based on completely randomized design in three replications with Cleopatra mandarin (Citrus reshni and Poncirus trifoliata as tolerant and sensitive controls along with 13 genotypes. Pollen grains of these genotypes were cultured in media containing different levels of sodium chloride (0, 0.87, 1.6, 2.4, 3.1 dS/m along with 15% sucrose, 0.7% agar and 100 mg/L boric acid. In order to understand the biochemical responses of pollen grains to salt stress, they were cultured in liquid media with three levels of salinity (i.e. 0, 0.87 and 1.6 dS/m and then the amounts of total protein and enzyme activities of superoxide dismutase (SOD and ascorbate peroxidase (APX were evaluated. Significant differences of pollen germination (P ≤ 0.01 were observed in different salinity levels, but there were no significant differences in pollen tube growth. Pollen germination in Cleopatra was greater in comparison to Poncirus trifoliate, indicating that Cleopatra is a tolerant cultivar. The amounts of total protein and enzyme activities of SOD and APX were influenced by genotypes, salinity levels and their interactions (P ≤ 0.01. Considering the fastness and accuracy of this type of experiment, the evaluation of citrus pollen responses may, potentially, be hired as an initial screening criteria for detecting salt-sensitive varieties from the tolerant citrus ones.

Machine learning applied to the prediction of citrus production

International Nuclear Information System (INIS)

Díaz, I.; Mazza, S.M.; Combarro, E.F.; Giménez, L.I.; Gaiad, J.E.

2017-01-01

An in-depth knowledge about variables affecting production is required in order to predict global production and take decisions in agriculture. Machine learning is a technique used in agricultural planning and precision agriculture. This work (i) studies the effectiveness of machine learning techniques for predicting orchards production; and (ii) variables affecting this production were also identified. Data from 964 orchards of lemon, mandarin, and orange in Corrientes, Argentina are analysed. Graphic and analytical descriptive statistics, correlation coefficients, principal component analysis and Biplot were performed. Production was predicted via M5-Prime, a model regression tree constructor which produces a classification based on piecewise linear functions. For all the species studied, the most informative variable was the trees' age; in mandarin and orange orchards, age was followed by between and within row distances; irrigation also affected mandarin production. Also, the performance of M5-Prime in the prediction of production is adequate, as shown when measured with correlation coefficients (~0.8) and relative mean absolute error (~0.1). These results show that M5-Prime is an appropriate method to classify citrus orchards according to production and, in addition, it allows for identifying the most informative variables affecting production by tree.

Machine learning applied to the prediction of citrus production

Directory of Open Access Journals (Sweden)

Irene Díaz

2017-07-01

Full Text Available An in-depth knowledge about variables affecting production is required in order to predict global production and take decisions in agriculture. Machine learning is a technique used in agricultural planning and precision agriculture. This work (i studies the effectiveness of machine learning techniques for predicting orchards production; and (ii variables affecting this production were also identified. Data from 964 orchards of lemon, mandarin, and orange in Corrientes, Argentina are analysed. Graphic and analytical descriptive statistics, correlation coefficients, principal component analysis and Biplot were performed. Production was predicted via M5-Prime, a model regression tree constructor which produces a classification based on piecewise linear functions. For all the species studied, the most informative variable was the trees’ age; in mandarin and orange orchards, age was followed by between and within row distances; irrigation also affected mandarin production. Also, the performance of M5-Prime in the prediction of production is adequate, as shown when measured with correlation coefficients (~0.8 and relative mean absolute error (~0.1. These results show that M5-Prime is an appropriate method to classify citrus orchards according to production and, in addition, it allows for identifying the most informative variables affecting production by tree.

Machine learning applied to the prediction of citrus production

Energy Technology Data Exchange (ETDEWEB)

Díaz, I.; Mazza, S.M.; Combarro, E.F.; Giménez, L.I.; Gaiad, J.E.

2017-07-01

An in-depth knowledge about variables affecting production is required in order to predict global production and take decisions in agriculture. Machine learning is a technique used in agricultural planning and precision agriculture. This work (i) studies the effectiveness of machine learning techniques for predicting orchards production; and (ii) variables affecting this production were also identified. Data from 964 orchards of lemon, mandarin, and orange in Corrientes, Argentina are analysed. Graphic and analytical descriptive statistics, correlation coefficients, principal component analysis and Biplot were performed. Production was predicted via M5-Prime, a model regression tree constructor which produces a classification based on piecewise linear functions. For all the species studied, the most informative variable was the trees' age; in mandarin and orange orchards, age was followed by between and within row distances; irrigation also affected mandarin production. Also, the performance of M5-Prime in the prediction of production is adequate, as shown when measured with correlation coefficients (~0.8) and relative mean absolute error (~0.1). These results show that M5-Prime is an appropriate method to classify citrus orchards according to production and, in addition, it allows for identifying the most informative variables affecting production by tree.

Citrus Functional Genomics and Molecular Modeling in Relation to Citrus sinensis (Sweet Orange) Infection with Xylella fastidiosa (Citrus Variegated Chlorosis).

Science.gov (United States)

Dwivedi, Upendra N; Tiwari, Sameeksha; Prasanna, Pragya; Awasthi, Manika; Singh, Swati; Pandey, Veda P

2016-08-01

Citrus are among the economically most important fruit tree crops in the world. Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa infection, is a serious disease limiting citrus production at a global scale. With availability of citrus genomic resources, it is now possible to compare citrus expressed sequence tag (EST) data sets and identify single-nucleotide polymorphisms (SNPs) within and among different citrus cultivars that can be exploited for citrus resistance to infections, citrus breeding, among others. We report here, for the first time, SNPs in the EST data sets of X. fastidiosa-infected Citrus sinensis (sweet orange) and their functional annotation that revealed the involvement of eight C. sinensis candidate genes in CVC pathogenesis. Among these genes were xyloglucan endotransglycosylase, myo-inositol-1-phosphate synthase, and peroxidase were found to be involved in plant cell wall metabolism. These have been further investigated by molecular modeling for their role in CVC infection and defense. Molecular docking analyses of the wild and the mutant (SNP containing) types of the selected three enzymes with their respective substrates revealed a significant decrease in the binding affinity of substrates for the mutant enzymes, thus suggesting a decrease in the catalytic efficiency of these enzymes during infection, thereby facilitating a favorable condition for infection by the pathogen. These findings offer novel agrigenomics insights in developing future molecular targets and strategies for citrus fruit cultivation in ways that are resistant to X. fastidiosa infection, and by extension, with greater harvesting efficiency and economic value.

78 FR 41259 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus

Science.gov (United States)

2013-07-10

... therefore opposed importation of fresh citrus fruit from Uruguay until its effectiveness could be validated...'' imports. The commenter stated that this argument is invalid due to the year-round marketing of citrus... metric tons, which is less than 3 percent of U.S. production. Uruguay's total fresh orange and lemon...

Oxygenated heterocyclic compounds to differentiate Citrus spp. essential oils through metabolomic strategies.

Science.gov (United States)

Masson, Jerome; Liberto, Erica; Beolor, Jean-Claude; Brevard, Hugues; Bicchi, Carlo; Rubiolo, Patrizia

2016-09-01

This study aimed to characterise and discriminate 44 authenticated commercial samples of citrus essential oils (EO) from seven species (bergamot, lemon, bigarade, orange, mandarin, grapefruit, lime) by analysing the non-volatile oxygenated heterocyclic compounds (OHC) by UHPLC/TOF-HRMS, multivariate data analysis (PCA, PLS-DA) and metabolomic strategies; the OHC fraction includes coumarins, furocoumarins, and polymethoxylated flavonoids. Two different approaches were adopted: (i) targeted profiling based on quantifying 18 furocoumarins and coumarins, some of which are regulated by law, and (ii) targeted fingerprinting based on 140 OHCs reported in citrus essential oils, from which 38 discriminant markers were defined. This approach correctly discriminated the Citrus species; its "sensitivity" to relatively low adulteration rate (10%) was highly satisfactory. The proposed method is complementary to that of analysing the citrus EO volatile part by GC techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

A new modified resource budget model for nonlinear dynamics in citrus production

International Nuclear Information System (INIS)

Ye, Xujun; Sakai, Kenshi

2016-01-01

Highlights: • A theoretical modeling and simulation study of the nonlinear dynamics in citrus is conducted. • New leaf growth is incorporated into the model as a major factor responsible for the yield oscillations. • A Ricker-type equation for the relationship between costs for flowering and fruiting is proposed. • A generic form of the resource budget model for the nonlinear dynamics in citrus is obtained. • The new model is tested with experimental data for two citrus trees. - Abstract : Alternate bearing or masting is a general yield variability phenomenon in perennial tree crops. This paper first presents a theoretical modeling and simulation study of the mechanism for this dynamics in citrus, and then provides a test of the proposed models using data from a previous 16-year experiment in a citrus orchard. Our previous studies suggest that the mutual effects between vegetative and reproductive growths caused by resource allocation and budgeting in plant body might be considered as a major factor responsible for the yield oscillations in citrus. Based on the resource budget model proposed by Isagi et al. (J Theor Biol. 1997;187:231-9), we first introduce the new leaf growth as a major energy consumption component into the model. Further, we introduce a nonlinear Ricker-type equation to replace the linear relationship between costs for flowering and fruiting used in Isagi's model. Model simulations demonstrate that the proposed new models can successfully simulate the reproductive behaviors of citrus trees with different fruiting dynamics. These results may enrich the mechanical dynamics in tree crop reproductive models and help us to better understand the dynamics of vegetative-reproductive growth interactions in a real environment.

Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

Science.gov (United States)

Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

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.

[Climatic suitability of citrus in subtropical China].

Science.gov (United States)

Duan, Hai-Lai; Qian, Huai-Sui; Li, Ming-Xia; Du, Yao-Dong

2010-08-01

By applying the theories of ecological suitability and the methods of fuzzy mathematics, this paper established a climatic suitability model for citrus, calculated and evaluated the climatic suitability and its spatiotemporal differences for citrus production in subtropical China, and analyzed the climatic suitability of citrus at its different growth stages and the mean climatic suitability of citrus in different regions of subtropical China. The results showed that the citrus in subtropical China had a lower climatic suitability and a higher risk at its flower bud differentiation stage, budding stage, and fruit maturity stage, but a higher climatic suitability and a lower risk at other growth stages. Cold damage and summer drought were the key issues affecting the citrus production in subtropical China. The citrus temperature suitability represented a latitudinal zonal pattern, i. e., decreased with increasing latitude; its precipitation suitability was high in the line of "Sheyang-Napo", medium in the southeast of the line, low in the northwest of the line, and non in high mountainous area; while the sunlight suitability was in line with the actual duration of sunshine, namely, higher in high-latitude areas than in low-latitude areas, and higher in high-altitude areas than in plain areas. Limited by temperature factor, the climatic suitability was in accordance with temperature suitability, i. e., south parts had a higher suitability than north parts, basically representing latitudinal zonal pattern. From the analysis of the inter-annual changes of citrus climatic suitability, it could be seen that the citrus climatic suitability in subtropical China was decreasing, and had obvious regional differences, suggesting that climate change could bring about the changes in the regions suitable for citrus production and in the key stages of citrus growth.

Energy use in citrus production of Mazandaran province in Iran ...

African Journals Online (AJOL)

The total energy requirement under citrus farming was 17,112.2 MJ ha-1, whereas 36.3 and 33.62% was consumed due to fertilisers and pesticides, respectively. Renewable energy was about 12% of total energy input. The energy ratio, productivities, specific and net energy gain were 1.71, 0.905, 1.104 and 12,251.4 MJ ...

Development of algorithms for detecting citrus canker based on hyperspectral reflectance imaging.

Science.gov (United States)

Li, Jiangbo; Rao, Xiuqin; Ying, Yibin

2012-01-15

Automated discrimination of fruits with canker from other fruit with normal surface and different type of peel defects has become a helpful task to enhance the competitiveness and profitability of the citrus industry. Over the last several years, hyperspectral imaging technology has received increasing attention in the agricultural products inspection field. This paper studied the feasibility of classification of citrus canker from other peel conditions including normal surface and nine peel defects by hyperspectal imaging. A combination algorithm based on principal component analysis and the two-band ratio (Q(687/630)) method was proposed. Since fewer wavelengths were desired in order to develop a rapid multispectral imaging system, the canker classification performance of the two-band ratio (Q(687/630)) method alone was also evaluated. The proposed combination approach and two-band ratio method alone resulted in overall classification accuracy for training set samples and test set samples of 99.5%, 84.5% and 98.2%, 82.9%, respectively. The proposed combination approach was more efficient for classifying canker against various conditions under reflectance hyperspectral imagery. However, the two-band ratio (Q(687/630)) method alone also demonstrated effectiveness in discriminating citrus canker from normal fruit and other peel diseases except for copper burn and anthracnose. Copyright © 2011 Society of Chemical Industry.

Citrus sinensis annotation project (CAP): a comprehensive database for sweet orange genome.

Science.gov (United States)

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-based organization of sweet orange genomic data, which integrates ab initio gene prediction, EST, RNA-seq and RNA-paired end tag (RNA-PET) evidence-based gene annotation. Furthermore, we provide a user-friendly web interface to show the predicted protein-protein interactions (PPIs) and metabolic pathways in sweet orange. CAP provides comprehensive information beneficial to the researchers of sweet orange and other woody plants, which is freely available at http://citrus.hzau.edu.cn/.

Development of loop-mediated isothermal amplification and SYBR green real-time PCR methods for the detection of Citrus yellow mosaic badnavirus in citrus species.

Science.gov (United States)

Anthony Johnson, A M; Dasgupta, I; Sai Gopal, D V R

2014-07-01

Citrus yellow mosaic badnavirus (CMBV) is an important pathogen in southern India spread by infected citrus propagules. One of the measures to arrest the spread of CMBV is to develop methods to screen and certify citrus propagules as CMBV-free. The methods loop-mediated isothermal amplification (LAMP) and SYBR green real-time PCR (SGRTPCR) have been developed for the efficient detection of CMBV in citrus propagules. This paper compares the sensitivities of LAMP and SGRTPCR with polymerase chain reaction (PCR) for the detection of CMBV. Whereas PCR and LAMP were able to detect CMBV from a minimum of 10 ng of total DNA of infected leaf samples, SGRTPCR could detect the same from 1 ng of total DNA. Using SGRTPCR, the viral titres were estimated to be the highest in rough lemon and lowest in Nagpur Mandarin of the five naturally infected citrus species tested. The results will help in designing suitable strategies for the sensitive detection of CMBV from citrus propagules. Copyright © 2014 Elsevier B.V. All rights reserved.

Nutritional deficiency in citrus with symptoms of citrus variegated chlorosis disease

Directory of Open Access Journals (Sweden)

ME. Silva-Stenico

Full Text Available It is well known that citrus plants that have been infected by Xylella fastidiosa display nutritional deficiencies, probably caused by production of extracellular polymers by the bacteria that block normal nutrient flow through the xylem. The aim of this work was to study the mineral composition of specific foliar areas in different stages of infection in citrus. Thus, the concentrations of macro and micronutrients in leaves of citrus infected by X. fastidiosa were measured. Samples from four infected citrus orchards in the State of São Paulo, Brazil, were respectively collected from Santa Rita do Passa Quatro, Neves Paulista, Gavião Peixoto and Paraíso counties. The presence of X. fastidiosa in leaves was confirmed by polymerase chain reaction (PCR using specific PCR primers. To understand the variation in leaf-nutrient content in citrus plants, we used foliar nutrient values from control (non-symptomatic plants as a reference. Chemometric analysis showed that the deficiency of P and K in symptomatic trees for all orchards and high concentrations of Fe, Mn and Zn were observed in chlorotic areas, although other studies revealed deficiency of zinc in leaves. This is the first report showing that a correlation between chlorotic citrus leaf and higher concentrations of Fe, Mn and Zn are observed when infected and healthy plants were compared.

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...

Citrus water use in South Africa

CSIR Research Space (South Africa)

Vahrmeijer, JT

2012-09-01

Full Text Available scheduling is needed to justify the quantity of water needed for the production of citrus. Models, which are formidable tools to predict water use and crop performance, are therefore vital to provide accurate estimates of citrus water use across different...

Production of Pectin-Cellulose Biofilms: A New Approach for Citrus Waste Recycling

Directory of Open Access Journals (Sweden)

Veronika Bátori

2017-01-01

Full Text Available While citrus waste is abundantly generated, the disposal methods used today remain unsatisfactory: they can be deleterious for ruminants, can cause soil salinity, or are not economically feasible; yet citrus waste consists of various valuable polymers. This paper introduces a novel environmentally safe approach that utilizes citrus waste polymers as a biobased and biodegradable film, for example, for food packaging. Orange waste has been investigated for biofilm production, using the gelling ability of pectin and the strength of cellulosic fibres. A casting method was used to form a film from the previously washed, dried, and milled orange waste. Two film-drying methods, a laboratory oven and an incubator shaker, were compared. FE-SEM images confirmed a smoother film morphology when the incubator shaker was used for drying. The tensile strength of the films was 31.67 ± 4.21 and 34.76 ± 2.64 MPa, respectively, for the oven-dried and incubator-dried films, which is within the range of different commodity plastics. Additionally, biodegradability of the films was confirmed under anaerobic conditions. Films showed an opaque appearance with yellowish colour.

(JASR) VOL. 10, No. 2, 2010 69 CITRUS FARMERS PRODUCTION

African Journals Online (AJOL)

oma

Emerging trends and advances in the citrus industry globally necessitates updating ... citrus is ranked first among other fruit crops by farmers (NIHORT, 2000). .... the arduous task of producing horticultural crops which are pest, diseases and ...

Citrus and Prunuscopia-like retrotransposons.

Science.gov (United States)

Asíns, M J; Monforte, A J; Mestre, P F; Carbonell, E A

1999-08-01

Many of the world's most important citrus cultivars ("Washington Navel", satsumas, clementines) have arisen through somatic mutation. This phenomenon occurs fairly often in the various species and varieties of the genus.The presence of copia-like retrotransposons has been investigated in fruit trees, especially citrus, by using a PCR assay designed to detect copia-like reverse transcriptase (RT) sequences. Amplification products from a genotype of each the following species Citrus sinensis, Citrus grandis, Citrus clementina, Prunus armeniaca and Prunus amygdalus, were cloned and some of them sequenced. Southern-blot hybridization using RT clones as probes showed that multiple copies are integrated throughout the citrus genome, while only 1-3 copies are detected in the P. armeniaca genome, which is in accordance with the Citrus and Prunus genome sizes. Sequence analysis of RT clones allowed a search for homologous sequences within three gene banks. The most similar ones correspond to RT domains of copia-like retrotransposons from unrelated plant species. Cluster analysis of these sequences has shown a great heterogeneity among RT domains cloned from the same genotype. This finding supports the hypothesis that horizontal transmission of retrotransposons has occurred in the past. The species presenting a RT sequence most similar to citrus RT clones is Gnetum montanum, a gymnosperm whose distribution area coincides with two of the main centers of origin of Citrus spp. A new C-methylated restriction DNA fragment containing a RT sequence is present in navel sweet oranges, but not in Valencia oranges from which the former originated suggesting, that retrotransposon activity might be, at least in part, involved in the genetic variability among sweet orange cultivars. Given that retrotransposons are quite abundant throughout the citrus genome, their activity should be investigated thoroughly before commercializing any transgenic citrus plant where the transgene(s) is part

Taxonomy and phylogeny of the genus citrus based on the nuclear ribosomal dna its region sequence

International Nuclear Information System (INIS)

Sun, Y.L.

2015-01-01

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)

Multiplexed lateral flow microarray assay for detection of citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis pv citri

Energy Technology Data Exchange (ETDEWEB)

Cary,; Bruce, R [Santa Fe, NM; Stubben, Christopher J [Los Alamos, NM

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.

Land cover classification of VHR airborne images for citrus grove identification

Science.gov (United States)

Amorós López, J.; Izquierdo Verdiguier, E.; Gómez Chova, L.; Muñoz Marí, J.; Rodríguez Barreiro, J. Z.; Camps Valls, G.; Calpe Maravilla, J.

Managing land resources using remote sensing techniques is becoming a common practice. However, data analysis procedures should satisfy the high accuracy levels demanded by users (public or private companies and governments) in order to be extensively used. This paper presents a multi-stage classification scheme to update the citrus Geographical Information System (GIS) of the Comunidad Valenciana region (Spain). Spain is the first citrus fruit producer in Europe and the fourth in the world. In particular, citrus fruits represent 67% of the agricultural production in this region, with a total production of 4.24 million tons (campaign 2006-2007). The citrus GIS inventory, created in 2001, needs to be regularly updated in order to monitor changes quickly enough, and allow appropriate policy making and citrus production forecasting. Automatic methods are proposed in this work to facilitate this update, whose processing scheme is summarized as follows. First, an object-oriented feature extraction process is carried out for each cadastral parcel from very high spatial resolution aerial images (0.5 m). Next, several automatic classifiers (decision trees, artificial neural networks, and support vector machines) are trained and combined to improve the final classification accuracy. Finally, the citrus GIS is automatically updated if a high enough level of confidence, based on the agreement between classifiers, is achieved. This is the case for 85% of the parcels and accuracy results exceed 94%. The remaining parcels are classified by expert photo-interpreters in order to guarantee the high accuracy demanded by policy makers.

Odorants for surveillance and control of the Asian Citrus Psyllid (Diaphorina citri.

Directory of Open Access Journals (Sweden)

Iliano V Coutinho-Abreu

Full Text Available 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.In this study, we performed single-unit electrophysiology to identify odorants that are strong activators, inhibitors, and prolonged activators of ACP odorant receptor neurons (ORNs. We identified a suite of odorants that activated the ORNs with high specificity and sensitivity, which may be useful in eliciting behavior such as attraction. In separate experiments, we also identified odorants that evoked prolonged ORN responses and antagonistic odorants able to suppress neuronal responses to activators, both of which can be useful in lowering attraction to hosts. In field trials, we tested the electrophysiologically identified activating odorants and identified a 3-odor blend that enhances trap catches by ∼230%.These findings provide a set of odorants that can be used to develop affordable and safe odor-based surveillance and masking strategies for this dangerous pest insect.

Bacillus subtilis based-formulation for the control of postbloom fruit drop of citrus.

Science.gov (United States)

Klein, Mariana Nadjara; da Silva, Aline Caroline; Kupper, Katia Cristina

2016-12-01

Postbloom fruit drop (PFD) caused by Colletotrichum acutatum affects flowers and causes early fruit drop in all commercial varieties of citrus. Biological control with the isolate ACB-69 of Bacillus subtilis has been considered as a potential method for controlling this disease. This study aimed to develop and optimize a B. subtilis based-formulation with a potential for large-scale applications and evaluate its effect on C. acutatum in vitro and in vivo. Bacillus subtilis based-formulations were developed using different carrier materials, and their ability to control PFD was evaluated. The results of the assays led to the selection of the B. subtilis based-formulation with talc + urea (0.02 %) and talc + ammonium molybdate (1 mM), which inhibited mycelial growth and germination of C. acutatum. Studies with detached citrus flowers showed that the formulations were effective in controlling the pathogen. In field conditions, talc + urea (0.02 %) provided 73 % asymptomatic citrus flowers and 56 % of the average number of effective fruit (ANEF), equating with fungicide treatment. On the contrary, non-treated trees had 8.8 % of asymptomatic citrus flowers and 0.83 % ANEF. The results suggest that B. subtilis based-formulations with talc as the carrier supplemented with a nitrogen source had a high potential for PFD control.

Effects of citrus pulp, fish by-product and Bacillus subtilis fermentation biomass on growth performance, nutrient digestibility, and fecal microflora of weanling pigs.

Science.gov (United States)

Noh, Hyun Suk; Ingale, Santosh Laxman; Lee, Su Hyup; Kim, Kwang Hyun; Kwon, Ill Kyong; Kim, Young Hwa; Chae, Byung Jo

2014-01-01

An experiment was conducted to investigate the effects of dietary supplementation with citrus pulp, fish by-product, and Bacillus subtilis fermentation biomass on the growth performance, apparent total tract digestibility (ATTD) of nutrients, and fecal microflora of weanling pigs. A total of 180 weaned piglets (Landrace × Yorkshire × Duroc) were randomly allotted to three treatments on the basis of body weight (BW). There were six replicate pens in each treatment with 10 piglets per pen. Dietary treatments were corn-soybean meal-based basal diet supplemented with 0 (control), 2.5, and 5.0% citrus pulp, fish by-product, and B. subtilis fermentation biomass. The isocaloric and isoproteineous experimental diets were fed in mash form in two phases (d 0 ~ 14, phase I and d 15 ~ 28, phase II). Dietary treatments had significant linear effects on gain to feed ratio (G:F) in all periods, whereas significant linear effects on ATTD of dry matter (DM), gross energy (GE), and ash were only observed in phase I. Piglets fed diet supplemented with 5.0% citrus pulp, fish by-product, and B. subtilis fermentation biomass showed greater (p by-product and B. subtilis fermentation biomass showed greater (p by-product, and B. subtilis fermentation biomass has the potential to improve the feed efficiency, nutrient digestibility, and fecal microflora of weanling pigs.

Sustainable Use of Pesticide Applications in Citrus: A Support Tool for Volume Rate Adjustment

Directory of Open Access Journals (Sweden)

Cruz Garcerá

2017-06-01

Full Text Available Rational application of pesticides by properly adjusting the amount of product to the actual needs and specific conditions for application is a key factor for sustainable plant protection. However, current plant protection product (PPP labels registered for citrus in EU are usually expressed as concentration (%; rate/hl and/or as the maximum dose of product per unit of ground surface, without taking into account those conditions. In this work, the fundamentals of a support tool, called CitrusVol, developed to recommend mix volume rates in PPP applications in citrus orchards using airblast sprayers, are presented. This tool takes into consideration crop characteristics (geometry, leaf area density, pests, and product and application efficiency, and it is based on scientific data obtained previously regarding the minimum deposit required to achieve maximum efficacy, efficiency of airblast sprayers in citrus orchards, and characterization of the crop. The use of this tool in several commercial orchards allowed a reduction of the volume rate and the PPPs used in comparison with the commonly used by farmers of between 11% and 74%, with an average of 31%, without affecting the efficacy. CitrusVol is freely available on a website and in an app for smartphones.

Nutritive value of citrus co-products in rabbit feeding

Directory of Open Access Journals (Sweden)

J. Carlos de Blas

2018-03-01

Full Text Available Pulps from different citrus fruits are relevant agro-industrial co-products in the Mediterranean area in terms of amounts produced and availability. Moreover, part of the product is dehydrated, which increases its interest in monogastric species such as rabbits. Seventy eight samples from various Spanish producers using several types of fresh fruits (orange, tangerine, lemon and pomelo and different processing methods of orange and tangerine samples (either fresh or dried after adding Ca(OH2 were analysed for their chemical composition and in vitro digestibility. Average dry matter (DM contents of ash, neutral detergent fibre, acid detergent fibre, acid detergent lignin (ADL, soluble fibre, crude protein (CP, insoluble neutral and acid detergent CP, ether extract and gross energy were 49.0, 226, 139, 12.1, 213, 71.2, 13.1, 4.2, 30.5 g and 17.8 MJ/kg DM, respectively. Mean DM and CP in vitro digestibility were 86.7 and 95.6%, respectively. Digestible energy was estimated to be 15.1 MJ/kg DM. A high variability (coefficient of variation from 17% for CP to 60% for ADL was observed among the samples for most of the traits studied, which was partially explained by the effects of type of fruit and processing. Lemon pulps had on average higher ash and fibre but lower sugar contents than the other pulps. Dehydration processes increased ash content (almost double than for fresh pulp due to lime addition. As regards the current results, citrus pulp has potential for use in rabbit diets as a source of energy and soluble fibre.

Citrus plastid-related gene profiling based on expressed sequence tag analyses

Directory of Open Access Journals (Sweden)

Tercilio Calsa Jr.

2007-01-01

Full Text Available Plastid-related sequences, derived from putative nuclear or plastome genes, were searched in a large collection of expressed sequence tags (ESTs and genomic sequences from the Citrus Biotechnology initiative in Brazil. The identified putative Citrus chloroplast gene sequences were compared to those from Arabidopsis, Eucalyptus and Pinus. Differential expression profiling for plastid-directed nuclear-encoded proteins and photosynthesis-related gene expression variation between Citrus sinensis and Citrus reticulata, when inoculated or not with Xylella fastidiosa, were also analyzed. Presumed Citrus plastome regions were more similar to Eucalyptus. Some putative genes appeared to be preferentially expressed in vegetative tissues (leaves and bark or in reproductive organs (flowers and fruits. Genes preferentially expressed in fruit and flower may be associated with hypothetical physiological functions. Expression pattern clustering analysis suggested that photosynthesis- and carbon fixation-related genes appeared to be up- or down-regulated in a resistant or susceptible Citrus species after Xylella inoculation in comparison to non-infected controls, generating novel information which may be helpful to develop novel genetic manipulation strategies to control Citrus variegated chlorosis (CVC.

Production, soil erosion and economic failure in new citrus plantations in Eastern Spain

Science.gov (United States)

Giménez Morera, Antonio; Carles membrado, Joan; Cerdà, Artemi; Ángel González Peñaloza, Félix

2013-04-01

Eastern Spain has been worldwide well known by the high quality citrus production (Piqueras, 2012). During the last century, the export of València's oranges contributed to a high income in Spain albeit during the last decade the revenues for the small farmers were short (Bono, 2010). The orange agricultural specialization in València begun at the end of the eighteenth century in the town of Carcaixent, close to the Xúquer river, where the first commercial orange groves were planted. This was due to the climatic conditions (no frosts) and the traditional flood irrigation systems. The orange trade was not important until the second half of the nineteenth century, due to a combination of factors: i) the increasing demand of oranges from the United Kingdom, first, and then from Germany, France and other north-european industrialized countries; ii) the highly productive capacity of the Valencian soil thanks to its mild weather and irrigated fields; iii) the open mindedness of Valencian farmers towards innovation; and, iv) the developemnt of a railways network which made it possible to bring the oranges into the shipment ports (Bono, 2010; Piqueras, 2012). The Valencian orange trade knew its peak during the period 1925-1930 but later it experienced an economic crisis because of wars (both in Spain and Europe) and did not recover until the 1960's (Piqueras, 1999; Bono, 2010). After Spain's EEC (European Economic Community) membership (1986) and the creation of EU (1993) Valencian citrus sector grew: new orange groves were planted, new commercial varieties (especially mandarins) were promoted, and exports increased. Nevertheless, nowadays Valencian orange sector suffers from a structural problem: the small farm size and the lack of a good commercial network of distribution. But in spite of the current crisis, the orange groves' impact on landscape is still huge in Valencia, since it creates a thick forest of orange trees stretching not only the floodplains but also

Annotation of the Asian citrus psyllid genome reveals a reduced innate immune system

Science.gov (United States)

Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuway...

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.

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

Science.gov (United States)

2011-04-27

... for all germplasm and budwood destined for propagation in nurseries within the State, construction and... movement of citrus nursery stock is considered to be a high-risk pathway for citrus canker and citrus..., we did not initiate rulemaking at that time to establish such a systems approach. Rather, we decided...

Citrus tissue culture employing vegetative explants.

Science.gov (United States)

Chaturvedi, H C; Singh, S K; Sharma, A K; Agnihotri, S

2001-11-01

Citrus being a number one fruit of the world due to its high nutritional value, huge production of fruits and fruit products, the citrus industry may be considered a major fruit industry. Though citrus orchard area in India is comparable to USA, the produce is far less, while its export is nil. Biotechnology has played an outstanding role in boosting the citrus industry, e.g., in Spain, which is now the biggest exporter of citrus fruit with the application of micrografting. Amongst the fruit trees, perhaps the maximum tissue culture research has been done in citrus during the past four decades, however, the results of practical value are meagre. The shortfalls in citrus tissue culture research and some advancements made in this direction along with bright prospects are highlighted, restricting the review to vegetative explants only. Whilst utilization of nucellar embryogenesis is limited to rootstocks, the other aspects, like, regeneration and proliferation of shoot meristems measuring 200 microm in length--a global breakthrough--of two commercially important scion species, Citrus aurantifolia and C. sinensis and an important rootstock, C. limonia, improvement of micrografting technique, cloning of the same two scion species as well as some Indian rootstock species, employing nodal stem segments of mature trees, of immense practical value have been elaborated. A rare phenomenon of shift in the morphogenetic pattern of differentiation from shoot bud differentiation to embryoid formation occurred during the long-term culture of stem callus of C. grandis. Stem callus-regenerated plants of C. aurantifolia, C. sinensis and C. grandis showed variation in their ploidy levels and a somaclonal variant of C. sinensis, which produced seedless fruits was isolated. Tailoring of rooting in microshoots to a tap root-like system by changing the inorganic salt composition of the rooting medium, resulting in 100% transplant success, and germplasm preservation through normal growth

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

Science.gov (United States)

2013-10-24

... that seed transmission may occur. The pathogen can also be transmitted by two insect vectors in the... by the Secretary prior to movement. Citrus canker is a plant disease that is caused by a complex of....75-6. Citrus greening, also known as Huanglongbing disease of citrus, is considered to be one of the...

Effect of Citrus aurantifolia swingle essential oils on methyl mercaptan production of Porphyromonas gingivalis

Directory of Open Access Journals (Sweden)

Anindya Prima Yusinta

2013-03-01

Full Text Available Background: Halitosis is a term used to describe an unpleasant odors emanating timely from oral cavity. The unpleasant smell of breath most common caused from volatile sulphure compound (VSC. Methyl mercaptan is the major component of VSC. P. gingivalis produced large amount of methyl mercaptan. The essential oils of Citrus aurantifolia swingle contain antibacterial component. Purpose: The purpose of this study was to determine the effect of essential oil of Citrus aurantifolia swingle on the production of methyl mercaptan compounds in P. gingivalis. Methods: Bacterial suspension of P. gingivalis in TSB medium with 108 CFU/ml concentration cultured in a microplate and added by the essential oils of Citrus aurantifolia swingle with 1%, 2%, 3% and 4% concentration. Distilled water was used as negative control and 0.2% Chlorhexidine mouthwash was used as a positive control. Microplate was incubated anaerobically for 48 hours. After the periode of incubation, 0.6% methionine as the exogenous substrate and 0.06% DTNB as a reagen for determining methyl mercaptan concentration were added to each wells. The microplate was futher incubated for 12 hours. Concentration of methyl mercaptan produced by the P. gingivalis was measured spectrophotometrically using microplate reader at 415 nm. Results: One-way ANOVA showed that the essential oil of Citrus aurantifolia swingle take effect on the concentration of methyl mercaptan produced by P. gingivalis. LSD test results indicated that there was a significant difference of methyl mercaptan concentration between treatment groups of the essential oils of Citrus aurantifolia swingle and distilled water that used as negative control. Conclusion: The essential oil of Citrus aurantifolia swingle has decreased the production of methyl mercaptan produced by P. gingivalis.Latar belakang: Halitosis adalah istilah yang digunakan untuk menggambarkan bau tidak sedap yang berasal dari rongga mulut. Penyebab utama halitosis

Immunogenesity of spesific protein molecular weight 16 KDa (PS16 leaf of siam citrus infected by citrus vein phloem degeneration (CVPD disease

Directory of Open Access Journals (Sweden)

Made Sritamin

2012-02-01

Full Text Available Citrus Vein Phloem degeneration (CVPD is an important citrus disese, which damaged citrus plantation and causing decrease of citrus production. In Indonesia, the CVPD disease caused by Liberobacter asiaticum bactery and the disease spread out by vectir insect Diaphorina citri and using infected bud in wood grafting. In infected citrus plant, two specific protein molecules with molecular weigt 16 kDa and 66 kDa are found. These protein molecules are not found in healthy citrus plant. The immunogenicity of PS16 accumulated on leaf of citrus plant infected by CVPD is known yet. The research material were leaves of citrus plant infected CVPD, leaves of healthy citrus plant and reagent used these research are for isolation of the total protein leaf of citrus plant, SDS-PAGE electroforesis, electroelution of PS16, ELISA Methods, Dot-Blot Method, anti-PS16 as aprimery antibody and secondary antibody is anti-Rabbit IgG Conjugated AP. The result of the research showed that of PS16 accumulated on leaf of citrus plant infected CVPD has immunogenic character. It is indicated by increase of the titer anti-PS16 after first immunization ang 2nd booster by indirect ELISA method and can be used to induce antibody (anti-PS16 and so showed that positive reaction between PS16 with anti-PS16. It is indicated by purples dark blue on cellulose membrane by Dot Blot method.

Intensification of citrus production and soil loss in Eastern Spain

Science.gov (United States)

Cerdà, A.; González Peñaloza, F. A.; Burguet, M.; Giménez Morera, A.

2012-04-01

After land abandonment for five decades (Arnáez et al., 2010; Belmonte Serrato et al., 1999) as a widespread process in Spain, agriculture intensification is taken place. This is changing the nature of the soil erosion processes as they were known (Cerdà, 1997; Cammeraat and Imeson, 1999; Ruiz Sinoga et al., 2010; Zavala et al., 2010). Citrus production are being reallocated on slopes due to the new irrigation systems (drip-irrigation), the thermic inversion on the bottom of the valley and then the frost affecting the plantations, the high prices of the bottom valley lands and the investment in agriculture from other economic sectors such as tourism and industry. Those new plantations are based on intense pesticides and herbicides use, and erosion processes are triggered due to the sloping surface developed (Cerdà et al., 2010). Five study sites were selected in the Montesa Municipality research zone, where an increase in the orange and clementines plantations were found during the last 20 years. Measurements were perfomed by a simple method, which consist in measuring the surface characteristics: stoniness, crust, herbs, bare soil, sheet flow, rills and gullies. One thousand meters were monitored at each of the study sites and measurements were done in January and August with a precision of 1 cm. The results show that the erosion rates are controlled by the sheet erosion (78,4 %), although rill and gullies exist (managed new citrus plantation non sustainable. The intensification of agriculture is triggering new soil erosion processes to be added to the traditional ones (García Ruiz and López Bermúdez, 2009). This research study is being supported by the the research project CGL2008-02879/BTE

Studies on the development of functional powder from citrus peel.

Science.gov (United States)

Kang, H J; Chawla, S P; Jo, C; Kwon, J H; Byun, M W

2006-03-01

The suitability of citrus peels, generated as a by-product of the juice industry, as a source of antioxidants was investigated. Citrus peel powder was prepared by lyophilizing 70% ethanol extract from citrus peels. Extraction was carried out at room temperature (20 degrees C) for 72 h. The extract was subjected to gamma-irradiation treatment (20 kGy). The aqueous solutions of citrus peel powder were examined for color characteristics and antioxidant potential in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, beta-carotene bleaching and nitrite scavenging activities. There were significant changes in Hunter color values due to irradiation. The a*- and b*-values decreased due to radiation treatment. DPPH radical scavenging, beta-carotene bleaching and nitrite scavenging activities were not affected by irradiation treatment. Nitrite scavenging activity was the highest in the extract at pH 1.2 followed by pH 4.2 and 6.0. These functional properties of the aqueous solution were found to be stable in heat treatment. It could significantly improve oxidative stability of lipids in fish meat system. Based on these results there may be opportunities to use citrus peel powder as a functional component in the food processing industry with gamma irradiation treatment improving its color characteristics without adversely influencing the functional properties.

Evaluation of Antibacterial Activities of Citrus limon, Citrus reticulata, and Citrus grandis Against Pathogenic Bacteria

Directory of Open Access Journals (Sweden)

Sholeh Saeb

2016-11-01

Full Text Available Background: Microorganisms resistant to most antibiotics are rapidly spreading, and there is an urgent and continuous need for novel antimicrobial compounds. The genus Citrus belongs to the family Rutaceae has many biologically active secondary metabolites. Objectives: The purpose of this study was to evaluate antimicrobial activity of essential oil and extract of Lemon (Citrus limon, Mandarin (Citrus reticulata and Pummelo (Citrus grandis against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella typhi. Materials and Methods: The fresh Citrus leaves were shade-dried and powdered. Antimicrobial metabolites were extracted from them by 80% methanol for extract and using a Clevenger-type apparatus for essential oil. Eight different concentrations of the each leaf extract and essential oil were prepared. The antimicrobial susceptibility assay of Citrus leaves metabolites were subjected against four bacterial strains by agar disc diffusion and E-test method. Results: In this study, minimum inhibitory concentrations (MIC of different Citrus leaf extracts were determined against all four food-borne pathogens. The C. grandis leaf essential oil had potent antimicrobial activity against all four pathogens, and the C. limon leaf essential oil was effective on Gram-positive bacteria. S. typhi was resistant against two leaves essential oils. Conclusions: The results showed that there was no antimicrobial activity effect in all extracts on tested bacteria. In this study, the antibacterial effect of essential oil of Citrus leaves on four strains of pathogenic microorganisms was confirmed. The C. grandis leaf essential oil had the most powerful antimicrobial properties, suggesting its potential application as natural preservative in foods or an effective medicine against different pathogenic microbes. Key words: Antibacterial activity, E-test, Citr

Assessment of different pre-treatment methods for the removal of limonene in citrus waste and their effect on methane potential and methane production rate.

Science.gov (United States)

Ruiz, Begoña; de Benito, Amparo; Rivera, José Daniel; Flotats, Xavier

2016-12-01

The objective of this study was to assess the limonene removal efficiency of three pre-treatment methods when applied to citrus waste and to evaluate their effects on the biochemical methane potential and the methane production rate using batch anaerobic tests. The methods tested were based on removal (biological pretreatment by fungi) or recovery (steam distillation and ethanol extraction) of limonene. All the treatments decreased the concentration of limonene in orange peel, with average efficiencies of 22%, 44% and 100% for the biological treatment, steam distillation and ethanol extraction, respectively. By-products from limonene biodegradation by fungi exhibited an inhibitory effect also, not making interesting the biological pretreatment. The methane potential and production rate of the treated orange peel increased significantly after applying the recovery strategies, which separated and recovered simultaneously other inhibitory components of the citrus essential oil. Apart from the high recovery efficiency of the ethanol extraction process, it presented a favourable energy balance. © The Author(s) 2016.

AN EXPLORATION OF FACTORS AFFECTING DEVELOPMENT OF CITRUS INDUSTRY IN TANZANIA: EMPIRICAL EVIDENCE FROM MUHEZA DISTRICT, TANGA REGION

Directory of Open Access Journals (Sweden)

Robert Makorere

2014-04-01

Full Text Available The paper stresses on understanding factors affecting development of citrus industry in Tanzania particularly in Muheza District, in Tanga region. Citrus fruit is one of the most important crops in Muheza District of Tanga region in Tanzania particularly in improving rural farmers’ income. The study employed institutional framework methodology. The study disclosed that the government of Tanzania has been implementing various agricultural development programmes in improving citrus fruit production as well as to enhance farmers’ income. However, yet the results reveal that the citrus farming practices in the surveyed area are not well developed. And these are because citruses are still grown under rain fed regime without any form of irrigation, citrus seedlings are produced by individual farmers locally in their backyard nurseries. There is no professional company responsible for seedling production. Also, citrus farmers’ skills in citrus husbandry practices are limited. Lastly, all citrus varieties used contain many seeds in the citrus fruits whereas the market demands seedless citrus fruits. It is therefore, recommended that the policy maker should focus on development of citrus industry in Tanzania using proper institutional framework support, which could increase growth and development of citrus production through the provision of subsides for inputs to reduce cost of production and enlightenment campaigns to improve farmer’s knowledge and technical skills on how to reach lucrative markets.

Application of Particle Swarm Optimization Algorithm for Optimizing ANN Model in Recognizing Ripeness of Citrus

Science.gov (United States)

Diyana Rosli, Anis; Adenan, Nur Sabrina; Hashim, Hadzli; Ezan Abdullah, Noor; Sulaiman, Suhaimi; Baharudin, Rohaiza

2018-03-01

This paper shows findings of the application of Particle Swarm Optimization (PSO) algorithm in optimizing an Artificial Neural Network that could categorize between ripeness and unripeness stage of citrus suhuensis. The algorithm would adjust the network connections weights and adapt its values during training for best results at the output. Initially, citrus suhuensis fruit’s skin is measured using optically non-destructive method via spectrometer. The spectrometer would transmit VIS (visible spectrum) photonic light radiation to the surface (skin of citrus) of the sample. The reflected light from the sample’s surface would be received and measured by the same spectrometer in terms of reflectance percentage based on VIS range. These measured data are used to train and test the best optimized ANN model. The accuracy is based on receiver operating characteristic (ROC) performance. The result outcomes from this investigation have shown that the achieved accuracy for the optimized is 70.5% with a sensitivity and specificity of 60.1% and 80.0% respectively.

Improved annotation of the insect vector of citrus greening disease: Biocuration by a diverse genomics community

Science.gov (United States)

The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the pathogen associated with citrus Huanglongbing (HLB, citrus greening). HLB threatens citrus production worldwide. Suppression or reduction of the insect vector usin...

Saving Citrus: Does the Next Generation See GM Science as a Solution?

Science.gov (United States)

Rumble, Joy N.; Ruth, Taylor K.; Owens, Courtney T.; Lamm, Alexa J.; Taylor, Melissa R.; Ellis, Jason D.

2016-01-01

Citrus is one of Florida's most prominent commodities, providing 66% of the total United States' value for oranges. Florida's citrus production decreased 21% in 2014 from the previous season, partly due to the disease citrus greening. The science of genetic modification (GM) is one of the most promising solutions to the problem. However, a…

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.

Characterization and typification of citrus production systems in the department of Meta

Directory of Open Access Journals (Sweden)

José Alejandro Cleves-Leguízamo

2014-04-01

Full Text Available Agriculture is a co-evolutionary process between society and nature. Agroecology is an environmental science which focuses on ecosystem-culture and society-nature interactive systems, the effect of human intervention in the transformation of ecosystems. The central objects are agroecosystems and the units of study are production units. These production units are conceived of as agricultural systems and are found in the crossroads of multiple interactions between biophysical, socioeconomical, cultural, and production components, which must be analyzed with an integrated concept. In the present study, a characterization and typification of the citrus agroecosystems of the department of Meta were pursued (Colombia. The pertinence of implementing the methodology designed by the Latin-American Center for Rural Development (Centro Latinoamericano para el Desarrollo Rural-RIMISP was evaluated, grouping the variables with a focus on an analysis of livelihoods. A survey and interview were defined as methods of collecting the primary information in the municipalities of Puerto López, Villavicencio, Granada, Lejanías, Guamal and San Martin, where 78.4% of the citrus area of the department is found. This study involved the selection and definition of the evaluation variables, validation and adjustment of said variables, collection of primary and secondary information, and the application of multivariate statistical analysis techniques to conform and characterize the recommendation domains or groups. The more important results indicated that it is possible to increase knowledge of the interrelations that exist between the different components of farm agroecosystems and their relationship with the principal agroecological structure. The existence of six agricultural groups or recommendation domains was established, with some productive characteristics very similar within the group but very heterogeneous to the outside of the group, with particular

Citrus fruit flavor and aroma biosynthesis: isolation, functional characterization, and developmental regulation of Cstps1, a key gene in the production of the sesquiterpene aroma compound valencene.

Science.gov (United States)

Sharon-Asa, Liat; Shalit, Moshe; Frydman, Ahuva; Bar, Einat; Holland, Doron; Or, Etti; Lavi, Uri; Lewinsohn, Efraim; Eyal, Yoram

2003-12-01

Citrus fruits possess unique aromas rarely found in other fruit species. While fruit flavor is composed of complex combinations of soluble and volatile compounds, several low-abundance sesquiterpenes, such as valencene, nootkatone, alpha-sinensal, and beta-sinensal, stand out in citrus as important flavor and aroma compounds. The profile of terpenoid volatiles in various citrus species and their importance as aroma compounds have been studied in detail, but much is still lacking in our understanding of the physiological, biochemical, and genetic regulation of their production. Here, we report on the isolation, functional expression, and developmental regulation of Cstps1, a sesquiterpene synthase-encoding gene, involved in citrus aroma formation. The recombinant enzyme encoded by Cstps1 was shown to convert farnesyl diphosphate to a single sesquiterpene product identified as valencene by gas chromatography-mass spectrometry (GC-MS). Phylogenetic analysis of plant terpene synthase genes localized Cstps1 to the group of angiosperm sesquiterpene synthases. Within this group, Cstps1 belongs to a subgroup of citrus sesquiterpene synthases. Cstps1 was found to be developmentally regulated: transcript was found to accumulate only towards fruit maturation, corresponding well with the timing of valencene accumulation in fruit. Although citrus fruits are non-climacteric, valencene accumulation and Cstps1 expression were found to be responsive to ethylene, providing further evidence for the role of ethylene in the final stages of citrus fruit ripening. Isolation of the gene encoding valencene synthase provides a tool for an in-depth study of the regulation of aroma compound biosynthesis in citrus and for metabolic engineering for fruit flavor characteristics.

Encapsulation of Polymethoxyflavones in Citrus Oil Emulsion-Based Delivery Systems.

Science.gov (United States)

Yang, Ying; Zhao, Chengying; Chen, Jingjing; Tian, Guifang; McClements, David Julian; Xiao, Hang; Zheng, Jinkai

2017-03-01

The purpose of this work was to elucidate the effects of citrus oil type on polymethoxyflavone (PMF) solubility and on the physicochemical properties of PMF-loaded emulsion-based delivery systems. Citrus oils were extracted from mandarin, orange, sweet orange, and bergamot. The major constituents were determined by GC/MS: sweet orange oil (97.4% d-limonene); mandarin oil (72.4% d-limonene); orange oil (67.2% d-limonene); and bergamot oil (34.6% linalyl acetate and 25.3% d-limonene). PMF-loaded emulsions were fabricated using 10% oil phase (containing 0.1% w/v nobiletin or tangeretin) and 90% aqueous phase (containing 1% w/v Tween 80) using high-pressure homogenization. Delivery systems prepared using mandarin oil had the largest mean droplet diameters (386 or 400 nm), followed by orange oil (338 or 390 nm), bergamot oil (129 or 133 nm), and sweet orange oil (122 or 126 nm) for nobiletin- or tangeretin-loaded emulsions, respectively. The optical clarity of the emulsions increased with decreasing droplet size due to reduced light scattering. The viscosities of the emulsions (with or without PMFs) were similar (1.3 to 1.4 mPa·s), despite appreciable differences in oil phase viscosity. The loading capacity and encapsulation efficiency of the emulsions depended on carrier oil type, with bergamot oil giving the highest loading capacity. In summary, differences in the composition and physical characteristics of citrus oils led to PMF-loaded emulsions with different encapsulation and physicochemical characteristics. These results will facilitate the rational design of emulsion-based delivery systems for encapsulation of PMFs and other nutraceuticals in functional foods and beverages.

Citrus leprosis transmission by Brevipalpus yothersi mites through non citrus hosts

Directory of Open Access Journals (Sweden)

Guillermo León M.

2017-05-01

Full Text Available Citrus leprosis virus (C i LV was detected in Colombia at the eastern plains in 2004; it is a threat the disease spreads to other regions of the country. The main vector is Brevipalpus yothersi Baker (formerly identified as Brevipalpus phoenicis. This research determined the viability of B. yothersi to transmit C i LV to citrus plants, after been hosted in non-citrus plants. To virus acquisition, mites spent three days on symptomatic orange (Citrus x sinensis leaves positives to C i LV-C2; then mites were placed on six non-citrus plants (Dieffenbachia sp., Hibiscus rosa-sinensis,Codiaeum variegatum, Swinglea glutinosa, Sida acutaand Stachytarpheta cayennensis. A randomized design with 6 treatments and 4 replicates was carried out. After scheduled time in non-citrus plants, mites were three days relocated on C. x sinensis healthy plants. Leaves of receptor plants, were evaluated to the occurrence or absence of symptoms and collected for RT-PCR tests. B. yothersi mites were able to transmit the C i LV virus over 85 % of Valencia orange plants (Citrus x sinensis L., after feeding from 2-20 days on non-citrus host plants. The first leprosis symptoms on C. x sinensis leaves was confirmed from 14 to 51 days after transmission. The present research work further established that C i LV-C2 is a persistently transmitted virus. The implement quarantine diagnostic measures to prevent spread of CiLV to disease-free zones is suggested.

Efficient somatic embryo production of Limau madu ( Citrus ...

African Journals Online (AJOL)

Effects of N6-benzylaminopurine (BAP) concentration, initial cell density and carbon sources and concentrations for producing cell suspension and somatic embryos of Limau madu (Citrus suhuiensis Hort. ex Tanaka) were investigated using cell suspension culture. Cells were first inoculated into Murashige and Skoog (MS) ...

Efficient somatic embryo production of Limau madu (Citrus ...

African Journals Online (AJOL)

fbn

(Citrus suhuiensis Hort. ex Tanaka) in liquid culture. Dita Agisimanto1*, Normah Mohd Noor1,2, Rusli Ibrahim3 and Azhar Mohamad3. 1School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600. Bangi, Selangor, Malaysia. 2Institute of Systems Biology ...

CHEMICAL COMPOSITION AND TOXICITY OF CITRUS ESSENTIAL OILS ON Dysmicoccus brevipes (HEMIPTERA: PSEUDOCOCCIDAE)

OpenAIRE

MARTINS, GISELE DOS SANTOS OLIVEIRA; ZAGO, HUGO BOLSONI; COSTA, ADILSON VIDAL; ARAUJO JUNIOR, LUIS MOREIRA DE; CARVALHO, JOSÉ ROMÁRIO DE

2017-01-01

ABSTRACT The insect Dysmicoccus brevipes (Hemiptera: Pseudococcidae) has been reported as an important pest for several crops, especially coffee. The citrus essential oils can be obtained as by-products of the citrus-processing industry and have been tested as an alternative to control different insect groups. Therefore, the objective of this work was to determine the chemical composition and evaluate the toxicity of commercial sweet orange (Citrus sinensis), bitter orange (Citrus aurantium) ...

Phylogenetic Relationships of Citrus and Its Relatives Based on matK Gene Sequences

Science.gov (United States)

Penjor, Tshering; Uehara, Miki; Ide, Manami; Matsumoto, Natsumi; Matsumoto, Ryoji

2013-01-01

The genus Citrus includes mandarin, orange, lemon, grapefruit and lime, which have high economic and nutritional value. The family Rutaceae can be divided into 7 subfamilies, including Aurantioideae. The genus Citrus belongs to the subfamily Aurantioideae. In this study, we sequenced the chloroplast matK genes of 135 accessions from 22 genera of Aurantioideae and analyzed them phylogenetically. Our study includes many accessions that have not been examined in other studies. The subfamily Aurantioideae has been classified into 2 tribes, Clauseneae and Citreae, and our current molecular analysis clearly discriminate Citreae from Clauseneae by using only 1 chloroplast DNA sequence. Our study confirms previous observations on the molecular phylogeny of Aurantioideae in many aspects. However, we have provided novel information on these genetic relationships. For example, inconsistent with the previous observation, and consistent with our preliminary study using the chloroplast rbcL genes, our analysis showed that Feroniella oblata is not nested in Citrus species and is closely related with Feronia limonia. Furthermore, we have shown that Murraya paniculata is similar to Merrillia caloxylon and is dissimilar to Murraya koenigii. We found that “true citrus fruit trees” could be divided into 2 subclusters. One subcluster included Citrus, Fortunella, and Poncirus, while the other cluster included Microcitrus and Eremocitrus. Compared to previous studies, our current study is the most extensive phylogenetic study of Citrus species since it includes 93 accessions. The results indicate that Citrus species can be classified into 3 clusters: a citron cluster, a pummelo cluster, and a mandarin cluster. Although most mandarin accessions belonged to the mandarin cluster, we found some exceptions. We also obtained the information on the genetic background of various species of acid citrus grown in Japan. Because the genus Citrus contains many important accessions, we have

Phylogenetic relationships of citrus and its relatives based on matK gene sequences.

Directory of Open Access Journals (Sweden)

Tshering Penjor

Full Text Available The genus Citrus includes mandarin, orange, lemon, grapefruit and lime, which have high economic and nutritional value. The family Rutaceae can be divided into 7 subfamilies, including Aurantioideae. The genus Citrus belongs to the subfamily Aurantioideae. In this study, we sequenced the chloroplast matK genes of 135 accessions from 22 genera of Aurantioideae and analyzed them phylogenetically. Our study includes many accessions that have not been examined in other studies. The subfamily Aurantioideae has been classified into 2 tribes, Clauseneae and Citreae, and our current molecular analysis clearly discriminate Citreae from Clauseneae by using only 1 chloroplast DNA sequence. Our study confirms previous observations on the molecular phylogeny of Aurantioideae in many aspects. However, we have provided novel information on these genetic relationships. For example, inconsistent with the previous observation, and consistent with our preliminary study using the chloroplast rbcL genes, our analysis showed that Feroniella oblata is not nested in Citrus species and is closely related with Feronia limonia. Furthermore, we have shown that Murraya paniculata is similar to Merrillia caloxylon and is dissimilar to Murraya koenigii. We found that "true citrus fruit trees" could be divided into 2 subclusters. One subcluster included Citrus, Fortunella, and Poncirus, while the other cluster included Microcitrus and Eremocitrus. Compared to previous studies, our current study is the most extensive phylogenetic study of Citrus species since it includes 93 accessions. The results indicate that Citrus species can be classified into 3 clusters: a citron cluster, a pummelo cluster, and a mandarin cluster. Although most mandarin accessions belonged to the mandarin cluster, we found some exceptions. We also obtained the information on the genetic background of various species of acid citrus grown in Japan. Because the genus Citrus contains many important accessions

Phylogenetic relationships of citrus and its relatives based on matK gene sequences.

Science.gov (United States)

Penjor, Tshering; Yamamoto, Masashi; Uehara, Miki; Ide, Manami; Matsumoto, Natsumi; Matsumoto, Ryoji; Nagano, Yukio

2013-01-01

The genus Citrus includes mandarin, orange, lemon, grapefruit and lime, which have high economic and nutritional value. The family Rutaceae can be divided into 7 subfamilies, including Aurantioideae. The genus Citrus belongs to the subfamily Aurantioideae. In this study, we sequenced the chloroplast matK genes of 135 accessions from 22 genera of Aurantioideae and analyzed them phylogenetically. Our study includes many accessions that have not been examined in other studies. The subfamily Aurantioideae has been classified into 2 tribes, Clauseneae and Citreae, and our current molecular analysis clearly discriminate Citreae from Clauseneae by using only 1 chloroplast DNA sequence. Our study confirms previous observations on the molecular phylogeny of Aurantioideae in many aspects. However, we have provided novel information on these genetic relationships. For example, inconsistent with the previous observation, and consistent with our preliminary study using the chloroplast rbcL genes, our analysis showed that Feroniella oblata is not nested in Citrus species and is closely related with Feronia limonia. Furthermore, we have shown that Murraya paniculata is similar to Merrillia caloxylon and is dissimilar to Murraya koenigii. We found that "true citrus fruit trees" could be divided into 2 subclusters. One subcluster included Citrus, Fortunella, and Poncirus, while the other cluster included Microcitrus and Eremocitrus. Compared to previous studies, our current study is the most extensive phylogenetic study of Citrus species since it includes 93 accessions. The results indicate that Citrus species can be classified into 3 clusters: a citron cluster, a pummelo cluster, and a mandarin cluster. Although most mandarin accessions belonged to the mandarin cluster, we found some exceptions. We also obtained the information on the genetic background of various species of acid citrus grown in Japan. Because the genus Citrus contains many important accessions, we have

Detection of Anomalies in Citrus Leaves Using Laser-Induced Breakdown Spectroscopy (LIBS).

Science.gov (United States)

Sankaran, Sindhuja; Ehsani, Reza; Morgan, Kelly T

2015-08-01

Nutrient assessment and management are important to maintain productivity in citrus orchards. In this study, laser-induced breakdown spectroscopy (LIBS) was applied for rapid and real-time detection of citrus anomalies. Laser-induced breakdown spectroscopy spectra were collected from citrus leaves with anomalies such as diseases (Huanglongbing, citrus canker) and nutrient deficiencies (iron, manganese, magnesium, zinc), and compared with those of healthy leaves. Baseline correction, wavelet multivariate denoising, and normalization techniques were applied to the LIBS spectra before analysis. After spectral pre-processing, features were extracted using principal component analysis and classified using two models, quadratic discriminant analysis and support vector machine (SVM). The SVM resulted in a high average classification accuracy of 97.5%, with high average canker classification accuracy (96.5%). LIBS peak analysis indicated that high intensities at 229.7, 247.9, 280.3, 393.5, 397.0, and 769.8 nm were observed of 11 peaks found in all the samples. Future studies using controlled experiments with variable nutrient applications are required for quantification of foliar nutrients by using LIBS-based sensing.

Aproveitamento da casca de citros na perspectiva de alimentos: prospecção da atividade antibacteriana Utilization of citrus by-products in food perspective: screening of antibacterial activity

Directory of Open Access Journals (Sweden)

Carin Gerhardt

2012-05-01

export of orange juice. The State of Rio Grande Do Sul is an important producer of citrus. During farming and processing of citrus, tons of residues are generated, with low commercial value and great potential for use in the field of food production. These residues possess many nutrients, pigments and bioactive compounds, as well as low toxicity and cost. There is evidence that the peel of citrus have antibacterial and antifungal activity. In this work, we aim to determine the antibacterial activity of ethanolic extracts of citrus peels in the perspective of disinfection and preservation of food, presenting sustainable and natural alternatives directed at consumers concerned with health. Ethanolic extracts of crude peel of ripe ponkan tangerine (Citrus reticulata Blanco, pomelo (Citrus maxima (Burm. Merr. and rangpur lime (Citrus limonia Osbeck were obtained from ecological family farms. Their antibacterial activities were evaluated regarding Minimal Inhibitory Concentration (MIC and Minimal Bactericidal Concentration (MBC against five different bacterial strains. The rangpur lime extract presented the best antibacterial activity, with about 24 mg.mL-1 MIC and 42 mg.mL-1 MBC for the most resistant strain. Pseudomonas aeruginosa was the most sensitive strain. All ethanolic extracts inhibited or inactivated all tested strains, indicating they could be used as natural alternatives in food disinfection and preservation.

Citrus Production, Constraints and Management Practices in Ethiopia

African Journals Online (AJOL)

home

2014-05-16

May 16, 2014 ... Citrus is economically important fruit crop in Ethiopia. However, its .... water. Sterilized leaves or fruit peels were cut, and four to six leaf discs or peel pieces were placed on each Petri dish containing potato dextrose agar (PDA) in five replicates ... banana, avocado and papaya), vegetable crops (primarily.

Effective antibiotics against 'Candidatus Liberibacter asiaticus' in HLB-affected citrus plants identified via the graft-based evaluation.

Science.gov (United States)

Zhang, Muqing; Guo, Ying; Powell, Charles A; Doud, Melissa S; Yang, Chuanyu; Duan, Yongping

2014-01-01

Citrus huanglongbing (HLB), caused by three species of fastidious, phloem-limited 'Candidatus Liberibacter', is one of the most destructive diseases of citrus worldwide. To date, there is no established cure for this century-old and yet, newly emerging disease. As a potential control strategy for citrus HLB, 31 antibiotics were screened for effectiveness and phytotoxicity using the optimized graft-based screening system with 'Candidatus Liberibacter asiaticus' (Las)-infected citrus scions. Actidione and Oxytetracycline were the most phytotoxic to citrus with less than 10% of scions surviving and growing; therefore, this data was not used in additional analyses. Results of principal component (PCA) and hierarchical clustering analyses (HCA) demonstrated that 29 antibiotics were clustered into 3 groups: highly effective, partly effective, and not effective. In spite of different modes of actions, a number of antibiotics such as, Ampicillin, Carbenicillin, Penicillin, Cefalexin, Rifampicin and Sulfadimethoxine were all highly effective in eliminating or suppressing Candidatus Liberibacter asiaticus indicated by both the lowest Las infection rate and titers of the treated scions and inoculated rootstock. The non-effective group, including 11 antibiotics alone with three controls, such as Amikacin, Cinoxacin, Gentamicin, Kasugamycin, Lincomycin, Neomycin, Polymixin B and Tobramycin, did not eliminate or suppress Las in the tested concentrations, resulting in plants with increased titers of Las. The other 12 antibiotics partly eliminated or suppressed Las in the treated and graft-inoculated plants. The effective and non-phytotoxic antibiotics could be potential candidates for control of citrus HLB, either for the rescue of infected citrus germplasm or for restricted field application.

Complex history of admixture during citrus domestication revealed by genome analysis

Energy Technology Data Exchange (ETDEWEB)

Wu, G. Albert; Prochnik, Simon; Jenkins, Jerry; Salse, Jerome; Hellsten, Uffe; Murat, Florent; Perrier, Xavier; Ruiz, Manuel; Scalabrin, Simone; Terol, Javier; Takita, Marco Aur& #233; lio,; Labadie, Karine; Poulain, Julie; Couloux, Arnaud; Jabbari, Kamel; Cattonaro, Federica; Fabbro, Cristian Del; Pinosio, Sara; Zuccolo, Andrea; Chapman, Jarrod; Grimwood, Jane; Tadeo, Francisco; Estornell, Leandro H.; Mu?oz-Sanz, Juan V.; Ibanez, Victoria; Herrero-Ortega, Amparo; Aleza, Pablo; P& #233; rez, Juli& #225; n P& #233; rez,; Ramon, Daniel; Brunel, Dominique; Luro, Francois; Chen, Chunxian; Farmerie, William G.; Desany, Brian; Kodira, Chinnappa; Mohiuddin, Mohammed; Harkins, Tim; Fredrikson, Karin; Burns, Paul; Lomsadze, Alexandre; Borodovsky, Mark; Reforgiato, Giuseppe; Freitas-Astua, Juliana; Quetier, Francis; Navarro, Luis; Roose, Mikeal; Wincker, Patrick; Schmutz, Jeremy; Morgante, Michele; Machado, Marcos Antonio; Talon, Manuel; Jaillon, Olivier; Ollitrault, Patrick; Gmitter, Frederick; Rokhsar, Daniel

2014-06-30

vulnerable to disease outbreaks, including citrus greening disease (also known as Huanglongbing) that is rapidly spreading throughout the world's major citrus producing regions1. Understanding the population genomics and domestication of citrus will enable strategies for improvements to citrus including resistance to greening and other diseases. The domestication and distribution of edible citrus types began several thousand years ago in Southeast Asia and spread globally following ancient land and sea routes. The lineages that gave rise to most modern cultivated varieties, however, are lost in undocumented antiquity, and their identities remain controversial2, 3. Several features of Citrus biology and cultivation make deciphering these origins difficult. Cultivated varieties are typically propagated clonally by grafting and through asexual seed production (apomixis via nucellar polyembryony) to maintain desirable combinations of traits (Fig. 1). Thus many important cultivar groups have characteristic basic genotypes that presumably arose through interspecific hybridization and/or successive introgressive hybridizations of wild ancestral species. These domestication events predated the global expansion of citrus cultivation by hundreds or perhaps thousands of years, with no record of the domestication process. Diversity within such groups arises through accumulated somatic mutations, generally without sexual recombination, either as limb sports on trees or variants among apomictic seedling progeny. Two wild species are believed to have contributed to domesticated pummelos, mandarins and oranges. Based on morphology and genetic markers, pummelos have generally been identified with the wild species C. maxima (Burm.) Merrill that is indigenous to Southeast Asia. Although mandarins are similarly widely identified with the species C. reticulata Blanco 4-6, wild populations of C. reticulata have not been definitively described. Various authors have taken dif

Genome wide selection in Citrus breeding.

Science.gov (United States)

Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

2016-10-17

Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq TM (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

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

Directory of Open Access Journals (Sweden)

Audray Dugrand-Judek

Full Text Available 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

Inhibitory effect of a formulated extract from multiple citrus peels on LPS-induced inflammation in RAW 246.7 macrophages

Directory of Open Access Journals (Sweden)

Tadahiro Etoh

2013-06-01

Full Text Available ABSTRACTBackground: Formulated Citrus Peel Extract (GL made from the peels of six citrus fruits available in Japan, namely navel oranges, citrus hassaku, citrus limon, citrus natsudaidai, citrus miyauchi and satsuma, was initially developed as a cosmetic product to protect skin from UV irradiation. Anecdotal evidences of anti-cancer property of GL have been reported by consumers based on the cases such as topical application for melanoma, and oral ingestion for prostate, lung and liver cancers.Those anecdotal reports stimulated us to investigate anti-tumorigenesis activity of GL. In the previous study, we reported that the topical application of GL inhibited DMBA/TPA-induced skin tumor formation by decreasing inflammatory gene parameters.Objective: In this study, we mainly investigated the effect of GL on translocation of NF-kB together with production of nitric-oxide and TNF-α induced by LPS in RAW 264.7 cells.Results: This investigation showed that GL decreased the release of TNF-α and nitric oxide from macrophage RAW264.7 cells stimulated by LPS in a dose-dependent manner. In addition, GL suppressed the expression of iNOS and nuclear translocation of NF-kB in RAW264.7 cells, inhibited the degradation of IκB-α, and scavenged hydroxyl radicals (DMPO/OH adduct in vitro.Conclusions: Our findings suggest that GL suppresses the inflammation in vitro, and exerts chemopreventive activity through the inhibition of production of TNF-α and iNOS proteins due to the inhibition of nuclear translocation of NF-kB and oxidative stress. GL appears to be a novel functional natural product capable of preventing inflammation and inflammation-associated tumorigenesis.Keywords: GL, Citrus peel extract, anti-inflammation, Nitric oxide, iNOS, NF-kB, TNF-α

The WRKY Transcription Factor Family in Citrus: Valuable and Useful Candidate Genes for Citrus Breeding.

Science.gov (United States)

Ayadi, M; Hanana, M; Kharrat, N; Merchaoui, H; Marzoug, R Ben; Lauvergeat, V; Rebaï, A; Mzid, R

2016-10-01

WRKY transcription factors belong to a large family of plant transcriptional regulators whose members have been reported to be involved in a wide range of biological roles including plant development, adaptation to environmental constraints and response to several diseases. However, little or poor information is available about WRKY's in Citrus. The recent release of completely assembled genomes sequences of Citrus sinensis and Citrus clementina and the availability of ESTs sequences from other citrus species allowed us to perform a genome survey for Citrus WRKY proteins. In the present study, we identified 100 WRKY members from C. sinensis (51), C. clementina (48) and Citrus unshiu (1), and analyzed their chromosomal distribution, gene structure, gene duplication, syntenic relation and phylogenetic analysis. A phylogenetic tree of 100 Citrus WRKY sequences with their orthologs from Arabidopsis has distinguished seven groups. The CsWRKY genes were distributed across all ten sweet orange chromosomes. A comprehensive approach and an integrative analysis of Citrus WRKY gene expression revealed variable profiles of expression within tissues and stress conditions indicating functional diversification. Thus, candidate Citrus WRKY genes have been proposed as potentially involved in fruit acidification, essential oil biosynthesis and abiotic/biotic stress tolerance. Our results provided essential prerequisites for further WRKY genes cloning and functional analysis with an aim of citrus crop improvement.

Citrus Tristeza Virus: An Increasing Trend in the Virus Occurrence ...

African Journals Online (AJOL)

Citrus tristeza clostervirus (CTV) is one of the most damaging fruit viruses playing havoc in citrus orchards around the world. Here, we report, an ELISA-based indexing of citrus trees over a period of eight years (2002 to 2010) in Northwest Pakistan, revealing that the incidence of CTV is increasing mainly with the distribution ...

Citrus genebank collections: International collaboration opportunities between the U.S. and Russia

Science.gov (United States)

Citrus germplasm is conserved in genebanks at sites around the world to provide genetic resources for breeding and research programs. The value of genebank collections is particularly evident as diseases and climate change threaten citrus production areas. We provide historical, inventory, and maint...

[Estimation and Visualization of Nitrogen Content in Citrus Canopy Based on Two Band Vegetation Index (TBVI)].

Science.gov (United States)

Wang, Qiao-nan; Ye, Xu-jun; Li, Jin-meng; Xiao, Yu-zhao; He, Yong

2015-03-01

Nitrogen is a necessary and important element for the growth and development of fruit orchards. Timely, accurate and nondestructive monitoring of nitrogen status in fruit orchards would help maintain the fruit quality and efficient production of the orchard, and mitigate the pollution of water resources caused by excessive nitrogen fertilization. This study investigated the capability of hyperspectral imagery for estimating and visualizing the nitrogen content in citrus canopy. Hyperspectral images were obtained for leaf samples in laboratory as well as for the whole canopy in the field with ImSpector V10E (Spectral Imaging Ltd., Oulu, Finland). The spectral datas for each leaf sample were represented by the average spectral data extracted from the selected region of interest (ROI) in the hyperspectral images with the aid of ENVI software. The nitrogen content in each leaf sample was measured by the Dumas combustion method with the rapid N cube (Elementar Analytical, Germany). Simple correlation analysis and the two band vegetation index (TBVI) were then used to develop the spectra data-based nitrogen content prediction models. Results obtained through the formula calculation indicated that the model with the two band vegetation index (TBVI) based on the wavelengths 811 and 856 nm achieved the optimal estimation of nitrogen content in citrus leaves (R2 = 0.607 1). Furthermore, the canopy image for the identified TBVI was calculated, and the nitrogen content of the canopy was visualized by incorporating the model into the TBVI image. The tender leaves, middle-aged leaves and elder leaves showed distinct nitrogen status from highto low-levels in the canopy image. The results suggested the potential of hyperspectral imagery for the nondestructive detection and diagnosis of nitrogen status in citrus canopy in real time. Different from previous studies focused on nitrogen content prediction at leaf level, this study succeeded in predicting and visualizing the nutrient

Comparative study of the hypocholesterolemic, antidiabetic effects of four agro-waste Citrus peels cultivars and their HPLC standardization

Directory of Open Access Journals (Sweden)

Nesrin M. Fayek

Full Text Available ABSTRACT Citrus is an economically important fruit for Egypt, but its peel also is one of the major sources of agricultural waste. Due to its fermentation, this waste causes many economic and environmental problems. Therefore it is worthwhile to investigate ways to make use of this citrus waste generated by the juice industry. This study was aimed to explore the hypocholesterolemic, antidiabetic activities of four varieties of citrus peels agrowastes, to isolate the main flavonoids in the active fractions and to quantify them by HPLC method for nutraceutical purposes. All the tested samples of the agro-waste Citrus fruits peels showed significant decrease in cholesterol, triacylglyceride and glucose. The most decrease in cholesterol level was observed by mandarin peels aqueous homogenate and its hexane fraction (59.3% and 56.8%, respectively reaching the same effect as the reference drug used (54.7%. Mostly, all samples decrease triacylglyceride (by 36%–80.6% better than the reference drug used (by 35%, while, glucose was decreased (by 71.1%–82.8 and 68.6%–79.6%, respectively mostly by the aqueous homogenates (except lime and alcoholic extracts (except mandarin of Citrus fruits peels better than the reference drug used (by 68.3%. All the isolated pectin, from the four cultivars, has significant effect on the three parameters. The comparative HPLC rapid quantification of nobiletin in the different by-product citrus varieties hexane fractions revealed that nobiletin is present in higher concentration in mandarin (10.14% than the other species. Nobiletin and 4′,5,7,8-tetramethoxy flavone were isolated from mandarin peels hexane fraction by chromatographic fractionation. This is the first report of the comparative HPLC quantification of nobiletin and biological studies of different citrus peels species as agro-waste products. Based on these results, we suggest the possibility that Citrus fruits peels may be considered as an antidiabetic and

Agrobacterium-mediated transformation of Citrus sinensis and Citrus limonia epicotyl segments

OpenAIRE

Almeida,Weliton Antonio Bastos de; Mourão Filho,Francisco de Assis Alves; Mendes,Beatriz Madalena Januzzi; Pavan,Alexandra; Rodriguez,Adriana Pinheiro Martinelli

2003-01-01

Genetic transformation allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. The objective of this research was to establish a protocol for genetic transformation of Valencia and Natal sweet oranges (Citrus sinensis L. Osbeck) and Rangpur lime (Citrus limonia L. Osbeck). Epicotyl segments of germinated in vitro plantlets (three weeks in darkness and two weeks in a 16-h photoperiod) were used...

Incorporation of citrus essential oils into bacterial cellulose-based edible films and assessment of their physical properties

Science.gov (United States)

Indrarti, L.; Indriyati

2017-03-01

The use of edible films in food protection and preservation has recently gained more interest since they offer several advantages over synthetic packaging materials. Biocellulose (BC) offers great opportunity as edible film due to their unique physical and mechanical properties. In this study, biocellulose films were prepared by solution casting with addition of 30% carboxymethyl cellulose (CMC) and 30% glycerol as the homogenizer and plasticizer, respectively. Furthermore, various citrus essential oils (EOs) including lemon, lime, and sweet orange were added at 50% w/w of BC dried weight. The solutions were then cast on the tray and allowed to dry in the air convection oven at 40°C overnight. The films were characterized for water solubility, tensile strength (TS), elongation at break (EB), water vapour transmission rate (WVTR), and color. Those characteristics may influence consumer acceptability of the packaged products. Results revealed that addition of lemon and sweet orange EOs into BC-based edible film decreased water solubility and TS, but improved EB, as these oils acted as plasticizers in the film. However, different trend was observed for BC-based film incorporated with lime oil, which had higher solubility and TS, but lower EB and WVTR compared with that of control film. Addition of citrus EOs into BC-based films did not have much effect on color properties as stated in L*, a*, and b* values.

Botanical insecticides in controlling Kelly's citrus thrips (Thysanoptera: Thripidae) on organic grapefruits.

Science.gov (United States)

Vassiliou, V A

2011-12-01

Kelly's citrus thrips, Pezothrips kellyanus (Bagnall) (Thysanoptera: Thripidae) was first recorded in Cyprus in 1996 and became an economic citrus pest. In Cyprus, Kelly's citrus thrips larvae cause feeding damage mainly on immature lemon and grapefruit fruits. Use of botanical insecticides is considered an alternative tool compared with synthetic chemicals, in offering solutions for healthy and sustainable citrus production. During 2008-2010, the efficacy of the botanical insecticides azadirachtin (Neemex 0.3%W/W and Oikos 10 EC), garlic extract (Alsa), and pyrethrins (Vioryl 5%SC) was evaluated in field trials against Kelly's citrus thrips larval stage I and II aiming at controlling the pest's population and damage to organic grapefruit fruits. In each of the trial years treatments with pyrethrins and azadirachtin (Neemex 0.3%W/W) were the most effective against Kelly's citrus thrips compared with the untreated control (for 2008: P extract showed the lowest effect from all the botanicals used compared with the untreated control.

Effect of genotype and environment on citrus juice carotenoid content.

Science.gov (United States)

Dhuique-Mayer, Claudie; Fanciullino, Anne-Laure; Dubois, Cecile; Ollitrault, Patrick

2009-10-14

A selection of orange and mandarin varieties belonging to the same Citrus accession and cultivated in Mediterranean (Corsica), subtropical (New Caledonia), and tropical areas (principally Tahiti) were studied to assess the effect of genotype and environmental conditions on citrus juice carotenoid content. Juices from three sweet orange cultivars, that is, Pera, Sanguinelli, and Valencia ( Citrus sinensis (L.) Osbeck), and two mandarin species ( Citrus deliciosa Ten and Citrus clementina Hort. ex Tan), were analyzed by HPLC using a C(30) column. Annual carotenoid content variations in Corsican fruits were evaluated. They were found to be very limited compared to variations due to varietal influences. The statistical analysis (PCA, dissimilarity tree) results based on the different carotenoid compounds showed that citrus juice from Corsica had a higher carotenoid content than citrus juices from tropical origins. The tropical citrus juices were clearly differentiated from citrus juices from Corsica, and close correlations were obtained between beta-cryptoxanthin and phytoene (r = 0.931) and beta-carotene and phytoene (r = 0.918). More broadly, Mediterranean conditions amplified interspecific differentiation, especially by increasing the beta-cryptoxanthin and cis-violaxanthin content in oranges and beta-carotene and phytoene-phytofluene content in mandarins. Thus, at a quantitative level, environmental conditions also had a major role in determining the levels of carotenoids of nutritional interest, such as the main provitamin A carotenoids in citrus juice (beta-cryptoxanthin and beta-carotene).

Citrus huanglongbing: validation of Real-Time PCR (qPCR for the detection of Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus in Colombia

Directory of Open Access Journals (Sweden)

Jorge Evelio Ángel

2014-12-01

Full Text Available Citrus huanglongbing (HLB is the most destructive citrus disease. Two of the three known HLB-associated Candidatus Liberibacter species were recently found to be present in the Americas. In this study, eggs, nymphs and adults of Diaphorina citri Kuwayama (Hemiptera: Liviidae and suspect citrus plant materials were collected in 25 municipalities in the departments of Cundinamarca, Santander, Valle del Cauca, Meta and Quindio (Colombia. The detection sensitivity, specificity and assay performance of the 16S rDNA-based real-time PCR (qPCR were validated for the field survey of the disease in Colombia. The validation confirmed the reliability and robustness of the real-time PCR method for the detection of HLB bacteria in host citrus plant tissues and the vector D. citri. The diagnosis was performed for Candidatus Liberibacter asiaticus (Ca. L. asiaticus and for Candidatus Liberibacter americanus (Ca. L. americanus on 168 citrus plant material samples and 239 insect samples. Neither Ca. L. asiaticus nor Ca. L. americanus were detected in the host plants or insects vector, confirming the absence of the disease in the citrus-producing areas of Colombia.

EFFECTIVENESS OF HUANGLONGBING VECTOR (DIAPHORINA CITRI KUWAYAMA CONTROL IN CITRUS GROWER GROUP BASED IN SAMBAS REGENCY OF WEST KALIMANTAN, INDONESIA

Directory of Open Access Journals (Sweden)

Supriyanto A.

2017-12-01

Full Text Available The purpose of this study was to determine the effectiveness of Huanglongbing vector control based on Citrus Grower Group recommendation. Studies have been carried out in 2010 in Tebas Sungai village, Sambas district, with 11 tangerine groves owned by growers in the Citrus grower Association of Sambas district. The tangerine grove that been used are, one grower's orchard as a demonstration plot in a particular citrus grower group (orchard I; five other citrus orchards with different ownership at the same citrus grower Group (orchard II, as well as five other citrus orchard with different ownership which each of them spreads over five different citrus grower groups outside the farm demonstration plots (orchard III. The recommendation technology for controlling Huanglongbing vector which applied in this experiment, included bark painting by systemic insecticide of imidacloprid for two each 1.5-month and spray using contact insecticide with dimethoate to the plant crown which application time been alternated after bark painting application. The effectiveness of technology implementation is measured by a decrease psyllid populations found in citrus samples in adult stage, nymphs and eggs that were observed at regular intervals every two weeks during the flushing to the 14th week after the first treatment. The results showed that recommended treatment technology were absolutely proven to reduce Huanglongbing vector population in significant, namely in the orchard I, II, and III respectively at 95.3%, 84.7%, and 72% for stage adult; 97.3 %, 80%, and 100% for stage nymphs; and 98.5%, 100% and 100% for the egg stage.

77 FR 59709 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

Science.gov (United States)

2012-10-01

... occur. The pathogen can also be transmitted by two insect vectors in the family Psyllidae: Diaphorina... California due to the presence of Asian citrus psyllid (ACP), a vector of the bacterial pathogen that causes... INFORMATION: Background Citrus greening, also known as Huanglongbing disease of citrus, is considered to be...

Two of a kind but different: Luminescent carbon quantum dots from Citrus peels for iron and tartrazine sensing and cell imaging.

Science.gov (United States)

Chatzimitakos, Theodoros; Kasouni, Athanasia; Sygellou, Lamprini; Avgeropoulos, Apostolos; Troganis, Anastasios; Stalikas, Constantine

2017-12-01

Citrus sinensis and Citrus limon peels were used to synthesize two different kinds of carbon quantum dots (CQDs) via an unsophisticated and inexpensive carbonization procedure. The proposed synthesis is straightforward and adheres to the principles of green chemistry since no organic solvents are used and no toxic by-products are formed, while the residual resources employed facilitate the large scale synthesis of dots. The Citrus sinensis and Citrus limon peels are proved to be excellent precursors for the synthesis of CQDs with highly practical applications. The CQDs display strong excitation-independent, blue fluorescence, which is stable over time. Splendid water dispersibility, photostability and stability over a wide range of pH are some of the main advantages of the CQDs, which enable them to be used as a fluorescent probes. Although many of their features are alike, our findings demonstrate that each kind of the CQDs lend itself to quite distinct analytical applications. The developed fluorescent probes possess high potential for sensitive and selective detection of Fe 3+ (Citrus sinensis CQDs) and tartrazine (Citrus limon CQDs) via a quenching mechanism. The decrease in fluorescence intensity is in linear relationship with the concentrations of Fe 3+ and tartrazine in the ranges of 0.01-1.0μM and 0.6-23.5μΜ, respectively. Moreover, their low cytotoxicity reinforces their applicability towards cell bioimaging and intracellular detection of Fe 3+ , which were further studied. Copyright © 2017 Elsevier B.V. All rights reserved.

Current status of the Citrus leprosis virus (CiLV -C and its vector Brevipalpus phoenicis (Geijskes

Directory of Open Access Journals (Sweden)

Guillermo León M

2012-08-01

Full Text Available The Citrus leprosis virus CiLV-C is a quarantine disease of economic importance. Over the past 15 years, this disease has spread to several countries of Central and South America. Colombia has about 45,000 hectares of citrus planted with an annual production of 750,000 tonnes. The CiLV-C has only been detected in the departments of Meta, Casanare and recently Tolima. Meta has 4,300 hectares representing 10% of the national cultivated area, and Casanare, where CiLV-C appeared in 2004, has no more than 500 ha planted with citrus. The presence of the Citrus leprosis virus in Colombia could affect the international market for citrus, other crops and ornamental plants with the United States and other countries without the disease. The false spider mite Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae is the main vector of the CiLV-C. Disease management is based on control programs of the vector and diminishing host plants. Chemical mite control is expensive, wasteful and generates resistance to different acaricides. This paper provides basic information on CiLV-C and its vector, advances in diagnosis and methods to control the disease and prevention of its spread

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.

Effect of Nigerian citrus ( Citrus sinensis Osbeck) honey on ethanol ...

African Journals Online (AJOL)

The effect of Nigerian citrus (Citrus sinensis Osbeck) honey on ethanol metabolism was tested using 45 consenting individuals in apparent good health and between the ages of 25 and 35 years. The subjects were moderate social drinkers matched in terms of body weight and build. The results obtained showed that on ...

An Ecoinformatics Approach to Field-Scale Evaluation of Insecticide Effects in California Citrus: Are Citrus Thrips and Citrus Red Mite Induced Pests?

Science.gov (United States)

Livingston, George; Hack, Lindsey; Steinmann, Kimberly P; Grafton-Cardwell, Elizabeth E; Rosenheim, Jay A

2018-05-28

Experimental approaches to studying the consequences of pesticide use, including impacts on beneficial insects, are vital; however, they can be limited in scale and realism. We show that an ecoinformatics approach that leverages existing data on pesticides, pests, and beneficials across multiple fields can provide complementary insights. We do this using a multi-year dataset (2002-2013) on pesticide applications and density estimates of two pests, citrus thrips (Scirtothrips citri (Moulton [Thysanoptera: Thripidae])) and citrus red mites (Panonychus citri McGregor [Acari: Tetranychidae]), and a natural enemy (Euseius spp. predatory mites) collected from citrus groves in the San Joaquin Valley of California. Using correlative analyses, we investigated the long-term consequences of pesticide use on S. citri and P. citri population densities to evaluate the hypothesis that the pest status of these species is largely due to the disruption of natural biological control-i.e., these are induced pests. We also evaluated short-term pesticide efficacy (suppression of citrus thrips and citrus red mite populations immediately post-application) and asked if it was correlated with the suppression of Euseius predator populations. Although the short-term efficacy of different pesticides varied significantly, our dataset does not suggest that the use of citrus pesticides suppressed Euseius densities or worsened pest problems. We also find that there is no general trade-off between pesticide efficacy and pesticide risk to Eusieus, such that highly effective and minimally disruptive compounds were available to citrus growers during the studied time period.

Evaluation of resistance to asiatic citrus canker among selections of pera sweet orange (Citrus sinensis)

Science.gov (United States)

Asiatic citrus canker (ACC, caused by the bacterium Xanthomonas citri subsp. citri) is a destructive disease of citrus in Brazil and in several other citrus-producing countries. ACC management is problematic, and bactericides such as copper can be reasonably efficacious but do not completely control...

Quantitative distribution of 'Candidatus Liberibacter asiaticus' in citrus plants with citrus huanglongbing.

Science.gov (United States)

Li, Wenbin; Levy, Laurene; Hartung, John S

2009-02-01

Citrus huanglongbing (HLB), or greening disease, is strongly associated with any of three nonculturable gram-negative bacteria belonging to 'Candidatus Liberibacter spp.' 'Ca. Liberibacter spp.' are transmitted by citrus psyllids to all commercial cultivars of citrus. The diseases can be lethal to citrus and have recently become widespread in both São Paulo, Brazil, and Florida, United States, the locations of the largest citrus industries in the world. Asiatic HLB, the form of the disease found in Florida, is associated with 'Ca. Liberibacter asiaticus' and is the subject of this report. The nonculturable nature of the pathogen has hampered research and little is known about the distribution of 'Ca. L. asiaticus' in infected trees. In this study, we have used a quantitative polymerase chain reaction assay to systematically quantify the distribution of 'Ca. L. asiaticus' genomes in tissues of six species of citrus either identified in the field during survey efforts in Florida or propagated in a greenhouse in Beltsville, MD. The populations of 'Ca. L. asiaticus' inferred from the distribution of 16S rDNA sequences specific for 'Ca. L. asiaticus' in leaf midribs, leaf blades, and bark samples varied by a factor of 1,000 among samples prepared from the six citrus species tested and by a factor of 100 between two sweet orange trees tested. In naturally infected trees, above-ground portions of the tree averaged 10(10) 'Ca. L. asiaticus' genomes per gram of tissue. Similar levels of 'Ca. L. asiaticus' genomes were observed in some but not all root samples from the same plants. In samples taken from greenhouse-inoculated trees, levels of 'Ca. L. asiaticus' genomes varied systematically from 10(4) genomes/g at the graft inoculation site to 10(10) genomes/g in some leaf petioles. Root samples from these trees also contained 'Ca. L. asiaticus' at 10(7) genomes/g. In symptomatic fruit tissues, 'Ca. L. asiaticus' genomes were also readily detected and quantified. The highest

Chlorophyll Fluorescence Imaging Uncovers Photosynthetic Fingerprint of Citrus Huanglongbing

Directory of Open Access Journals (Sweden)

Haiyan Cen

2017-08-01

Full Text Available Huanglongbing (HLB is one of the most destructive diseases of citrus, which has posed a serious threat to the global citrus production. This research was aimed to explore the use of chlorophyll fluorescence imaging combined with feature selection to characterize and detect the HLB disease. Chlorophyll fluorescence images of citrus leaf samples were measured by an in-house chlorophyll fluorescence imaging system. The commonly used chlorophyll fluorescence parameters provided the first screening of HLB disease. To further explore the photosynthetic fingerprint of HLB infected leaves, three feature selection methods combined with the supervised classifiers were employed to identify the unique fluorescence signature of HLB and perform the three-class classification (i.e., healthy, HLB infected, and nutrient deficient leaves. Unlike the commonly used fluorescence parameters, this novel data-driven approach by using the combination of the mean fluorescence parameters and image features gave the best classification performance with the accuracy of 97%, and presented a better interpretation for the spatial heterogeneity of photochemical and non-photochemical components in HLB infected citrus leaves. These results imply the potential of the proposed approach for the citrus HLB disease diagnosis, and also provide a valuable insight for the photosynthetic response to the HLB disease.

Antibacterial Effects of Citrus aurantium on Bacteria Isolated from Urinary Tract Infection

Directory of Open Access Journals (Sweden)

Masoud Dadashi

2015-10-01

Full Text Available Background :  Emerging antibacterial resistance rates and beta-lactamase producing bacteria recovered from UTI is an increasing problem in different regions, limiting therapeutic options. Therefore, this survey consider to use the extract and essence of the citrus aurantium (which have a so many rate of planting in Iran and also survey on extract on bacteria whose cause urinary tract infections, and compare this with common antibiotics. Methods and Materials: This study was experimental design.We have been isolate the E.coli,Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae and Enterococcus faecalis from UTI and then determine of antibacterial effect of Citrus aurantium against this bacteria with subculture and put the exact diagnosis on them. Antibacterial effects of the herb extract by well diffusion assay and  nalidixic acid and Co-trimoxazol were evaluated by method of agar disc diffusion. Results:Enterococcus faecalis had 100% sensitivity against of extract,essence and Co-trimoxazole , and 80% against nalidixic acid . E.coli had 100% sensitivity against Co-trimoxazol, nalidixic acid and it was totally resistance to extract and essence.Klebsiella Pneumonie had 80% to Co-trimoxazol, 75% to nalidixic acid and resistance against extract and essence.Streptococcus agalactiae was 100% sensitivity to essence and Co-trimoxazol and 90% against nalidixic acid and shown 80% sensitivity against extract.Staphylococcus aureus MRSA shown 100% sensitivity against Co-trimoxazol and 70% sensitivity against essence, extract and nalidixic acid. Conclusion: Detection of antibiotic resistance among isolates is important in prevention and control of infections. In this study, it was shown that extracts of citrus aurantium have high antibacterial effects on gram positive bacteria compare to gram negative bacteria.

Sampling Methods for Detection and Monitoring of the Asian Citrus Psyllid (Hemiptera: Psyllidae).

Science.gov (United States)

Monzo, C; Arevalo, H A; Jones, M M; Vanaclocha, P; Croxton, S D; Qureshi, J A; Stansly, P A

2015-06-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama is a key pest of citrus due to its role as vector of citrus greening disease or "huanglongbing." ACP monitoring is considered an indispensable tool for management of vector and disease. In the present study, datasets collected between 2009 and 2013 from 245 citrus blocks were used to evaluate precision, sensitivity for detection, and efficiency of five sampling methods. The number of samples needed to reach a 0.25 standard error-mean ratio was estimated using Taylor's power law and used to compare precision among sampling methods. Comparison of detection sensitivity and time expenditure (cost) between stem-tap and other sampling methodologies conducted consecutively at the same location were also assessed. Stem-tap sampling was the most efficient sampling method when ACP densities were moderate to high and served as the basis for comparison with all other methods. Protocols that grouped trees near randomly selected locations across the block were more efficient than sampling trees at random across the block. Sweep net sampling was similar to stem-taps in number of captures per sampled unit, but less precise at any ACP density. Yellow sticky traps were 14 times more sensitive than stem-taps but much more time consuming and thus less efficient except at very low population densities. Visual sampling was efficient for detecting and monitoring ACP at low densities. Suction sampling was time consuming and taxing but the most sensitive of all methods for detection of sparse populations. This information can be used to optimize ACP monitoring efforts. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The "Phantom Costs" of Florida's Citrus Industry

OpenAIRE

Muraro, Ronald P.; Roka, Fritz M.; Spreen, Thomas H.

2006-01-01

Regulatory compliance, the "phantom costs of production," is an increasingly "fact-of-life" for U.S. agriculture. A survey was developed and implemented to enumerate regulatory compliance costs for Florida's 748,500 acres citrus industry. Complying with 61 production related regulations, 643,757 hours were expended at a total annual cost of over $24.3 million.

Metalized polyethylene mulch to repel Asian citrus psyllid, slow spread of huanglongbing and improve growth of new citrus plantings.

Science.gov (United States)

Croxton, Scott D; Stansly, Philip A

2014-02-01

Greening or huanglongbing (HLB) is a debilitating disease of citrus caused by Candidatus Liberibactor asiaticus and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. HLB now occurs worldwide in all major citrus growing regions except the Mediterranean and Australia. Management relies principally on insecticidal control of the ACP vector, but is insufficient, even for young trees which are most susceptible to the disease. We tested the ability of metalized polyethylene mulch to repel adult ACP as well as effects on incidence of HLB and early tree growth. Metalized mulch significantly reduced ACP populations and HLB incidence compared to whiteface mulch or bare ground. In addition, metalized mulch, together with the associated drip irrigation and fertigation system, increased soil moisture, reduced weed pressure, and increased tree growth rate. Metalized mulch slows spread of ACP and therefore HLB pressure on young citrus trees. Metalized mulch can thereby augment current control measures for young trees based primarily on systemic insecticides. Additional costs could be compensated for by increased tree growth rate which would shorten time to crop profitability. These advantages make a compelling case for large-scale trials using metalized mulch in young citrus plantings threatened by HLB. © 2013 Society of Chemical Industry.

Microjets of citrus fruit

Science.gov (United States)

Smith, Nicholas; Dickerson, Andrew

2017-11-01

The rupture of oil glands in the citrus exocarp is a common experience to the discerning citrus consumer. When peeled, oil cavities housed with the citrus exocarp often rupture outwardly in response to externally applied bending stresses. Bending of the peel compresses the soft material surrounding the glands, the albedo, increasing fluid pressure. Ultimately, the fluid pressure exceeds the failure strength of the outermost membrane, the flavedo. The ensuing high-velocity discharge of oil and exhaustive emptying of oil glands creates a novel method for jetting small quantities of the aromatic and volatile oil. We compare the jetting behavior across five citrus hybrids through high-speed videography and material testing of exocarps. The jetting oil undergoes an initial acceleration surpassing 5,000 gravities, reaching velocities in excess of 10 m/s. Film of citrus jets and mimicking jets in the lab reveal their high level of instability is caused by irregular and non-circular orifice geometry. Through material characterization and bending simulations, we rationalize the combination of material properties necessary to generate the internal gland pressures required for explosive dispersal.

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...

Concerning of Defects in Design and Manufacture of the Products. Case Study: Redesign of the Citrus Juicer

Directory of Open Access Journals (Sweden)

Bogdan BUCUR

2015-12-01

Full Text Available Industrial products market is marked by a series of mistakes resulting from their design and manufacture. These defects are due to a superficial conceptual analysis, with emphasis on manufacturing to lower cost price, without a few aspects like: functional, ergonomic, aesthetic and cultural in product development. This analysis is important because it combines all these aspects and which aim the final solution of the optimized product. This paper proposes a method of study that identifies those aspects of the analysis of a product on the market that is a citrus juicer. Redesigning the product is made using AutoCAD and Inventor Autodesk design environment. The method proposed in this paper it will be applied to any industrial product, respecting their particularities.

Estimation of Fluoride Concentration of Various Citrus and Non-Citrus Fruits Commonly Consumed and Commercially Available in Mathura City

Directory of Open Access Journals (Sweden)

Navin Anand Ingle

2013-01-01

Full Text Available Background: Since fluoride is available from various sources, the total ingestion of fluoride by a person should be estimated taking into consideration the fluoride consumed from all the sources including fruits. There are very few epidemiological studies carried out associated with fluoride estimation in fruit samplesand especially in the Indian scenario Objective: To estimate and compare the fluoride concentration of different commercially available citrus and non-citrus fruits in Mathura city. Materials & Method: Fifteen different types of fruits commercially available and consumed by people ofMathura City were collected. Out of the 15 fruit samples 5 were citrus fruits and 10 were non-citrus fruits. The fluoride estimation of fruit samples was done at Central Laboratory,Lucknow. Juices of all 15 fruit samples were prepared, from each sample 10 ml of juice was measured and fluoride testing of each sample was carried out by using Orion 4 star -ion electrode analyzer. The collected data was analyzed using the statistical software program SPSS, version 17. Results: The fluoride concentration in citrus fruits ranged from 0.04ppm (Orange to 0.08 ppm (Tomato while in non-citrus fruits it ranged from 0.04ppm (chikoo to 0.18 ppm (Guava. No significant difference was observed between the mean fluoride concentration of citrus and non citrus fruits. Conclusions: Both citrus and non citrus fruits have fluorides. Guava was found to have the maximumamount of fluoridecontent (0.18 ppm among both the citrus and non citrus fruits.

Phyllosticta species on citrus: Risk estimation of resistance to QoI fungicides and identification of species with cytochrome b gene sequences

NARCIS (Netherlands)

Stammler, G.; Schutte, G.C.; Speakman, J.; Miessner, S.; Crous, P.W.

2013-01-01

Isolates of three fungal species associated with citrus, Phyllosticta citricarpa, Phyllosticta citriasiana and Phyllosticta capitalensis, collected from different citrus growing countries of the world, were investigated for their sensitivities to the QoI fungicides pyraclostrobin and azoxystrobin.

ENZYMATIC KINETIC STUDY HYDROLASE FROM CITRUS

Directory of Open Access Journals (Sweden)

Israel Hernández

2015-09-01

Full Text Available In this paper the degrading activity of enzymes derived from orange peels (Citrus x sinensis, grapefruit (Citrus paradise and pineapple (Ananas comosus on the organic matter in wastewater is evaluated. This activity is measured indirectly by quantifying the biochemical oxygen demand (COD before and after degradation process based on a period of time using the HACH DR / 2010, and then the kinetic study was performed by the differential method and integral with the experimental data, obtaining a reaction order of 1 to pectinase (orange, and order 2 for bromelain (pineapple.

Toxicidade diferencial de produtos à base de abamectina ao ácaro Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae em citros Differential toxicity of abamectin based products over Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae mite in citrus

Directory of Open Access Journals (Sweden)

Daniel Júnior de Andrade

2010-03-01

Full Text Available O ácaro Brevipalpus phoenicis é uma das principais pragas dos citros por ser vetor do "Citrus Leprosis Virus" (CiLV, agente causal da leprose, uma das mais graves doenças da citricultura. Objetivou-se avaliar o efeito tóxico de produtos à base de abamectina sobre o ácaro B. phoenicis. Foram realizados um experimento de ação direta e três de ação residual no Laboratório de Acarologia do Departamento de Proteção de Plantas (Fitossanidade da FCAV - UNESP, Jaboticabal-SP. O delineamento adotado nos bioensaios foi o inteiramente casualizado, onde 10 tratamentos foram repetidos 7 vezes, sendo cada repetição composta por um fruto de laranja. Os tratamentos estudados (mL p.c./100 L de água foram: Acaramik a 20; 30; 40 e 50 mL; Vertimec a 30 e 40 mL; Abamectin Nortox a 30 e 40 mL; Tricofol a 77 mL e uma testemunha sem aplicação. Utilizaram-se frutos com presença de verrugose, que foram lavados e parcialmente parafinados, deixando-se uma área sem parafina, que foi circundada com cola entomológica para contenção dos ácaros. Transferiram-se 20 ácaros adultos B. phoenicis para cada fruto. No bioensaio de ação direta, a transferência foi realizada antes das aplicações e, nos bioensaios de ação residual, aos 5; 10 e 15 dias após a aplicação dos produtos. A aplicação dos produtos sobre os frutos foi realizada em Torre de Potter. Os resultados obtidos nos bioensaios evidenciaram que os melhores tratamentos foram: Tricofol a 77 mL, Acaramik a 40 e 50 mL e Vertimec a 40 mL. De forma geral, os produtos testados podem ser utilizados no controle do ácaro B. phoenicis.The mite Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae is one of the most important pests in Brazil citrus plantation, because it is the virus "Citrus Leprosis Virus" (CiLV vector, one of the most serious citrus plantation diseases. The purpose of this experiment was to evaluate the toxical effect of abamectin in the mite B. phoenicis. It was performed

Effects on Asian Citrus Psyllid (Diaphorina citri Kuwayama) feeding behavior of fenpropathrin and chlorpyrifos within 24 hours of application

Science.gov (United States)

Huanglongbing (HLB), also known as citrus greening disease, is one of the most destructive diseases affecting citrus production. The phloem-limited bacterium associated with HLB is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). One component of HLB managem...

Detection of Citrus Trees from Uav Dsms

Science.gov (United States)

Ok, A. O.; Ozdarici-Ok, A.

2017-05-01

This paper presents an automated approach to detect citrus trees from digitals surface models (DSMs) as a single source. The DSMs in this study are generated from Unmanned Aerial Vehicles (UAVs), and the proposed approach first considers the symmetric nature of the citrus trees, and it computes the orientation-based radial symmetry in an efficient way. The approach also takes into account the local maxima (LM) information to verify the output of the radial symmetry. Our contributions in this study are twofold: (i) Such an integrated approach (symmetry + LM) has not been tested to detect (citrus) trees (in orchards), and (ii) the validity of such an integrated approach has not been experienced for an input, e.g. a single DSM. Experiments are performed on five test patches. The results reveal that our approach is capable of counting most of the citrus trees without manual intervention. Comparison to the state-of-the-art reveals that the proposed approach provides notable detection performance by providing the best balance between precision and recall measures.

Expression patterns of flowering genes in leaves of 'Pineapple' sweet orange [Citrus sinensis (L.) Osbeck] and pummelo (Citrus grandis Osbeck).

Science.gov (United States)

Pajon, Melanie; Febres, Vicente J; Moore, Gloria A

2017-08-30

In citrus the transition from juvenility to mature phase is marked by the capability of a tree to flower and fruit consistently. The long period of juvenility in citrus severely impedes the use of genetic based strategies to improve fruit quality, disease resistance, and responses to abiotic environmental factors. One of the genes whose expression signals flower development in many plant species is FLOWERING LOCUS T (FT). In this study, gene expression levels of flowering genes CiFT1, CiFT2 and CiFT3 were determined using reverse-transcription quantitative real-time PCR in citrus trees over a 1 year period in Florida. Distinct genotypes of citrus trees of different ages were used. In mature trees of pummelo (Citrus grandis Osbeck) and 'Pineapple' sweet orange (Citrus sinensis (L.) Osbeck) the expression of all three CiFT genes was coordinated and significantly higher in April, after flowering was over, regardless of whether they were in the greenhouse or in the field. Interestingly, immature 'Pineapple' seedlings showed significantly high levels of CiFT3 expression in April and June, while CiFT1 and CiFT2 were highest in June, and hence their expression induction was not simultaneous as in mature plants. In mature citrus trees the induction of CiFTs expression in leaves occurs at the end of spring and after flowering has taken place suggesting it is not associated with dormancy interruption and further flower bud development but is probably involved with shoot apex differentiation and flower bud determination. CiFTs were also seasonally induced in immature seedlings, indicating that additional factors must be suppressing flowering induction and their expression has other functions.

An Evaluation of the Genetic Diversity of Xylella fastidiosa Isolated from Diseased Citrus and Coffee in São Paulo, Brazil.

Science.gov (United States)

Qin, X; Miranda, V S; Machado, M A; Lemos, E G; Hartung, J S

2001-06-01

ABSTRACT Strains of Xylella fastidiosa, isolated from sweet orange trees (Citrus sinensis) and coffee trees (Coffea arabica) with symptoms of citrus variegated chlorosis and Requeima do Café, respectively, were indistinguishable based on repetitive extragenic palindromic polymerase chain reaction (PCR) and enterobacterial repetitive intergenic consensus PCR assays. These strains were also indistinguishable with a previously described PCR assay that distinguished the citrus strains from all other strains of Xylella fastidiosa. Because we were not able to document any genomic diversity in our collection of Xylella fastidiosa strains isolated from diseased citrus, the observed gradient of increasing disease severity from southern to northern regions of São Paulo State is unlikely due to the presence of significantly different strains of the pathogen in the different regions. When comparisons were made to reference strains of Xylella fastidiosa isolated from other hosts using these methods, four groups were consistently identified consistent with the hosts and regions from which the strains originated: citrus and coffee, grapevine and almond, mulberry, and elm, plum, and oak. Independent results from random amplified polymorphic DNA (RAPD) PCR assays were also consistent with these results; however, two of the primers tested in RAPD-PCR were able to distinguish the coffee and citrus strains. Sequence comparisons of a PCR product amplified from all strains of Xylella fastidiosa confirmed the presence of a CfoI polymorphism that can be used to distinguish the citrus strains from all others. The ability to distinguish Xylella fastidiosa strains from citrus and coffee with a PCR-based assay will be useful in epidemiological and etiological studies of this pathogen.

Toxin production by Fusarium solani from declining citrus plants and ...

African Journals Online (AJOL)

The highest Fusarium sp. followed by Aspergillus, Phytophthora, Pythium, Penicillium and Alternaria species were remote from the collected samples of roots and soil from the four tehsils of Sargodha district of Pakistan. The maximum Fusarium sp. was isolated from the roots of declining citrus trees from tehsil Bhalwal ...

Behavioral responses of male Diaphorina citri (Hemiptera: Liviidae) to mating communication signals from vibration traps in citrus (Sapindales: Rutaceae) trees

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the bacterium causing citrus greening disease, which has devastated citrus production worldwide wherever it has been introduced. To help monitor and target D citri populations in commercial groves, thereby facilitating more effective manag...

Citrus leprosis virus N: A New Dichorhavirus Causing Citrus Leprosis Disease.

Science.gov (United States)

Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Tassi, Aline Daniele; Kitajima, Elliot Watanabe; Harakava, Ricardo; Salaroli, Renato Barbosa; Freitas-Astúa, Juliana

2017-08-01

Citrus leprosis (CL) is a viral disease endemic to the Western Hemisphere that produces local necrotic and chlorotic lesions on leaves, branches, and fruit and causes serious yield reduction in citrus orchards. Samples of sweet orange (Citrus × sinensis) trees showing CL symptoms were collected during a survey in noncommercial citrus areas in the southeast region of Brazil in 2013 to 2016. Transmission electron microscopy analyses of foliar lesions confirmed the presence of rod-like viral particles commonly associated with CL in the nucleus and cytoplasm of infected cells. However, every attempt to identify these particles by reverse-transcription polymerase chain reaction tests failed, even though all described primers for the detection of known CL-causing cileviruses and dichorhaviruses were used. Next-generation sequencing of total RNA extracts from three symptomatic samples revealed the genome of distinct, although highly related (>92% nucleotide sequence identity), viruses whose genetic organization is similar to that of dichorhaviruses. The genome sequence of these viruses showed trees and those used for the transmission of one of the characterized isolates to Arabidopsis plants were anatomically recognized as Brevipalpus phoenicis sensu stricto. Molecular and biological features indicate that the identified viruses belong to a new species of CL-associated dichorhavirus, which we propose to call Citrus leprosis N dichorhavirus. Our results, while emphasizing the increasing diversity of viruses causing CL disease, lead to a reevaluation of the nomenclature of those viruses assigned to the genus Dichorhavirus. In this regard, a comprehensive discussion is presented.

Tetraploid Carrizo citrange rootstock (Citrus sinensis Osb.×Poncirus trifoliata L. Raf.) enhances natural chilling stress tolerance of common clementine (Citrus clementina Hort. ex Tan).

Science.gov (United States)

Oustric, Julie; Morillon, Raphaël; Luro, François; Herbette, Stéphane; Lourkisti, Radia; Giannettini, Jean; Berti, Liliane; Santini, Jérémie

2017-07-01

Low temperatures can disturb the development, growth and geographic distribution of plants, particularly cold-sensitive plants in the Mediterranean area, where temperatures can reach seasonally low levels. In citrus crops, scion/rootstock combinations are used to improve fruit production and quality, and increase tolerance to biotic and abiotic stresses. In the last decade, several studies have shown that tetraploid citrus seedlings or rootstocks are more tolerant to abiotic stress than their respective diploid. The objective of this study was to test whether the use of tetraploid rootstocks can improve the chilling tolerance of the scion. We compared physiological and biochemical responses to low seasonal temperatures of common Clementine (Citrus sinensis Osb.×Poncirus trifoliata L. Raf.) grafted on diploid and tetraploid Carrizo citrange rootstocks, named C/2xCC and C/4xCC, respectively. During the coldest months, C/4xCC showed a smaller decrease in net photosynthesis (Pn), stomatal conductance (G s ), chlorophyll fluorescence (F v /F m ), and starch levels, and lower levels of malondialdehyde and electrolyte leakage than C/2xCC. Specific activities of catalase (CAT), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) were higher in C/4xCC during the cold period, whereas chlorophyll, proline, ascorbate and hydrogen peroxide (H 2 O 2 ) levels and superoxide dismutase (SOD) activity did not vary significantly between C/4xCC and C/2xCC throughout the study period. Taken together, these results demonstrate that tetraploid Carrizo citrange rootstock improves the chilling tolerance of common clementine (scion) thanks to a part of the antioxidant system. Copyright © 2017. Published by Elsevier GmbH.

Overexpression of a modified plant thionin enhances disease resistance to citrus canker and huanglongbing (HLB, citrus greening)

Science.gov (United States)

Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized e...

Weeping dragon, a unique ornamenal citrus

Science.gov (United States)

‘Weeping Dragon’ is a new ornamental citrus cultivar developed by intercrossing of two unusual and unique citrus types, Poncirus trifoliata cultivated variety (cv.) Flying Dragon, and Citrus sinensis cv. ‘Cipo’. This new hybrid cultivar combines strongly contorted and weeping growth traits in a smal...

Co-Production of Fungal Biomass Derived Constituents and Ethanol from Citrus Wastes Free Sugars without Auxiliary Nutrients in Airlift Bioreactor.

Science.gov (United States)

Satari, Behzad; Karimi, Keikhosro; Taherzadeh, Mohammad J; Zamani, Akram

2016-02-26

The potential of two zygomycetes fungi, Mucor indicus and Rhizopus oryzae, in assimilating citrus waste free sugars (CWFS) and producing fungal chitosan, oil, and protein as well as ethanol was investigated. Extraction of free sugars from citrus waste can reduce its environmental impact by decreasing the possibility of wild microorganisms growth and formation of bad odors, a typical problem facing the citrus industries. A total sugar concentration of 25.1 g/L was obtained by water extraction of citrus waste at room temperature, used for fungal cultivation in shake flasks and airlift bioreactor with no additional nutrients. In shake flasks cultivations, the fungi were only able to assimilate glucose, while fructose remained almost intact. In contrast, the cultivation of M. indicus and R. oryzae in the four-liter airlift bioreactor resulted in the consumption of almost all sugars and production of 250 and 280 g fungal biomass per kg of consumed sugar, respectively. These biomasses correspondingly contained 40% and 51% protein and 9.8% and 4.4% oil. Furthermore, the fungal cell walls, obtained after removing the alkali soluble fraction of the fungi, contained 0.61 and 0.69 g chitin and chitosan per g of cell wall for M. indicus and R. oryzae, respectively. Moreover, the maximum ethanol yield of 36% and 18% was obtained from M. indicus and R. oryzae, respectively. Furthermore, that M. indicus grew as clump mycelia in the airlift bioreactor, while R. oryzae formed spherical suspended pellets, is a promising feature towards industrialization of the process.

Co-Production of Fungal Biomass Derived Constituents and Ethanol from Citrus Wastes Free Sugars without Auxiliary Nutrients in Airlift Bioreactor

Directory of Open Access Journals (Sweden)

Behzad Satari

2016-02-01

Full Text Available The potential of two zygomycetes fungi, Mucor indicus and Rhizopus oryzae, in assimilating citrus waste free sugars (CWFS and producing fungal chitosan, oil, and protein as well as ethanol was investigated. Extraction of free sugars from citrus waste can reduce its environmental impact by decreasing the possibility of wild microorganisms growth and formation of bad odors, a typical problem facing the citrus industries. A total sugar concentration of 25.1 g/L was obtained by water extraction of citrus waste at room temperature, used for fungal cultivation in shake flasks and airlift bioreactor with no additional nutrients. In shake flasks cultivations, the fungi were only able to assimilate glucose, while fructose remained almost intact. In contrast, the cultivation of M. indicus and R. oryzae in the four-liter airlift bioreactor resulted in the consumption of almost all sugars and production of 250 and 280 g fungal biomass per kg of consumed sugar, respectively. These biomasses correspondingly contained 40% and 51% protein and 9.8% and 4.4% oil. Furthermore, the fungal cell walls, obtained after removing the alkali soluble fraction of the fungi, contained 0.61 and 0.69 g chitin and chitosan per g of cell wall for M. indicus and R. oryzae, respectively. Moreover, the maximum ethanol yield of 36% and 18% was obtained from M. indicus and R. oryzae, respectively. Furthermore, that M. indicus grew as clump mycelia in the airlift bioreactor, while R. oryzae formed spherical suspended pellets, is a promising feature towards industrialization of the process.

Metabolism of s-triazine herbicides in tea and citrus plants

International Nuclear Information System (INIS)

Kakhniashvili, Kh.A.; Durmishidze, S.V.; Gigauri, M.Sh.

1989-01-01

The authors studied processes involved in assimilation, transport, and conversion of 14 C-atrazine and 14 C-simazine in plants of tea (Thea sinensis L.), lemon (Citrus limon Burm.), and orange (Citrus sinensis Osbeck). The main products of metabolism of the investigated herbicides in different organs of the indicated plants are isolated and identified. It is established that conjugates of hydroxytriazined with peptides and proteins accumulate in the plant cell. A new pathway of atrazine metabolism is clarified in the work, the indicated pathway involving two-component conjugates with peptides and glucose. The authors discuss the role played by oxidative conversions in detoxication of atrazine and simazine in the investigated plants, and identify the end products of oxidation

Effects of oxamyl on the citrus nematode, Tylenchulus semipenetrans, and on infection of sweet orange.

Science.gov (United States)

Baines, R C; Small, R H

1976-04-01

Foliar sprays of 4 microg/ml oxamyl on sweet orange trees in a greenhouse slightly depressed the number of Tylenchulus semipenetrans larvae obtained from roots and soil, but similar treatments were not effective in two orchards. Soil drench treatments decreased the number of citrus nematode larvae obtained from roots or soil of citrus plants grown itt a greenhouse and in orchards. Exposure to 5-10 microg/ml of oxamyl in water was lethal to only a few second-stage larvae treated 10 days, and many second-stage larvae in 2.0 microg/ml oxamyl recovered motility when transferred to fresh water. Aqueous solutions of 50 and 100 microg/ml of oxamyl were toxic to citrus nematode larvae. Additional observations indicate that oxamyl interfered with hatch of citrus nematode larvae and was nematistatic and/or protected sweet orange roots from infection. Oxamyl degraded at different rates in two soils. The number of citrus nematode larvae that infected and developed on sweet orange roots was increased by an undetermined product of the degradation of oxamyl in soil, water, and possibly within plants. This product apparently was translocated in roots.

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.

SCREENING FITOKIMIA, AKTIVITAS ANTIOKSIDAN DAN ANTIMIKROBA PADA BUAH JERUK LEMON(Citrus limon DAN JERUK NIPIS (Citrus aurantiifolia

Directory of Open Access Journals (Sweden)

Anindya Nirmala Permata

2018-03-01

Full Text Available The desire to live healthy by eating natural foods and drinks into the lifestyle of the community. Orange becomes one of the fruits that become functional food to maintain and maintain health. The purpose of this research is to know the difference of antioxidant and antimicrobial activity on Citrus limon and Citrus aurantiifolia. The research method is laboratory experimental research with descriptive analysis. This research was conducted in February-April 2017 at the Laboratory of Plant Biological Microbiology and Plant Chemistry Department of Biology State University of Malang. Phytochemical screening by color reaction method, total phenol with Folin Ciocalteu method, antioxidant activity with DPPH method and antimicrobial activity with disc method. Screening results show the presence of saponins and alkaloids but there are no flavonoids, terpenoids and tannins. Total phenol test showed total phenol content in Lemon (Citrus limon of 110,25 mg GAE / 100ml while in Lime (Citrus aurantiifolia 116,5 mg GAE / 100ml. The antioxidant activity of Lemon Citrus (Citrus limon 49.593 g / ml and Lime (Citrus aurantiifolia 49.589g / ml. Antimicrobial activity test obtained the highest zone of resistance at 100% concentration of each citrus fruit. The conclusion of this study is that there is a difference of antioxidant and antimicrobial activity in both oranges, where the lemon fruits (C.limon antioxidant activity is higher than and Lime (C. aurantiifolia, while the antimicrobial activity of lemon (C. aurantiifolia is higher Rather than lemon (C.limon.

Phagostimulants for the Asian citrus psyllid also elicit volatile release from citrus leaves

Science.gov (United States)

Chemical cues that elicit orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. We identified an optimal blend ratio of formic and acetic acids that stimulate...

Compatibility of Isaria fumosorosea (Hypocreales: Cordycipitaceae Blastospores with Agricultural Chemicals Used for Management of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

Directory of Open Access Journals (Sweden)

Pasco B. Avery

2013-11-01

Full Text Available Biorational insecticides are being increasingly emphasized for inclusion in integrated pest management programs for invasive insects. The entomopathogenic fungus, Isaria fumosorosea, can be used to help manage the Asian citrus psyllid with minimal impact on beneficial arthropods, but its effectiveness may be compromised by agrochemicals used to control concurrent arthropod pests and diseases. We evaluated the compatibility of I. fumosorosea blastospores with a range of spray oils and copper-based fungicides registered for use in citrus groves. Results of laboratory and greenhouse tests showed a range of responses of the fungus to the different materials, including compatibility and incompatibility. Overall, I. fumosorosea growth in vitro was reduced least by petroleum-based materials and most by botanical oils and borax, and some of the copper-based fungicides, suggesting that tank mixing of I. fumosorosea with these latter products should be avoided. However, equivalent negative effects of test materials on fungal pathogenicity were not always observed in tests with adult psyllids. We hypothesize that some oils enhanced adherence of blastospores to the insect cuticle, overcoming negative impacts on germination. Our data show that care should be taken in selecting appropriate agrochemicals for tank-mixing with commercial formulations of entomopathogenic fungi for management of citrus pests. The prospects of using I. fumosorosea for managing the invasive Asian citrus psyllid and other citrus pests are discussed.

“Gold” Pressed Essential Oil: An Essay on the Volatile Fragment from Citrus Juice Industry By-Products Chemistry and Bioactivity

Directory of Open Access Journals (Sweden)

V. N. Kapsaski-Kanelli

2017-01-01

Full Text Available Present essay explores the potentials of Citrus juice industry’s by-products as alternative bioactive natural products resources. Four crude Cold Pressed Essential Oils (CPEOs, derived from orange, lemon, grapefruit, and mandarin, were studied. All CPEOs were subjected to water distillation, in order to obtain the volatile fragment, which was further fractionated with respect to distillation period in two parts, concluding to eight samples. These samples along with the four original CPEOs were assessed in relation to their phytochemical content and their repellent and larvicidal properties against Asian Tiger Mosquito. The volatiles recovery rates ranged from 74% to 88% of the CPEO. Limonene presented a significant increase in all samples ranging from 8% to 52% of the respective CPEO’s content and peaked in mandarin’s 2nd volatile fragment which comprised 97% of the essential oil. The refinement process presented clear impacts on both bioassays: a significant increase in larvicidal potency was observed, annotated best by the improvement by 1100% and 1300% of the grapefruit volatile fractions; repellence testing provided only one significant result, the decrease of landings by 50% as a response to mandarin’s second volatile fraction. The applied methodology thus may be considered for the improvement of Citrus juice industry’s by-products chemistry and bioactivity.

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

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

International Nuclear Information System (INIS)

Sadaf, S.; Shahid, M.; Iqbal, Z.

2009-01-01

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)

[Characterization of a bacterial biocontrol strain 1404 and its efficacy in controlling postharvest citrus anthracnose].

Science.gov (United States)

Wang, Qian; Hu, Chunjin; Ke, Fanggang; Huang, Siliang; Li, Qiqin

2010-09-01

Anthracnose caused by Colletotrichum gloeosporioides (Penz.) Sacc. is a main disease in citrus production. To develop an effective biocontrol measure against citrus postharvest anthracnose, we screened antagonistic microbes and obtained a bacterial strain 1404 from the rhizospheric soil of chili plants in Nanning city, Guangxi, China. The objectives of the present study were to: (1) identify and characterize the antagonistic bacterium; and (2) to evaluate the efficacy of the antagonistic strain in controlling citrus postharvest anthracnose disease. Strain 1404 was identified by comparing its 16S rDNA sequence with related bacteria from GenBank database, as well as analyzing its morphological, physiological and biochemical characters. The antagonistic stability of the strain 1404 was determined by continuously transferring it on artificial media. The effect of the strain on suppressing citrus anthracnose at postharvest stage was tested by stab inoculation method. The 16S rDNA of strain 1404 was amplified with primers PF1 (5'-AGAGTTTGATCATGGCTCAG-3') and PR1 (5'-TACGGTTACCTTGTTACGACTT-3') and its sequence submitted to GenBank (accession number: GU361113). Strain 1404 clustered with the GenBank-derived Brevibacillus brevis strains in the 16S-rDNA-sequence-based phylogenetic tree at 100% bootstrap level. The morphological traits, physiological and biochemical characters of strain 1404 agreed with that of Brevibacillus brevis. Less change in the suppressive ability of antagonist against growth of Colletotrichum gloeosporioides was observed during four continuous transfers on artificial media. The average control efficacy of the strain was 64. 9 % against the disease 20 days after the antagonist application. Strain 1404 was identified as Brevibacillus brevis based on its morphological traits, phyiological and biochemical characters as well as 16S rDNA sequence analysis. The antagonist was approved to be a promising biocontrol agent. This is the first report of

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.

Structural characterization of the thermally-tolerant pectin methylesterase purified from Citrus sinensis fruit and its gene sequence

Science.gov (United States)

Despite the longstanding importance for the thermally-tolerant pectin methylesterase (TT-PME) activity in citrus juice processing and product quality, unequivocal identification of the protein and its corresponding gene has remained elusive. We purified TT-PME from sweet orange [Citrus sinensis (L.)...

A filter paper-based liquid culture system for citrus shoot organogenesis - a mixture-amount experiment

Science.gov (United States)

The objective of this study was to determine the effects of a static liquid culture system on shoot regeneration from citrus epicotyl explants. Two citrus types were used, Carrizo citrange and Ridge Pineapple sweet orange. A liquid culture system comprised of a Petri dish, cellulose filter paper dis...

Development and systematic validation of qPCR assays for rapid and reliable differentiation of Xylella fastidiosa strains causing citrus variegated chlorosis.

Science.gov (United States)

Li, Wenbin; Teixeira, Diva C; Hartung, John S; Huang, Qi; Duan, Yongping; Zhou, Lijuan; Chen, Jianchi; Lin, Hong; Lopes, Silvio; Ayres, A Juliano; Levy, Laurene

2013-01-01

The xylem-limited, Gram-negative, fastidious plant bacterium Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC), a destructive disease affecting approximately half of the citrus plantations in the State of São Paulo, Brazil. The disease was recently found in Central America and is threatening the multi-billion U.S. citrus industry. Many strains of X. fastidiosa are pathogens or endophytes in various plants growing in the U.S., and some strains cross infect several host plants. In this study, a TaqMan-based assay targeting the 16S rDNA signature region was developed for the identification of X. fastidiosa at the species level. Another TaqMan-based assay was developed for the specific identification of the CVC strains. Both new assays have been systematically validated in comparison with the primer/probe sets from four previously published assays on one platform and under similar PCR conditions, and shown to be superior. The species specific assay detected all X. fastidiosa strains and did not amplify any other citrus pathogen or endophyte tested. The CVC-specific assay detected all CVC strains but did not amplify any non-CVC X. fastidiosa nor any other citrus pathogen or endophyte evaluated. Both sets were multiplexed with a reliable internal control assay targeting host plant DNA, and their diagnostic specificity and sensitivity remained unchanged. This internal control provides quality assurance for DNA extraction, performance of PCR reagents, platforms and operators. The limit of detection for both assays was equivalent to 2 to 10 cells of X. fastidiosa per reaction for field citrus samples. Petioles and midribs of symptomatic leaves of sweet orange harbored the highest populations of X. fastidiosa, providing the best materials for detection of the pathogen. These new species specific assay will be invaluable for molecular identification of X. fastidiosa at the species level, and the CVC specific assay will be very powerful for the

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

Effects of concentrate type and chromium propionate on insulin sensitivity, productive and reproductive parameters of lactating dairy cows consuming excessive energy.

Science.gov (United States)

Leiva, T; Cooke, R F; Brandão, A P; Pardelli, U; Rodrigues, R O; Corrá, F N; Vasconcelos, J L M

2017-03-01

This experiment compared insulin sensitivity parameters, milk production and reproductive outcomes in lactating dairy cows consuming excessive energy, and receiving in a 2×2 factorial arrangement design: (1) concentrate based on ground corn (CRN; n=13) or citrus pulp (PLP; n=13), and (2) supplemented (n=14) or not (n=12) with 2.5 g/day of chromium (Cr)-propionate. During the experiment (day 0 to 182), 26 multiparous, non-pregnant, lactating Gir×Holstein cows (initial days in milk=80±2) were offered corn silage for ad libitum consumption, and individually received concentrate formulated to allow diets to provide 160% of their daily requirements of net energy for lactation. Cow BW and body condition score (BCS) were recorded weekly. Milk production was recorded daily and milk samples collected weekly. Blood samples were collected weekly before the morning concentrate feeding. Glucose tolerance tests (GTT; 0.5 g of glucose/kg of BW) were performed on days -3, 60, 120 and 180. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up on days -1, 82 and 162. No treatment differences were detected (P⩾0.25) for BW and BCS change during the experiment. Within weekly blood samples, concentrations of serum insulin and glucose, as well as insulin : glucose ratio were similar among treatments (P⩾0.19), whereas CRN had less (Pinsulin : glucose ratio. Serum insulin concentrations were less (P=0.04) in CRN supplemented with Cr-propionate compared with non-supplemented CRN (8.2 v. 13.5 µIU/ml, respectively; SEM=1.7), whereas Cr-propionate supplementation did not impact (P=0.70) serum insulin within PLP cows. Milk production, milk fat and solid concentrations were similar (P⩾0.48) between treatments. However, CRN had greater (Pdairy cows consuming excessive energy did not improve insulin sensitivity, milk production and reproductive outcomes, whereas Cr-propionate supplementation only enhanced insulin sensitivity in cows receiving a

Technological Advances in Huanglongbing (HLB or Citrus Greening Disease Management

Directory of Open Access Journals (Sweden)

Krishna Prasad Paudyal

2015-12-01

Full Text Available Huanglongbing (HLB, previously citrus greening disease, is the most destructive of citrus species causing major threat to the world citrus industry. The disease was reported from China in 1919 and now known to occur in more than 40 different countries of Asia, Africa, South and North America. Three species of gram negative bacterium namely Candidatus Liberibacter asiaticus, Candidatus Liberibacter africanus and Candidatus Liberibacter americanus are the casual organisms of HLB, respectively prevailing in the continent of Asia, Africa and South America. It is one of the most extensively researched subjects in citriculture world. HLB was detected in 2004 and 2005, respectively in San Paulo of Brazil and Florida of USA: the two leading citrus production hub of the world causing huge economic loss within 5 years of first detection. Since then research on HLB detection and management was further accelerated in American continents. This paper presents the scientific advancement made on detection, spread, economic losses caused by HLB in different parts of the world and controlling management strategies. Remarkable achievements have been made on HLB detection techniques including iodine test, qPCR and more recently in spectroscopy. While efforts are being made to develop resistance varieties using conventional and biotechnological tools management strategy which includes reduction of inoculums source, vector control and replant with disease-free planting materials still remains major option for HLB control. Citrus intercropping with guava have shown promising results for vector reduction.

The potential for citrus cryotherapy

Science.gov (United States)

Citrus collections of pathogen-free plants are needed for breeding, research, and distribution to the user community. The Citrus Research Board funded research project “Development of cryotherapy as an improved method of eliminating graft transmissible pathogens in Citrus” sought to use cryotherapy,...

DNA Barcode Reference Library for the African Citrus Triozid, Trioza erytreae (Hemiptera: Triozidae): Vector of African Citrus Greening.

Science.gov (United States)

Khamis, F M; Rwomushana, I; Ombura, L O; Cook, G; Mohamed, S A; Tanga, C M; Nderitu, P W; Borgemeister, C; Sétamou, M; Grout, T G; Ekesi, S

2017-12-05

Citrus (Citrus spp.) production continues to decline in East Africa, particularly in Kenya and Tanzania, the two major producers in the region. This decline is attributed to pests and diseases including infestation by the African citrus triozid, Trioza erytreae (Del Guercio) (Hemiptera: Triozidae). Besides direct feeding damage by adults and immature stages, T. erytreae is the main vector of 'Candidatus Liberibacter africanus', the causative agent of Greening disease in Africa, closely related to Huanglongbing. This study aimed to generate a novel barcode reference library for T. erytreae in order to use DNA barcoding as a rapid tool for accurate identification of the pest to aid phytosanitary measures. Triozid samples were collected from citrus orchards in Kenya, Tanzania, and South Africa and from alternative host plants. Sequences generated from populations in the study showed very low variability within acceptable ranges of species. All samples analyzed were linked to T. erytreae of GenBank accession number KU517195. Phylogeny of samples in this study and other Trioza reference species was inferred using the Maximum Likelihood method. The phylogenetic tree was paraphyletic with two distinct branches. The first branch had two clusters: 1) cluster of all populations analyzed with GenBank accession of T. erytreae and 2) cluster of all the other GenBank accession of Trioza species analyzed except T. incrustata Percy, 2016 (KT588307.1), T. eugeniae Froggatt (KY294637.1), and T. grallata Percy, 2016 (KT588308.1) that occupied the second branch as outgroups forming sister clade relationships. These results were further substantiated with genetic distance values and principal component analyses. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Quantitative analysis of flavanones from citrus fruits by using mesoporous molecular sieve-based miniaturized solid phase extraction coupled to ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

Science.gov (United States)

Cao, Wan; Ye, Li-Hong; Cao, Jun; Xu, Jing-Jing; Peng, Li-Qing; Zhu, Qiong-Yao; Zhang, Qian-Yun; Hu, Shuai-Shuai

2015-08-07

An analytical procedure based on miniaturized solid phase extraction (SPE) and ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed and validated for determination of six flavanones in Citrus fruits. The mesoporous molecular sieve SBA-15 as a solid sorbent was characterised by Fourier transform-infrared spectroscopy and scanning electron microscopy. Additionally, compared with reported extraction techniques, the mesoporous SBA-15 based SPE method possessed the advantages of shorter analysis time and higher sensitivity. Furthermore, considering the different nature of the tested compounds, all of the parameters, including the SBA-15 amount, solution pH, elution solvent, and the sorbent type, were investigated in detail. Under the optimum condition, the instrumental detection and quantitation limits calculated were less than 4.26 and 14.29ngmL(-1), respectively. The recoveries obtained for all the analytes were ranging from 89.22% to 103.46%. The experimental results suggested that SBA-15 was a promising material for the purification and enrichment of target flavanones from complex citrus fruit samples. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

In vivo anti-carcinogenic property of a formulated citrus peel extract

Directory of Open Access Journals (Sweden)

Michiko Suzawa

2014-03-01

Full Text Available Background: Cancer is one of the two leading fatal diseases humans face. Synthesized drugs available for cancer intervention have many limitations in applications and effectiveness and are often associated with serious of side effects, which can further damage the patients’ quality of life. Recently, the development of natural-product-based and therapeutically sound anti-cancer agents have gained popularity in the fields of functional and medical foods, which may exhibit advantages of minimal toxicity and multiple active molecular components. Citrus peel or its extract has been reported to have potent pharmacological activities and health benefits because of abundant flavonoids present in citrus fruits, particularly in the peels. Results: The results of these studies demonstrated the efficacy of Gold Lotion (GL, an extract of multiple varieties of citrus peels that contains abundant flavonoids, including a high percentage of polymethoxylflavones (PMFs, which can protect against skin cancer, colon cancer, and prostate cancer in mice. These results are clearly promising and warrant a human trial with GL in future studies. Summary: Briefly, these data have demonstrated that GL is efficacious in preventing and treating cancer in several model systems. This review summarizes the results of currently available data regarding the in vivo anti-cancer activity of GL, and identifies opportunities for subsequent human clinical trials to assess preventive and therapeutic effects in the near future.

Evaluation of systemic neonicotinoid insecticides for the management of the Asian citrus psyllid Diaphorina citri on containerized citrus.

Science.gov (United States)

Byrne, Frank J; Daugherty, Matthew P; Grafton-Cardwell, Elizabeth E; Bethke, James A; Morse, Joseph G

2017-03-01

Studies were conducted to evaluate uptake and retention of three systemic neonicotinoid insecticides, dinotefuran, imidacloprid and thiamethoxam, in potted citrus nursery plants treated at standard label rates. Infestation of these plants placed at a field site with moderate levels of Asian citrus psyllid (ACP) was monitored for 14 weeks following treatments, and insecticide residues in leaf tissue were quantified using enzyme-linked immunosorbent assay (ELISA). Bioassays were conducted using leaves harvested on various dates post-treatment to compare the efficacies of residues against adult ACP. Residues of the three neonicotinoids were detected in leaf tissues within 1 week after treatment. Peak concentrations established at 1 week for imidacloprid and dinotefuran and at 2 weeks for thiamethoxam. Imidacloprid and thiamethoxam outperformed the control and dinotefuran treatments at protecting trees from infestations by ACP eggs and nymphs. For a given insecticide concentration in leaf tissue, thiamethoxam induced the highest mortality of the three insecticides, and dinotefuran was the least toxic. If the time needed to achieve effective thresholds of a systemic neonicotinoid is known, treatments at production facilities could be scheduled that would minimize unnecessary post-treatment holding periods and ensure maximum retention of effective concentrations after the plants have shipped to retail outlets. The rapid uptake of the insecticides and retention at effective concentrations in containerized citrus suggest that the current 30 day post-treatment shipping restriction from production facilities to retail outlets outside of quarantine could be shortened to 14 days. Thiamethoxam should be added to the list of approved nursery treatments. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

H NMR analyses of Citrus macrophylla subjected to Asian citrus psyllid (Diaphorina citri Kuwayama) feeding

Science.gov (United States)

The Asian citrus psyllid (ACP) is a phloem feeding insect that can host and transmit the bacterium Candidatus Liberibacter asiaticus (CLas), which is the putative causative agent of the economically important citrus disease, Huanglongbing (HLB). ACP are widespread in Florida, and are spreading in Ca...

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.

Effect of gamma radiation on the titrable acidity and vitamin c content of citrus fruits

OpenAIRE

Iftekhar Ahmad

2012-01-01

The study was carried out to assess effect of gamma radiation on the acidity and vitamin C content of the Citrus macroptera (Satkora) and Citrus assamensis (Ginger lime). Irradiation with doses 0.5, 1.0, 2.0, 3.0 kGy were applied to assess the effect on the titrable acidity and vitamin C contents every one week interval for total five weeks. Both titrable acidity and vitamin C content of C. macroptera, and C. assamensis are sensitive to both gamma radiation and storage time; have decreased wi...

Current situation of "Candidatus Liberibacter asiaticus" in Guangdong, P.R. China, where citrus huanglongbing was first described

Science.gov (United States)

Citrus Huanglongbing (HLB, yellow shoot disease) was observed in Guangdong Province, Peoples’ Republic of China in the late 1800s and is endemic there, particularly in the coastal Chaoshan and Pearl River Delta plains. Since the 1990s, the center of citrus production in Guangdong has gradually shif...

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

Science.gov (United States)

2013-02-06

...] australis, causal agent of sweet orange scab); and a pathogen (Xanthomonas citri subsp. citri, causal agent... oranges (Citrus sinensis (L.) Osbeck), lemons (C. limon (L.) Burm. f.), four species of mandarins (C... of the reading room). The PRA, titled ``Importation of Fresh Citrus Fruit, including Sweet Orange...

Citrus plant nutritional profile in relation to huanglongbing prevalence in Pakistan

International Nuclear Information System (INIS)

Razi, M.F.U.D.; Khan, I.A.; Jaskani, M.J.

2011-01-01

Citrus is an important fruit crop in Pakistan that requires proper crop nutrition and disease management strategies as it is a tree crop and withstands harsh seasonal conditions for decades. Huanglongbing (HLB) is a century old, devastating disease of citrus caused by phloem limiting bacteria of the alpha-proteobacteria subdivision. As disease has no known cure, so, effective prevention methods are useful in crop management. Improper crop nutrition impairs plant genetic resistance to invasive pathogens, decreases yield and reduces productive life of the plant. In this study we selected 116 citrus trees from 43 orchard of Punjab for a nutritional assessment. All the trees were showing HLB symptoms and were subjected to NPK and Zn analysis as well as molecular detection of Candidatus L. asiaticus, the pathogen associated with HLB. Nitrogen and Zn were significantly higher (P=0.05) in HLB infected trees. Out of 48 diseased trees, 19, 43 and 27 were deficient in nitrogen, phosphorous and potash, respectively. Our study concludes that there is no relationship between nutritional deficiency status and HLB incidence in citrus; however, nutritional treatments may help in stress relief to infected plants. (author)

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...

A set of primers for analyzing chloroplast DNA diversity in Citrus and related genera.

Science.gov (United States)

Cheng, Yunjiang; de Vicente, M Carmen; Meng, Haijun; Guo, Wenwu; Tao, Nengguo; Deng, Xiuxin

2005-06-01

Chloroplast simple sequence repeat (cpSSR) markers in Citrus were developed and used to analyze chloroplast diversity of Citrus and closely related genera. Fourteen cpSSR primer pairs from the chloroplast genomes of tobacco (Nicotiana tabacum L.) and Arabidopsis were found useful for analyzing the Citrus chloroplast genome (cpDNA) and recoded with the prefix SPCC (SSR Primers for Citrus Chloroplast). Eleven of the 14 primer pairs revealed some degree of polymorphism among 34 genotypes of Citrus, Fortunella, Poncirus and some of their hybrids, with polymorphism information content (PIC) values ranging from 0.057 to 0.732, and 18 haplotypes were identified. The cpSSR data were analyzed with NTSYS-pc software, and the genetic relationships suggested by the unweighted pair group method based on arithmetic means (UPGMA) dendrogram were congruent with previous taxonomic investigations: the results showed that all samples fell into seven major clusters, i.e., Citrus medica L., Poncirus, Fortunella, C. ichangensis Blanco, C. reticulata Swingle, C. aurantifolia (Christm.) Swingle and C. grandis (L.) Osbeck. The results of previous studies combined with our cpSSR analyses revealed that: (1) Calamondin (C. madurensis Swingle) is the result of hybridization between kumquat (Fortunella) and mandarin (C. reticulata), where kumquat acted as the female parent; (2) Ichang papeda (C. ichangensis) has a unique taxonomic status; and (3) although Bendiguangju mandarin (C. reticulata) and Satsuma mandarin (C. reticulata) are similar in fruit shape and leaf morphology, they have different maternal parents. Bendiguangju mandarin has the same cytoplasm as sweet orange (C. sinensis), whereas Satsuma mandarin has the cytoplasm of C. reticulata. Seventeen PCR products from SPCC1 and 21 from SPCC11 were cloned and sequenced. The results revealed that mononucleotide repeats as well as insertions and deletions of small segments of DNA were associated with SPCC1 polymorphism, whereas polymorphism

Enhanced Acquisition Rates of 'Candidatus Liberibacter asiaticus' by the Asian Citrus Psyllid (Hemiptera: Liviidae) in the Presence of Vegetative Flush Growth in Citrus.

Science.gov (United States)

Sétamou, Mamoudou; Alabi, Olufemi J; Kunta, Madhurababu; Jifon, John L; da Graça, John V

2016-10-01

The Asian citrus psyllid preferentially feeds and exclusively reproduces on young, newly emerged flush shoots of citrus. Asian citrus psyllid nymphs feed and complete their life stages on these flush shoots. Recent studies conducted under greenhouse conditions have shown that the transmission rates of 'Candidatus Liberibacter asiaticus' (CLas), the putative causal agent of huanglongbing disease of citrus, are enhanced when flush shoots are present. However, it is unclear if CLas acquisition by migrant adult Asian citrus psyllids is similarly enhanced. To address this knowledge gap, cohorts of Asian citrus psyllid adults were allowed 1-wk acquisition access period (AAP) on flushing and nonflushing shoots of qPCR-tested symptomatic (CLas+) and asymptomatic (CLas-) 10-yr-old sweet orange trees under field conditions. After the AAP, they were tested for CLas by qPCR. Progeny Asian citrus psyllid adults that emerged 4 wk post-AAP were similarly retrieved and tested. Eighty percent of flushing and 30% of nonflushing CLas+ trees produced infective Asian citrus psyllid adults, indicating that flush shoots have greater potential to be inoculum sources for CLas acquisition. Concomitantly, 21.1% and 6.0% infective adults were retrieved, respectively, from flushing and nonflushing CLas+ trees, indicating that Asian citrus psyllid adults acquire CLas more efficiently from flush shoots relative to mature shoots. In addition, 12.1% of infective Asian citrus psyllid adult progeny were obtained from 70% of flushing CLas+ trees. Significantly lower mean Ct values were also obtained from infective adults retrieved from flushing relative to nonflushing trees. The results underscore the role of flush shoots in CLas acquisition and the need to protect citrus trees from Asian citrus psyllid infestations during flush cycles. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email

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

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

Whole plant destructive screening for huanglongbing susceptibility with conetainer seedlings exposed to no-choice Asian citrus psyllid inoculation

Science.gov (United States)

Huanglongbing (HLB) is associated with Candidatus Liberibacter asiaticus (Las) and is vectored by the Asian Citrus Psyllid (ACP, Diaphorina citri). HLB is devastating the Florida citrus industry, with production reduced by 60 percent in the last 12 years, and HLB is considered the greatest threat to...

Citrus pulp pellets as an additive for orange bagasse silage

Directory of Open Access Journals (Sweden)

R. K. Grizotto

2017-03-01

Full Text Available This study evaluated the fermentation profile of orange bagasse ensiled with three levels of dry matter (DM using citrus pulp pellets as a moisture-absorbing additive. Thirty experimental silos (3 treatments, 5 storage times, 2 replicates were prepared using 25-liter plastic buckets containing orange bagasse and three levels of pelleted citrus pulp (0, 6% and 20% as additive. A completely randomized design with repeated measures over time was used. The periods of anaerobic storage were 3, 7, 14, 28 and 56 days. Natural orange bagasse contained 13.9% DM, which increased to 19.1% and 25.5% with the inclusion of 6% and 20% citrus pulp pellets, respectively. The apparent density was inversely correlated with DM content and a higher level of compaction (982 kg/m3 was observed in the mass ensiled with the lowest DM level (13.9%. Additionally, lower compaction (910 kg/m3 was found in the mass ensiled with the additive. The chemical composition of the mass ensiled with or without citrus pulp pellets did not differ significantly in terms of protein, ether extract, neutral detergent fiber, lignin or in vitro DM digestibility (P≥0.05, as expected. Thus, it was possible to analyze only the effect of the inclusion of citrus pulp pellets on the increase in DM content. The inclusion of 20% of the additive reduced (P<0.01 losses due to effluent (98% less and gas production (81% less compared to the control treatment at the end of the anaerobic storage period. In this treatment, a higher (P≤0.05 log number of lactic acid bacteria (4.61 log CFU/g was also observed compared to the other treatments, indicating that the increase in DM favored the growth of these bacteria. In addition, the low yeast count (about 1 log CFU/g sample and the pH below 4.0, which were probably due to the production of lactic and acetic acids, show that the orange bagasse is rich in fermentable soluble carbohydrates and is indicated for ensiling. In conclusion, orange bagasse can be

Citrus leprosis and its status in Florida and Texas: past and present.

Science.gov (United States)

Childers, C C; Rodrigues, J C V; Derrick, K S; Achor, D S; French, J V; Welbourn, W C; Ochoa, R; Kitajima, E W

2003-01-01

According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus industry prior to 1925. This was supported with photographs showing typical leprosis symptoms on citrus leaves, fruit, and twigs. Support for the past occurrence of citrus leprosis in Florida includes: (1) presence of twig lesions in affected orange blocks in addition to lesions on fruits and leaves and corresponding absence of similar lesions on grapefruit; (2) yield reduction and die-back on infected trees; and (3) spread of the disease between 1906 and 1925. Transmission electron microscopy (TEM) examination of tissue samples from leprosis-like injuries to orange and grapefruit leaves from Florida in 1997, and fruits from grapefruit and sweet orange varieties from Texas in 1999 and 2000 did not contain leprosis-like viral particles or viroplasm inclusions. In contrast, leprosis viroplasm inclusions were readily identified by TEM within green non-senescent tissues surrounding leprosis lesions in two of every three orange leaf samples and half of the fruit samples obtained from Piracicaba, Brazil. Symptoms of leprosis were not seen in any of the 24,555 orange trees examined across Florida during 2001 and 2002. The authors conclude that citrus leprosis no longer exists in Florida nor occurs in Texas citrus based on: (1) lack of leprosis symptoms on leaves, fruit, and twigs of sweet orange citrus varieties surveyed in Florida: (2) failure to find virus particles or viroplasm inclusion bodies in suspect samples from both Florida and Texas examined by TEM; (3) absence of documented reports by others on the presence of characteristic leprosis symptoms in Florida; (4) lack of its documented occurrence in dooryard trees or abandoned or minimal pesticide citrus orchard sites in Florida. In view of the serious threat to citrus in the U.S., every effort must be taken to quarantine the importation of both citrus and woody ornamental plants that serve as hosts for Brevipalpus

'Psyllid purple’: evidence of behavior-based utilization by the Asian citrus psyllid of a combination of short and long wavelengths

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri, is the vector of huanglongbing, the most serious disease affecting citrus globally. In Florida alone, D. citri has resulted in billions of dollars of damage and has spread to all the citrus growing regions of North America. The visual behavior of D. citri ...

Occurrence and Distribution of Citrus tristeza virus (CTV in the Jordan Valley

Directory of Open Access Journals (Sweden)

G. Anfoka

2005-04-01

Full Text Available In a survey conducted in 2002 and 2003, Citrus tristeza virus (CTV was detected in the Jordan Valley. The direct tissue blot immunoassay (DTBIA indicated that 12.7 and 15.2% of samples tested in the central and northern Jordan Valley respectively were infected with CTV. Similar results showed that all citrus species grown in the Jordan Valley were susceptible to CTV. DAS-ELISA analysis of samples from a citrus orchard in the Dir Alla area with severe CTV symptoms indicated that 49% of samples were infected with CTV. Using a CTV specific primer pair (CTV1/CTV10, the coat protein gene of the virus was successfully amplified from leaf extracts obtained from CTVinfected trees by IC-RT-PCR. After cloning and sequencing the coat protein gene, the sequence of the amplified product was deposited in the GenBank.

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...

Field validation of a system for autodissemination of an entomopathogenic fungus, Isaria fumosorosea, to control the Asian citrus psyllid on residential citrus

Science.gov (United States)

The citrus industries of California and Texas share a pressing problem with the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) and huanglongbing (HLB) spreading in residential citrus near commercial groves. Insecticidal treatment of residential trees for the psyllid is problem...

Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4) Treated Rats.

Science.gov (United States)

Chowdhury, Mohammed Riaz Hasan; Sagor, Md Abu Taher; Tabassum, Nabila; Potol, Md Abdullah; Hossain, Hemayet; Alam, Md Ashraful

2015-01-01

Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (-)-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4) treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA), nitric oxide, advanced protein oxidation products level (APOP), and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level) and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats.

Supplementation of Citrus maxima Peel Powder Prevented Oxidative Stress, Fibrosis, and Hepatic Damage in Carbon Tetrachloride (CCl4 Treated Rats

Directory of Open Access Journals (Sweden)

Mohammed Riaz Hasan Chowdhury

2015-01-01

Full Text Available Citrus maxima peel is rich in natural phenolic compounds and has a long use in the traditional medicine. HPLC-DAD analysis on Citrus maxima peel powder exhibited the presence of various phenolic compounds such as caffeic acid and (−-epicatechin. To determine the plausible hepatoprotective activity of Citrus maxima peel powder, we used carbon tetrachloride (CCl4 treated rat model. Liver damage in rats was confirmed by measuring the AST, ALT, and ALP enzyme activities. In addition, lipid peroxidation products (MDA, nitric oxide, advanced protein oxidation products level (APOP, and catalase activities were also analyzed along with the histological profiling for the inflammatory cell infiltration, collagen, and iron deposition in liver. Dietary supplementation of Citrus maxima peel powder exhibited significant reduction of serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. Moreover, Citrus maxima peel powder also showed a significant reduction of the oxidative stress markers (MDA, NO, and APOP level and restored the catalase activity in CCl4 treated rats. Histological examination of the liver section revealed reduced inflammatory cells infiltration, collagen, and iron deposition in CCl4 treated rats. The results from this study demonstrated that Citrus maxima peel powder produced significant hepatoprotective action in CCl4 administered rats.

Investigation of the effects of irradiation for quarantine treatment purposes on food quality and hygiene in citrus fruits

International Nuclear Information System (INIS)

2010-01-01

Mediterranean fruit fly (Ceratitis capitata) is a major problem in citrus production sector in Turkey. In order to overcome this problem, required irradiation doses were investigated for the quarantine treatment for 'Yafa' orange (Citrus sinensis (L) Osb.), 'Star ruby' grapefruit (Citrus paradisi Macf.); 'Satsuma' tangerine (Citrus reticulata Blanco) in this project. Chemical, physical and microbiological properties of unirradiated and irradiated (0.5, 1.0 and 1.5 kGy) fruits were determined in terms of weight loss, water soluble dry matter, pH, titratable acidity, alcohol insoluble pectin, apparent color of fruits, reducing sugar, total carotenoid, flavonoid, vitamin C contents, sensory properties of fruits, total aerob mesophilic bacteria and total yeast and mould counts of fruits. Results showed that, 0.1 kGy gamma irradiation dose is sufficient for effective quarantine treatment against the Mediterranean fruit fly in citrus fruits, low dose irradiation (≤1.0 kGy) applications had no detrimental effects on citrus fruits' quality except tangerines, microbial load of fruits were seriously affected by irradiation at 1.0 kGy. In addition, under this work we noticed that, irradiated citrus fruits could be detected by using DNA comet analysis method.

Ectopic expression of MdSPDS1 in sweet orange (Citrus sinensis Osbeck) reduces canker susceptibility: involvement of H₂O₂ production and transcriptional alteration.

Science.gov (United States)

Fu, Xing-Zheng; Chen, Chuan-Wu; Wang, Yin; Liu, Ji-Hong; Moriguchi, Takaya

2011-03-28

Enormous work has shown that polyamines are involved in a variety of physiological processes, but information is scarce on the potential of modifying disease response through genetic transformation of a polyamine biosynthetic gene. In the present work, an apple spermidine synthase gene (MdSPDS1) was introduced into sweet orange (Citrus sinensis Osbeck 'Anliucheng') via Agrobacterium-mediated transformation of embryogenic calluses. Two transgenic lines (TG4 and TG9) varied in the transgene expression and cellular endogenous polyamine contents. Pinprick inoculation demonstrated that the transgenic lines were less susceptible to Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus canker, than the wild type plants (WT). In addition, our data showed that upon Xac attack TG9 had significantly higher free spermine (Spm) and polyamine oxidase (PAO) activity when compared with the WT, concurrent with an apparent hypersensitive response and the accumulation of more H₂O₂. Pretreatment of TG9 leaves with guazatine acetate, an inhibitor of PAO, repressed PAO activity and reduced H₂O₂ accumulation, leading to more conspicuous disease symptoms than the controls when both were challenged with Xac. Moreover, mRNA levels of most of the defense-related genes involved in synthesis of pathogenesis-related protein and jasmonic acid were upregulated in TG9 than in the WT regardless of Xac infection. Our results demonstrated that overexpression of the MdSPDS1 gene prominently lowered the sensitivity of the transgenic plants to canker. This may be, at least partially, correlated with the generation of more H₂O₂ due to increased production of polyamines and enhanced PAO-mediated catabolism, triggering hypersensitive response or activation of defense-related genes.

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM).

Science.gov (United States)

Fletcher, Evelyn; Morgan, Kelly T; Qureshi, Jawwad A; Leiva, Jorge A; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0-45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4-8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and the

Genome editing of the disease susceptibility gene CsLOB1 in citrus confers resistance to citrus canker.

Science.gov (United States)

Jia, Hongge; Zhang, Yunzeng; Orbović, Vladimir; Xu, Jin; White, Frank F; Jones, Jeffrey B; Wang, Nian

2017-07-01

Citrus is a highly valued tree crop worldwide, while, at the same time, citrus production faces many biotic challenges, including bacterial canker and Huanglongbing (HLB). Breeding for disease-resistant varieties is the most efficient and sustainable approach to control plant diseases. Traditional breeding of citrus varieties is challenging due to multiple limitations, including polyploidy, polyembryony, extended juvenility and long crossing cycles. Targeted genome editing technology has the potential to shorten varietal development for some traits, including disease resistance. Here, we used CRISPR/Cas9/sgRNA technology to modify the canker susceptibility gene CsLOB1 in Duncan grapefruit. Six independent lines, D LOB 2, D LOB 3, D LOB 9, D LOB 10, D LOB 11 and D LOB 12, were generated. Targeted next-generation sequencing of the six lines showed the mutation rate was 31.58%, 23.80%, 89.36%, 88.79%, 46.91% and 51.12% for D LOB 2, D LOB 3, D LOB 9, D LOB 10, D LOB 11 and D LOB 12, respectively, of the cells in each line. D LOB 2 and D LOB 3 showed canker symptoms similar to wild-type grapefruit, when inoculated with the pathogen Xanthomonas citri subsp. citri (Xcc). No canker symptoms were observed on D LOB 9, D LOB 10, D LOB 11 and D LOB 12 at 4 days postinoculation (DPI) with Xcc. Pustules caused by Xcc were observed on D LOB 9, D LOB 10, D LOB 11 and D LOB 12 in later stages, which were much reduced compared to that on wild-type grapefruit. The pustules on D LOB 9 and D LOB 10 did not develop into typical canker symptoms. No side effects and off-target mutations were detected in the mutated plants. This study indicates that genome editing using CRISPR technology will provide a promising pathway to generate disease-resistant citrus varieties. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Viability of and Escherichia coli O157:H7 and Listeria monocytogenes in a delicatessen appetizer (yogurt-based) salad as affected by citrus extract (Citrox©) and storage temperature.

Science.gov (United States)

Tsiraki, Maria I; Yehia, Hany M; Elobeid, Tahra; Osaili, Tareq; Sakkas, Hercules; Savvaidis, Ioannis N

2018-02-01

The antimicrobial effect of citrus extract (at 1 mL/kg [C1] and 2 mL/kg [C2]) on naturally occurring microbiota and inoculated pathogens (E. coli O157:H7 and L. monocytogenes at ca. 6 log cfu/g) in the traditional Greek yogurt-based salad Tzatziki stored at 4, 10, or 21 °C, was examined. Lactic acid bacteria (LAB) were high (8.0-8.5 log cfu/g) and varied only minimally for both the control (untreated) and the citrus extract-treated salad samples, whereas the higher citrus extract concentration yielded the lowest yeast populations, irrespective of temperature, during the entire storage period. Populations of inoculated E. coli (6 log cfu/g) declined in both untreated and citrus extract-treated samples from day 0-70, 35, and 15 at 4, 10, and 21 °C, respectively. Citrus extract had a significant effect on the survival of the inoculated E. coli O157:H7, with reductions of 2.8-4.8 log cfu/g in the citrus extract-treated samples at the end of the storage period. Our data show that L. monocytogenes survived in both untreated and citrus extract-treated samples during the entire storage period, irrespective of the storage temperature. The higher concentration of citrus extract had a significant effect on the survival of L. monocytogenes in the treated samples, and reductions of 1.5-3.0 logs were noted on final day 70, 35 and 15 at 4, 10 and 21 °C, respectively. The results of our study demonstrated the potential of citrus extract as a natural compound that can control the growth of food-borne pathogenic bacteria, such as E. coli O157:H7 and L. monocytogenes in Tzatziki, a yogurt-based salad. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of an in vitro skin sensitization test based on ROS production in THP-1 cells.

Science.gov (United States)

Saito, Kazutoshi; Miyazawa, Masaaki; Nukada, Yuko; Sakaguchi, Hitoshi; Nishiyama, Naohiro

2013-03-01

Recently, it has been reported that reactive oxygen species (ROS) produced by contact allergens can affect dendritic cell migration and contact hypersensitivity. The aim of the present study was to develop a new in vitro assay that could predict the skin sensitizing potential of chemicals by measuring ROS production in THP-1 (human monocytic leukemia cell line) cells. THP-1 cells were pre-loaded with a ROS sensitive fluorescent dye, 5-(and 6-)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA), for 15min, then incubated with test chemicals for 30min. The fluorescence intensity was measured by flow cytometry. For the skin sensitizers, 25 out of 30 induced over a 2-fold ROS production at more than 90% of cell viability. In contrast, increases were only seen in 4 out of 20 non-sensitizers. The overall accuracy for the local lymph node assay (LLNA) was 82% for 50 chemicals tested. A correlation was found between the estimated concentration showing 2-fold ROS production in the ROS assay and the EC3 values (estimated concentration required to induce positive response) of the LLNA. These results indicated that the THP-1 cell-based ROS assay was a rapid and highly sensitive detection system able to predict skin sensitizing potentials and potency of chemicals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dancy mandarin: a new alternative for citrus growing in the piedmont plains of Colombia

Directory of Open Access Journals (Sweden)

Diana Mateus Cagua

2015-01-01

Full Text Available The major citrus production of the world are located between 20-40 degrees north and south latitude. In these conditions the mandarins get the best internal and external qualities. ‘Arrayana’ is the main mandarin cultivated in Colombia tropical lowlands (around 04° N. This variety is characterized by a high concentration of the harvest in december and january because it has only one principal bloom in the year (two weeks after onset of rainy season; and an average external quality that prevents it from being highly competitive. Both conditions reduce the profitability of citrus growers in the region. In order to identify and develop mandarin genotypes who obtain outstanding qualities in tropical lowlands, was evaluated at Corpoica La Libertad Research Center (Villavicencio, Meta the Dancy variety since 2000 (Citrus reticulata Blanco var. Dancy for vegetative growth, fruit yield, quality and consumer acceptance through a hedonic test. This information was compared with that obtained in experimental field of Arrayana tangerine; both were grafted on ‘Cleopatra’ mandarin rootstock (Citrus reshni hort. ex Tanaka. The outstanding fruit quality of Dancy (TSS: 10,8; TSS/TA ratio: 18,1; fruit weight: 145,85 g and high cumulative production confirms the adaptation of the variety to the conditions of the Foothills of Meta department; while good consumer acceptance, suggests its recommendation to be established as complementary to the Arrayana’s production. The evaluated clone is susceptible to Alternaria which may limit its cultivation in tropical medium lands conditions where the rainfall regime is bimodal and relative humidity can be high.

Genetic diversity of citrus bacterial canker pathogens preserved in herbarium specimens.

Science.gov (United States)

Li, Wenbin; Song, Qijian; Brlansky, Ronald H; Hartung, John S

2007-11-20

Citrus bacterial canker (CBC) caused by Xanthomonas axonopodis pv. citri (Xac) was first documented in India and Java in the mid 19th century. Since that time, the known distribution of the disease has steadily increased. Concurrent with the dispersion of the pathogen, the diversity of described strains continues to increase, with novel strains appearing in Saudi Arabia, Iran, and Florida in the last decade. Herbarium specimens of infected plants provide an historical record documenting both the geographic distribution and genetic diversity of the pathogen in the past. However, no method was available to assess the genetic diversity within these herbarium samples. We have developed a method, insertion event scanning (IES), and applied the method to characterize the diversity present within CBC populations documented as herbarium specimens over the past century. IES is based on the specific amplification of junction fragments that define insertion events. The potential for IES in current forensic applications is demonstrated by finding an exact match of pathogen genotypes preserved in herbarium specimens from Japan and Florida, demonstrating the source of the original outbreak of citrus canker in Florida in 1911. IES is a very sensitive technique for differentiating bacterial strains and can be applied to any of the several hundred bacteria for which full genomic sequence data are available.

Scientific Opinion on the request from the USA regarding export of Florida citrus fruit to the EU

DEFF Research Database (Denmark)

Baker, R.; Candresse, T.; Dormannsné Simon, E.

2011-01-01

Following a request from the EU Commission, the EFSA PLH Panel conducted a scientific opinion on risk analysis and supporting documents provided by APHIS/USDA in support of the request to remove the Union's plant health import requirement that citrus fruit imported into the EU be sourced from...... host is rare. But the withdrawal of the current EU requirement that citrus fruit imported into the EU be sourced from groves where no symptoms of citrus canker have been observed in the field of production and in its immediate vicinity since the beginning of the last cycle of vegetation, will increase...

Homologues of CsLOB1 in citrus function as disease susceptibility genes in citrus canker.

Science.gov (United States)

Zhang, Junli; Huguet-Tapia, Jose Carlos; Hu, Yang; Jones, Jeffrey; Wang, Nian; Liu, Sanzhen; White, Frank F

2017-08-01

The lateral organ boundary domain (LBD) genes encode a group of plant-specific proteins that function as transcription factors in the regulation of plant growth and development. Citrus sinensis lateral organ boundary 1 (CsLOB1) is a member of the LBD family and functions as a disease susceptibility gene in citrus bacterial canker (CBC). Thirty-four LBD members have been identified from the Citrus sinensis genome. We assessed the potential for additional members of LBD genes in citrus to function as surrogates for CsLOB1 in CBC, and compared host gene expression on induction of different LBD genes. Using custom-designed transcription activator-like (TAL) effectors, two members of the same clade as CsLOB1, named CsLOB2 and CsLOB3, were found to be capable of functioning similarly to CsLOB1 in CBC. RNA sequencing and quantitative reverse transcription-polymerase chain reaction analyses revealed a set of cell wall metabolic genes that are associated with CsLOB1, CsLOB2 and CsLOB3 expression and may represent downstream genes involved in CBC. © 2016 BSPP AND JOHN WILEY & SONS LTD.

In silico analysis of phytohormone metabolism and communication pathways in citrus transcriptome

Directory of Open Access Journals (Sweden)

Vera Quecini

2007-01-01

Full Text Available Plant hormones play a crucial role in integrating endogenous and exogenous signals and in determining developmental responses to form the plant body throughout its life cycle. In citrus species, several economically important processes are controlled by phytohormones, including seed germination, secondary growth, fruit abscission and ripening. Integrative genomics is a powerful tool for linking newly researched organisms, such as tropical woody species, to functional studies already carried out on established model organisms. Based on gene orthology analyses and expression patterns, we searched the Citrus Genome Sequencing Consortium (CitEST database for Expressed Sequence Tags (EST consensus sequences sharing similarity to known components of hormone metabolism and signaling pathways in model species. More than 600 homologs of functionally characterized hormone metabolism and signal transduction members from model species were identified in citrus, allowing us to propose a framework for phytohormone signaling mechanisms in citrus. A number of components from hormone-related metabolic pathways were absent in citrus, suggesting the presence of distinct metabolic pathways. Our results demonstrated the power of comparative genomics between model systems and economically important crop species to elucidate several aspects of plant physiology and metabolism.

Evaluation of Chemical Composition and Biological Activities of Citrus pseudolimon and Citrus grandis Peel Essential Oils

International Nuclear Information System (INIS)

Sajid, A.; Hanif, M.A.; Shahid, M.

2016-01-01

Essential oils and their volatile constituents are used extensively to prevent and treat human diseases. In the past decades, worldwide demand for citrus essential oils has greatly increased. Citrus essential oils containing 85-99 percent volatile and 1-15 percent non-volatile components. Essential oils from Citrus pseudolimon and Citrus grandis peels were extracted through steam distillation and characterized by GC-MS. C. pseudolimon has thirty six and C. grandis has thirty three total components; limonene 47.07 percent and 71.48 percent was the major component in both oils respectively. Antioxidant activity was checked by 2, 2-diphenyl-1-picrylhydrazyl radical assay and β-carotene/linoleic acid bleaching test. Both oils have modest activity. The antimicrobial potential was assessed against different bacterial and fungus strains. C. pseudolimon oil possessed strong activity against all tested strains while C. grandis has moderate activity. The antitumor activity was evaluated by potato disc assay, C. pseudolimon showed 81.25 inhibition. Hence the essential oils could have a great potential in pharmaceutical industry. (author)

Drought Tip: Irrigating Citrus with Limited Water

OpenAIRE

Faber, Ben

2015-01-01

As an evergreen in California's Mediterranean climate, with wet winters and dry summers, citrus requires some water all year long. Depending on the cultivar and rootstock, citrus can sustain certain levels of drought stress.

Isolation and identification of citrus psorosis virus Egyptian isolate (CPsV-EG).

Science.gov (United States)

Ghazal, S A; El-Dougdoug, Kh A; Mousa, A A; Fahmy, H; Sofy, A R

2008-01-01

Citrus psorosis ophiovirus (CPsV), is considered to be of the most serious and deter mental virus pathogen's citrus species trees in Egypt. CPsV-EG was isolated from infected citrus grapefruit (C. paradisi Macf.) at Agric. Res. Centre (ARC). The grapefruit which used for CPsV-EG isolate was found to be free from CTV, CEVd and Spiroplasma citri where as gave -ve results with DTBIA, tissue print hybridization and Diene's stain respectively. CPsV-EG was detected on the basis of biological indexing by graft inoculation which gave oak leaf pattern (OLP) on Dweet tangor and serological assay by DAS-ELISA using Mab specific CPsV. CPsV-EG was reacted with variable responses on 16 host plants belonging to 6 families. Only 8 host plants are susceptible and showed visible external symptoms which appeared as local, systemic and local followed by systemic infections. CPsV-EG isolate was transmitted from infected citrus to citrus by syringe and grafting and herbaceous plants by forefinger inoculation and syringe. The woody indicators and rootstocks were differed in response to CPsV-EG isolate which appeared as no-response, response, sensitivity and hypersensitivity. The serological characters represented as the antigenic determinants of CPsV-EG isolate related to monoclonal antibodies specific CPsV strain where as appeared precipitation reaction by DAS-ELISA and DTBIA. The partial fragment of RNA3 (coat protein gene) of CPsV-EG (-1140bp and -571bp) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) from grapefruit tissues using two sets primers specific CPsV (CPV3 and CPV4) and (PS66 and PS65) respectively. The virus under study was identified as CPsV-EG isolate according to biological, serological and molecular characters.

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.

Anaerobic digestion of citrus waste using two-stage membrane bioreactor

Science.gov (United States)

Millati, Ria; Lukitawesa; Dwi Permanasari, Ervina; Wulan Sari, Kartika; Nur Cahyanto, Muhammad; Niklasson, Claes; Taherzadeh, Mohammad J.

2018-03-01

Anaerobic digestion is a promising method to treat citrus waste. However, the presence of limonene in citrus waste inhibits anaerobic digestion process. Limonene is an antimicrobial compound and could inhibit methane forming bacteria that takes a longer time to recover than the injured acid forming bacteria. Hence, volatile fatty acids will be accumulated and methane production will be decreased. One way to solve this problem is by conducting anaerobic digestion process into two stages. The first step is aimed for hydrolysis, acidogenesis, and acetogenesis reactions and the second stage is aimed for methanogenesis reaction. The separation of the system would further allow each stage in their optimum conditions making the process more stable. In this research, anaerobic digestion was carried out in batch operations using 120 ml-glass bottle bioreactors in 2 stages. The first stage was performed in free-cells bioreactor, whereas the second stage was performed in both bioreactor of free cells and membrane bioreactor. In the first stage, the reactor was set into ‘anaerobic’ and ‘semi-aerobic’ conditions to examine the effect of oxygen on facultative anaerobic bacteria in acid production. In the second stage, the protection of membrane towards the cells against limonene was tested. For the first stage, the basal medium was prepared with 1.5 g VS of inoculum and 4.5 g VS of citrus waste. The digestion process was carried out at 55°C for four days. For the second stage, the membrane bioreactor was prepared with 3 g of cells that were encased and sealed in a 3×6 cm2 polyvinylidene fluoride membrane. The medium contained 40 ml basal medium and 10 ml liquid from the first stage. The bioreactors were incubated at 55°C for 2 days under anaerobic condition. The results from the first stage showed that the maximum total sugar under ‘anaerobic’ and ‘semi-aerobic’ conditions was 294.3 g/l and 244.7 g/l, respectively. The corresponding values for total volatile

Expression and functional analysis of citrus carotene hydroxylases: unravelling the xanthophyll biosynthesis in citrus fruits.

Science.gov (United States)

Ma, Gang; Zhang, Lancui; Yungyuen, Witchulada; Tsukamoto, Issei; Iijima, Natsumi; Oikawa, Michiru; Yamawaki, Kazuki; Yahata, Masaki; Kato, Masaya

2016-06-29

Xanthophylls are oxygenated carotenoids and fulfill critical roles in plant growth and development. In plants, two different types of carotene hydroxylases, non-heme di-iron and heme-containing cytochrome P450, were reported to be involved in the biosynthesis of xanthophyll. Citrus fruits accumulate a high amount of xanthophylls, especially β,β-xanthophylls. To date, however, the roles of carotene hydroxylases in regulating xanthophyll content and composition have not been elucidated. In the present study, the roles of four carotene hydroxylase genes (CitHYb, CitCYP97A, CitCYP97B, and CitCYP97C) in the biosynthesis of xanthophyll in citrus fruits were investigated. Phylogenetic analysis showed that the four citrus carotene hydroxylases presented in four distinct clusters which have been identified in higher plants. CitHYb was a non-heme di-iron carotene hydroxylase, while CitCYP97A, CitCYP97B, and CitCYP97C were heme-containing cytochrome P450-type carotene hydroxylases. Gene expression results showed that the expression of CitHYb increased in the flavedo and juice sacs during the ripening process, which was well consistent with the accumulation of β,β-xanthophyll in citrus fruits. The expression of CitCYP97A and CitCYP97C increased with a peak in November, which might lead to an increase of lutein in the juice sacs during the ripening process. The expression level of CitCYP97B was much lower than that of CitHYb, CitCYP97A, and CitCYP97C in the juice sacs during the ripening process. Functional analysis showed that the CitHYb was able to catalyze the hydroxylation of the β-rings of β-carotene and α-carotene in Escherichia coli BL21 (DE3) cells. Meanwhile, when CitHYb was co-expressed with CitCYP97C, α-carotene was hydroxylated on the β-ring and ε-ring sequentially to produce lutein. CitHYb was a key gene for β,β-xanthophyll biosynthesis in citrus fruits. CitCYP97C functioned as an ε-ring hydroxylase to produce lutein using zeinoxanthin as a substrate

Evaluating citrus germplasm for huanglongbing (HLB) resistance: USDA-ARS Inoculation Program

Science.gov (United States)

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it vectors bacteria responsible for a serious disease of citrus known as huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program for screening citrus germplasm for resistance to the di...

Citrus Polyphenol Hesperidin Stimulates Production of Nitric Oxide in Endothelial Cells while Improving Endothelial Function and Reducing Inflammatory Markers in Patients with Metabolic Syndrome

Science.gov (United States)

Rizza, Stefano; Muniyappa, Ranganath; Iantorno, Micaela; Kim, Jeong-a; Chen, Hui; Pullikotil, Philomena; Senese, Nicoletta; Tesauro, Manfredi; Lauro, Davide; Cardillo, Carmine

2011-01-01

Context: Hesperidin, a citrus flavonoid, and its metabolite hesperetin may have vascular actions relevant to their health benefits. Molecular and physiological mechanisms of hesperetin actions are unknown. Objective: We tested whether hesperetin stimulates production of nitric oxide (NO) from vascular endothelium and evaluated endothelial function in subjects with metabolic syndrome on oral hesperidin therapy. Design, Setting, and Interventions: Cellular mechanisms of action of hesperetin were evaluated in bovine aortic endothelial cells (BAEC) in primary culture. A randomized, placebo-controlled, double-blind, crossover trial examined whether oral hesperidin administration (500 mg once daily for 3 wk) improves endothelial function in individuals with metabolic syndrome (n = 24). Main Outcome Measure: We measured the difference in brachial artery flow-mediated dilation between placebo and hesperidin treatment periods. Results: Treatment of BAEC with hesperetin acutely stimulated phosphorylation of Src, Akt, AMP kinase, and endothelial NO synthase to produce NO; this required generation of H2O2. Increased adhesion of monocytes to BAEC and expression of vascular cell adhesion molecule-1 in response to TNF-α treatment was reduced by pretreatment with hesperetin. In the clinical study, when compared with placebo, hesperidin treatment increased flow-mediated dilation (10.26 ± 1.19 vs. 7.78 ± 0.76%; P = 0.02) and reduced concentrations of circulating inflammatory biomarkers (high-sensitivity C-reactive protein, serum amyloid A protein, soluble E-selectin). Conclusions: Novel mechanisms for hesperetin action in endothelial cells inform effects of oral hesperidin treatment to improve endothelial dysfunction and reduce circulating markers of inflammation in our exploratory clinical trial. Hesperetin has vasculoprotective actions that may explain beneficial cardiovascular effects of citrus consumption. PMID:21346065

Huanglongbing increases Diplodia Stem End Rot in Citrus sinensis

Science.gov (United States)

Huanglongbing (HLB), one of the most devastating diseases of citrus is caused by the a-Proteobacteria Candidatus Liberibacter. Diplodia natalensis Pole-Evans is a fungal pathogen which has been known to cause a postharvest stem-end rot of citrus, the pathogen infects citrus fruit under the calyx, an...

Bacterial diversity analysis of Huanglongbing pathogen-infected citrus, using PhyloChip and 16S rRNA gene clone library sequencing

Energy Technology Data Exchange (ETDEWEB)

Shankar Sagaram, U.; DeAngelis, K.M.; Trivedi, P.; Andersen, G.L.; Lu, S.-E.; Wang, N.

2009-03-01

The bacterial diversity associated with citrus leaf midribs was characterized 1 from citrus groves that contained the Huanglongbing (HLB) pathogen, which has yet to be cultivated in vitro. We employed a combination of high-density phylogenetic 16S rDNA microarray and 16S rDNA clone library sequencing to determine the microbial community composition of symptomatic and asymptomatic citrus midribs. Our results revealed that citrus leaf midribs can support a diversity of microbes. PhyloChip analysis indicated that 47 orders of bacteria from 15 phyla were present in the citrus leaf midribs while 20 orders from phyla were observed with the cloning and sequencing method. PhyloChip arrays indicated that nine taxa were significantly more abundant in symptomatic midribs compared to asymptomatic midribs. Candidatus Liberibacter asiaticus (Las) was detected at a very low level in asymptomatic plants, but was over 200 times more abundant in symptomatic plants. The PhyloChip analysis was further verified by sequencing 16S rDNA clone libraries, which indicated the dominance of Las in symptomatic leaves. These data implicate Las as the pathogen responsible for HLB disease. Citrus is the most important commercial fruit crop in Florida. In recent years, citrus Huanglongbing (HLB), also called citrus greening, has severely affected Florida's citrus production and hence has drawn an enormous amount of attention. HLB is one of the most devastating diseases of citrus (6,13), characterized by blotchy mottling with green islands on leaves, as well as stunting, fruit decline, and small, lopsided fruits with poor coloration. The disease tends to be associated with a phloem-limited fastidious {alpha}-proteobacterium given a provisional Candidatus status (Candidatus Liberobacter spp. later changed to Candidatus Liberibacter spp.) in nomenclature (18,25,34). Previous studies indicate that HLB infection causes disorder in the phloem and severely impairs the translocation of assimilates in

A novel hybridization approach for detection of citrus viroids.

Science.gov (United States)

Murcia, N; Serra, P; Olmos, A; Duran-Vila, N

2009-04-01

Citrus plants are natural hosts of several viroid species all belonging to the family Pospiviroidae. Previous attempts to detect viroids from field-grown species and cultivars yielded erratic results unless analyses were performed using Etrog citron a secondary bio-amplification host. To overcome the use of Etrog citron a number of RT-PCR approaches have been proposed with different degrees of success. Here we report the suitability of an easy to handle northern hybridization protocol for viroid detection of samples collected from field-grown citrus species and cultivars. The protocol involves: (i) Nucleic acid preparations from bark tissue samples collected from field-grown trees regardless of the growing season and storage conditions; (ii) Separation in 5% PAGE or 1% agarose, blotting to membrane and fixing; (iii) Hybridization with viroid-specific DIG-labelled probes and detection with anti-DIG-alkaline phosphatase conjugate and autoradiography with the CSPD substrate. The method has been tested with viroid-infected trees of sweet orange, lemon, mandarin, grapefruit, sour orange, Swingle citrumello, Tahiti lime and Mexican lime. This novel hybridization approach is extremely sensitive, easy to handle and shortens the time needed for reliable viroid indexing tests. The suitability of PCR generated DIG-labelled probes and the sensitivity achieved when the samples are separated and blotted from non-denaturing gels are discussed.

Expression and Purification of Coat Protein of Citrus Tristeza Virus ...

African Journals Online (AJOL)

Ethiopian Institute of Agricultural Research, P.O. Box 436 Nazareth, Ethiopia ... Citrus is one of the major fruit crop in Thailand and in present day production value of ..... The QIAexpressionist™ A handbook for high-level expression and ... application of a multiplex reverse-transcription polymerase chain reaction assay for.

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)

Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

Science.gov (United States)

Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

2013-04-01

Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip

Quantitation of flavonoid constituents in citrus fruits.

Science.gov (United States)

Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M

1999-09-01

Twenty-four flavonoids have been determined in 66 Citrus species and near-citrus relatives, grown in the same field and year, by means of reversed phase high-performance liquid chromatography analysis. Statistical methods have been applied to find relations among the species. The F ratios of 21 flavonoids obtained by applying ANOVA analysis are significant, indicating that a classification of the species using these variables is reasonable to pursue. Principal component analysis revealed that the distributions of Citrus species belonging to different classes were largely in accordance with Tanaka's classification system.

[Citrus boron nutrient level and its impact factors in the Three Gorges Reservoir region of Chongqing, China].

Science.gov (United States)

Zhou, Wei; Peng, Liang-Zhi; Chun, Chang-Pin; Jiang, Cai-Lun; Ling, Li-Li; Wang, Nan-Qi; Xing, Fei; Huang, Yi

2014-04-01

To investigate the level of boron nutrient in citrus and its impact factors, a total of 954 citrus leaf samples and 302 soil samples were collected from representative orchards in the 12 main citrus production counties in the Three Gorges Reservoir region of Chongqing to determine the boron content in citrus leaves, as well as the relationships between leaf boron content with soil available boron content, soil pH value, cultivar, rootstock and the age of tree. Results indicated that the leaf samples from 41.6% orchards (tree did affect the leaf boron content. The leaves from the orchards with soil pH of 4.5-6.4 demonstrated significantly higher boron contents than with the soil pH of 6.5-8.5. The leaf boron contents in the different cultivars was ranged as Satsuma mandarin > pomelo > valencia orange > sweet orange > tangor > navel orange. The citrus on trifoliate orange and sour pomelo rootstocks had significantly higher leaf boron contents than on Carrizo citrange and red tangerine rootstocks. Compared with the adult citrus trees (above 8 year-old), 6.6% more of leaf samples of younger trees (3 to 8 year-old) contained boron contents in the optimum range (35-100 mg x kg(-1)).

TYPOLOGY OF FAMILY PRODUCTION UNITS OF TRADICIONAL AGROFORESTY SYSTEM OF COFFEE-BANANA-CITRUS IN THE COUNTRY TLAPACOYAN, VERACRUZ

Directory of Open Access Journals (Sweden)

R. Cruz A.

2015-12-01

Full Text Available Coffee production is one of the most important activities in the town of Tlapacoyan, Veracruz unfortunately, prices and technologies focused on the monoculture production system have reduced the activity. The study of family production units (FPU, with the construction of a typology and an agronomic characterization of producers, carried out in the traditional agroforestry system of coffee-banana-citrus contributes to further analysis in public policies. This study was conducted in six communities through field work, coffee producers records and open interviews with authorities. A census of 33 individuals was built and questionnaires were applied as a part of the survey, which used multivariate analysis to establish categories of UPF. Each category was described in agronomic terms based on incomes and costs. Three categories were determined according to surface size, labor work and technological level, including diversification of costs of incomes. As a conclusion, this study has contributed to rethink about new supporting strategies for coffee producers, and government policies and supporting programs which will mean a better family income that will take into account differences such as the size varying from 5 to 27 ha. Labor work available varies among categories and technification defines the type and number of vehicles, because it refers to an activity that generates beneficial incomes to producers. We conclude that this heads of the UPF have traditional management of the 3 components, integrating productive practical and the system is dependent on labor.

Citrus tristeza virus: An increasing trend in the virus occurrence and ...

African Journals Online (AJOL)

ABC

2015-07-29

Jul 29, 2015 ... Citrus tristeza clostervirus (CTV) is one of the most damaging fruit viruses playing havoc in citrus ... diseases of citrus trees reported in Pakistan are tristeza, .... bark. Vein clearing and stem pitting were also observed on sweet orange trees sour ..... disposal of source of inoculum by removing old citrus trees ...

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.

Understanding the dynamics of citrus water use

CSIR Research Space (South Africa)

Taylor, NJ

2012-12-01

Full Text Available The quantification of water use of citrus orchards is important in order to prevent stress developing in the orchard and to avoid wasting precious water resources. Measurement of citrus orchard water use is not possible under all environ-mental...

(HLB) infected citrus

African Journals Online (AJOL)

ONOS

2010-09-06

Sep 6, 2010 ... 1Departments of Crop Science, Faculty of Agriculture, University Putra Malaysia, 43400 Serdang, Selangor Darul ... Huanglongbing (HLB) disease, also known as citrus ..... Huanglongbing: A destructive, newly-emerging,.

Quantification of Xylella fastidiosa from Citrus Trees by Real-Time Polymerase Chain Reaction Assay.

Science.gov (United States)

Oliveira, Antonio C; Vallim, Marcelo A; Semighini, Camile P; Araújo, Welington L; Goldman, Gustavo H; Machado, Marcos A

2002-10-01

ABSTRACT Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC), a destructive disease of sweet orange cultivars in Brazil. Polymerase chain reaction (PCR)-based assays constitute the principal diagnostic method for detection of these bacteria. In this work, we established a real-time quantitative PCR (QPCR) assay to quantify X. fastidiosa in naturally and artificially infected citrus. The X. fastidiosa cell number detected in the leaves increased according to the age of the leaf, and bacteria were not detected in the upper midrib section in young leaves, indicating temporal and spatial distribution patterns of bacteria, respectively. In addition, the X. fastidiosa cell number quantified in leaves of 'Pera' orange and 'Murcott' tangor reflected the susceptible and resistant status of these citrus cultivars. None of the 12 endophytic citrus bacteria or the four strains of X. fastidiosa nonpathogenic to citrus that were tested showed an increase in the fluorescence signal during QPCR. In contrast, all 10 CVC-causing strains exhibited an increase in fluorescence signal, thus indicating the specificity of this QPCR assay. Our QPCR provides a powerful tool for studies of different aspects of the Xylella-citrus interactions, and can be incorporated into breeding programs in order to select CVC-resistant plants more quickly.

Citrus Flavonoid Supplementation Improves Exercise Performance in Trained Athletes

Directory of Open Access Journals (Sweden)

Elvera Overdevest, Jeroen A. Wouters, Kevin H.M. Wolfs, Job J.M. van Leeuwen, Sam Possemiers

2018-03-01

Full Text Available Previous studies have shown that polyphenol supplementation may be an effective strategy to improve exercise performance, due to their antioxidant character and ability to stimulate NO production. These properties may contribute to exercise performance, yet no conclusive research has been performed in exploring the direct effects of citrus flavonoids on human exercise performance. Therefore, the purpose of this study was to assess whether supplementation of a customized citrus flavonoid (CF extract for 4 weeks improves cycling time-trial performance in trained male athletes. In a double-blind, randomized, parallel study, 39 healthy, trained males were given a daily dose of either 500 mg of a customized citrus flavonoid extract (CF or a placebo for 4 weeks. Exercise performance was tested by means of a time-trial test on a cycle ergometer, during which participants had to generate as much power as possible for duration of 10 minutes. Absolute power output significantly increased with 14.9 ± 3.9 W after 4 weeks of CF supplementation, corresponding with a 5.0% increase, compared to 3.8 ± 3.2 W (1.3% increase in placebo (p < 0.05. In addition, oxygen consumption/power ratio significantly decreased in the CF group compared to placebo (p = 0.001, and a trend was found in the change in peak power output in CF (18.2 ± 23.2 W versus placebo (-28.4 ± 17.6 W; p = 0.116. The current study is the first convincing report that citrus flavonoid supplementation can improve exercise performance, as shown by a significant increase in power output during the exercise test.

Asian citrus psyllid RNAi pathway - RNAi evidence

Science.gov (United States)

In silico analyses of the draft genome of Diaphorina citri, the Asian citrus psyllid, for genes within the Ribonucleic acid interference(RNAi), pathway was successful. The psyllid is the vector of the plant-infecting bacterium, Candidatus Liberibacter asiaticus (CLas), which is linked to citrus gree...

Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement.

Science.gov (United States)

Omar, Ahmad A; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W

2016-01-01

The genus Citrus contains numerous fresh and processed fruit cultivars that are economically important worldwide. New cultivars are needed to battle industry threatening diseases and to create new marketing opportunities. Citrus improvement by conventional methods alone has many limitations that can be overcome by applications of emerging biotechnologies, generally requiring cell to plant regeneration. Many citrus genotypes are amenable to somatic embryogenesis, which became a key regeneration pathway in many experimental approaches to cultivar improvement. This chapter provides a brief history of plant somatic embryogenesis with focus on citrus, followed by a discussion of proven applications in biotechnology-facilitated citrus improvement techniques, such as somatic hybridization, somatic cybridization, genetic transformation, and the exploitation of somaclonal variation. Finally, two important new protocols that feature plant regeneration via somatic embryogenesis are provided: protoplast transformation and Agrobacterium-mediated transformation of embryogenic cell suspension cultures.

Proximity to citrus influences Pierce's disease in Temecula Valley vineyards

OpenAIRE

Perring, Thomas M.; Farrar, Charles A.; Blua, Matthew

2001-01-01

Pierce's disease has caused extensive losses to grapes in the Temecula Valley. The primary vector of Pierce's disease in the region is the glassy-winged sharpshooter (GWSS), which has been found in large numbers in citrus trees. We examined the role of citrus in the Temecula Valley Pierce's disease epidemic and found that citrus groves have influenced the incidence and severity of Pierce's disease in grapes. Because GWSS inhabit citrus in large numbers, California grape growers should take ad...

Partial dehydration and cryopreservation of Citrus seeds.

Science.gov (United States)

Graiver, Natalia; Califano, Alicia; Zaritzky, Noemí

2011-11-01

Three categories of seed storage behavior are generally recognized among plant species: orthodox, intermediate and recalcitrant. Intermediate seeds cannot be stored in liquid nitrogen (LN) without a previous partial dehydration process. The water content (WC) of the seeds at the moment of immersion in LN must be regarded as the most critical factor in cryopreservation. The purpose of this study was to investigate the basis of the optimal hydration status for cryopreservation of Citrus seeds: C. sinensis (sweet orange), C. paradisi (grapefruit), C. reticulata (mandarin) in LN. To study the tolerance to dehydration and LN exposure, seeds were desiccated by equilibration at relative humidities between 11 and 95%. Sorption isotherms were determined and modeled; lipid content of the seeds was measured. Seed desiccation sensitivity was quantified by the quantal response model. Differential scanning calorimetry (DSC) thermograms were determined on cotyledon tissue at different moisture contents to measure ice melting enthalpies and unfrozen WC. Samples of total seed lipid extract were also analyzed by DSC to identify lipid transitions in the thermograms. The limit of hydration for LN Citrus seeds treatment corresponded to the unfrozen WC in the tissue, confirming that seed survival strictly depended on avoidance of intracellular ice formation. Copyright © 2011 Society of Chemical Industry.

Radiosensitivity of protoplasts of orange (Citrus sinensis)

International Nuclear Information System (INIS)

Goldman, M.H.S.; Ando, A.

1990-01-01

Full text: The Radiation Genetics Section of the Centre for Nuclear Energy in Agriculture (CENA), University of Sao Paulo, is utilising both ''in vivo'' and ''in vitro'' methods for mutation induction in Citrus, cv. ''Pera'', aiming at resistance to citrus canker. The experiments carried out so far determined the methodology to isolate protoplasts and their sensitivity to gamma-rays. Regarding the culture of protoplasts from embryogenic callus, the best experimental conditions were: enzymatic digestion for 5 h on a medium containing cellulase (307.6 mg/10 ml), macerozyme (30.3 mg/10 ml), mannitol (328.0 mM) and sucrose (336.2 mM) as osmotic stabilisers. The isolation efficiency of 1.2x10 6 viable protoplasts/g will make it possible to use protoplasts in mutation breeding. To determine radiosensitivity of protoplasts, gamma-irradiation from 60 Co source was conducted 42 h after their isolation. This time interval is recommended because during this period protoplasts will reach the stage prior to or at the first mitotic division. Survivals were determined by metylen-blue dyeing, and the LD 50 was found to be around 37.5 Gy. Any difference compared with other authors might be due to different genotypes used or different methods of calculation of survival. (author)

Deposit of pesticides without and with adjuvants on citrus seedlings following different intervals of artificial rain

Directory of Open Access Journals (Sweden)

Ricardo Augusto Decaro

2016-01-01

Full Text Available ABSTRACT: For a crop protection product to achieve its goal, the product must be applied and remain on the leaves until it is absorbed. This situation may be compromised due to rainfall after spraying, thus necessitating reapplication which increase the overall cost. Application technology research has focused on alternatives and solutions to mitigate this effect through the use of adjuvants. The objective of this research was to evaluate the deposit of spraying liquid on citrus seedlings using the products spirodiclofen, propargite, imidacloprid, lambda cyhalothrin, copper oxychloride, and copper hydroxide with water mixed with the adjuvants polydimethylsiloxane and phosphatidylcholine. Seedlings were subjected to simulated rains of 10mm at intervals of 1, 6, 12 and 24h after spraying, and the remaining deposits of spraying liquid per leaf area were analyzed by spectrophotometry by assessing a metallic marker previously added in the spraying liquids. Variables were subjected to analysis of variance and Tukey's test (P<0.05. The rains that occurred soon after spraying resulted in decreased spraying liquids deposits on citrus leaves. Adjuvant phosphatidylcholine promoted the greatest retention of spraying liquid on citrus leaves after rainfall.

Resistance of sweet orange Pera (Citrus sinensis) genotypes to Xanthomonas citri subsp. citri under field conditions

Science.gov (United States)

Citrus canker control is based on protection measures and eradication of plants infected with Xanthomonas citri subsp. citri. Although these measures show satisfactory results, the use of resistant genotypes is an important alternative for citrus canker control. The aim of this study was to evaluate...

Citrus paradisi: an effective bio-adsorbent for arsenic (v) remediation

International Nuclear Information System (INIS)

Khaskheli, M.I.; Memon, S.Q.; Parveen, S.

2014-01-01

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)

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 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.

One Target, Two Mechanisms: The Impact of 'Candidatus Liberibacter asiaticus' and Its Vector, Diaphorina citri, on Citrus Leaf Pigments.

Science.gov (United States)

Killiny, Nabil; Nehela, Yasser

2017-07-01

Huanglongbing (HLB) is currently the largest threat to global citrus production. We examined the effect of HLB pathogen 'Candidatus Liberibacter asiaticus' infection or infestation by its vector, Diaphorina citri, on 'Valencia' sweet orange leaf pigments using high-performance liquid chromatography, followed by gene expression analysis for 46 involved genes in carotenoid and chlorophyll biosynthesis pathways. Both 'Ca. L. asiaticus' and D. citri alter the total citrus leaf pigment balance with a greater impact by 'Ca. L. asiaticus'. Although zeaxanthin was accumulated in 'Ca. L. asiaticus'-infected leaves, chlorophyllide a was increased in D. citri-infested plants. Our findings support the idea that both 'Ca. L. asiaticus' and D. citri affect the citrus pigments and promote symptom development but using two different mechanisms. 'Ca. L. asiaticus' promotes chlorophyll degradation but accelerates the biosynthesis of carotenoid pigments, resulting in accumulation of abscisic acid and its precursor, zeaxanthin. Zeaxanthin also has a photoprotective role. By contrast, D. citri induced the degradation of most carotenoids and accelerated chlorophyll biosynthesis, leading to chlorophyllide a accumulation. Chlorophyllide a might have an antiherbivory role. Accordingly, we suggest that citrus plants try to defend themselves against 'Ca. L. asiaticus' or D. citri using multifaceted defense systems, based on the stressor type. These findings will help in better understanding the tritrophic interactions among plant, pathogen, and vector.

Chemistry and Pharmacology of Citrus sinensis

Directory of Open Access Journals (Sweden)

Juan Manuel J. Favela-Hernández

2016-02-01

Full Text Available 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.

Selection processes in a citrus hybrid population using RAPD markers

Directory of Open Access Journals (Sweden)

Oliveira Roberto Pedroso de

2003-01-01

Full Text Available The objective of this work was to evaluate the processes of selection in a citrus hybrid population using segregation analysis of RAPD markers. The segregation of 123 RAPD markers between 'Cravo' mandarin (Citrus reticulata Blanco and 'Pêra' sweet orange (C. sinensis (L. Osbeck was analysed in a F1 progeny of 94 hybrids. Genetic composition, diversity, heterozygosity, differences in chromosomal structure and the presence of deleterious recessive genes are discussed based on the segregation ratios obtained. A high percentage of markers had a skeweness of the 1:1 expected segregation ratio in the F1 population. Many markers showed a 3:1 segregation ratio in both varieties and 1:3 in 'Pêra' sweet orange, probably due to directional selection processes. The distribution analysis of the frequencies of the segregant markers in a hybrid population is a simple method which allows a better understanding of the genetics of citrus group.

Effect of intercropping of maize in citrus orchards on citrus leaf miner infestation and population of its natural enemies

International Nuclear Information System (INIS)

Ahmed, S.; Khan, M.A.; Qasam, M.

2012-01-01

An experiment was conducted to determine the effect of intercropping of maize fodder in months of monsoon (July to October), in Faisalabad, Pakistan, on infestation of citrus leaf miner (CLM) (Phyllocnistis citrella Stanton) and its predators. Lemon, Kinnow, Grapefruit and Musambi intercropped with and without maize were selected for recording data on these insects. Percent leaf miner infestation and number of predators were recorded from randomly selected branches of citrus trees. Results showed that intercropped plots of each variety had low infestation of citrus miner and high population of coccinellids and Chrysoperla carnea and Musambi was 8.40+-0.144 and 12.72+-0.171 in intercropped and 9.12+-0.169 and 14.52+-0.200 in wihtout intercropped plots, respectively. Interaction of population of Chrysoperla carnea and coccinellids was non-significant for months, varieties and intercropping but was significant within months, varieties and intercropping. The possibility of using maize fodder as intercrop in autumn in citrus is discussed. (author)

Evaluating Sustainable Competitive Advantages in Brazilian and U.S. Processed Citrus Supply Chains: An Application of Porter’s Diamond Framework

Directory of Open Access Journals (Sweden)

James A. Sterns

2010-05-01

Full Text Available The processed citrus industries of Sao Paulo, Brazil and Florida, United States collectively account for over 80 percent of world orange juice production. In recent years, both industries have been confronted with serious plant disease outbreaks. Porter’s Diamond framework is used to assess the strenghts and weakness of the processed citrus industry in each country to confront the combined challenge of effectively combating these diseases while maintaining market competitiveness. Although Sao Paulo and Florida produce a similar product, the Porter’s Diamond framework reveals that there are significant diffences in the organizational structure of the two industries. The article concludes with an analysis of how these differences will impact each industry’s ability to sustain its global leadership in the international processed citrus market.

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...

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.

A novel carotenoid cleavage activity involved in the biosynthesis of Citrus fruit-specific apocarotenoid pigments

KAUST Repository

Rodrigo, María J.

2013-09-04

Citrus is the first tree crop in terms of fruit production. The colour of Citrus fruit is one of the main quality attributes, caused by the accumulation of carotenoids and their derivative C30 apocarotenoids, mainly ?-citraurin (3-hydroxy-?-apo-8?-carotenal), which provide an attractive orange-reddish tint to the peel of oranges and mandarins. Though carotenoid biosynthesis and its regulation have been extensively studied in Citrus fruits, little is known about the formation of C30 apocarotenoids. The aim of this study was to the identify carotenoid cleavage enzyme(s) [CCD(s)] involved in the peel-specific C30 apocarotenoids. In silico data mining revealed a new family of five CCD4-type genes in Citrus. One gene of this family, CCD4b1, was expressed in reproductive and vegetative tissues of different Citrus species in a pattern correlating with the accumulation of C30 apocarotenoids. Moreover, developmental processes and treatments which alter Citrus fruit peel pigmentation led to changes of ?-citraurin content and CCD4b1 transcript levels. These results point to the involvement of CCD4b1 in ?-citraurin formation and indicate that the accumulation of this compound is determined by the availability of the presumed precursors zeaxanthin and ?-cryptoxanthin. Functional analysis of CCD4b1 by in vitro assays unequivocally demonstrated the asymmetric cleavage activity at the 7?,8? double bond in zeaxanthin and ?-cryptoxanthin, confrming its role in C30 apocarotenoid biosynthesis. Thus, a novel plant carotenoid cleavage activity targeting the 7?,8? double bond of cyclic C40 carotenoids has been identified. These results suggest that the presented enzyme is responsible for the biosynthesis of C30 apocarotenoids in Citrus which are key pigments in fruit coloration. The Author 2013.

A novel carotenoid cleavage activity involved in the biosynthesis of Citrus fruit-specific apocarotenoid pigments

KAUST Repository

Rodrigo, Marí a J.; Alqué zar, Berta; Aló s, Enriqueta; Medina, Ví ctor; Carmona, Lourdes; Bruno, Mark; Al-Babili, Salim; Zacarí as, Lorenzo

2013-01-01

Citrus is the first tree crop in terms of fruit production. The colour of Citrus fruit is one of the main quality attributes, caused by the accumulation of carotenoids and their derivative C30 apocarotenoids, mainly ?-citraurin (3-hydroxy-?-apo-8?-carotenal), which provide an attractive orange-reddish tint to the peel of oranges and mandarins. Though carotenoid biosynthesis and its regulation have been extensively studied in Citrus fruits, little is known about the formation of C30 apocarotenoids. The aim of this study was to the identify carotenoid cleavage enzyme(s) [CCD(s)] involved in the peel-specific C30 apocarotenoids. In silico data mining revealed a new family of five CCD4-type genes in Citrus. One gene of this family, CCD4b1, was expressed in reproductive and vegetative tissues of different Citrus species in a pattern correlating with the accumulation of C30 apocarotenoids. Moreover, developmental processes and treatments which alter Citrus fruit peel pigmentation led to changes of ?-citraurin content and CCD4b1 transcript levels. These results point to the involvement of CCD4b1 in ?-citraurin formation and indicate that the accumulation of this compound is determined by the availability of the presumed precursors zeaxanthin and ?-cryptoxanthin. Functional analysis of CCD4b1 by in vitro assays unequivocally demonstrated the asymmetric cleavage activity at the 7?,8? double bond in zeaxanthin and ?-cryptoxanthin, confrming its role in C30 apocarotenoid biosynthesis. Thus, a novel plant carotenoid cleavage activity targeting the 7?,8? double bond of cyclic C40 carotenoids has been identified. These results suggest that the presented enzyme is responsible for the biosynthesis of C30 apocarotenoids in Citrus which are key pigments in fruit coloration. The Author 2013.

Comparative toxicity of pesticides in three phytoseiid mites with different life-style occurring in citrus: Euseius stipulatus, Neoseiulus californicus and Phytoseiulus persimilis.

Science.gov (United States)

Argolo, Poliane Sá; Jacas, Josep A; Urbaneja, Alberto

2014-01-01

Conservation and augmentative biological control strategies have been developed to take full advantage of the natural enemies that occur in Spanish citrus orchards. Among them, the predatory mites Euseius stipulatus, Neoseiulus californicus and Phytoseiulus persimilis play an important role in the biological control of tetranychid mites. However, these predatory mites are often affected by pesticides and information about the side-effects of these products against these beneficial arthropods is essential to guarantee their efficacy. The side-effects of some pesticides remain unknown and the primary aim of this study was to fill this gap. We have further used this information and that collected from other sources to compare the response of these three mite species to pesticides. Based on this information, E. stipulatus has the most tolerant species, followed by N. californicus and P. persimilis. Therefore, using E. stipulatus as an indicator species in citrus may have led to the paradox of selecting presumed selective pesticides resulting in excessive impact on N. californicus and, especially on P. persimilis. Because these two latter species are considered key for the biological control of T. urticae in citrus, especially clementines, in Spain, we propose to use P. persimilis as the relevant indicator of such effects on predacious mites occurring in citrus instead of E. stipulatus. This change could have a dramatic impact on the satisfactory control of tetranychid mites in citrus in the near future.

Modeling the incidence of citrus canker in leaves of the sweet orange variety ‘Pera’

Directory of Open Access Journals (Sweden)

Danielle da Silva Pompeu

2017-01-01

Full Text Available Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri, is one of the most important diseases of citrus. The use of resistant genotypes plays an important role in the management and control of the disease and is the most environmentally sustainable approach to disease control. Citrus canker incidence was recorded in an experiment on nine genotypes of the sweet orange variety ‘Pera’ grafted on four rootstocks. The experiment was started in 2010 and the incidence of citrus canker on the leaves was recorded on a quarterly basis. The incidence data from the experiment were analyzed using a zero-inflated Beta regression model (RBIZ, which is the appropriate method to describe data with large numbers of zeros. Based on the residual analysis, the data fit the model well. The discrete component of the explanatory variable, rootstock, was not significant as a factor affecting the onset of disease, in contrast with the continuous component, genotype, which was significant in explaining the incidence of citrus canker.

Response of sweet orange (Citrus sinensis) to 'Candidatus Liberibacter asiaticus' infection: microscopy and microarray analyses.

Science.gov (United States)

Kim, Jeong-Soon; Sagaram, Uma Shankar; Burns, Jacqueline K; Li, Jian-Liang; Wang, Nian

2009-01-01

Citrus greening or huanglongbing (HLB) is a devastating disease of citrus. HLB is associated with the phloem-limited fastidious prokaryotic alpha-proteobacterium 'Candidatus Liberibacter spp.' In this report, we used sweet orange (Citrus sinensis) leaf tissue infected with 'Ca. Liberibacter asiaticus' and compared this with healthy controls. Investigation of the host response was examined with citrus microarray hybridization based on 33,879 expressed sequence tag sequences from several citrus species and hybrids. The microarray analysis indicated that HLB infection significantly affected expression of 624 genes whose encoded proteins were categorized according to function. The categories included genes associated with sugar metabolism, plant defense, phytohormone, and cell wall metabolism, as well as 14 other gene categories. The anatomical analyses indicated that HLB bacterium infection caused phloem disruption, sucrose accumulation, and plugged sieve pores. The up-regulation of three key starch biosynthetic genes including ADP-glucose pyrophosphorylase, starch synthase, granule-bound starch synthase and starch debranching enzyme likely contributed to accumulation of starch in HLB-affected leaves. The HLB-associated phloem blockage resulted from the plugged sieve pores rather than the HLB bacterial aggregates since 'Ca. Liberibacter asiaticus' does not form aggregate in citrus. The up-regulation of pp2 gene is related to callose deposition to plug the sieve pores in HLB-affected plants.

Nota técnica: Producción de leche con ensilaje de hollejo de cítrico Technical note: Milk production with citrus pulp silage

Directory of Open Access Journals (Sweden)

I.L Montejo

2008-06-01

Full Text Available Se elaboraron 90 t de ensilaje de hollejo de cítrico con el objetivo de evaluar su efecto en la producción de leche en vacas de mediano potencial. Los ensilajes se confeccionaron mediante la tecnología de capas sucesivas; el tiempo de conservación fue prefijado a los 60 días. Las mediciones fueron: MS, FB, PB, N-NH3/ Nt (% y pH. Se utilizaron seis vacas F-2 (75% Holstein x 25% Cebú distribuidas en un diseño Switch Back para estudiar las siguientes dietas: A pastoreo a voluntad (16 horas; y B pastoreo restringido (8 horas más ensilaje (90% de hollejo de cítrico más 10% de bagazo de caña a voluntad. Ambos tratamientos recibieron ,5 kg de concentrado comercial en el ordeño. La carga fue de 1,1 vacas/ha y se efectuó un solo ordeño al día, en el horario de la mañana. El consumo de ensilaje (base húmeda fue de 13,9 kg/animal/día (tratamiento B y se encontró diferencia significativa (PNinety tons of citrus pulp silage were elaborated with the objective of evaluating their effect on milk production in medium potential cows. The silages were made by means of the technology of successive layers; the conservation time was prefixed at 60 days. The measurements were: DM, CF, CP, N-NH3/Nt (% and pH. Six F-2 (75% Holstein x 25% Zebu cows were used, distributed in a Switch Back design for studying the following diets: A grazing ad libitum (16 hours; and B restricted grazing (8 hours plus silage (90% citrus pulp plus 10% sugarcane bagasse ad libitum. Both treatments received 0,5 kg of commercial concentrate at milking. The stocking rate was 1,1 cows/ha and only one milking a day was performed in the morning hours. The silage intake (humid base was 13,9 kg/animal/day (treatment B and significant difference was found (P<0,05 for milk production between treatments A (7,3 kg/cow/day and B (6,4 kg/cow/day; however, no variations were observed in the percentages of fat, crude protein, non fatty solids and total solids; a change in the body condition

Deciphering the Bacterial Microbiome in Huanglongbing-Affected Citrus Treated with Thermotherapy and Sulfonamide Antibiotics.

Directory of Open Access Journals (Sweden)

Chuanyu Yang

Full Text Available Huanglongbing (HLB is a serious citrus disease that threatens the citrus industry. In previous studies, sulfonamide antibiotics and heat treatment suppressed 'Candidatus Liberibacter asiaticus' (Las, but did not completely eliminate the Las. Furthermore, there are few reports studying the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics. In this study, combinations of heat (45°C or 40°C and sulfonamide treatment (sulfathiazole sodium-STZ, or sulfadimethoxine sodium-SDX were applied to HLB-affected citrus. The bacterial microbiome of HLB-affected citrus following thermotherapy and/or chemotherapy was characterized by PhyloChipTMG3-based metagenomics. Our results showed that the combination of thermotherapy at 45°C and chemotherapy with STZ and SDX was more effective against HLB than thermotherapy alone, chemotherapy alone, or a combination of thermotherapy at 40°C and chemotherapy. The PhyloChipTMG3-based results indicated that 311 empirical Operational Taxonomic Units (eOTUs were detected in 26 phyla. Cyanobacteria (18.01% were dominant after thermo-chemotherapy. Thermotherapy at 45°C decreased eOTUs (64.43% in leaf samples, compared with thermotherapy at 40°C (73.96% or without thermotherapy (90.68% and it also reduced bacterial family biodiversity. The eOTU in phylum Proteobacteria was reduced significantly and eOTU_28, representing "Candidatus Liberibacter," was not detected following thermotherapy at 45°C. Following antibiotic treatment with SDX and STZ, there was enhanced abundance of specific eOTUs belonging to the families Streptomycetaceae, Desulfobacteraceae, Chitinophagaceae, and Xanthomonadaceae, which may be implicated in increased resistance to plant pathogens. Our study further develops an integrated strategy for combating HLB, and also provides new insight into the bacterial microbiome of HLB-affected citrus treated by heat and sulfonamide antibiotics.

Effect of gamma radiation on the titrable acidity and vitamin c content of citrus fruits

Directory of Open Access Journals (Sweden)

Iftekhar Ahmad

2012-06-01

Full Text Available The study was carried out to assess effect of gamma radiation on the acidity and vitamin C content of the Citrus macroptera (Satkora and Citrus assamensis (Ginger lime. Irradiation with doses 0.5, 1.0, 2.0, 3.0 kGy were applied to assess the effect on the titrable acidity and vitamin C contents every one week interval for total five weeks. Both titrable acidity and vitamin C content of C. macroptera, and C. assamensis are sensitive to both gamma radiation and storage time; have decreased with increase of radiation does as well as storage time and this changes of vitamin C and titrable acidity content with gamma radiation and increasing storage period have found statistically significant.

Functional Characterization of a Flavonoid Glycosyltransferase in Sweet Orange (Citrus sinensis).

Science.gov (United States)

Liu, Xiaogang; Lin, Cailing; Ma, Xiaodi; Tan, Yan; Wang, Jiuzhao; Zeng, Ming

2018-01-01

Fruits of sweet orange ( Citrus sinensis ), a popular commercial Citrus species, contain high concentrations of flavonoids beneficial to human health. These fruits predominantly accumulate O -glycosylated flavonoids, in which the disaccharides [neohesperidose (rhamnosyl-α-1,2-glucose) or rutinose (rhamnosyl-α-1,6-glucose)] are linked to the flavonoid aglycones through the 3- or 7-hydroxyl sites. The biotransformation of the flavonoid aglycones into O -rutinosides or O -neohesperidosides in the Citrus plants usually consists of two glycosylation reactions involving a series of uridine diphosphate-sugar dependent glycosyltransferases (UGTs). Although several genes encoding flavonoid UGTs have been functionally characterized in the Citrus plants, full elucidation of the flavonoid glycosylation process remains elusive. Based on the available genomic and transcriptome data, we isolated a UGT with a high expression level in the sweet orange fruits that possibly encodes a flavonoid glucosyltransferase and/or rhamnosyltransferase. Biochemical analyses revealed that a broad range of flavonoid substrates could be glucosylated at their 3- and/or 7-hydrogen sites by the recombinant enzyme, including hesperetin, naringenin, diosmetin, quercetin, and kaempferol. Furthermore, overexpression of the gene could significantly increase the accumulations of quercetin 7- O -rhamnoside, quercetin 7- O -glucoside, and kaempferol 7- O -glucoside, implying that the enzyme has flavonoid 7- O -glucosyltransferase and 7- O -rhamnosyltransferase activities in vivo .

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.

Evidence for host plant preference by Iphiseiodes quadripilis (Acari: Phytoseiidae) on Citrus.

Science.gov (United States)

Villanueva, Raul T; Childers, Carl C

2006-01-01

In this study, we present field and laboratory evidence on the preference of Iphiseiodes quadripilis (Banks) for grapefruit (Citrus paradisi Macfadyen) leaves compared with sweet orange (Citrus sinensis (L.) Osbeck) leaves. This preference was confirmed in four orchards whether leaf samples were taken from either border trees of contiguous grapefruit or sweet orange or interior row trees with both citrus species in adjacent rows. Iphiseiodes quadripilis was most abundant in grapefruit trees in spite of the greater abundance of the Texas citrus mite, Eutetranychus banksi (McGregor) (Acari: Tetranychidae) in sweet orange trees. Similar preference responses were observed in laboratory tests using a Y-tube olfactometer whether I. quadripilis were collected from sweet orange or grapefruit. Iphiseiodes quadripilis collected from grapefruit trees showed significant preference for grapefruit over sweet orange leaves in contact choice tests using an arena of alternating leaf strips (12 mm long x 2 mm wide) of sweet orange and grapefruit. However, I. quadripilis collected from sweet orange trees did not show preference for either grapefruit or sweet orange leaves. Based on these results, grapefruit leaves foster some unknown factor or factors that retain I. quadripilis in greater numbers compared with sweet orange leaves.

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.

The Types of Essentials Oil Components Isolated From the Leaves of Citrus Aurantifolia and Citrus Nobilis

OpenAIRE

Wulandari, Mutiara Juni; Mohammad Anwar Jamaludin,, Lailatul Riska, Agustin Laela Prunama; Mumun Nurmilawati, Indra Fauzi

2015-01-01

Essential oil or known as the eteris oil (etheric oil) was result from secondary metabolism of a plant. In general essential oil contains of citronellal, Citronelal, Citronelol, Limonen, β-Pinene dan sabinene. The components essential oil derived from citrus plants commonly used by perfume industry, on other hand it is used as essentials oil orange flavour addition in some drinks and food, and also as an antioxidant and anti cancer. One of the essential oil is produced by Citrus aurantifolia ...

Citrus nobiletin suppresses inducible nitric oxide synthase gene expression in interleukin-1β-treated hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Yoshigai, Emi [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Machida, Toru [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okuyama, Tetsuya [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Mori, Masatoshi; Murase, Hiromitsu; Yamanishi, Ryota [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okumura, Tadayoshi [Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga (Japan); Department of Surgery, Kansai Medical University, Hirakata, Osaka (Japan); Ikeya, Yukinobu [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga (Japan); Nishino, Hoyoku [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Department of Biochemistry, Kyoto Prefectural University of Medicine, Kyoto (Japan); Nishizawa, Mikio, E-mail: nishizaw@sk.ritsumei.ac.jp [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan)

2013-09-13

Highlights: •Nobiletin is a polymethoxylated flavone that is abundant in citrus peels. •Nobiletin is a major constituent of the Citrus unshiu peel extract. •Nobiletin suppresses induction of NO and reduces iNOS expression in hepatocytes. •Nobiletin reduces the iNOS promoter activity and the DNA-binding activity of NF-κB. -- Abstract: Background: Nobiletin is a polymethoxylated flavone that is abundant in the peels of citrus fruits, such as Citrus unshiu (Satsuma mandarin) and Citrus sinensis. The dried peels of C. unshiu (chinpi) have been included in several formulae of Japanese Kampo medicines. Nobiletin may suppress the induction of inducible nitric oxide synthase (iNOS), which synthesizes the inflammatory mediator nitric oxide (NO) in hepatocytes. Methods: A C. unshiu peel (CUP) extract was prepared. Primary cultured rat hepatocytes were treated with the CUP extract or nobiletin in the presence of interleukin 1β (IL-1β), which induces iNOS expression. NO production and iNOS gene expression were analyzed. Results: High-performance liquid chromatography analyses revealed that the nobiletin content in the CUP extract was 0.14%. Nobiletin dose-dependently reduced the NO levels and decreased iNOS expression at the protein, mRNA and antisense transcript levels. Flavone, which does not contain any methoxy groups, also suppressed iNOS induction. Nobiletin reduced the transcriptional activity of iNOS promoter-luciferase constructs and the DNA-binding activity of nuclear factor κB (NF-κB) in the nuclei. Conclusions: The suppression of iNOS induction by nobiletin suggests that nobiletin may be responsible for the anti-inflammatory effects of citrus peels and have a therapeutic potential for liver diseases.

Effect of postharvest practices including degreening on citrus carpoplane microbial biomes.

Science.gov (United States)

Gomba, A; Chidamba, L; Korsten, L

2017-04-01

To investigate the effect of commercial citrus packhouse processing steps on the fruit surface microbiome of Clementines and Palmer navel oranges. Viable bacteria, yeast and fungi counts, and the pyrosequencing analysis of the 16S rRNA and ITS were used to evaluate the community structure and population dynamics of phylloepiphytic bacteria and fungi associated with commercial postharvest processing. Drenching significantly reduced microbial counts in all cases except for yeasts on navels, while the extent of degreening effects varied between the citrus varieties. Pyrosequencing analysis showed a total of 4409 bacteria and 5792 fungi nonchimeric unique sequences with an average of 1102 bacteria and 1448 fungi reads per sample. Dominant phyla on the citrus carpoplane were Proteobacteria (53·5%), Actinobacteria (19·9%), Bacteroidetes (5·6%) and Deinococcus-Thermus (5·4%) for bacteria and Ascomycota (80·5%) and Basidiomycota (9·8%) for fungi. Beginning with freshly harvested fruit fungal diversity declined significantly after drenching, but had little effect on bacteria and populations recovered during degreening treatments, including those for Penicillium sp. Packhouse processing greatly influences microbial communities on the citrus carpoplane. A broad orange biome was described with pyrosequencing and gave insight into the likely survival and persistence of pathogens, especially as they may affect the quality and safety of the packed product. A close examination of the microbiota of fruit and the impact of intervention strategies on the ecological balance may provide a more durable approach to reduce losses and spoilage. © 2017 The Society for Applied Microbiology.

Ectopic expression of MdSPDS1 in sweet orange (Citrus sinensis Osbeck reduces canker susceptibility: involvement of H2O2 production and transcriptional alteration

Directory of Open Access Journals (Sweden)

Wang Yin

2011-03-01

Full Text Available Abstract Background Enormous work has shown that polyamines are involved in a variety of physiological processes, but information is scarce on the potential of modifying disease response through genetic transformation of a polyamine biosynthetic gene. Results In the present work, an apple spermidine synthase gene (MdSPDS1 was introduced into sweet orange (Citrus sinensis Osbeck 'Anliucheng' via Agrobacterium-mediated transformation of embryogenic calluses. Two transgenic lines (TG4 and TG9 varied in the transgene expression and cellular endogenous polyamine contents. Pinprick inoculation demonstrated that the transgenic lines were less susceptible to Xanthomonas axonopodis pv. citri (Xac, the causal agent of citrus canker, than the wild type plants (WT. In addition, our data showed that upon Xac attack TG9 had significantly higher free spermine (Spm and polyamine oxidase (PAO activity when compared with the WT, concurrent with an apparent hypersensitive response and the accumulation of more H2O2. Pretreatment of TG9 leaves with guazatine acetate, an inhibitor of PAO, repressed PAO activity and reduced H2O2 accumulation, leading to more conspicuous disease symptoms than the controls when both were challenged with Xac. Moreover, mRNA levels of most of the defense-related genes involved in synthesis of pathogenesis-related protein and jasmonic acid were upregulated in TG9 than in the WT regardless of Xac infection. Conclusion Our results demonstrated that overexpression of the MdSPDS1 gene prominently lowered the sensitivity of the transgenic plants to canker. This may be, at least partially, correlated with the generation of more H2O2 due to increased production of polyamines and enhanced PAO-mediated catabolism, triggering hypersensitive response or activation of defense-related genes.

Citrus fruit quality assessment; producer and consumer perspectives

Science.gov (United States)

Consumption of citrus fruit and juices is popular with consumers worldwide and makes an important contribution to a healthy diet. Nevertheless, consumer preferences for citrus have undergone significant changes over the last twenty years and it is important to understand what consumers are looking ...

Citrus Seed Oils Efficacy against Larvae of Aedes aegypti

Directory of Open Access Journals (Sweden)

Hazrat Bilal

2017-10-01

Full Text Available Background: Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti.Methods: Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae.Result: Among the Citrus cultivar seed oil, rough lemon (Citrus jambhiri had the lowest LC50 value (200.79ppm, while musambi (C. sinensis var musambi had the highest LC50 value (457.30ppm after 24 h of exposure.Conclusion: Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. ae­gypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine opera­tional feasibility.

Influence of feeding supplements of almond hulls and ensiled citrus pulp on the milk production, milk composition, and methane emissions of dairy cows.

Science.gov (United States)

Williams, S R O; Chaves, A V; Deighton, M H; Jacobs, J L; Hannah, M C; Ribaux, B E; Morris, G L; Wales, W J; Moate, P J

2018-03-01

Almond hulls and citrus pulp have been fed to dairy cows with variable responses for milk production, but no information exists on their effect on enteric methane emissions. This experiment examined the effects of dietary supplementation with either almond hulls or ensiled citrus pulp on the milk yield, milk composition, and enteric methane emissions of dairy cows. Thirty-two Holstein dairy cows in mid lactation were offered 1 of 3 diets over a 28-d experiment. Twelve cows received a control (CON) diet, 10 cows a diet containing almond hulls (ALH), and 10 cows a diet containing ensiled citrus pulp (CIT). All cows were offered 6.0 kg of dry matter (DM)/d of crushed corn, 2.0 kg of DM/d of cold-pressed canola, and 0.2 kg of DM/d of a mineral mix. In addition, cows fed the CON diet were offered 14.5 kg of DM/d of alfalfa cubes; cows fed the ALH diet were offered 10.5 kg of DM/d of alfalfa cubes and 4.0 kg of DM/d of almond hulls; and cows on the CIT diet were offered 11.5 kg of DM/d of alfalfa cubes and 3.0 kg of DM/d of ensiled citrus pulp. Milk yield was measured daily and milk composition was measured on 4 d of each week. Individual cow methane emissions were measured by a sulfur hexafluoride tracer technique on d 24 to 28 of the experiment. The mean milk yield of cows fed the CON diet (27.4 kg/d) was greater than the mean milk yield of cows fed the ALH diet (24.6 kg/cow per day), whereas the mean milk yield of cows fed the CIT diet (26.2 kg/cow per day) was not different from the mean milk yield from cows fed the other 2 diets. Dietary treatment did not influence the concentrations of milk fat, protein, and lactose or fat yields, but the mean protein yield from cows fed the CON diet (0.87 kg/d) was greater than that from cows fed the ALH diet (0.78 kg/d) but not different to those fed the CIT diet (0.85 kg/d). In general, we found no differences in the proportion of individual fatty acids in milk. The mean pH of ruminal fluid from cows offered the CON diet was not

The effects of citrus rootstocks on Valencia Late and Rhode Red ...

African Journals Online (AJOL)

For N, K, Mg, Mn and Cu, Carrizo citrange has the highest means while Troyer and sour orange have the highest concentrations for P and. Fe, and Ca, Zn and Na, respectively. We recommend utilizations of Carrizo and Troyer citrange rootstocks for eastern Mediterranean region citrus production as they had higher ability to ...

Development of sparse-seeded mutant kinnow (Citrus reticulata ...

African Journals Online (AJOL)

... crops like citrus, induced mutation for seedlessness in Kinnow with gamma irradiation of dormant bud which was attempted at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. Dormant bud irradiation-cum-grafting technique was employed, using the Citrus jambhiri rootstock for propagation of the scion.

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 ...

A phagostimulant blend for the Asian citrus psyllid

Science.gov (United States)

Chemical cues that condition orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. Previous work in our lab identified a blend of formic and acetic acids as s...

Biogas Production from Citrus Wastes and Chicken Feather: Pretreatment and Codigestion

Energy Technology Data Exchange (ETDEWEB)

Forgacs, Gergely

2012-07-01

Anaerobic digestion is a sustainable and economically feasible waste management technology, which lowers the emission of greenhouse gases (GHGs), decreases the soil and water pollution, and reduces the dependence on fossil fuels. The present thesis investigates the anaerobic digestion of waste from food-processing industries, including citrus wastes (CWs) from juice processing and chicken feather from poultry slaughterhouses. Juice processing industries generate 15-25 million tons of citrus wastes every year. Utilization of CWs is not yet resolved, since drying or incineration processes are costly, due to the high moisture content; and biological processes are hindered by its peel oil content, primarily the D-limonene. Anaerobic digestion of untreated CWs consequently results in process failure because of the inhibiting effect of the produced and accumulated VFAs. The current thesis involves the development of a steam explosion pretreatment step. The methane yield increased by 426 % to 0.537 Nm{sup 3}/kg VS by employing the steam explosion treatment at 150 deg C for 20 min, which opened up the compact structure of the CWs and removed 94 % of the D-limonene. The developed process enables a production of 104 m{sup 3} methane and 8.4 L limonene from one ton of fresh CWs. Poultry slaughterhouses generate a significant amount of feather every year. Feathers are basically composed of keratin, an extremely strong and resistible structural protein. Methane yield from feather is low, around 0.18 Nm{sup 3}/kg VS, which corresponds to only one third of the theoretical yield. In the present study, chemical, enzymatic and biological pretreatment methods were investigated to improve the biogas yield of feather waste. Chemical pretreatment with Ca(OH){sub 2} under relatively mild conditions (0.1 g Ca(OH){sub 2}/g TS{sub feather}, 100 deg C, 30 min) improved the methane yield to 0.40 Nm{sup 3}/kg VS, corresponding to 80 % of the theoretical yield. However, prior to digestion, the

Survey of current crop management practices in a mixed-ricefield landscape, Mekong Delta, Vietnam - potential of habitat manipulation for improved control of citrus leafminer and citrus red mite

NARCIS (Netherlands)

Mele, van P.; Lenteren, van J.C.

2002-01-01

In the Mekong Delta, Vietnam, the citrus leafminer Phyllocnistis citrella (CLM) and the citrus red mite Panonychus citri are major pests in both sweet orange (Citrus sinensis) and Tieu mandarin (C. reticulata). Survey data indicate that these pest problems might be aggravated after farmers have

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 in...

The Role of Rootstock in Antioxidant Activity of Citrus Fruit: Comparison of Antioxidant Activity of The Fruits of Two Commercial Citrus Varieties With The Fruits of Four Different Rootstocks

Directory of Open Access Journals (Sweden)

N . Hemmati

2016-02-01

Full Text Available Introduction: all fruits that called citrus are from rutaceae family and aurantioideae subfamily. This subfamily have more than 33 different genus that only three of its genus (citrus, poncirus and fortunella have economic aspects and in citrus producing country are important. It's reported that orange skin has a phenolic compounds which play a role in natural defense mechanism. Also various compounds of phenolic and antioxidant have a major role in fruit tolerance to stressful condition suh as cold and drought. Metabolites found in citrus fruits have antioxidant properties and it's very useful in pharmaceutical, food and cosmetics industries. Oranges, like other citrus fruits, are an excellent source of vitamin C; Vitamin C is a powerful natural antioxidant. Consumption of foods rich in vitamin C helps the body develop resistance against infectious agents and scavenge harmful, pro-inflammatory free radicals from the blood. Various factors such as rootstock type can effect on quality and quantity of citrus fruits. Also, the usage of rootstock causes the change in plant characteristics such as flowering time, ripening time, fruit quality and antioxidant characters of the fruits. Other factors except the rootstock such as scion, geographical and climate factors are effective on producing secondary metabolites. Also active substances or secondary metabolites are producing by the conduction of genetic processes, but their production are being effected by other factors obviously. The aim of this study is to investigating the biochemical changes grafted tree fruit that affected by rootstock with study the correlation between grafted tree and rootstock changes. Materials and Methods: This study was done to compare the amount of total phenol, total flavonoids and antioxidant features of fruit flesh and skin with investigating the effect of cultivar and rootstock on these parameters based on completely randomized factorial design with three replications

Produção de mudas cítricas em diferentes porta-enxertos e substratos comerciais Citrus nursery production with different rootstocks and commercial substrates

Directory of Open Access Journals (Sweden)

Mário Luís Fochesato

2006-10-01

Full Text Available Analisou-se o desenvolvimento de duas variedades-copa enxertadas sobre diversos porta-enxertos e produzidas em substratos comerciais sob ambiente protegido. O experimento foi desenvolvido em casa de vegetação na Estação Experimental Agronômica da UFRGS, em Eldorado do Sul, RS, no período de fevereiro a novembro/2004. O delineamento experimental foi de blocos casualizados em esquema fatorial 2x3x3, sendo testados: 2 variedades-copa (laranjeira "Valência" - C. sinensis [L.] Osbeck e tangerineira "Montenegrina" - C. sinensis Tenore, 3 porta-enxertos (Trifoliata - C. sinensis [L.] Raf.; citrangeiro "C13" - Citrus sinensis [L.] Osbeck x P. trifoliata [L.] Raf.; e limoeiro "Cravo" - C. limonia Osbeck e 3 substratos comerciais (Comercial 1, 2 e 3, e As mudas foram produzidas em citropotes de quatro litros, com sistema de irrigação por gotejamento. A análise revelou que o substrato Comercial 2 possibilitou maior desenvolvimento vegetativo às variedades-copa. O porta-enxerto citrangeiro "C13" pode ser uma alternativa aos porta-enxertos tradicionais usados no Brasil.The vegetative development of citrus nursery varieties grafted on three rootstocks at greenhouse conditions under different commercial substrates was evaluated. The experiment, randomized blocks, in a 2x3x3 factorial, was conducted at the research station of the Uiversidade Federal do Rio Grande do Sul, Eldorado do Sul, RS, Brazil, from February to November 2004. The treatments were two citrus varieties ('Valencia' Orange - Citrus sinensis [L.] Osb. and 'Montenegrina' mandarin - Citrus deliciosa Ten., citrus rootstoocks (Trifoliate orange - C. sinensis (L. Raf., citrange 'C13' - P. trifoliata x Citrus sinensis (L. Osb. and 'Rangpur' lemon - C. limonia Osb. and substrates (Commercial 1, 2, and 3. Plants were grown in containers (4 L with drip irrigation system. The Commercial 2 substrate showed the best performance in inducing plant growth. The citrange 'C13' may be an alternative to

Health risk assessment of citrus contaminated with heavy metals in Hamedan city, potential risk of Al and Cu

Directory of Open Access Journals (Sweden)

Oshin Rezaei Raja

2016-08-01

Full Text Available Background: Fruits especially citrus species are an integral part of human diet. Contamination of foodstuffs by heavy and toxic metals via environmental pollution has become an inevitable challenge these days. Therefore, the effect of pollutants on food safety for human consumption is a global public concern. In this regards, this study was conducted for Al and Cu health risk assessment through the consumption of citrus species (orange, grapefruit, sweet lime and tangerine in Hamedan city in 2015. Methods: After collecting and preparing 4 samples from each citrus species with acid digestion method, the concentrations of Al and Cu were determined using inductively coupled plasma optical emission spectrometry (ICP–OES with three replications. In addition, SPSS was employed to compare the mean concentrations of metals with maximum permissible limits (MPL of the World Health Organization (WHO. Results: The results showed that the mean concentrations of Al in citrus samples were 3.25±0.35 mg/kg and higher than WHO maximum permissible limits. The mean concentrations of Cu in citrus samples with 0.16±0.05 mg/kg are lower than WHO maximum permissible limits. Also, the computed health risk assessment revealed that there was no potential risk for children and adult by consuming the studied citrus. Conclusion: Based on the results, consumption of citrus species has no adverse effect on the consumers’ health, but as a result of the increased utilization of agricultural inputs (metal based fertilizers and pesticides, sewage sludge and wastewater by farmers and orchardists, regular periodic monitoring of chemical pollutants content in foodstuffs are recommended for food safety.

Factors influencing Agrobacterium-mediated embryogenic callus transformation of Valencia sweet orange (Citrus sinensis) containing the pTA29-barnase gene.

Science.gov (United States)

Li, D D; Shi, W; Deng, X X

2003-12-01

Valencia sweet orange (Citrus sinensis (L.) Osbeck) calluses were used as explants to develop a new transformation system for citrus mediated by Agrobacterium tumefaciens. Factors affecting Agrobacterium-mediated transformation efficiency included mode of pre-cultivation, temperature of cocultivation and presence of acetosyringone (AS). The highest transformation efficiency was obtained with a 4-day pre-cultivation period in liquid medium. Transformation efficiency was higher when cocultivation was performed for 3 days at 19 degrees C than at 23 or 28 degrees C. Almost no resistant callus was obtained if the cocultivation medium lacked AS. The transformation procedure yielded transgenic Valencia plants containing the pTA29-barnase gene, as verified by PCR amplification and confirmed by Southern blotting. Because male sterility is a common factor leading to seedlessness in citrus cultivars with parthenocarpic characteristics, production of seedless citrus genotypes by Agrobacterium-mediated genetic transformation is a promising alternative to conventional breeding methods.

Risk assessment of various insecticides used for management of Asian citrus psyllid, Diaphorina citri in Florida citrus, against honey bee, Apis mellifera.

Science.gov (United States)

Chen, Xue Dong; Gill, Torrence A; Pelz-Stelinski, Kirsten S; Stelinski, Lukasz L

2017-04-01

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest of citrus trees worldwide. A wide variety of insecticides are used to manage D. citri populations within citrus groves in Florida. However, in areas shared by citrus growers and beekeepers the use of insecticides may increase the risks of Apis mellifera  L. (Hymenoptera: Apidae) loss and contaminated honey. The objective of this research was to determine the environmental toxicity of insecticides, spanning five different modes of action used to control D. citri, to A. mellifera. The insecticides investigated were imidacloprid, fenpropathrin, dimethoate, spinetoram and diflubenzuron. In laboratory experiments, LD 50 values were determined and ranged from 0.10 to 0.53 ng/μl for imidacloprid, fenpropathrin, dimethoate and spinetoram. LD 50 values for diflubenzuron were >1000 ng/μl. Also, a hazard quotient was determined and ranged from 1130.43 to 10893.27 for imidacloprid, fenpropathrin, dimethoate, and spinetoram. This quotient was mellifera 3 and 7 days after application. Spinetoram and imidacloprid were moderately toxic to A. mellifera at the recommended rates for D. citri. Diflubenzuron was not toxic to A. mellifera in the field as compared with untreated control plots. Phenoloxidase (PO) activity of A. mellifera was higher than in untreated controls when A. mellifera were exposed to 14 days old residues. The results indicate that diflubenzuron may be safe to apply in citrus when A. mellifera are foraging, while most insecticides used for management of D. citri in citrus are likely hazardous under various exposure scenarios.

Towards the identification of flower-specific genes in Citrus spp

Directory of Open Access Journals (Sweden)

Marcelo Carnier Dornelas

2007-01-01

Full Text Available Citrus sinensis is a perennial woody species, for which genetic approaches to the study of reproductive development are not readily amenable. Here, the usefulness of the CitEST Expressed Sequence Tag (EST database is demonstrated as a reliable new resource for identifying novel genes exclusively related to Citrus reproductive biology. We performed the analysis of an EST dataset of the CitEST Project containing 4,330 flower-derived cDNA sequences. Relying on bioinformatics tools, sequences exclusively present in this flower-derived sequence collection were selected and used for the identification of Citrus putative flower-specific genes. Our analysis revealed several Citrus sequences showing significant similarity to conserved genes known to have flower-specific expression and possessing functions related to flower metabolism and/or reproductive development in diverse plant species. Comparison of the Citrus flower-specific sequences with all available plant peptide sequences unraveled 247 unique transcripts not identified elsewhere within the plant kingdom. Additionally, 49 transcripts, for which no biological function could be attributed by means of sequence comparisons, were found to be conserved among plant species. These results allow further gene expression analysis and possibly novel approaches to the understanding of reproductive development in Citrus.

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/p3...

Factors affecting transmission rates of 'Candidatus Liberibacter asiaticus' by Asian citrus psyllid

Science.gov (United States)

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it transmits a bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) responsible for a serious disease of citrus known as Asiatic huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program...

Phenotypic and Genotypic Evaluation of Pseudomonas syringae pv. syringae Strains, Causing Citrus Blast in the West of Mazandaran and the East of Guilan

Directory of Open Access Journals (Sweden)

S. Sameie-Shirkadeh

2017-01-01

Full Text Available Introduction: P. syringae pv. syringae (P.s.s, the causal agent of blast of citrus trees, is one of the most important plant pathogens in the world. P.s.s is unique among most P. syringae pathovars according to its ability to cause disease in over 180 species of plants in several unrelated genera. Traditionally, Strains of P.s.s are identified on the basis of biochemical and nutritional tests and symptom expression in host plants. Genomic fingerprinting methods based on the polymerase chain reaction (PCR have been applied for identification and classification of plant-associated bacteria to the subspecies level. The objectives of this study were the phenotypic and molecular evaluation of P.s. pv. syringae strains causing citrus blast in the West of Mazandaran and the East of Guilan, and study of genetic diversity of P.s.s isolates of citrus by using ERIC and REP-PCR markers. Materials and Methods: During 2011 to 2012, citrus infected tissues were sampled from different orchards in the West of Mazandaran and the East of Guilan. Bacterial phenotypes were studied based on standard physiological and biochemical tests. Gram reaction was determined by potassium hydroxide solubility test (KOH test. Strains were grown on King'B medium (KB and fluorescent pigment production was evaluated. Levan formation, oxidase reaction, potato soft rot, Arginine dihydrolase and induction of the hypersensitive reaction in tobacco leaves (LOPAT tests, were done as described by Schadd et al. The standard strains of P.s. pv. syringae form IVIA were used as reference strains in this study. Pathogenicity Test was done as described by Yessad et al. Citrus seedlings were maintained in a greenhouse at 20°C. In addition, a PCR-based method was used to confirm the genus and species of bacteria by using bacterial specific primer pair’s designed for a specific gene of syringomycin B. Genetic diversity among the strains, was studied by rep-PCR fingerprinting. Genomic

Citrus stand ages regulate the fraction alteration of soil organic carbon under a citrus/Stropharua rugodo-annulata intercropping system in the Three Gorges Reservoir area, China.

Science.gov (United States)

Zhang, Yang; Ni, Jiupai; Yang, John; Zhang, Tong; Xie, Deti

2017-08-01

Soil carbon fractionation is a valuable indicator in assessing stabilization of soil organic matter and soil quality. However, limited studies have addressed how different vegetation stand ages under intercropping agroforestry systems, could affect organic carbon (OC) accumulation in bulk soil and its physical fractions. A field study thus investigated the impact of citrus plantation age (15-, 25-, and 45-year citrus) on the bulk soil organic carbon (SOC) and SOC fractions and yields of Stropharia rugoso-annulata (SRA) in the Three Gorges Reservoir area, Chongqing, China. Results indicated that the intercropping practice of SRA with citrus significantly increased the SOC by 57.4-61.6% in topsoil (0-10 cm) and by 24.8-39.9% in subsoil (10-30 cm). With a significantly higher enhancement under the 25-year citrus stand than the other two stands, all these citrus stands of three ages also resulted in a significant increase of free particulate OC (fPOC, 60.1-62.4% in topsoil and 34.8-46.7% in subsoil), intra-micro aggregate particulate OC (iPOC, 167.6-206.0% in topsoil and 2.77-61.09% in subsoil), and mineral-associated OC (MOC, 43.6-46.5% in topsoil and 26.0-51.5% in subsoil). However, there were no significant differences in yields of SRA under three citrus stands. Our results demonstrated that citrus stand ages did play an important role in soil carbon sequestration and fractionation under a citrus/SRA intercropping system, which could therefore provide a sustainable agroforestry system to enhance concurrently the SOC accumulation while mitigating farmland CO 2 emission.

(Liberibacter spp.) associated with citrus greening disease in Uganda

African Journals Online (AJOL)

ACSS

Citrus is one of the largest fruit crops grown in Uganda ... of several citrus industries in Asia and. Africa (da Graca ... role in transmission of HLB, psyllid feeding ... The Indian Ocean islands of Reunion and ..... Pacific Grove, California: Duxbury ...

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

International Nuclear Information System (INIS)

Islam, N. U.; Shahid, M.; Ahsan, F.; Khan, I.; Shah, M. R.; Khan, M. A.

2015-01-01

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)

Overexpression of a citrus NDR1 ortholog increases disease resistance in Arabidopsis

Science.gov (United States)

Emerging devastating diseases, such as Huanglongbing (HLB) and citrus canker, have caused tremendous losses to the citrus industry worldwide. Genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. The key to the success of this approach r...

Descriptions of new varieties recently distributed from the Citrus Clonal Protection Program

Science.gov (United States)

The Citrus Clonal Protection Program (CCPP) is operated through the Department of Plant Pathology and Microbiology at University of California (UC) Riverside and is funded in large part by The California Citrus Research Board (CRB). The CCPP processes citrus propagative material in two phases. First...

Small RNA profiling reveals phosphorus deficiency as a contributing factor in symptom expression for citrus huanglongbing disease.

Science.gov (United States)

Zhao, Hongwei; Sun, Ruobai; Albrecht, Ute; Padmanabhan, Chellappan; Wang, Airong; Coffey, Michael D; Girke, Thomas; Wang, Zonghua; Close, Timothy J; Roose, Mikeal; Yokomi, Raymond K; Folimonova, Svetlana; Vidalakis, Georgios; Rouse, Robert; Bowman, Kim D; Jin, Hailing

2013-03-01

Huanglongbing (HLB) is a devastating citrus disease that is associated with bacteria of the genus 'Candidatus Liberibacter' (Ca. L.). Powerful diagnostic tools and management strategies are desired to control HLB. Host small RNAs (sRNA) play a vital role in regulating host responses to pathogen infection and are used as early diagnostic markers for many human diseases, including cancers. To determine whether citrus sRNAs regulate host responses to HLB, sRNAs were profiled from Citrus sinensis 10 and 14 weeks post grafting with Ca. L. asiaticus (Las)-positive or healthy tissue. Ten new microRNAs (miRNAs), 76 conserved miRNAs, and many small interfering RNAs (siRNAs) were discovered. Several miRNAs and siRNAs were highly induced by Las infection, and can be potentially developed into early diagnosis markers of HLB. miR399, which is induced by phosphorus starvation in other plant species, was induced specifically by infection of Las but not Spiroplasma citri that causes citrus stubborn-a disease with symptoms similar to HLB. We found a 35% reduction of phosphorus in Las-positive citrus trees compared to healthy trees. Applying phosphorus oxyanion solutions to HLB-positive sweet orange trees reduced HLB symptom severity and significantly improved fruit production during a 3-year field trial in south-west Florida. Our molecular, physiological, and field data suggest that phosphorus deficiency is linked to HLB disease symptomology.

Incidence and epidemiology of Citrus tristeza virus in the Valencian community of Spain.

Science.gov (United States)

Cambra, M; Gorris, M T; Marroquín, C; Román, M P; Olmos, A; Martínez, M C; de Mendoza, A H; López, A; Navarro, L

2000-11-01

The first outbreak of citrus tristeza disease in Spain caused by Citrus tristeza virus (CTV) was recorded in 1957 in the Valencian Community (VC). In total c. 40 million trees, mainly of sweet orange and mandarin grafted on sour orange rootstocks, declined due to CTV. Large-scale surveys in different municipalities of the VC indicated that the disease spread very fast. Incidence increased from 11% in 1989 to 53% in 1998. Toxoptera aurantii and Aphis spiraecola (inefficient aphid vectors of CTV) predominated before 1985-87. Since then the relatively efficient vector Aphis gossypii has become dominant and induced an epidemic that has been modelled. The large number of A.gossypii that visited each clementine tree (estimated to exceed 97000 per year) explained the difference between the temporal pattern of spread of CTV in clementine which followed the Gompertz model and that in sweet orange (logistic model). The susceptibility of the different citrus species to CTV infection by aphids seems to depend on the number of young, succulent shoots produced. The epidemiological data allowed specific recommendations to be made to growers in order to facilitate a change to a modern citrus industry based on the use of selected varieties grafted on tristeza-tolerant rootstocks produced within a certification scheme. This has been done already in almost 90% of the VC citrus-growing area. The tristeza problem has been solved unless more aggressive isolates are introduced and become prevalent.

Identification of zygotic and nucellar seedlings in citrus interspecific ...

African Journals Online (AJOL)

ajl yemi

2011-12-19

Dec 19, 2011 ... Department of Plant Breeding and Improvement, Iran Citrus Research Institute, Mottahari Street, Ramsar, .... (C. aurantium) rootstock plants for further agronomic evaluation .... literatures may be attributed to pollination efficiency and ... zygotic seedlings in Swingle citromelo Citrus paradisi × Poncirus tifoliata.

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

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...

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.

Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

Science.gov (United States)

Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

2011-02-01

The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

Heat treatment eliminates 'Candidatus Liberibacter asiaticus' from infected citrus trees under controlled conditions.

Science.gov (United States)

Hoffman, Michele T; Doud, Melissa S; Williams, Lisa; Zhang, Mu-Qing; Ding, Fang; Stover, Ed; Hall, David; Zhang, Shouan; Jones, Lisa; Gooch, Mark; Fleites, Laura; Dixon, Wayne; Gabriel, Dean; Duan, Yong-Ping

2013-01-01

Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide. The three known causal agents of HLB are species of α-proteobacteria: 'Candidatus Liberibacter asiaticus', 'Ca. L. africanus', and 'Ca. L. americanus'. Previous studies have found distinct variations in temperature sensitivity and tolerance among these species. Here, we describe the use of controlled heat treatments to cure HLB caused by 'Ca. L. asiaticus', the most prevalent and heat-tolerant species. Using temperature-controlled growth chambers, we evaluated the time duration and temperature required to suppress or eliminate the 'Ca. L. asiaticus' bacterium in citrus, using various temperature treatments for time periods ranging from 2 days to 4 months. Results of quantitative polymerase chain reaction (qPCR) after treatment illustrate significant decreases in the 'Ca. L. asiaticus' bacterial titer, combined with healthy vigorous growth by all surviving trees. Repeated qPCR testing confirmed that previously infected, heat-treated plants showed no detectable levels of 'Ca. L. asiaticus', while untreated control plants remained highly infected. Continuous thermal exposure to 40 to 42°C for a minimum of 48 h was sufficient to significantly reduce titer or eliminate 'Ca. L. asiaticus' bacteria entirely in HLB-affected citrus seedlings. This method may be useful for the control of 'Ca. Liberibacter'-infected plants in nursery and greenhouse settings.

Inhibitory effect of Epstein-Barr virus activation by Citrus fruits, a cancer chemopreventor.

Science.gov (United States)

Iwase, Y; Takemura, Y; Ju-ichi, M; Kawaii, S; Yano, M; Okuda, Y; Mukainaka, T; Tsuruta, A; Okuda, M; Takayasu, J; Tokuda, H; Nishino, H

1999-05-24

To search useful compounds in Citrus fruit for cancer chemoprevention, we carried out a primary screening of extracts of fruit peels and seeds from 78 species of the genus Citrus and those from two Fortunella and one Poncirus species, which were closely related to the genus Citrus. These Citrus extracts inhibited the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) as a useful screening method for anti-tumor promoters. Our results indicated that Citrus containing substances may be inhibit susceptibility factors involved in the events leading to the development of cancer.

Polyclonal antibodies against the recombinantly expressed coat protein of the Citrus psorosis virus

Directory of Open Access Journals (Sweden)

Reda Salem

2018-05-01

Full Text Available Psorosis is a damaging disease of citrus that is widespread in many parts of the world. Citrus psorosis virus (CPsV, the type species of the genus Ophiovirus, is the putative causal agent of psorosis. Detection of CPsV by laboratory methods, serology in particular is a primary requirement for large-scale surveys but their production has been impaired by the difficulty of obtaining sufficient clean antigen for immunization. Specific PAbs against coat protein were produced in E. coli using recombinant DNA approach. The full length CP gene fragment was amplified by RT-PCR using total RNA extracted from CPsV infected citrus leaves and CP specific primers. The obtained product (1320bp was cloned, sequenced and sub-cloned into pET-30(+ expression vector. Expression was induced and screened in different bacterial clones by the presence of the expressed protein (48kDa and optimized in one clone. Expressed CP was purified using batch chromatography under denaturing conditions. Specificity of expressed protein was demonstrated by ELISA before used as antigen for raising PAbs in mice. Specificity of the raised PAbs to CPsV was verified by ELISA and western blotting. The raised PAbs were showed highly effectiveness in screening by ELISA comparing with the commercial antibodies purchased from Agritest, Valanzano, Italy.The expression of CPsV CP gene in E. coli, production of PAbs using recombinant protein as an antigen, the suitability of these antibodies for use in immunodiagnostics against the CPsV Egyptian isolate have been accomplished in this work. Keywords: CPsV, CP, PAbs, RT-PCR, ELISA, Western blotting

The Effects of Ensiled Berseem Clover and Citrus Pulp Mixture on Performance of Zel Fattened Lambs

Directory of Open Access Journals (Sweden)

maedeh feyz

2016-08-01

Full Text Available Introduction Feed contributes about 75% of the total cost of animal production, therefore utilizing of by-products such as Berseem clover and citrus pulp, as nutritive and low cost components of rations would decrease the production cost. In north of Iran over autumn and winter, utilizing of these by-products in making of silage as feed for ruminants provides good feed ingredient especially in feedlot operations, also eliminates pathogens, and reduces the effect of drugs and pesticides that are used locally without a serious control or discipline. However, little information available on utilizing silage made from these local by-products. The objectives of this research were to investigate the effects of ensiled Berseem clover and orange peels mixture on intake, digestibility, chewing behavior and performance of Zel fattening lambs. Materials and methods Twenty male Zel lambs fed with five experimental rations containing basal concentrate and 35% Berseem clover silage as: 1 without additives, 2 supplemented with 40% dried orange peels, 3 supplemented with 40% dried tangerine peel, 4 supplemented with 35% dried tangerine peel and 5% ground barley and 5 supplemented with 35% dried orange peels and 5% ground barley. Lambs were housed in individual box and fed ad libitum, twice daily at 09:00 and 21:00 h with total mixed rations as experimental treatments, allowing for at least 10% residuals (as-fed basis. Water and mineralized salt stone were available throughout the experiment. Feed particle size distribution, geometric mean and the standard deviation of geometric mean were determined by dry sieving in four replicates, using two set of Penn State particle separator. Feed, feces and orts were analyzed for dry matter, Kjeldahl N, ether extract, organic matter and ash at 605°C, neutral and acid detergent fiber (NDF and ADF when α-amylase being added for concentrates during NDF extraction; sodium sulfite was not added. Neutral detergent fiber was

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...

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.

Early events of citrus greening (Huanglongbing) disease development at the ultrastructural level.

Science.gov (United States)

Folimonova, Svetlana Y; Achor, Diann S

2010-09-01

Citrus greening (Huanglongbing [HLB]) is one of the most destructive diseases of citrus worldwide. The causal agent of HLB in Florida is thought to be 'Candidatus Liberibacter asiaticus'. Understanding of the early events in HLB infection is critical for the development of effective measures to control the disease. In this work, we conducted cytopathological studies by following the development of the disease in citrus trees graft inoculated with 'Ca. L. asiaticus'-containing material under greenhouse conditions to examine the correlation between ultrastructural changes and symptom production, with the main objective of characterizing the early events of infection. Based on our observations, one of the first degenerative changes induced upon invasion of the pathogen appears to be swelling of middle lamella between cell walls surrounding sieve elements. This anatomical aberration was often observed in samples from newly growing flushes in inoculated sweet orange and grapefruit trees at the early "presymptomatic" stage of HLB infection. Development of symptoms and their progression correlated with an increasing degree of microscopic aberrations. Remarkably, the ability to observe the bacterium in the infected tissue also correlated with the degree of the disease progression. Large numbers of bacterial cells were found in phloem sieve tubes in tissue samples from presymptomatic young flushes. In contrast, we did not observe the bacteria in highly symptomatic leaf samples, suggesting a possibility that, at more advanced stages of the disease, a major proportion of 'Ca. L. asiaticus' is present in a nonviable state. We trust that observations reported here advance our understanding of how 'Ca. L. asiaticus' causes disease. Furthermore, they may be an important aid in answering a question: when and where within an infected tree the tissue serves as a better inoculum source for acquisition and transmission of the bacterium by its psyllid vector.

Reaction of detached leaves of different varieties of sweet orange (Citrus sinensis L. Osbeck) to inoculation with Xanthomonas citri subsp. citri (ex Hasse) Gabriel et al.

Science.gov (United States)

Asiatic citrus canker (ACC) (caused by Xanthomonas citri subsp citri, Xcc) is a major disease of citrus in wet tropical and subtropical production regions. Screening for resistance is important to breeding programs. The objective of this study was to evaluate a detached leaf method to compare nine d...

Alternative oxidase (AOX) constitutes a small family of proteins in Citrus clementina and Citrus sinensis L. Osb.

Science.gov (United States)

Araújo Castro, Jacqueline; Gomes Ferreira, Monique Drielle; Santana Silva, Raner José; Andrade, Bruno Silva; Micheli, Fabienne

2017-01-01

The alternative oxidase (AOX) protein is present in plants, fungi, protozoa and some invertebrates. It is involved in the mitochondrial respiratory chain, providing an alternative route for the transport of electrons, leading to the reduction of oxygen to form water. The present study aimed to characterize the family of AOX genes in mandarin (Citrus clementina) and sweet orange (Citrus sinensis) at nucleotide and protein levels, including promoter analysis, phylogenetic analysis and C. sinensis gene expression. This study also aimed to do the homology modeling of one AOX isoform (CcAOXd). Moreover, the molecular docking of the CcAOXd protein with the ubiquinone (UQ) was performed. Four AOX genes were identified in each citrus species. These genes have an open reading frame (ORF) ranging from 852 bp to 1150 bp and a number of exons ranging from 4 to 9. The 1500 bp-upstream region of each AOX gene contained regulatory cis-elements related to internal and external response factors. CsAOX genes showed a differential expression in citrus tissues. All AOX proteins were predicted to be located in mitochondria. They contained the conserved motifs LET, NERMHL, LEEEA and RADE-H as well as several putative post-translational modification sites. The CcAOXd protein was modeled by homology to the AOX of Trypanosona brucei (45% of identity). The 3-D structure of CcAOXd showed the presence of two hydrophobic helices that could be involved in the anchoring of the protein in the inner mitochondrial membrane. The active site of the protein is located in a hydrophobic environment deep inside the AOX structure and contains a diiron center. The molecular docking of CcAOXd with UQ showed that the binding site is a recessed pocket formed by the helices and submerged in the membrane. These data are important for future functional studies of citrus AOX genes and/or proteins, as well as for biotechnological approaches leading to AOX inhibition using UQ homologs.

β-Cryptoxanthin and Zeaxanthin Pigments Accumulation to Induce Orange Color on Citrus Fruits

Science.gov (United States)

Hidayati Sumiasih, Inanpi; Poerwanto, Roedhy; Efendi, Darda; Agusta, Andria; Yuliani, Sri

2018-01-01

Degreening, a transformation process of green color on citrus peel to be orange color on tropical low-land citrus fruits often fails. Orange color of the citrus peel comes from the mixture carotenoid pigments, such as zeaxanthine and mainly β-cryptoxanthin and β-citraurin. The accumulation of β-citraurin occurs when the fruits are exposed to low temperature, and otherwise, it will fail to occur. Precooling treatment on lowland tropical citrus fruits is expected to stimulate the accumulation of β-citraurin. The results showed the most favorable color obtained from precooling and 24-hour ethylene exposure duration. This treatment could decrease total chlorophyll and β-carotene content as well as proven to increase 3 times the accumulation of β-cryptoxanthin in accelerating the appearance of bright orange color on citrus peel. Degreening gave no significant effect to internal quality of Citrus reticulata.

Absence of furanocoumarins in Advantra Z® (Citrus aurantium, bitter orange) extracts.

Science.gov (United States)

Stohs, Sidney J; Miller, Howard; Romano, Felice

2014-09-01

Grapefruit (Citrus paradisi) juice is known for its ability to alter drug metabolism through inhibition of the cytochrome P450-3A4 (CYP3A4) system, and result in drug-food interactions that may be life threatening. The primary active ingredients in grapefruit responsible for these effects are the furanocoumarins bergapten, bergamottin, and 6',7'-dihydroxybergamottin (DHB). Bergamottin and DHB appear to be the most important in terms of adverse drug interactions. Furanocoumarins are present in the juices and fruits of other Citrus species including C. aurantium (bitter oranges). Bergapten is the predominant furanocoumarin in bitter orange. Bitter orange extracts are widely used in products associated with weight loss, sports performance, and energy production. Questions have been raised about the potential of bitter orange extracts to cause drug interactions. This study examined the furanocoumarin content of four standardized bitter orange extracts (Advantra Z®) by liquid chromatography-mass spectroscopy. The results indicated that the total furanocoumarin content of each of the four extracts was less than 20 μg/g, amounts insufficient to exert significant effects on the metabolism of susceptible drugs in human subjects at the doses commonly used for these extracts.

First record of Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) in citrus in Brazil.

Science.gov (United States)

Lemos, W P; da Silva, R A; Araújo, S C A; Oliveira, E L A; da Silva, W R

2011-01-01

Anastrepha serpentina (Wiedemann) is recorded for the first time in citrus (Rutaceae) in Brazil. Specimens were obtained from sweet orange (Citrus sinensis) sampled in the municipalities of Belém and Capitão Poço, and from mandarin orange (Citrus reticulata) from Tomé-Açu, state of Pará, Brazil.

First record of Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) in citrus in Brazil

OpenAIRE

Lemos, WP; Silva, RA da; Araújo, SCA; Oliveira, ELA; Silva, WR da

2011-01-01

Anastrepha serpentina (Wiedemann) is recorded for the first time in citrus (Rutaceae) in Brazil. Specimens were obtained from sweet orange (Citrus sinensis) sampled in the municipalities of Belém and Capitão Poço, and from mandarin orange (Citrus reticulata) from Tomé-Açu, state of Pará, Brazil.

Exploiting BAC-end sequences for the mining, characterization and utility of new short sequences repeat (SSR) markers in Citrus.

Science.gov (United States)

Biswas, Manosh Kumar; Chai, Lijun; Mayer, Christoph; Xu, Qiang; Guo, Wenwu; Deng, Xiuxin

2012-05-01

The aim of this study was to develop a large set of microsatellite markers based on publicly available BAC-end sequences (BESs), and to evaluate their transferability, discriminating capacity of genotypes and mapping ability in Citrus. A set of 1,281 simple sequence repeat (SSR) markers were developed from the 46,339 Citrus clementina BAC-end sequences (BES), of them 20.67% contained SSR longer than 20 bp, corresponding to roughly one perfect SSR per 2.04 kb. The most abundant motifs were di-nucleotide (16.82%) repeats. Among all repeat motifs (TA/AT)n is the most abundant (8.38%), followed by (AG/CT)n (4.51%). Most of the BES-SSR are located in the non-coding region, but 1.3% of BES-SSRs were found to be associated with transposable element (TE). A total of 400 novel SSR primer pairs were synthesized and their transferability and polymorphism tested on a set of 16 Citrus and Citrus relative's species. Among these 333 (83.25%) were successfully amplified and 260 (65.00%) showed cross-species transferability with Poncirus trifoliata and Fortunella sp. These cross-species transferable markers could be useful for cultivar identification, for genomic study of Citrus, Poncirus and Fortunella sp. Utility of the developed SSR marker was demonstrated by identifying a set of 118 markers each for construction of linkage map of Citrus reticulata and Poncirus trifoliata. Genetic diversity and phylogenetic relationship among 40 Citrus and its related species were conducted with the aid of 25 randomly selected SSR primer pairs and results revealed that citrus genomic SSRs are superior to genic SSR for genetic diversity and germplasm characterization of Citrus spp.

Exogenous application of the plant signalers methyl jasmonate & salicylic acid induces changes in volatile emissions from citrus foliage & influences the aggregation behavior of ACP (Diaphorina citri), vector of Huanglongbing

Science.gov (United States)

Huanglongbing or citrus greening is a destructive disease that threatens citrus production worldwide; it is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently the disease is untreatable and control efforts focus on intensive insecticide use to contro...

Murcott seedless: influence of gamma irradiation on citrus production and fruit quality

Energy Technology Data Exchange (ETDEWEB)

Bermejo, A.; Pardo, J.; Cano, A.

2012-11-01

A Seedlessness is an important economic trait relating to fruit quality, and gamma irradiation is a common technique used to obtain seedless citrus fruits. Herein, we report a study of new seedless Murcott mandarin clones obtained by bud irradiation from the self-compatible not parthenocarpic Murcott mandarin. All irradiated clones examined presented lower seed numbers (from 0.23 to 2.47 seeds per fruit) and reduced pollen germination (from 1.40% to 8.55%) whereas the wild-type Murcott showed an average number of 9.03 seeds per fruit and a pollen germination value of 47.15%. Fruit quality and nutritional bio-components were affected differently; some clones presented no changes compared to the control Murcott mandarin, while other clones showed significant differences. High-performance liquid chromatographic methods were used to identify and quantify of these compounds, using photodiode array, mass and refractive index detectors. Our results indicated high contents in natural antioxidants as vitamin C (from 20.13 to 25.73 mg/100 mL) and phenolic compounds, as flavonoids, in these citrus varieties cultived under the Mediterranean climate. Some of these clones, which ripen late in the season and whose fruit quality is maintained or improved, are in the process of registration. In conclusion, budwood irradiation is a suitable technique to improve cultivars, produce seedless cultivars, adjust ripening time or raise the content of health-promoting compounds. Also this study investigates the influence of temperature during flowering on the number of seeds formed. Findings indicate that low temperatures during flower formation decreased pollen germination and seed number. (Author) 35 refs.

Innate immune system capabilities of the Asian citrus psyllid, Diaphorina citri.

Science.gov (United States)

Arp, Alex P; Martini, Xavier; Pelz-Stelinski, Kirsten S

2017-09-01

Citrus production worldwide is currently threatened by Huanglongbing, or citrus greening disease. The associated pathogen, Candidatus Liberibacter asiaticus (CLas), is transmitted by the Asian citrus psyllid, Diaphorina citri. Annotation of the D. citri genome revealed a reduced innate immune system lacking a number of antimicrobial peptides and the Imd pathway associated with defense against Gram-negative bacteria. We characterized this apparent immune reduction in survival assays in which D. citri were exposed to Gram-negative or Gram-positive bacteria. D. citri experienced significant mortality when exposed to Serratia marcescens (Gram-negative) through oral ingestion or by septic injury. Escherichia coli (Gram-negative) also caused significant D. citri mortality, but only when inoculated at high concentrations through oral ingestion or by septic injury. Neither Micrococcus luteus (Gram-positive) or Bacillus subtilis (Gram-positive) caused significant mortality as compared to controls in any experiment. E. coli titers increased rapidly following exposure, while M. luteus titer remained stable for 72 h. We demonstrate that D. citri is capable of defending against E. coli, a Gram-negative bacterium, despite lacking the Imd defense pathway. The tolerance of D. citri to M. luteus infection, yet inability to effectively clear infections, presents questions to efficacy of D. citri immune response to effectively clear Gram-positive infections. Copyright © 2017. Published by Elsevier Inc.

Population structure and diversity of citrus tristeza virus (CTV) isolates in Hunan province, China.

Science.gov (United States)

Xiao, Cui; Yao, Run-Xian; Li, Fang; Dai, Su-Ming; Licciardello, Grazia; Catara, Antonino; Gentile, Alessandra; Deng, Zi-Niu

2017-02-01

Stem-pitting (SP) is the main type of citrus tristeza virus (CTV) that causes severe damage to citrus trees, especially those of sweet orange, in Hunan province, China. Understanding the local CTV population structure should provide clues for effective mild strain cross-protection (MSCP) of the SP strain of CTV. In this study, markers for the p23 gene, multiple molecular markers (MMMs), and sequence analysis of the three silencing suppressor genes (p20, p23 and p25) were employed to analyze the genetic diversity and genotype composition of the CTV population based on 51 CTV-positive samples collected from 14 citrus orchards scattered around six major citrus-growing areas of Hunan. The results indicated that the CTV population structure was extremely complex and that infection was highly mixed. In total, p23 gene markers resulted in six profiles, and MMMs demonstrated 25 profiles. The severe VT and T3 types appeared to be predominantly associated with SP, while the mild T30 and RB types were related to asymptomatic samples. Based on phylogenetic analysis of the amino acid sequences of p20, p23 and p25, 19 representative CTV samples were classified into seven recently established CTV groups and a potentially novel one. A high level of genetic diversity, as well as potential recombination, was revealed among different CTV isolates. Five pure SP severe and two pure mild strains were identified by genotype composition analysis. Taken together, the results update the genetic diversity of CTV in Hunan with the detection of one possible novel strain, and this information might be applicable for the selection of appropriate mild CTV strains for controlling citrus SP disease through cross-protection.

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri, vector of Huanglongbing.

Directory of Open Access Journals (Sweden)

Joseph M Patt

Full Text Available Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las. Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri. Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ, a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing.

Science.gov (United States)

Patt, Joseph M; Robbins, Paul S; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

2018-01-01

Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing

Science.gov (United States)

Robbins, Paul S.; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

2018-01-01

Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected ‘Valencia’ sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

Repellency of Selected Psidium guajava cultivars to the Asian citrus psyllid, Diaphorina citri

Science.gov (United States)

Asiatic huanglongbing (HLB)(also known as citrus greening disease) is the most devastating disease of citrus worldwide. It is caused by a bacterium ‘Candidatus Liberibacter asiaticus’ and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. Considerable research has been conducted toward...

Comparative transcriptional survey between self-incompatibility and self-compatibility in Citrus reticulata Blanco.

Science.gov (United States)

Ma, Yuewen; Li, Qiulei; Hu, Guibing; Qin, Yonghua

2017-04-20

Seedlessness is an excellent economical trait, and self-incompatibility (SI) is one of important factors resulting in seedless fruit in Citrus. However, SI molecular mechanism in Citrus is still unclear. In this study, RNA-Seq technology was used to identify differentially expressed genes related to SI reaction of 'Wuzishatangju' (Citrus reticulata Blanco). A total of 35.67GB raw RNA-Seq data was generated and was de novo assembled into 50,364 unigenes with an average length of 897bp and N50 value of 1549. Twenty-three candidate unigenes related to SI were analyzed using qPCR at different tissues and stages after self- and cross-pollination. Seven pollen S genes (Unigene0050323, Unigene0001060, Unigene0004230, Unigene0004222, Unigene0012037, Unigene0048889 and Unigene0004272), three pistil S genes (Unigene0019191, Unigene0040115, Unigene0036542) and three genes (Unigene0038751, Unigene0031435 and Unigene0029897) associated with the pathway of ubiquitin-mediated proteolysis were identified. Unigene0031435, Unigene0038751 and Unigene0029897 are probably involved in SI reaction of 'Wuzishatangju' based on expression analyses. The present study provides a new insight into the molecular mechanism of SI in Citrus at the transcriptional level. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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 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.

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.

Production of interstocked 'Pera' sweet orange nursey trees on 'Volkamer' lemon and 'Swingle' citrumelo rootstocks

OpenAIRE

Girardi,Eduardo Augusto; Mourão Filho,Francisco de Assis Alves

2006-01-01

Incompatibility among certain citrus scion and rootstock cultivars can be avoided through interstocking. 'Pera' sweet orange (Citrus sinensis L. Osbeck) nursery tree production was evaluated on 'Swingle' citrumelo (Poncirus trifoliata (L.) Raf x Citrus paradisi Macf) and 'Volkamer' lemon (Citrus volkameriana Pasquale) incompatible rootstocks, using 'Valencia' and 'Hamlin' sweet oranges (Citrus sinensis L. Osbeck), 'Sunki' mandarin (Citrus sunki Hort. ex Tanaka), and 'Cleopatra' mandarin (Citr...

A low-energy, cost-effective approach to fruit and citrus peel waste processing for bioethanol production

International Nuclear Information System (INIS)

Choi, In Seong; Lee, Yoon Gyo; Khanal, Sarmir Kumar; Park, Bok Jae; Bae, Hyeun-Jong

2015-01-01

Highlights: • Simple bioprocess of bioethanol production from fruit wastes containing D-limonene. • Two in-house enzymatic bioconversion rates were approximately 90%. • Limonene recovery column (LRC) was designed for absorption of D-limonene. • Ethanol production by immobilized yeast fermentation and LRC was 12-fold greater. - Abstract: Large quantities of fruit waste are generated from agricultural processes worldwide. This waste is often simply dumped into landfills or the ocean. Fruit waste has high levels of sugars, including sucrose, glucose, and fructose, that can be fermented for bioethanol production. However, some fruit wastes, such as citrus peel waste (CPW), contain compounds that can inhibit fermentation and should be removed for efficient bioethanol production. We developed a novel approach for converting single-source CPW (i.e., orange, mandarin, grapefruit, lemon, or lime) or CPW in combination with other fruit waste (i.e., banana peel, apple pomace, and pear waste) to produce bioethanol. Two in-house enzymes were produced from Avicel and CPW and were tested with fruit waste at 12–15% (w/v) solid loading. The rates of enzymatic conversion of fruit waste to fermentable sugars were approximately 90% for all feedstocks after 48 h. We also designed a D-limonene removal column (LRC) that successfully removed this inhibitor from the fruit waste. When the LRC was coupled with an immobilized cell reactor (ICR), yeast fermentation resulted in ethanol concentrations (14.4–29.5 g/L) and yields (90.2–93.1%) that were 12-fold greater than products from ICR fermentation alone

[Parameter sensitivity of simulating net primary productivity of Larix olgensis forest based on BIOME-BGC model].

Science.gov (United States)

He, Li-hong; Wang, Hai-yan; Lei, Xiang-dong

2016-02-01

Model based on vegetation ecophysiological process contains many parameters, and reasonable parameter values will greatly improve simulation ability. Sensitivity analysis, as an important method to screen out the sensitive parameters, can comprehensively analyze how model parameters affect the simulation results. In this paper, we conducted parameter sensitivity analysis of BIOME-BGC model with a case study of simulating net primary productivity (NPP) of Larix olgensis forest in Wangqing, Jilin Province. First, with the contrastive analysis between field measurement data and the simulation results, we tested the BIOME-BGC model' s capability of simulating the NPP of L. olgensis forest. Then, Morris and EFAST sensitivity methods were used to screen the sensitive parameters that had strong influence on NPP. On this basis, we also quantitatively estimated the sensitivity of the screened parameters, and calculated the global, the first-order and the second-order sensitivity indices. The results showed that the BIOME-BGC model could well simulate the NPP of L. olgensis forest in the sample plot. The Morris sensitivity method provided a reliable parameter sensitivity analysis result under the condition of a relatively small sample size. The EFAST sensitivity method could quantitatively measure the impact of simulation result of a single parameter as well as the interaction between the parameters in BIOME-BGC model. The influential sensitive parameters for L. olgensis forest NPP were new stem carbon to new leaf carbon allocation and leaf carbon to nitrogen ratio, the effect of their interaction was significantly greater than the other parameter' teraction effect.

Systemic translocation and metabolism of 14C-metalaxyl in citrus

International Nuclear Information System (INIS)

Musumeci, M.R.; Ruegg, E.F.

1984-01-01

Systemic uptake and translocation of 14 C-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 14 C-metalaxyl. (M.A.C.) [pt

Biotechnological production of limonene in microorganisms

OpenAIRE

Jongedijk, Esmer; Cankar, Katarina; Buchhaupt, Markus; Schrader, Jens; Bouwmeester, Harro; Beekwilder, Jules

2016-01-01

This mini review describes novel, biotechnology-based, ways of producing the monoterpene limonene. Limonene is applied in relatively highly priced products, such as fragrances, and also has applications with lower value but large production volume, such as biomaterials. Limonene is currently produced as a side product from the citrus juice industry, but the availability and quality are fluctuating and may be insufficient for novel bulk applications. Therefore, complementary microbial producti...

Solar thermotherapy reduces the titer of ‘Candidatus Liberibacter asiaticus’ while enhancing canopy growth in HLB-affected residential and commercial citrus

Science.gov (United States)

Huanglongbing (HLB), a systemic and destructive disease of citrus, is associated with three species of a-proteobacteria, ‘Candidatus Liberibacter asiaticus’ (Las), ‘Ca. L. africanus’ and ‘Ca. L. americanus’. Previous studies have found distinct variations in temperature sensitivity and tolerance amo...

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.

Incidence of 'Candidatus Liberibacter asiaticus' in a Florida population of Asian citrus psyllid

Science.gov (United States)

A study was conducted to assess the incidence of a bacterium ‘Candidatus Liberibacter asiaticus’ in a Florida population of Asian citrus psyllid (ACP), Diaphorina citri. The bacterium is the presumed causal agent of Asiatic huanglongbing, a serious citrus disease also known as citrus greening or yel...

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.

Penggunaan Tepung Limbah Jus Jeruk (citrus sinensis dalam Ransum terhadap Kualitas Karkas Ayam Broiler

Directory of Open Access Journals (Sweden)

Ucop Haroen

2017-04-01

(The use of orange (citrus sinensis juice by products in the ration on carcass quality of broiler chickens ABSTRACT. This study was conducted to evaluate the effect of orange (Citrus sinensis juice by products in rations on (carcass quality ; weight of slaughter, carcass weight, carcasspercentages, abdominal fat weight and feed intake of broiler chicks. A total of two hundred unsexed 1 d-old chicks (Arbor Acres CP-707 used. The design used was Completely Randomized Design consisting of 5 treatments and 4 replications of each replication consisting of 10 chickens. Feed treatment consisted of P0 = 0% orange juice waste flour (positive control; P1 = 0% waste juice flour with 0.02% basitratin addition (negative control; P2 = 5% orange juice flour waste; P3 = 10% orange juice flour waste; P4 = 15% orange juice flour waste. The variables observed were carcass quality (cut weight, carcass weight, carcass percentage, carcass cholesterol, abdominal fat and ration consumption..The results showed that the use of orange juice flour in the ration significantly influenced (P <0.05 in reducing the consumption of ration, cut weight, carcass weight, carcass cholesterol and abdominal fat weight, but the use of orange juice waste flour in the ration did not affect the percentage of carcass . As a conclusion is the use of orange juice waste flour (Citrus sinensis can be used to a level of 5% in broiler chicken rations.

Design Development of Sprinkler Irrigation System To Protect The Failed Harvest of Citrus “Keprok 55” In Dry Season at Selorejo, Dau, Malang

Directory of Open Access Journals (Sweden)

Bambang Suharto

2016-07-01

Full Text Available This study is a part of ongoing research to mainstay citrus productivity in Malang region. Therefore, the specific aim of this study is developing the design of sprinkle irrigation in field. Selorejois central location of citrus production called “KEPROK 55” in Dau-Malang. The cultivation requires maintenance of soil and plants, in addition the lower of citrus production especially in dry season thus indispensable an effort to increase the production. Application of technology using sprinkle irrigation is expected to create the increasing of Citrus production. Result on research study show that the coefficient of uniformity tends to have same value on all the treatment that is above 98%, where the average value of the coefficient of uniformity was 98.8%. The highest value of the coefficient of uniformity achieved at combination of treatment P1T1 (pressure of 1 bar with a riser pipe 50 cm height that is equal to 99.78%. While the coefficient of uniformity was lowest at the combination of treatment P2T3 (pressure of 1.5 bar with a riser pipe 150 cm height by 96.6%. The pressure effected to the coefficient of uniformity indicates that the greater pressure exerted, then the coefficient of uniformity will be higher. It indicated at the treatment of pressure P1, P2, and P3 (1 bar, 1.5 bar and 2 bar that have the average coefficient of uniformity of 98.53%, 98.27%, and 99.64%.

Study of entomophatogenic fungus to control vector insect of citrus tristeza virus on citrus

Directory of Open Access Journals (Sweden)

Dwiastuti M.E.

2017-08-01

Full Text Available Citrus Tristeza Virus (CTV disease is a silent killer, which threatens to decrease productivity, quality and even death of citrus plants and the erosion of genetic resources. Spreading in the field very quickly by the intermediate insect vector pest, aphid (Toxoptera citricida, T. Aurantii and A. Gosypii. The microbes studied for potential biopesticide candidates are: Beauveria bassiana and Hirsutella citriformis, and Metarhizium anisopliae (Metch Sorokin previously reported to control Diaphorina citri pests resulting effectiveness of > 25% and was able to suppress yield loss up to 10%. The objectives of the study examined the effectiveness of entomopathogen in controlling the pest of CTV vector, Toxoptera citricida, in the laboratory and screen house, to findout the physiological, biochemical and molecular physiology of entomopathogen. The results showed that the best entomopathogen suspension concentration was B.bassiana 106 followed by H. citriformis 106 and M. anisopliae 106. Entomopatogen B. bassiana and H. citriformis effectively controled the CTV vector pest in the laboratory. In the semi-field experiments at the screen house, the most effective result was H.citriformis 106 and the combination of H.citriformis 106 + B.bassiana 106, killing up to 50% and 100% on day 7th H.citriformis had the most physiological character, was able to develop optimally at a temperature of 20-400C and humidity between 60-80%. The biochemical character of the entomopathogenic fungus B.bassiana contained cellulase enzyme and phosphate solvent and IAA hormone, at most compared to the others. H.citriformis had not been found to contain enzymes and hormones. The molecular biochemical characterization of entomopathogenic fungi using FS1 and NS2 primers more clearly distinguished isolates and entomopathogenic species.

Dermal safety assessment of Arm & Hammer laundry products formulated for sensitive skin.

Science.gov (United States)

Frederick, Douglas M; Vorwerk, Linda; Gupta, Archana; Ghassemi, Annahita

2017-09-01

The prevalence of sensitive skin among the general population in industrialized countries is reported to be over 50%. Sensitive skin subjects often report significant reactions to contact with cosmetics, soaps and other consumer products. This paper describes the overall skin compatibility and mildness program for a newly developed, lightly fragranced, colorant free laundry product (i.e. Arm & Hammer™ Sensitive Skin plus Skin-Friendly Fresh Scent), specially formulated for individuals with sensitive skin. The skin mildness of the product was compared to Arm & Hammer™ Free & Clear liquid laundry detergent with no fragrance or colorant, and an established history of safe use by sensitive skin consumers. The test material was a liquid laundry product with a light scent formulated for sensitive skin consumers (Arm & Hammer™ Sensitive Skin plus Skin-Friendly Fresh Scent). The product was compared to commercially marketed products for sensitive skin with a history of skin safety in the marketplace, including: a very similar product formulation (Arm & Hammer™ Free & Clear with no fragrance), and several selected competitors' products. Studies were conducted among individuals with self-assessed sensitive skin (based on a questionnaire) using standard protocols for the Human Repeat Insult Patch Test (HRIPT), 10-Day Cumulative Irritation, the Wrist Band Wear test, and the Safety In-Use testing. Responses in all protocols were evaluated by visual scoring of potential dermatologic reactions, and recording any sensory effects at the time of the examination. In addition, sensory effects collected from panelists' daily diaries were also evaluated. The HRIPT confirmed that neither the fragrance alone, nor the product formulation with fragrance, induced contact sensitization in sensitive skin subjects. The 10-Day cumulative irritation study conducted using sensitive skin subjects showed highly favorable skin compatibility, and the test product was comparable to the control

In vitro Propagation of Citrus limonia Osbeck Through Nucellar Embryo Culture

OpenAIRE

Alka Jajoo

2010-01-01

Citrus limonia Osbeck is a promising rootsctock for commercial citrus species with sturdy anddisease and drought resistant characters. A n efficient and highly reproducible plant regeneration protocol hasbeen developed from nucellar embryo of Citrus limonia. Murashige and Skoogs medium was used for plantregeneration from nucellar embryos. It was noted that 6-benzylaminopurine at a concentration of 2.22 mMinduced highest number of multiple shoots as 18.26 shoots per explant. O n transfer of in...

Insecticidal activity of some citrus oils against culex quinquefasciatus

International Nuclear Information System (INIS)

Saeed, H. M. A.

2009-01-01

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)

Compatibility and Efficacy of Isaria fumosorosea with Horticultural Oils for Mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae

Directory of Open Access Journals (Sweden)

Vivek Kumar

2017-10-01

Full Text Available Horticultural oils are an important component of integrated management programs of several phytophagous arthropods and pathogens affecting fruit, ornamentals and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological control agents can compromise efforts to develop eco-friendly management programs for important agricultural pests. In this study, we assessed the in vitro effect of selected refined petroleum oils used in citrus and other horticultural crops with a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea (PFR-97 under laboratory conditions. Further, we used leaf disk bioassays to evaluate the combined efficacy of petroleum oils and I. fumosorosea against the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, a major pest of citrus in the United States. All five petroleum oil treatments (Orchex, Sun Pure, Conoco Blend -1, Conoco Blend -2, and JMS were compatible with I. fumosorosea blastospores, as none of them were found to affect I. fumosorosea colony-forming units and radial fungal growth measured at 3, 6, 9, and 12 days post-inoculation. All mixed treatments performed better than I. fumosorosea alone against D. citri, where the highest mean survival time of D. citri was 12.5 ± 0.7 days. No significant differences in D. citri survival time and I. fumosorosea growth (fungal development index on dead cadavers, which is important for determining their horizontal transmission, were observed when mixed with Orchex, Sun Pure, Conoco Blend -2, and JMS. Results indicated that horticultural oils in combination with I. fumosorosea could offer citrus growers an alternative treatment for integrating into their current management programs while battling against D. citri in citrus production systems. Due to their eco-friendly, broad-spectrum effect, it could provide control against various citrus pests, while also encouraging the

Compatibility and Efficacy of Isaria fumosorosea with Horticultural Oils for Mitigation of the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Kumar, Vivek; Avery, Pasco B; Ahmed, Juthi; Cave, Ronald D; McKenzie, Cindy L; Osborne, Lance S

2017-10-31

Horticultural oils are an important component of integrated management programs of several phytophagous arthropods and pathogens affecting fruit, ornamentals and vegetables in greenhouse and field production systems. Although effective against the target pest, their incompatibility with biological control agents can compromise efforts to develop eco-friendly management programs for important agricultural pests. In this study, we assessed the in vitro effect of selected refined petroleum oils used in citrus and other horticultural crops with a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea (PFR-97) under laboratory conditions. Further, we used leaf disk bioassays to evaluate the combined efficacy of petroleum oils and I. fumosorosea against the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), a major pest of citrus in the United States. All five petroleum oil treatments (Orchex, Sun Pure, Conoco Blend -1, Conoco Blend -2, and JMS) were compatible with I. fumosorosea blastospores, as none of them were found to affect I. fumosorosea colony-forming units and radial fungal growth measured at 3, 6, 9, and 12 days post-inoculation. All mixed treatments performed better than I. fumosorosea alone against D. citri , where the highest mean survival time of D. citri was 12.5 ± 0.7 days. No significant differences in D. citri survival time and I. fumosorosea growth (fungal development index) on dead cadavers, which is important for determining their horizontal transmission, were observed when mixed with Orchex, Sun Pure, Conoco Blend -2, and JMS. Results indicated that horticultural oils in combination with I. fumosorosea could offer citrus growers an alternative treatment for integrating into their current management programs while battling against D. citri in citrus production systems. Due to their eco-friendly, broad-spectrum effect, it could provide control against various citrus pests, while also encouraging the retention of effective

Ceba de toros con dietas basadas en hollejos de cítrico frescos o conservados Bull fattening with diets based on fresh or preserved citrus pulp

Directory of Open Access Journals (Sweden)

F Ojeda

2012-12-01

Production Enterprise, Matanzas province, Cuba, a study was conducted for 138 days with 433 crossbred bulls of dairy breeds (Holstein x Zebu, in which a diet based on restricted grazing (four hours in the morning, green forage and citrus fruit pulp ad libitum, was evaluated, supplemented with grass hay, mineral salt and North gold. The citrus fruit pulp was supplied as silage since August 8 until October 31, and fresh since November 1st until December 24. The latter was enriched with urea, at a rate of 0,04 kg per 5 kg of citrus fruit pulp. In the rainy season, the forage showed the lowest DM percentages and the highest ME and PDIN values, with little variation between periods for PDIE. The fresh and ensiled citrus pulp maintained analogous values to other studies; the hay had low quality and forage intake was similar in both periods; preserved citrus pulp was less consumed than the fresh one. The gain was higher with preserved citrus pulp (0,593 vs. 0,556 kg/animal/day. Nutritional balances indicated that the DM and ME requirements were covered, although in nitrogen compounds inefficient utilization was made because there was excess of PDIE, which was not corrected through urea incorporation. In both periods the highest percentages of nutrient contributions corresponded to forage and citrus fruit pulp in its two modalities. The conversion values had a better response with silage (13,3 vs. 15,5 kg DM/kg of gain. The feasibility of using fresh or ensiled citrus fruit pulp is concluded; although, to increase gains and feeding conversion, it is necessary to increase protein supplementation and have feedstuffs which balance the quantities of PDIN and PDIE in the diets.

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

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Funds for the replacement of commercial citrus trees... trees. Subject to the availability of appropriated funds, the owner of a commercial citrus grove may be eligible to receive funds to replace commercial citrus trees in accordance with the provisions of this...

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.

Exogenous application of methyl jasmonate and salicylic acid on citrus foliage: Effecs on foliar volatiles and aggregation behavior of Asian citrus psyllid (Diaphorina citri)

Science.gov (United States)

Methyl jasmonate (MeJA) and salicylic acid (SA) are well-known activators of chemical defenses in plants. The SA pathway is involved in citrus response to infection by Candidatus Liberibacter asiaticus (CLas); less is known about the role of jasmonates in citrus defense response. We examined the eff...

Behavioral assay on Asian citrus psyllid attraction to orange jasmine

Science.gov (United States)

The Asian citrus psyllid (ACP) is an important pest because it transmits a bacterium putatively responsible for huanglongbing, a devastating citrus disease. Research on ACP chemical ecology is of interest with respect to identifying attractants and repellents for managing the psyllid. We report on a...

Assessment of citrus marketing in Benue and Kano states of Nigeria ...

African Journals Online (AJOL)

Assessment of citrus marketing in Benue and Kano states of Nigeria. ... tends towards pure competition. Keywords: Benue, citrus, gini coefficient, Kano, marketing, pure competition, traders. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

Diversity of endophytic bacterial populations and their interaction with Xylella fastidiosa in citrus plants

NARCIS (Netherlands)

Araujo, W.L.; Marcon, J.; jr. Maccheroni, W.; Elsas, van J.D.; Vuurde, van J.W.L.; Azevedo, de J.L.

2002-01-01

Citrus variegated chlorosis (CVC) is caused by Xylella fastidiosa, a phytopathogenic bacterium that can infect all Citrus sinensis cultivars. The endophytic bacterial communities of healthy, resistant, and CVC-affected citrus plants were studied by using cultivation as well as

EH AND S ANALYSIS OF DYE-SENSITIZED PHOTOVOLTAIC SOLAR CELL PRODUCTION

International Nuclear Information System (INIS)

BOWERMAN, B.; FTHENAKIS, V.

2001-01-01

Photovoltaic solar cells based on a dye-sensitized nanocrystalline titanium dioxide photoelectrode have been researched and reported since the early 1990's. Commercial production of dye-sensitized photovoltaic solar cells has recently been reported in Australia. In this report, current manufacturing methods are described, and estimates are made of annual chemical use and emissions during production. Environmental, health and safety considerations for handling these materials are discussed. This preliminary EH and S evaluation of dye-sensitized titanium dioxide solar cells indicates that some precautions will be necessary to mitigate hazards that could result in worker exposure. Additional information required for a more complete assessment is identified

Índice de qualidade em um latossolo amarelo coeso cultivado com citros Quality index in a cohesive yellow latosol cultivated with citrus

Directory of Open Access Journals (Sweden)

José Fernandes de Melo Filho

2009-12-01

Full Text Available O Brasil é o maior produtor mundial de citros e exportador de suco concentrado de laranja. Na região Nordeste, a citricultura tem grande importância social, onde é cultivada predominantemente por produtores com áreas menores do que 10 hectares, em solos como caráter coeso. Na Bahia, a citricultura é explorada sobre diversas condições tecnológicas, e especialmente nos Tabuleiros Costeiros os pomares têm baixa longevidade e produtividade em função das limitações dos solos coesos à produção agrícola. Este trabalho tem como objetivo determinar a qualidade física e química de um Latossolo Amarelo Coeso cultivado com citros. O estudo foi realizado na região do Recôncavo Baiano, em um pomar comercial de laranja "Pera" (Citrus sinensis L. Osb. sob porta-enxerto de limão-cravo (Citrus limonia L. Osb.. Para a determinação do índice de qualidade do solo (IQS, utilizou-se o método proposto por Karlen & Stott (1994, e amostras foram coletadas em duas camadas: 0,00 - 0,20 m e 0,20 - 0,40 m. Os resultados mostraram que o Latossolo Amarelo Coeso sob manejo tradicional para a cultura de citros apresentou índice de qualidade regular, com limitações determinadas pela elevada resistência do solo à penetração, baixa permeabilidade à água e baixo teor de matéria orgânica, o que resulta em limitações para permitir o crescimento e o aprofundamento do sistema radicular e prover o fornecimento e a disponibilidade de água para as plantas cítricas.Brazil is the greatest citrus producer and exporter of concentrated orange juice in the world. In the Northeast, the citriculture has a large social importance for farming family, which is predominantly cultivated for small farmers. In Bahia state the citriculture has been exploited under several technology conditions and especially in the Costal table lands soil the orchards have low longevity and productivity based on the cohesive soil limitations for rural production. The purpose of

Dissemination of Aleurocanthus woglumi in citrus plants, its natural enemies and new host plants in the state of Rio de Janeiro, Brazil

Directory of Open Access Journals (Sweden)

Rodrigo Garcia Alvim

Full Text Available ABSTRACT: Aleurocanthus woglumi is an exotic pest, widely disseminated in Brazil, with a high preference for citrus plants, but with a polyphagous feeding habit. The contribution of the state of Rio de Janeiro in the Brazilian production of citrus fruits is small; however, there are still public policies that encourage citrus production in the state. In 2010, the appearance of this pest in Rio de Janeiro was confirmed in the municipality of Cachoeiras de Macacu. The objectives of this research were to evaluate the dissemination of A. woglumi in this state, conduct a survey of new species of host plants, identify and evaluate the population of natural enemies present at two orchards that grow 'Tahiti' limes ( Citrus latifolia infested by the pest in Cachoeiras de Macacu, RJ, Brazil. In 19 municipalities, leaves of citrus and other species of plants presenting aleyrodid nymphs were collected, and yellow sticky traps were installed to capture adults for subsequent identification. At the 'Tahiti' lime orchards, the leaf collections were done to confirm the species of Aleyrodidae , and regarding A. woglumi , the natural enemies associated with this pest were collected directly from the infested plants. The results showed that A. woglumi is wide-spread in 12 municipalities. Three new host plants for A. woglumi were identified: Artocarpus heterophyllus ( Moraceae , Pouteria caimito ( Sapotaceae and Struthanthus flexicaulis ( Loranthaceae . In Cachoeiras de Macacu, a new species of parasitoid of A. woglumi nymphs was named: Encarsia pergandiella (Hymenoptera: Aphelinidae , while the insects in the Coccinellidae (Coleoptera family have stood out as predators of this pest.

Resistance evaluation of Pera (Citrus sinensis) genotypes to citrus canker in greenhouse conditions

Science.gov (United States)

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri results in serious yield losses and phytoregulation penalties. The use of resistant genotypes is recognized as an important tool to facilitate control of the pathogen. Studies have show that artificial inoculation results in typic...

Determination of limonin and nomilin contents in different citrus cultivars using high performance liquid chromatography

International Nuclear Information System (INIS)

Bilal, H.; Hassan, S.; Sahar, S.; Akram, W.; Sahar, S.

2013-01-01

High perlorrnance liquid chromatography (HPLC) analysis was done to quantify the amount of limonoids (nomilin and nomilin) in seven selected citrus cultivars. According to the HPLC analysis red blood orange (Citrus sinensis var red blood orange) had maximum amount of limonin (479.77 ug/rnl.), while rough lemon (Citrus jambhiri) had no limonin content. in case of nomonin, rough lemon (Citrus jambhir) had maximum amount of nomilin (54.23 micro g/ML)) while succari (citrus sinensis var succari) had very low amount of nomilin (0.37 micro g/Ml). (author)

First records of parasitoids attacking the Asian citrus psyllid in Ecuador

Directory of Open Access Journals (Sweden)

Diego E. Portalanza

Full Text Available ABSTRACT First records of parasitoids attacking the Asian citrus psyllid in Ecuador. The objective of the current study was to investigate the presence of natural enemies of Diaphorina citri (Hemiptera: Liviidae (the Asian citrus psyllid in Ecuador. Incidence of parasitoid Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae was assessed between November 2015 and March 2016, in Letamendi, Febres-Cordero and Tarqui, urban districts of Guayaquil. Highest incidence of parasitism occurred in those regions and seasons of the year with the highest temperatures commensurate with increase of citrus plant shoots. Similar to their host, these parasitoids appear to have established in Ecuador by accident, and were not the result of purposeful introduction. This fortuitous introduction is a potentially helpful tool in controlling the Asian citrus psyllid, and potentially Huanglongbing.

The Composition, Antioxidant and Antibacterial Activities of Cold-Pressed and Distilled Essential Oils of Citrus paradisi and Citrus grandis (L. Osbeck

Directory of Open Access Journals (Sweden)

Ming-Chiu Ou

2015-01-01

Full Text Available The chemical composition and functional activities of cold-pressed and water distilled peel essential oils of Citrus paradisi (C. paradisi and Citrus grandis (L. Osbeck (C. grandis were investigated in present study. Yields of cold-pressed oils were much higher than those of distilled oils. Limonene was the primary ingredient of essential oils of C. paradisi (cold 92.83%; distilled 96.06% and C. grandis (cold 32.63%; distilled 55.74%. In addition, C. grandis oils obtained were rich in oxygenated or nitrogenated compounds which may be involved in reducing cardiovascular diseases or enhancing sleep effectiveness. The order of free radical scavenging activities of 4 citrus oils was distilled C. paradisi oil > cold-pressed C. paradisi oil > distilled C. grandis oil > cold-pressed C. grandis oil. Cold-pressed C. grandis oil exhibited the lowest activity in all antioxidative assays. The order of antimicrobial activities of 4 citrus oils was distilled C. grandis oil, cold-pressed C. paradisi oil > distilled C. paradisi oil > cold-pressed C. paradisi oil. Surprisingly, distilled C. grandis oil exhibited better antimicrobial activities than distilled C. paradisi oil, especially against Escherichia coli and Salmonella enterica subsp. The results also indicated that the antimicrobial activities of essential oils may not relate to their antioxidative activities.

Acquisition, Replication and Inoculation of Candidatus Liberibacter asiaticus following Various Acquisition Periods on Huanglongbing-Infected Citrus by Nymphs and Adults of the Asian Citrus Psyllid.

Directory of Open Access Journals (Sweden)

El-Desouky Ammar

Full Text Available The Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, is the primary vector of Candidatus Liberibacter asiaticus (Las implicated as causative agent of citrus huanglongbing (citrus greening, currently the most serious citrus disease worldwide. Las is transmitted by D. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. Thus, we studied the effects of the acquisition access period (AAP by nymphs and adults of D. citri on Las acquisition, multiplication and inoculation/transmission. D. citri nymphs or adults (previously non-exposed to Las were caged on Las-infected citrus plants for an AAP of 1, 7 or 14 days. These 'Las-exposed' psyllids were then transferred weekly to healthy citrus or orange jasmine plants, and sampled via quantitative polymerase chain reaction (qPCR analysis 1-42 days post-first access to diseased plants (padp; all tested nymphs became adults 7-14 days padp. Our results indicate that following 1 or 7 day AAP as nymphs 49-59% of Las-exposed psyllids became Las-infected (qPCR-positive, whereas only 8-29% of the psyllids were infected following 1-14 day AAP as adults. Q-PCR analysis also indicated that Las titer in the Las-exposed psyllids (relative to that of the psyllid S20 ribosomal protein gene was: 1 significantly higher, and increasing at a faster rate, following Las acquisition as nymphs compared to that following Las acquisition as adults; 2 higher as post-acquisition time of psyllids on healthy plants increased reaching a peak at 14-28 days padp for nymphs and 21-35 days padp for adults, with Las titer decreasing or fluctuating after that; 3 higher with longer AAP on infected plants, especially with acquisition as adults. Our results strongly suggest that Las multiplies in both nymphs and adults of D. citri but attains much higher levels in a shorter period of time post-acquisition when acquired by nymphs than when acquired by

Biomethanization of citrus waste: Effect of waste characteristics and of storage on treatability and evaluation of limonene degradation.

Science.gov (United States)

Lotito, Adriana Maria; De Sanctis, Marco; Pastore, Carlo; Di Iaconi, Claudio

2018-06-01

This study proposes the evaluation of the suitability of mesophilic anaerobic digestion as a simple technology for the treatment of the citrus waste produced by small-medium agro-industrial enterprises involved in the transformation of Citrus fruits. Two different stocks of citrus peel waste were used (i.e., fresh and stored citrus peel waste), to evaluate the influence of waste composition (variability in the type of processed Citrus fruits) and of storage (potentially necessary to operate the anaerobic digester continuously over the whole year due to the seasonality of the production) on anaerobic degradation treatability. A thorough characterization of the two waste types has been performed, showing that the fresh one has a higher solid and organic content, and that, in spite of the similar values of oil fraction amounts, the two stocks are significantly different in the composition of essential oils (43% of limonene and 34% of linalyl acetate in the fresh citrus waste and 20% of limonene and 74% of linalyl acetate in the stored citrus waste). Contrarily to what observed in previous studies, anaerobic digestion was successful and no reactor acidification occurred. No inhibition by limonene and linalyl acetate even at the maximum applied organic load value (i.e., 2.72 gCOD waste /gVS inoculum ) was observed in the treatment of the stored waste, with limonene and linalyl acetate concentrations of 104 mg/l and 385 mg/l, respectively. On the contrary, some inhibition was detected with fresh citrus peel waste when the organic load increased from 2.21 to 2.88 gCOD waste /gVS inoculum , ascribable to limonene at initial concentration higher than 150 mg/l. A good conversion into methane was observed with fresh peel waste, up to 0.33  [Formula: see text] at the highest organic load, very close to the maximum theoretical value of 0.35 [Formula: see text] , while a lower efficiency was achieved with stored peel waste, with a reduction down to 0.24  [Formula: see

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

OpenAIRE

RUIZ FUERTES, BEGOÑA

2016-01-01

[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...

Genomic Analysis of Terpene Synthase Family and Functional Characterization of Seven Sesquiterpene Synthases from Citrus sinensis

Directory of Open Access Journals (Sweden)

Berta Alquézar

2017-08-01

Full Text Available Citrus aroma and flavor, chief traits of fruit quality, are derived from their high content in essential oils of most plant tissues, including leaves, stems, flowers, and fruits. Accumulated in secretory cavities, most components of these oils are volatile terpenes. They contribute to defense against herbivores and pathogens, and perhaps also protect tissues against abiotic stress. In spite of their importance, our understanding of the physiological, biochemical, and genetic regulation of citrus terpene volatiles is still limited. The availability of the sweet orange (Citrus sinensis L. Osbeck genome sequence allowed us to characterize for the first time the terpene synthase (TPS family in a citrus type. CsTPS is one of the largest angiosperm TPS families characterized so far, formed by 95 loci from which just 55 encode for putative functional TPSs. All TPS angiosperm families, TPS-a, TPS-b, TPS-c, TPS-e/f, and TPS-g were represented in the sweet orange genome, with 28, 18, 2, 2, and 5 putative full length genes each. Additionally, sweet orange β-farnesene synthase, (Z-β-cubebene/α-copaene synthase, two β-caryophyllene synthases, and three multiproduct enzymes yielding β-cadinene/α-copaene, β-elemene, and β-cadinene/ledene/allo-aromandendrene as major products were identified, and functionally characterized via in vivo recombinant Escherichia coli assays.

Production of interstocked 'Pera' sweet orange nursey trees on 'Volkamer' lemon and 'Swingle' citrumelo rootstocks

Directory of Open Access Journals (Sweden)

Girardi Eduardo Augusto

2006-01-01

Full Text Available Incompatibility among certain citrus scion and rootstock cultivars can be avoided through interstocking. 'Pera' sweet orange (Citrus sinensis L. Osbeck nursery tree production was evaluated on 'Swingle' citrumelo (Poncirus trifoliata (L. Raf x Citrus paradisi Macf and 'Volkamer' lemon (Citrus volkameriana Pasquale incompatible rootstocks, using 'Valencia' and 'Hamlin' sweet oranges (Citrus sinensis L. Osbeck, 'Sunki' mandarin (Citrus sunki Hort. ex Tanaka, and 'Cleopatra' mandarin (Citrus reshni Hort. ex Tanaka as interstocks. Citrus nursery trees interstocked with 'Pera' sweet orange on both rootstocks were used as control. 'Swingle' citrumelo led to the highest interstock bud take percentage, the greatest interstock height and rootstock diameter, as well as the highest scion and root system dry weight. Percentage of 'Pera' sweet orange dormant bud eye was greater for plants budded on 'Sunki' mandarin than those budded on 'Valencia' sweet orange. No symptoms of incompatibility were observed among any combinations of rootstocks, interstocks and scion. Production cycle can take up to 17 months with higher plant discard.

Infrared spectroscopy: a potential tool in huanglongbing and citrus variegated chlorosis diagnosis.

Science.gov (United States)

Cardinali, Marcelo Camponez do Brasil; Villas Boas, Paulino Ribeiro; Milori, Débora Marcondes Bastos Pereira; Ferreira, Ednaldo José; França e Silva, Marina; Machado, Marcos Antonio; Bellete, Barbara Sayuri; da Silva, Maria Fatima das Graças Fernandes

2012-03-15

Huanglongbing (HLB) and citrus variegated chlorosis (CVC) are serious threats to citrus production and have caused considerable economic losses worldwide, especially in Brazil, which is one of the biggest citrus producers in the world. Neither disease has a cure nor an efficient means of control. They are also generally confused with each other in the field since they share similar initial symptoms, e.g., yellowing blotchy leaves. The most efficient tool for detecting these diseases is by polymerase chain reaction (PCR). However, PCR is expensive, is not high throughput, and is subject to cross reaction and contamination. In this report, a diagnostic method is proposed for detecting HLB and CVC diseases in leaves of sweet orange trees using attenuated total reflectance Fourier transform infrared spectroscopy and the induced classifier via partial least-squares regression. Four different leaf types were considered: healthy, CVC-symptomatic, HLB-symptomatic, and HLB-asymptomatic. The results show a success rate of 93.8% in correctly identifying these different leaf types. In order to understand which compounds are responsible for the spectral differences between the leaf types, samples of carbohydrates starch, sucrose, and glucose, flavonoids hesperidin and naringin, and coumarin umbelliferone were also analyzed. The concentration of these compounds in leaves may vary due to biotic stresses. Copyright © 2012 Elsevier B.V. All rights reserved.

Integrating ecosystem services into risk management decisions: case study with Spanish citrus and the insecticide chlorpyrifos.

Science.gov (United States)

Deacon, Samantha; Norman, Steve; Nicolette, Joseph; Reub, Gregory; Greene, Gretchen; Osborn, Rachel; Andrews, Paul

2015-02-01

The European regulatory system for the approval of pesticides includes a thorough evaluation of risks to the environment and is designed to be protective of ecosystems. However, a decision to ban an agrochemical could also potentially have a negative impact on the value of ecosystem services, if resulting changes in crop management are damaging to ecosystems or result in negative socio-economic impacts. To support regulatory decision-making, consideration of ecosystem services to identify best environmental management options could be a way forward. There is generally a growing trend for the consideration of ecosystem services in decision making. Ecosystems provide the conditions for growing food, regulate water and provide wildlife habitats; these, amongst others, are known as ecosystem services. The objectives of this case study were to bring a holistic approach to decision making by valuing the environmental, social and economic benefits derived from the use of chlorpyrifos in Valencian citrus production. Spanish growers harvest between 5 and 6 milliont of citrus annually, worth an estimated €5 to 7 billion in food markets throughout Europe. The approach highlighted the potential for unintended negative consequences of regulatory decisions if the full context is not considered. In this study, rather than a regulatory restriction, the best option was the continued use of chlorpyrifos together with vegetated conservation patches as refuges for non-target insects. The conservation patches offset potential insecticidal impacts to insects whilst maintaining citrus production, farm income and the amenity value of the citrus landscape of Valencia. This was an initial proof-of-concept study and illustrates the importance of a wider perspective; other cases may have different outcomes depending on policies, the pesticide, crop scenarios, farm economics and the region. Copyright © 2014 Elsevier B.V. All rights reserved.

Isolation of Xylella fastidiosa from Citrus sinensis (L) Osb. And Vitis vinifera and study of genetic diversity in Costa Rica

International Nuclear Information System (INIS)

Aguilar Alvarez, Estela Yamileth

2007-01-01

Xylella fastidiosa is a plant pathogenic bacterium that causes diseases in different crops. Symptoms similar to those caused by citrus variegated chlorosis (CVC) were observed in sweet orange trees which served as shade and fences in coffee plantations in Costa Rica, in 2002. A total of 35 citrus trees and 24 vines from eight different districts and 3 respectively were evaluated by 'double antibody sandwich enzyme-linked immunosorbent assay' (DASELISA), resulting in 21 citrus and 19 positive vid. From four citrus trees and six of vines, were obtained six isolates and seven isolates respectively in solid medium, whose morphological and biochemical characteristics coincided with those reported in the literature as characteristic of X. fastidiosa. The identity of the isolates is confirmed by the chain polymerase reaction (PCR) using primers 272-1/272-2int and RST31/RST33. Three isolates from Grecia (Alajuela Province) amplified a band of 500pb using specific primers 272-2int/CVC-1 for strains of X. fastidiosa that cause CVC. The genetic variability of isolates from each other in comparison with isolates of coffee in Costa Rica, U.S. grapes and citrus in Brazil have been studied using techniques of random amplification polymorphism DNA (RAPD) and length polymorphisms of restriction fragments (RFLPs) of the products obtained with primers int/272-2int JB-1/JB-2 and 272-1. The results showed a clear separation between citrus isolates of Costa Rica; and, an association of three of them with the strains of citrus in Brasil. Also, an association between strains of coffee of Costa Rica with grape vines in the U.S. An association of molecular analysis confirmed the data variance. (author) [es

Characterization and classification of seven citrus herbs by liquid chromatography-quadrupole time-of-flight mass spectrometry and genetic algorithm optimized support vector machines.

Science.gov (United States)

Duan, Li; Guo, Long; Liu, Ke; Liu, E-Hu; Li, Ping

2014-04-25

Citrus herbs have been widely used in traditional medicine and cuisine in China and other countries since the ancient time. However, the authentication and quality control of Citrus herbs has always been a challenging task due to their similar morphological characteristics and the diversity of the multi-components existed in the complicated matrix. In the present investigation, we developed a novel strategy to characterize and classify seven Citrus herbs based on chromatographic analysis and chemometric methods. Firstly, the chemical constituents in seven Citrus herbs were globally characterized by liquid chromatography combined with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Based on their retention time, UV spectra and MS fragmentation behavior, a total of 75 compounds were identified or tentatively characterized in these herbal medicines. Secondly, a segmental monitoring method based on LC-variable wavelength detection was developed for simultaneous quantification of ten marker compounds in these Citrus herbs. Thirdly, based on the contents of the ten analytes, genetic algorithm optimized support vector machines (GA-SVM) was employed to differentiate and classify the 64 samples covering these seven herbs. The obtained classifier showed good prediction performance and the overall prediction accuracy reached 96.88%. The proposed strategy is expected to provide new insight for authentication and quality control of traditional herbs. Copyright © 2014 Elsevier B.V. All rights reserved.

GABA Pathway Rate-Limit Citrate Degradation in Postharvest Citrus Fruit Evidence from HB Pumelo (Citrus grandis) × Fairchild (Citrus reticulata) Hybrid Population.

Science.gov (United States)

Sheng, Ling; Shen, Dandan; Yang, Wei; Zhang, Mingfei; Zeng, Yunliu; Xu, Juan; Deng, Xiuxin; Cheng, Yunjiang

2017-03-01

Organic acids are a major index of fresh fruit marketing properties. However, the genetic effects on the organic acid level in postharvest citrus fruit still remain unknown. Here, we used the fruits of about 40 lines in a hybrid population (high-acid "HB Pumelo" × low-acid "Fairchild") to analyze the organic acid metabolism of postharvest citrus fruit. A transgressive content of titratable acid (TA) was observed, which was attributed to citrate accumulation. High- and low-acid fruits (No. 130, 168 and No. 080, 181, respectively) were chosen for further study. Gene expression analysis on citrate metabolism showed that the high accumulation of citrate could be attributed to the low activity of γ-aminobutyric acid (GABA) shunt, and was partially due to the block of tricarboxylic acid (TCA) cycle by low mitochondrial aconitase (m-ACO) expression. TA level was significantly negatively correlated with weight loss in fruits during postharvest storage, implying a close relationship between organic acid and water metabolism.

Correlation of electronic monitoring and stylet pathways elucidate the role of sclerenchymatous ring as a barrier to phloem feeding on citrus leaves by Asian citrus psyllid

Science.gov (United States)

Asian citrus psyllid (ACP, Diaphorina. citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Recent studies have shown a fibrous ring of thick-wal...

Characterization of citrus pectin samples extracted under different conditions: influence of acid type and pH of extraction

Science.gov (United States)

Kaya, Merve; Sousa, António G.; Crépeau, Marie-Jeanne; Sørensen, Susanne O.; Ralet, Marie-Christine

2014-01-01

Background and Aims Pectin is a complex macromolecule, the fine structure of which is influenced by many factors. It is used as a gelling, thickening and emulsifying agent in a wide range of applications, from food to pharmaceutical products. Current industrial pectin extraction processes are based on fruit peel, a waste product from the juicing industry, in which thousands of tons of citrus are processed worldwide every year. This study examines how pectin components vary in relation to the plant source (orange, lemon, lime, grapefruit) and considers the influence of extraction conditions on the chemical and macromolecular characteristics of pectin samples. Methods Citrus peel (orange, lemon, lime and grapefruit) from a commercial supplier was used as raw material. Pectin samples were obtained on a bulk plant scale (kilograms; harsh nitric acid, mild nitric acid and harsh oxalic acid extraction) and on a laboratory scale (grams; mild oxalic acid extraction). Pectin composition (acidic and neutral sugars) and physicochemical properties (molar mass and intrinsic viscosity) were determined. Key Results Oxalic acid extraction allowed the recovery of pectin samples of high molecular weight. Mild oxalic acid-extracted pectins were rich in long homogalacturonan stretches and contained rhamnogalacturonan I stretches with conserved side chains. Nitric acid-extracted pectins exhibited lower molecular weights and contained rhamnogalacturonan I stretches encompassing few and/or short side chains. Grapefruit pectin was found to have short side chains compared with orange, lime and lemon. Orange and grapefruit pectin samples were both particularly rich in rhamnogalacturonan I backbones. Conclusions Structural, and hence macromolecular, variations within the different citrus pectin samples were mainly related to their rhamnogalacturonan I contents and integrity, and, to a lesser extent, to the length of their homogalacturonan domains. PMID:25081519

Effect of citrus pulp on the viability of Saccharomyces boulardii in the presence of enteric pathogens

Science.gov (United States)

Saccharomyces cerevisiae subtype boulardii is frequently used as a dietary supplement to promote intestinal health and reduce the impact of growth of enteric pathogens in livestock, including cattle and swine. Citrus by-products are also fed as dietary supplements that have the additional benefit o...

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...

Soil organic matter on citrus plantation in Eastern Spain

Science.gov (United States)

Cerdà, Artemi; Pereira, Paulo; Novara, Agata; Prosdocimi, Massimo

2015-04-01

model (WATEM/SEDEM) in Northern Ethiopia. Land Degradation & Development 24, 188-204. DOI 10.1002/ldr.1121 Wu J., Li Q., Yan L. 1997. Effect of intercropping on soil erosion in young citrus plantation - a simulation study. Chinese Journal of Applied Ecology 8, 143-146. Wu, D.-M., Yu, Y.-C., Xia, L.-Z., Yin, S.-X., Yang, L.-Z. 2011. Soil fertility indices of citrus orchard land along topographic gradients in the three gorges area of China. Pedosphere 21, 782-792. Xu, Q. X., Wang, T. W., Cai, C. F., Li, Z. X., Shi, Z. H. 2012a. Effects of soil conservation on soil properties of citrus orchards in the Three-Gorges Area, China. Land Degradation & Development, 23(1), 34-42. Xu, Q., Wang, T., Li, Z., Cai, C., Shi, Z., Jiang, C. 2010. Effect of soil conservation measurements on runoff, erosion and plant production: A case study on steeplands from the Three Gorges Area, China. Journal of Food, Agriculture and Environment 8, 980-984. Xu, Q.X., Wang, T.W., Cai, C.F., Li, Z.X., Shi, Z.H. 2012b. Effects of soil conservation on soil properties of citrus orchards in the Three-Gorges Area, China. Land Degradation and Development 23, 34-42. Zhao, G., Mu, X., Wen, Z., Wang, F., Gao, P. 2013. Soil erosion, conservation, and eco-environment changes in the Loess Plateau of China. Land Degradation & Development, 24, 499- 510. DOI 10.1002/ldr.2246SP

Resistance of citrus genotypes to Phyllocnitis citrella Stainton (Lepidoptera: Gracillariidae).

Science.gov (United States)

Santos, M S; Vendramim, J D; Lourenção, A L; Pitta, R M; Martins, E S

2011-01-01

The development and reproduction of the citrus leafminer (CLM), Phyllocnistis citrella Stainton, were evaluated in six citrus genotypes in order to identify genotypes with resistance traits that could be applied in a program for the development of citrus varieties resistant to the citrus leafminer. Tests were conducted under controlled laboratory conditions (25 ± 1ºC, 70 ± 10% RH, and 14h photophase). Seedlings of each genotype tested were infested with eggs obtained from a stock colony of CLM maintained on 'Cravo' lemon (Citrus limonia L. Osbeck), and the duration and survival of the eggs, larval and pupal stages, pupal size and weight, fecundity and longevity of adults, and sex ratio were evaluated. No influence was observed on the duration and survival of eggs, larvae and pupae of P. citrella. However, pupae obtained in the hybrid C x R(4) were significantly smaller and lighter than pupae from the remaining treatments. Adult females from the hybrids C x R(4) and C x R(315) were the least fecund. However, the lowest value for the corrected reproductive potential (CRP) was recorded in the hybrid C x R(315), suggesting that this genotype is the least favorable for the development and reproduction of CLM. On the other hand, the highest CRP value obtained in the 'Rugoso' lemon confirms the susceptibility of this genotype, indicating it as the most suitable for CLM.

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

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Funds for the replacement of certified citrus nursery... nursery stock. Subject to the availability of appropriated funds, a commercial citrus nursery may be eligible to receive funds to replace certified citrus nursery stock in accordance with the provisions of...

Ectopic Expression of Xylella fastidiosa rpfF Conferring Production of Diffusible Signal Factor in Transgenic Tobacco and Citrus Alters Pathogen Behavior and Reduces Disease Severity.

Science.gov (United States)

Caserta, R; Souza-Neto, R R; Takita, M A; Lindow, S E; De Souza, A A

2017-11-01

The pathogenicity of Xylella fastidiosa is associated with its ability to colonize the xylem of host plants. Expression of genes contributing to xylem colonization are suppressed, while those necessary for insect vector acquisition are increased with increasing concentrations of diffusible signal factor (DSF), whose production is dependent on RpfF. We previously demonstrated that transgenic citrus plants ectopically expressing rpfF from a citrus strain of X. fastidiosa subsp. pauca exhibited less susceptibility to Xanthomonas citri subsp. citri, another pathogen whose virulence is modulated by DSF accumulation. Here, we demonstrate that ectopic expression of rpfF in both transgenic tobacco and sweet orange also confers a reduction in disease severity incited by X. fastidiosa and reduces its colonization of those plants. Decreased disease severity in the transgenic plants was generally associated with increased expression of genes conferring adhesiveness to the pathogen and decreased expression of genes necessary for active motility, accounting for the reduced population sizes achieved in the plants, apparently by limiting pathogen dispersal through the plant. Plant-derived DSF signal molecules in a host plant can, therefore, be exploited to interfere with more than one pathogen whose virulence is controlled by DSF signaling.

Detection of mechanical and disease stresses in citrus plants by fluorescence spectroscopy

Science.gov (United States)

Belasque, J., Jr.; Gasparoto, M. C. G.; Marcassa, L. G.

2008-04-01

We have investigated the detection of mechanical and disease stresses in citrus plants (Citrus limonia [L.] Osbeck) using laser-induced fluorescence spectroscopy. Due to its economic importance we have chosen to investigate the citrus canker disease, which is caused by the Xanthomonas axonopodis pv. citri bacteria. Mechanical stress was also studied because it plays an important role in the plant's infection by such bacteria. A laser-induced fluorescence spectroscopy system, composed of a spectrometer and a 532 nm10 mW excitation laser was used to perform fluorescence spectroscopy. The ratio of two chlorophyll fluorescence bands allows us to detect and discriminate between mechanical and disease stresses. This ability to discriminate may have an important application in the field to detect citrus canker infected trees.

Mass spectrometry and tandem mass spectrometry of citrus limonoids.

Science.gov (United States)

Tian, Qingguo; Schwartz, Steven J

2003-10-15

Methods for atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS) of citrus limonoid aglycones and electrospray ionization tandem mass spectrometry (ESI-MS/MS) of limonoid glucosides are reported. The fragmentation patterns of four citrus limonoid aglycones (limonin, nomilin, obacunone, and deacetylnomilin) and six limonoid glucosides, that is, limonin 17-beta-D-glucopyranoside (LG), nomilin 17-beta-D-glucopyranoside (NG), nomilinic acid 17-beta-D-glucopyranoside (NAG), deacetyl nomilinic acid 17-beta-D-glucopyranoside (DNAG), obacunone 17-beta-D-glucopyranoside (OG), and obacunoic acid 17-beta-D-glucopyranoside (OAG) were investigated using a quadruple mass spectrometer in low-energy collisionally activated dissociation (CAD). The four limonoid aglycones and four limonoid glucosides (LG, OG, NAG, and DNAG) were purified from citrus seeds; the other two limonoid glucosides (NG and OAG) were tentatively identified in the crude extract of grapefruit seeds by ESI mass spectrometry in both positive and negative ion analysis. Ammonium hydroxide or acetic acid was added to the mobile phase to facilitate ionization. During positive ion APCI analysis of limonoid aglycones, protonated molecular ion, [M + H]+, or adduct ion, [M + NH3 + H]-, was formed as base peaks when ammonium hydroxide was added to the mobile phase. Molecular anions or adduct ions with acetic acid ([M + HOAc - H] and [M + HOAc]-) or a deprotonated molecular ion were produced during negative ion APCI analysis of limonoid aglycones, depending on the mobile-phase modifier used. Positive ion ESI-MS of limonoid glucosides produced adduct ions of [M + H + NH3]+, [M + Na]+, and [M + K]+ when ammonium hydroxide was added to the mobile phase. After collisionally activated dissociation (CAD) of the limonoid aglycone molecular ions in negative ion APCI analysis, fragment ions indicated structural information of the precursor ions, showing the presence of methyl, carboxyl, and oxygenated ring

LRR-RLK family from two Citrus species: genome-wide identification and evolutionary aspects.

Science.gov (United States)

Magalhães, Diogo M; Scholte, Larissa L S; Silva, Nicholas V; Oliveira, Guilherme C; Zipfel, Cyril; Takita, Marco A; De Souza, Alessandra A

2016-08-12

Leucine-rich repeat receptor-like kinases (LRR-RLKs) represent the largest subfamily of plant RLKs. The functions of most LRR-RLKs have remained undiscovered, and a few that have been experimentally characterized have been shown to have important roles in growth and development as well as in defense responses. Although RLK subfamilies have been previously studied in many plants, no comprehensive study has been performed on this gene family in Citrus species, which have high economic importance and are frequent targets for emerging pathogens. In this study, we performed in silico analysis to identify and classify LRR-RLK homologues in the predicted proteomes of Citrus clementina (clementine) and Citrus sinensis (sweet orange). In addition, we used large-scale phylogenetic approaches to elucidate the evolutionary relationships of the LRR-RLKs and further narrowed the analysis to the LRR-XII group, which contains several previously described cell surface immune receptors. We built integrative protein signature databases for Citrus clementina and Citrus sinensis using all predicted protein sequences obtained from whole genomes. A total of 300 and 297 proteins were identified as LRR-RLKs in C. clementina and C. sinensis, respectively. Maximum-likelihood phylogenetic trees were estimated using Arabidopsis LRR-RLK as a template and they allowed us to classify Citrus LRR-RLKs into 16 groups. The LRR-XII group showed a remarkable expansion, containing approximately 150 paralogs encoded in each Citrus genome. Phylogenetic analysis also demonstrated the existence of two distinct LRR-XII clades, each one constituted mainly by RD and non-RD kinases. We identified 68 orthologous pairs from the C. clementina and C. sinensis LRR-XII genes. In addition, among the paralogs, we identified a subset of 78 and 62 clustered genes probably derived from tandem duplication events in the genomes of C. clementina and C. sinensis, respectively. This work provided the first comprehensive

Modeling the effect of pH on biosorption of heavy metals by citrus peels

International Nuclear Information System (INIS)

Schiewer, Silke; Patil, Santosh B.

2008-01-01

Biosorption by materials such as citrus peels could be a cost effective technique for removing toxic heavy metals from wastewater. Orange peels, lemon peels and lemon-based protonated pectin peels (PPP) had Langmuir sorption capacities of 0.7-1.2 mequiv./g (39-67 mg/g) of Cd per biosorbent dry weight. A potentiometric titration was interpreted using a continuous pK a spectrum approach. It revealed four acidic sites with pK a values of 3.8, 6.4, 8.4 and 10.7, and a total site quantity of 1.14 mequiv./g. Sorption isotherms of untreated citrus peels showed an unusual shape with two plateau values. Protonated pectin peels on the other hand showed a typical Langmuir behavior with a higher sorption capacity than untreated peels. At lower pH, metal binding was reduced due to increased competition by protons. This was modeled using pH-sensitive isotherm equations. It was not necessary to assume four binding sites; using one site with pK a 3.8 and a quantity of 1.14 mequiv./g was sufficient. It was possible to accurately predict metal uptake at one pH using the metal binding constant determined at a different pH. A 1:1 stoichiometry model fit the sorption isotherms shape better than a 1:2 stoichiometry. For constant pH, the 1:1 stoichiometry reduces to the Langmuir model

Modeling the effect of pH on biosorption of heavy metals by citrus peels

Energy Technology Data Exchange (ETDEWEB)

Schiewer, Silke [Department of Civil and Environmental Engineering, University of Alaska Fairbanks, PO Box 755900, Fairbanks, AK 99775 (United States)], E-mail: ffsos@uaf.edu; Patil, Santosh B. [Department of Civil and Environmental Engineering, University of Alaska Fairbanks, PO Box 755900, Fairbanks, AK 99775 (United States)

2008-08-30

Biosorption by materials such as citrus peels could be a cost effective technique for removing toxic heavy metals from wastewater. Orange peels, lemon peels and lemon-based protonated pectin peels (PPP) had Langmuir sorption capacities of 0.7-1.2 mequiv./g (39-67 mg/g) of Cd per biosorbent dry weight. A potentiometric titration was interpreted using a continuous pK{sub a} spectrum approach. It revealed four acidic sites with pK{sub a} values of 3.8, 6.4, 8.4 and 10.7, and a total site quantity of 1.14 mequiv./g. Sorption isotherms of untreated citrus peels showed an unusual shape with two plateau values. Protonated pectin peels on the other hand showed a typical Langmuir behavior with a higher sorption capacity than untreated peels. At lower pH, metal binding was reduced due to increased competition by protons. This was modeled using pH-sensitive isotherm equations. It was not necessary to assume four binding sites; using one site with pK{sub a} 3.8 and a quantity of 1.14 mequiv./g was sufficient. It was possible to accurately predict metal uptake at one pH using the metal binding constant determined at a different pH. A 1:1 stoichiometry model fit the sorption isotherms shape better than a 1:2 stoichiometry. For constant pH, the 1:1 stoichiometry reduces to the Langmuir model.

Toxic and hormetic-like effects of three components of citrus essential oils on adult Mediterranean fruit flies (Ceratitis capitata.

Directory of Open Access Journals (Sweden)

Stella A Papanastasiou

Full Text Available Plant essential oils (EOs and a wide range of their individual components are involved in a variety of biological interactions with insect pests including stimulatory, deterrent, toxic and even hormetic effects. Both the beneficial and toxic properties of citrus EOs on the Mediterranean fruit fly (medfly have been experimentally evidenced over the last years. However, no information is available regarding the toxic or beneficial effects of the major components of citrus EOs via contact with the adults of the Mediterranean fruit fly. In the present study, we explored the toxicity of limonene, linalool and α-pinene (3 of the main compounds of citrus EOs against adult medflies and identified the effects of sub-lethal doses of limonene on fitness traits in a relaxed [full diet (yeast and sugar] and in a stressful (sugar only feeding environment. Our results demonstrate that all three compounds inferred high toxicity to adult medflies regardless of the diet, with males being more sensitive than females. Sub-lethal doses of limonene (LD20 enhanced the lifespan of adult medflies when they were deprived of protein. Fecundity was positively affected when females were exposed to limonene sub-lethal doses. Therefore, limonene, a major constituent of citrus EOs, induces high mortality at increased doses and positive effects on life history traits of medfly adults through contact at low sub-lethal doses. A hormetic-like effect of limonene to adult medflies and its possible underlying mechanisms are discussed.

In vitro pollen germination of five citrus species

International Nuclear Information System (INIS)

Khan, S.A.; Perveen, A.

2014-01-01

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)

Exposure to Guava Affects Citrus Olfactory Cues and Attractiveness to Diaphorina citri (Hemiptera: Psyllidae).

Science.gov (United States)

Barman, Jagadish Chandra; Campbell, Stuart A; Zeng, Xinnian

2016-06-01

Intercropping can reduce agricultural pest incidence, and represents an important sustainable alternative to conventional pest control methods. Understanding the ecological mechanisms for intercropping could help optimize its use, particularly in tropical systems which present a large number of intercropping possibilities. Citrus is threatened worldwide by greening disease (huanglongbing, HLB) vectored by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). Control of HLB and citrus psyllid can be partially achieved through intercropping with guava, Psidium guajava L., but the mechanisms remain unclear. We tested the hypothesis that guava olfactory cues affect psyllid behavior by altering the attractiveness of citrus through plant-plant interactions. In choice and no-choice cage experiments, psyllid settlement was reduced on citrus shoots that had been exposed to guava shoot odors for at least 2 h. In Y-tube olfactometer experiments, psyllids oriented to odors of unexposed, compared with guava-exposed, citrus shoots. These behavioral results indicate that a mechanism for the success of guava intercropping for sustainable, ecological disease management may be the indirect effect of guava on citrus attractiveness. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

7 CFR 905.149 - Procedure for permitting growers to ship tree run citrus fruit.

Science.gov (United States)

2010-01-01

... Fruit § 905.149 Procedure for permitting growers to ship tree run citrus fruit. (a) Tree run citrus fruit. Tree run citrus fruit as referenced in this section is defined in the Florida Department of... grower shall apply to ship tree run fruit using a Grower Tree Run Certificate Application, furnished by...

Implementation evaluation of a culturally competent eye injury prevention program for citrus workers in a Florida migrant community.

Science.gov (United States)

Luque, John S; Monaghan, Paul; Contreras, Ricardo B; August, Euna; Baldwin, Julie A; Bryant, Carol A; McDermott, Robert J

2007-01-01

The Partnership for Citrus Worker Health (PCWH) is a coalition that connects academic institutions, public health agencies, industry and community-based organizations for implementation of an eye safety pilot project with citrus workers using the Camp Health Aide (CHA) model. This project was an implementation evaluation of an eye safety curriculum using modeling and peer-to-peer education among Mexican migrant citrus workers in a southwest Florida community to increase positive perceptions toward the use of safety eyewear and reduce occupational eye injuries. CHAs have been employed and trained in eye safety and health during harvesting seasons since 2004. Field observations, focus group interviews, and written questionnaires assessed program implementation and initial outcomes. There was an increase in positive perceptions toward use of safety eyewear between 2004 and 2005. Evaluation of training suggested ways to improve the curriculum. The modest literacy level of the CHAs necessitated some redesign of the curriculum and its implementation (e.g., introduction of and more reliance on use of training posters). PCWH benefited by extensive documentation of the training and supervision, a pilot project that demonstrated the potential effectiveness of CHAs, and having a well-defined target population of citrus workers (n = 427). Future research can rigorously test the effectiveness of CHAs in reducing eye injuries among citrus workers.

Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro

OpenAIRE

Ivanovi?, ?arko; Perovi?, Tatjana; Popovi?, Tatjana; Blagojevi?, Jovana; Trkulja, Nenad; Hrn?i?, Snje?ana

2017-01-01

Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (Citrus reticulata) in Montenegro, using multilocus sequence analysis of gyrB, rpoD, and gap1 gene sequences. Gene sequences from...

Preparation and quantification of the total phenolic products in Citrus fruit using solid-phase extraction coupled with high-performance liquid chromatography with diode array and UV detection.

Science.gov (United States)

Zeng, Honglian; Liu, Zhenli; Zhao, Siyu; Shu, Yisong; Song, Zhiqian; Wang, Chun; Dong, Yunzhuo; Ning, Zhangchi; He, Dan; Wang, Menglei; Lu, Cheng; Liu, Yuanyan; Lu, Aiping

2016-10-01

Citrus fruit is an important health-promoting food that is rich in dietary phenolic metabolites. Traditional Chinese medicines, such as Zhishi and Zhiqiao, come from young and immature fruits of Citrus cultivars. The preparation of diversified bioactive phenolic products and establishment of the corresponding quality control methodology are challenging and necessary. In the current study, four types of solid-phase extraction sorbents for the enrichment and clean-up of the phenolic matrix were evaluated. A solid-phase extraction column coated with Strata-X was finally used in the procedure. Twenty phenolic compounds were selected to evaluate the extraction performances of the sorbents using high-performance liquid chromatography analysis. Under the optimized conditions, good linearities were obtained with R 2 more than 0.9996 for all analytes with LODs of 0.04-1.012 μg/g. Intra- and interday relative standard deviation values were less than 3%, and the recovery was equal to or higher than 90.02%. Compared to non-solid-phase extraction process, the content of total phenolic products was elevated 35.55-68.48% with solid-phase extraction. Finally, the developed and validated method was successfully applied to the discrimination of Zhishi samples from different species as well as Zhishi and Zhiqiao samples in different development stages. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Simultaneous determination of pyraclostrobin and thiophanate-methyl and its metabolite carbendazim residues in soil and citrus by QuEChERS-liquid chromatography- tandem mass spectrometry].

Science.gov (United States)

Li, Fuqin; Shi, Lihong; Wang, Fei; Sun, Caiyuan; Kang, Di; Zhang, Yuping; Chen, Lingzhu; Hu, Deyu

2017-06-08

A QuEChERS-liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of pyraclostrobin, thiophanate-methyl and its metabolite carbendazim in soil and citrus. The samples were extracted with methanol or acetonitrile, purified by primary secondary amine (PSA), then separated by LC, detected in multiple reaction monitoring (MRM) mass spectrometry mode via positive electrospray ionization. The analytes were quantified by matrix-matched standard solutions with external standard method. The limits of quantification (LOQs) of pyraclostrobin, thiophanate-methyl and carbendazim in different matrices were 5.8-7.0 μg/kg, 9.3-14.1 μg/kg and 2.1-2.6 μg/kg, respectively. For all the samples, the spiked recoveries ranged from 75.48% to 109.18%, and the relative standard deviations (RSDs) were 0.60%-5.11% ( n =5). The method is quick, easy, effective, sensitive and accurate. The matrix-matched calibration solutions can efficiently compensate matrix effects of the pyraclostrobin, thiophanate-methyl and carbendazim in LC-MS/MS analysis. The established method can be applied to the residue analysis of the real samples of soil, citrus peel, citrus pulp and citrus fruits.

Extraction, Modelling and Purification of Flavonoids from Citrus Medica Peel

OpenAIRE

M. Parvathi Nandan; Vangalapati Meena

2015-01-01

Soxhlet extraction technique is widely employed for the extraction and separation of chemical constituents in the medicinal plants. Citrus medica L commonly called as Citron belongs to family Rutaceae, is a slow-growing shrub. It is mainly cultivated for the production of edible fruits which are sour in taste like lime and lemon and the main content of a citron fruit is the thick rind, which is very adherent to the segments. From the phytochemical analysis the peel extract is rich source of p...

Carcass characteristics and meat quality of heavy swine fed different citrus pulp levels

Directory of Open Access Journals (Sweden)

P.H. Watanabe

2010-08-01

Full Text Available An assay with 36 swine initially weighting 83.7±5.1kg body weight (BW was carried out to evaluate the effects of the use of different dietary citrus pulp levels, 0, 10%, 20%, and 30%, upon digestive organs weights, carcass characteristics, and meat quality of animals subjected to qualitative feed restriction program, and slaughtered at 130kg BW. Linear response (P0.05. Higher levels of citrus pulp neither decreased backfat thickness nor increased amount of lean meat, indicative that qualitative feed restriction was not efficient. Positive linear effect (P<0.05 on pH measured 24 hours after slaughter and negative linear effect (P<0.05 on color characteristics as function of citrus pulp dietary levels were verified. Citrus pulp addition in qualitative feed restriction program may not be effective. As no deleterious effects upon meat qualities were observed, citrus pulp can be used as an alternative feedstuff for finishing swine.

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.

Monoterpene biosynthesis in lemon (Citrus limon) cDNA isolation and functional analysis of four monoterpene synthases

NARCIS (Netherlands)

Lücker, J.; Tamer, El M.K.; Schwab, W.; Verstappen, F.W.A.; Plas, van der L.H.W.; Bouwmeester, H.J.; Verhoeven, H.A.

2002-01-01

Citrus limon possesses a high content and large variety of monoterpenoids, especially in the glands of the fruit flavedo. The genes responsible for the production of these monoterpenes have never been isolated. By applying a random sequencing approach to a cDNA library from mRNA isolated from the

Potential feedstock sources for ethanol production in Florida

Energy Technology Data Exchange (ETDEWEB)

Rahmani, Mohammad [Univ. of Florida, Gainesville, FL (United States); Hodges, Alan [Univ. of Florida, Gainesville, FL (United States)

2015-10-01

This study presents information on the potential feedstock sources that may be used for ethanol production in Florida. Several potential feedstocks for fuel ethanol production in Florida are discussed, such as, sugarcane, corn, citrus byproducts and sweet sorghum. Other probable impacts need to be analyzed for sugarcane to ethanol production as alternative uses of sugarcane may affect the quantity of sugar production in Florida. While citrus molasses is converted to ethanol as an established process, the cost of ethanol is higher, and the total amount of citrus molasses per year is insignificant. Sorghum cultivars have the potential for ethanol production. However, the agricultural practices for growing sweet sorghum for ethanol have not been established, and the conversion process must be tested and developed at a more expanded level. So far, only corn shipped from other states to Florida has been considered for ethanol production on a commercial scale. The economic feasibility of each of these crops requires further data and technical analysis.

Nuclear Species-Diagnostic SNP Markers Mined from 454 Amplicon Sequencing Reveal Admixture Genomic Structure of Modern Citrus Varieties

Science.gov (United States)

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

2015-01-01

Most cultivated Citrus species originated from interspecific hybridisation between four ancestral taxa (C. reticulata, C. maxima, C. medica, and C. micrantha) with limited further interspecific recombination due to vegetative propagation. This evolution resulted in admixture genomes with frequent interspecific heterozygosity. Moreover, a major part of the phenotypic diversity of edible citrus results from the initial differentiation between these taxa. Deciphering the phylogenomic structure of citrus germplasm is therefore essential for an efficient utilization of citrus biodiversity in breeding schemes. The objective of this work was to develop a set of species-diagnostic single nucleotide polymorphism (SNP) markers for the four Citrus ancestral taxa covering the nine chromosomes, and to use these markers to infer the phylogenomic structure of secondary species and modern cultivars. Species-diagnostic SNPs were mined from 454 amplicon sequencing of 57 gene fragments from 26 genotypes of the four basic taxa. Of the 1,053 SNPs mined from 28,507 kb sequence, 273 were found to be highly diagnostic for a single basic taxon. Species-diagnostic SNP markers (105) were used to analyse the admixture structure of varieties and rootstocks. This revealed C. maxima introgressions in most of the old and in all recent selections of mandarins, and suggested that C. reticulata × C. maxima reticulation and introgression processes were important in edible mandarin domestication. The large range of phylogenomic constitutions between C. reticulata and C. maxima revealed in mandarins, tangelos, tangors, sweet oranges, sour oranges, grapefruits, and orangelos is favourable for genetic association studies based on phylogenomic structures of the germplasm. Inferred admixture structures were in agreement with previous hypotheses regarding the origin of several secondary species and also revealed the probable origin of several acid citrus varieties. The developed species-diagnostic SNP

Identification of Putative Genes Involved in Limonoids Biosynthesis in Citrus by Comparative Transcriptomic Analysis

Directory of Open Access Journals (Sweden)

Fusheng Wang

2017-05-01

Full Text Available Limonoids produced by citrus are a group of highly bioactive secondary metabolites which provide health benefits for humans. Currently there is a lack of information derived from research on the genetic mechanisms controlling the biosynthesis of limonoids, which has limited the improvement of citrus for high production of limonoids. In this study, the transcriptome sequences of leaves, phloems and seeds of pummelo (Citrus grandis (L. Osbeck at different development stages with variances in limonoids contents were used for digital gene expression profiling analysis in order to identify the genes corresponding to the biosynthesis of limonoids. Pair-wise comparison of transcriptional profiles between different tissues identified 924 differentially expressed genes commonly shared between them. Expression pattern analysis suggested that 382 genes from three conjunctive groups of K-means clustering could be possibly related to the biosynthesis of limonoids. Correlation analysis with the samples from different genotypes, and different developing tissues of the citrus revealed that the expression of 15 candidate genes were highly correlated with the contents of limonoids. Among them, the cytochrome P450s (CYP450s and transcriptional factor MYB demonstrated significantly high correlation coefficients, which indicated the importance of those genes on the biosynthesis of limonoids. CiOSC gene encoding the critical enzyme oxidosqualene cyclase (OSC for biosynthesis of the precursor of triterpene scaffolds was found positively corresponding to the accumulation of limonoids during the development of seeds. Suppressing the expression of CiOSC with VIGS (Virus-induced gene silencing demonstrated that the level of gene silencing was significantly correlated to the reduction of limonoids contents. The results indicated that the CiOSC gene plays a pivotal role in biosynthesis of limonoids.

Health Assessment of Heavy Metal Pollution (Cadmium, Lead, Arsenic in Citrus Marketed in Tehran, Iran, 2015

Directory of Open Access Journals (Sweden)

Razieh Saleh

2017-03-01

Full Text Available Background & Aims of the Study: Today, the environment pollution with heavy metals has increased. It is important to study various types of pollutions specially those regarding fruits. The effect of pollutions on food safety for human consumption is a global concern.  This study was conducted for health assessment of heavy metals pollution (cadmium, lead, and arsenic in citrus marketed in Tehran, Iran in 2015. Materials & Methods: After collecting and preparing 2 samples from each citrus species (tangerine, grapefruit, sweet lime, sour orange, orange with acid digestion method, the citrus pulp and peel were surveyed. Inductively coupled plasma optical emission spectrometry (ICP-OES was used to determine the concentrations of heavy metals with three replications. Moreover, SPSS version 19 was employed to perform statistical analysis. Results: The results showed that the concentration average of Cadmium, Lead and Arsenic in citrus samples of the pulp parts were 19.73, 42.95 and 2.30 mg/kg and in peel parts were 20.09, 42.71 and 2.12 mg/kg, respectively. The average concentrations of heavy metals were higher than WHO maximum permissible limits. Conclusions: Based on these results, consumption of citrus species has no adverse effect on the consumers’ health (except Sweet lime, Orange, Tangerine and Grapefruit in lead is risky for adults and Sweet lime and Orange that Health Index in Lead and Arsenic and Sour Orange, Tangerine and Grapefruit that Health Index in Lead is more than 1 and is risky for children. Thus, individuals living in Tehran should be cautious about using these citrus fruits and researchers should try to obtain national standards in the field of entering these metals to food in environmental conditions that are in Iran.

Overexpression of a modified plant thionin enhances disease resistance to citrus canker and Huanglongbing (HLB)

Science.gov (United States)

Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States 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 ec...

Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

Directory of Open Access Journals (Sweden)

Muhammad Azam

2013-11-01

Full Text Available Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

Produção de frutos e incidência de cancro cítrico em laranjeiras "Monte Parnaso" enxertadas sobre sete porta-enxertos Fruit production and incidence of citrus canker lesions on "Monte Parnaso" navel orange budded on seven rootstocks

Directory of Open Access Journals (Sweden)

Bernadete Reis

2008-06-01

Full Text Available Porta-enxertos de citros podem exercer influência sobre a produção de frutos e suscetibilidade das plantas ao cancro cítrico. Este trabalho objetivou selecionar porta-enxertos que induzam elevado índice de produtividade e menor suscetibilidade das copas de laranjeiras-de-umbigo "Monte Parnaso"(Citrus sinensis à bactéria Xanthomonas axonopodis pv. citri, causadora do cancro cítrico (CC. O experimento foi desenvolvido em um pomar experimental com 10 anos de idade, plantado em espaçamento de 2,5 x 6,0m, no município de Butiá, no Estado do Rio Grande do Sul. O delineamento experimental foi em blocos ao acaso, com sete tratamentos e quatro repetições, usando duas plantas por parcela. Os tratamentos constaram dos seguintes porta-enxertos: limoeiros "Cravo" (C. limonia e "Volkameriano" (C. volkameriana., trifoliata "Flying Dragon" (Poncirus trifoliata., laranjeira "Caipira" (C. sinensis, citrangeiro "Troyer" (C. sinensis x P. trifoliata, tangerineira "Sunki" (C. sunki. e citrumeleiro "Swingle" (C. paradisi x P. trifoliata. Os parâmetros avaliados foram: incidência de CC em folhas e frutos em toda a planta e em ramos previamente selecionados, em diversas épocas. Verificou-se que as plantas enxertadas sobre citrumeleiro "Swingle" apresentaram o maior índice de produtividade e, à semelhança do "Flying Dragon", a menor incidência de CC, tanto nas folhas como nos frutos. Além disso, verificou-se também que as plantas enxertadas sobre os limoeiros "Cravo" e "Volkameriana", apesar de produzirem as mais elevadas cargas de frutos, foram as mais suscetíveis ao CC.Citrus rootstocks can exert some influences on fruit production and susceptibility of the plants to citrus canker (CC. This research was performed aiming to select rootstocks which induce higher productivity index and lower susceptibility of 'Monte Parnaso' navel orange (Citrus sinensis trees to the bacteria Xanthomonas axonopodis pv. citri. The research was carried out in an

Hybrid Origins of Citrus Varieties Inferred from DNA Marker Analysis of Nuclear and Organelle Genomes

Science.gov (United States)

Kitajima, Akira; Nonaka, Keisuke; Yoshioka, Terutaka; Ohta, Satoshi; Goto, Shingo; Toyoda, Atsushi; Fujiyama, Asao; Mochizuki, Takako; Nagasaki, Hideki; Kaminuma, Eli; Nakamura, Yasukazu

2016-01-01

Most indigenous citrus varieties are assumed to be natural hybrids, but their parentage has so far been determined in only a few cases because of their wide genetic diversity and the low transferability of DNA markers. Here we infer the parentage of indigenous citrus varieties using simple sequence repeat and indel markers developed from various citrus genome sequence resources. Parentage tests with 122 known hybrids using the selected DNA markers certify their transferability among those hybrids. Identity tests confirm that most variant strains are selected mutants, but we find four types of kunenbo (Citrus nobilis) and three types of tachibana (Citrus tachibana) for which we suggest different origins. Structure analysis with DNA markers that are in Hardy–Weinberg equilibrium deduce three basic taxa coinciding with the current understanding of citrus ancestors. Genotyping analysis of 101 indigenous citrus varieties with 123 selected DNA markers infers the parentages of 22 indigenous citrus varieties including Satsuma, Temple, and iyo, and single parents of 45 indigenous citrus varieties, including kunenbo, C. ichangensis, and Ichang lemon by allele-sharing and parentage tests. Genotyping analysis of chloroplast and mitochondrial genomes using 11 DNA markers classifies their cytoplasmic genotypes into 18 categories and deduces the combination of seed and pollen parents. Likelihood ratio analysis verifies the inferred parentages with significant scores. The reconstructed genealogy identifies 12 types of varieties consisting of Kishu, kunenbo, yuzu, koji, sour orange, dancy, kobeni mikan, sweet orange, tachibana, Cleopatra, willowleaf mandarin, and pummelo, which have played pivotal roles in the occurrence of these indigenous varieties. The inferred parentage of the indigenous varieties confirms their hybrid origins, as found by recent studies. PMID:27902727

Sum Insured Determination for Cereal, Citrus and Vineyards in the Spanish Agricultural Insurance System

Science.gov (United States)

Lozano, C.; Tarquis, A. M.; Gómez-Barona, J. A.

2012-04-01

In general, insurance is a form of risk management used to hedge against a contingent loss. The conventional definition is the equitable transfer of a risk of loss from one entity to another in exchange for a premium or a guaranteed and quantifiable small loss to prevent a large and possibly devastating loss being agricultural insurance a special line of property insurance. Agriculture insurance, as actually are designed in the Spanish scenario, were established in 1978. At the macroeconomic insurance studies scale, it is necessary to know a basic element for the insurance actuarial components: sum insured. When a new risk assessment has to be evaluated in the insurance framework, it is essential to determinate venture capital in the total Spanish agriculture. In this study, three different crops (cereal, citrus and vineyards) cases are showed to determinate sum insured as they are representative of the cases found in the Spanish agriculture. Crop sum insured is calculated by the product of crop surface, unit surface production and crop price insured. In the cereal case, winter as spring cereal sowing, represents the highest Spanish crop surface, above to 6 millions of hectares (ha). Meanwhile, the four citrus species (oranges, mandarins, lemons and grapefruits) occupied an extension just over 275.000 ha. On the other hand, vineyard target to wine process shows almost one million of ha in Spain. A new method has been applied to estimate crop sum insured in these three cases. Under the maximum economic impact assumption, the maximum market price has been used to insurance each species. Depending on crop and reliability of the data base available, the insured area or insured production has been used in this estimation. When for a certain crop varieties or type of varieties show different insurance prices a geometric average was used as average insurance price for that particular crop. One extreme difficult case was vineyards, where differentiate prices based on

Genome-wide comparative analysis reveals similar types of NBS genes in hybrid Citrus sinensis genome and original Citrus clementine genome and provides new insights into non-TIR NBS genes.

Directory of Open Access Journals (Sweden)

Yunsheng Wang

Full Text Available In this study, we identified and compared nucleotide-binding site (NBS domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China. Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approximately evenly numbered groups: one group contains the Toll-Interleukin receptor (TIR domain and two different Non-TIR groups in which most of proteins contain the Coiled Coil (CC domain. Motif analysis confirmed that the two groups of CC-containing NBS genes are from different evolutionary origins. We partitioned NBS genes into clades using NBS domain sequence distances and found most clades include NBS genes from all three Citrus genomes. This suggests that three Citrus genomes have similar numbers and types of NBS genes. We also mapped the re-sequenced reads of three pomelo and three mandarin genomes onto the C. sinensis genome. We found that most NBS genes of the hybrid C. sinensis genome have corresponding homologous genes in both pomelo and mandarin genomes. The homologous NBS genes in pomelo and mandarin suggest that the parental species of C. sinensis may contain similar types of NBS genes. This explains why the hybrid C. sinensis and original C. clementina have similar types of NBS genes in this study. Furthermore, we found that sequence variation amongst Citrus NBS genes were shaped by multiple independent and shared accelerated mutation accumulation events among different groups of NBS genes and in different Citrus genomes. Our comparative analyses yield valuable insight into the structure, organization and evolution of NBS genes in Citrus genomes. Furthermore, our comprehensive analysis showed that the non-TIR NBS genes can be divided into two groups that come from different evolutionary origins. This provides new insights into non-TIR genes, which have not received much attention.

Inducible expression of Bs2 R gene from Capsicum chacoense in sweet orange (Citrus sinensis L. Osbeck) confers enhanced resistance to citrus canker disease.

Science.gov (United States)

Sendín, Lorena Noelia; Orce, Ingrid Georgina; Gómez, Rocío Liliana; Enrique, Ramón; Grellet Bournonville, Carlos Froilán; Noguera, Aldo Sergio; Vojnov, Adrián Alberto; Marano, María Rosa; Castagnaro, Atilio Pedro; Filippone, María Paula

2017-04-01

Transgenic expression of the pepper Bs2 gene confers resistance to Xanthomonas campestris pv. vesicatoria (Xcv) pathogenic strains which contain the avrBs2 avirulence gene in susceptible pepper and tomato varieties. The avrBs2 gene is highly conserved among members of the Xanthomonas genus, and the avrBs2 of Xcv shares 96% homology with the avrBs2 of Xanthomonas citri subsp. citri (Xcc), the causal agent of citrus canker disease. A previous study showed that the transient expression of pepper Bs2 in lemon leaves reduced canker formation and induced plant defence mechanisms. In this work, the effect of the stable expression of Bs2 gene on citrus canker resistance was evaluated in transgenic plants of Citrus sinensis cv. Pineapple. Interestingly, Agrobacterium-mediated transformation of epicotyls was unsuccessful when a constitutive promoter (2× CaMV 35S) was used in the plasmid construction, but seven transgenic lines were obtained with a genetic construction harbouring Bs2 under the control of a pathogen-inducible promoter, from glutathione S-transferase gene from potato. A reduction of disease symptoms of up to 70% was observed in transgenic lines expressing Bs2 with respect to non-transformed control plants. This reduction was directly dependent on the Xcc avrBs2 gene since no effect was observed when a mutant strain of Xcc with a disruption in avrBs2 gene was used for inoculations. Additionally, a canker symptom reduction was correlated with levels of the Bs2 expression in transgenic plants, as assessed by real-time qPCR, and accompanied by the production of reactive oxygen species. These results indicate that the pepper Bs2 resistance gene is also functional in a family other than the Solanaceae, and could be considered for canker control.

Enhanced reliability and accuracy for field deployable bioforensic detection and discrimination of Xylella fastidiosa subsp. pauca, causal agent of citrus variegated chlorosis using razor ex technology and TaqMan quantitative PCR.

Science.gov (United States)

Ouyang, Ping; Arif, Mohammad; Fletcher, Jacqueline; Melcher, Ulrich; Ochoa Corona, Francisco Manuel

2013-01-01

A reliable, accurate and rapid multigene-based assay combining real time quantitative PCR (qPCR) and a Razor Ex BioDetection System (Razor Ex) was validated for detection of Xylella fastidiosa subsp. pauca (Xfp, a xylem-limited bacterium that causes citrus variegated chlorosis [CVC]). CVC, which is exotic to the United States, has spread through South and Central America and could significantly impact U.S. citrus if it arrives. A method for early, accurate and sensitive detection of Xfp in plant tissues is needed by plant health officials for inspection of products from quarantined locations, and by extension specialists for detection, identification and management of disease outbreaks and reservoir hosts. Two sets of specific PCR primers and probes, targeting Xfp genes for fimbrillin and the periplasmic iron-binding protein were designed. A third pair of primers targeting the conserved cobalamin synthesis protein gene was designed to detect all possible X. fastidiosa (Xf) strains. All three primer sets detected as little as 1 fg of plasmid DNA carrying X. fastidiosa target sequences and genomic DNA of Xfp at as little as 1 - 10 fg. The use of Razor Ex facilitates a rapid (about 30 min) in-field assay capability for detection of all Xf strains, and for specific detection of Xfp. Combined use of three primer sets targeting different genes increased the assay accuracy and broadened the range of detection. To our knowledge, this is the first report of a field-deployable rapid and reliable bioforensic detection and discrimination method for a bacterial phytopathogen based on multigene targets.

Infection Density Dynamics of the Citrus Greening Bacterium “Candidatus Liberibacter asiaticus” in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants

Science.gov (United States)

Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi

2015-01-01

Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, “Candidatus Liberibacter asiaticus,” and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of “Ca. Liberibacter asiaticus” in field populations of D. citri with experiments using field-collected insects to address how “Ca. Liberibacter asiaticus” infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from “Ca. Liberibacter asiaticus”-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were “Ca. Liberibacter asiaticus” positive. The infections were systemic across head-thorax and abdomen, ranging from 103 to 107 bacteria per insect. In spring, the infection densities were low in March, at ∼103 bacteria per insect, increasing up to 106 to 107 bacteria per insect in April and May, and decreasing to 105 to 106 bacteria per insect in late May, whereas the infection densities were constantly ∼106 to 107 bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with “Ca. Liberibacter asiaticus” infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected “Ca. Liberibacter asiaticus”-infected insects suggested that (i) “Ca. Liberibacter asiaticus”-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼106 bacteria per insect) of “Ca. Liberibacter asiaticus” density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits “Ca. Liberibacter asiaticus” to citrus plants in a stochastic manner. These

Evaluation of antioxidant potential of citrus peel extracts

International Nuclear Information System (INIS)

Chatha, S.A.S.; Hussain, A.I.; Asi, M.R.

2011-01-01

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)

Effects of Gibberellic Acid and Putrescine Treatments on Marketable and Some Quality Attributes Certains of Citrus Fruit (Citrus sinensis Cv. Hamlen

Directory of Open Access Journals (Sweden)

H. Azh

2014-04-01

Full Text Available Citrus fruit quality preserve the post harvest cause marketability increased. In this research, the effect of putrescin and gibberellic acid concentrations on storage life of sweet orange fruit (Hamlen cultivar was studied to in factorial design (3*3*6=54based on randomized complete block with six replications. Putrescin at three concentrations( 0, 1 and 2 mM and three level of gibberellic acid (0, 50 and 100 mg/L were sprayed on the tree at the physiological maturation stage and two weeks pre harvest. Fruit firmness, marketability, vitamin C, total acidity, total soluble solids (TSS and ratio of total soluble solids (TSS to total acidity were evaluated. The results showed that putrescin spraying at 1 mM significantly prevented fruit softening and preserved fruit firmness. Also putrescin treatment (1 mM preserved ideal marketability and was superior than other treatments. Gibberellic acid significantly preserved total acidity and total soluble solids. The interaction of gibberellic acid and putrescine also preserved significantly vitamin C. Therefore, the application of putrescine at 1 mM and gibberellic at 100 mg/L was recommended for preserve marketability, appearance and quality of citrus sinensis cv. Hamlen.

Quantitative study of flavonoids in leaves of citrus plants.

Science.gov (United States)

Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M; Koizumi, M; Ito, C; Furukawa, H

2000-09-01

Leaf flavonoids were quantitatively determined in 68 representative or economically important Citrus species, cultivars, and near-Citrus relatives. Contents of 23 flavonoids including 6 polymethoxylated flavones were analyzed by means of reversed phase HPLC analysis. Principal component analysis revealed that the 7 associations according to Tanaka's classification were observed, but some do overlap each other. Group VII species could be divided into two different subgroups, namely, the first-10-species class and the last-19-species class according to Tanaka's classification numbers.

Effects of Combined Heat and Preservative Treatment on Storability of Ponkan Fruit (Citrus reticulata Blanco cv. Ponkan during Postharvest Storage

Directory of Open Access Journals (Sweden)

Dandan Tang

2017-01-01

Full Text Available Heat treatment and preservative application have been widely used during postharvest storage of many fresh products, but the effect of their combination on citrus storage has rarely been investigated. In this study, the optimal heat treatment (HT conditions and HT combined with preservative treatment were investigated for Ponkan fruit (Citrus reticulata Blanco cv. Ponkan storage. Results indicated that HT at 55°C for 20 s can significantly reduce the decay rate of Ponkan fruit, and a combination of HT and 25% of the preservative dosage used in production of iminoctadine tris (albesilate, 2,4-dichlorophenoxyacetic acid, and imazalil significantly reduced the decay rate without affecting fruit quality. In addition, the increased fiber contents in fruit receiving the HT combined with preservative treatments may be a response preventing fungus infection and enhancing fruit storability and resistance. The above results suggested that the combination of HT and 25% of the preservative production dosage was optimal for controlling Ponkan fruit decay during storage.

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.

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...

Aspects of Salt Tolerance in a NaCl-Selected Stable Cell Line of Citrus sinensis.

Science.gov (United States)

Ben-Hayyim, G; Kochba, J

1983-07-01

A NaCl-tolerant cell line which was selected from ovular callus of ;Shamouti' orange (Citrus sinensis L. Osbeck) proved to be a true cell line variant. This conclusion is based on the following observations. (a) Cells which have been removed from the selection pressure for at least four passages retain the same NaCl tolerance as do cells which are kept constantly on 0.2 molar NaCl. (b) Na(+) and Cl(-) uptake are considerably lower in salt-tolerant cells (R-10) than in salt-sensitive cells (L-5) at a given external NaCl concentration. (c) Growth of salt-tolerant cells is markedly suppressed upon replacement of NaCl by KCl, whereas the growth of salt-sensitive cells is only slightly affected. Accumulation of K(+) and Cl(-) accompanies the inhibition of growth. Experiments carried out with sodium and potassium sulfate suggest that the toxic effect is due to the accumulated Cl(-). (d) Removal of Ca(2+) from the growth medium severely inhibits the growth of salt-tolerant cells in the presence of NaCl, while it has a minor effect on growth of salt-sensitive cells in the presence of NaCl. (e) Electron micrographs show that the salt-tolerant cells have very big vacuoles when exposed to salt, while the size of the vacuoles of the salt-sensitive cells does not change.

Infection Density Dynamics of the Citrus Greening Bacterium "Candidatus Liberibacter asiaticus" in Field Populations of the Psyllid Diaphorina citri and Its Relevance to the Efficiency of Pathogen Transmission to Citrus Plants.

Science.gov (United States)

Ukuda-Hosokawa, Rie; Sadoyama, Yasutsune; Kishaba, Misaki; Kuriwada, Takashi; Anbutsu, Hisashi; Fukatsu, Takema

2015-06-01

Huanglongbing, or citrus greening, is a devastating disease of citrus plants recently spreading worldwide, which is caused by an uncultivable bacterial pathogen, "Candidatus Liberibacter asiaticus," and vectored by a phloem-sucking insect, Diaphorina citri. We investigated the infection density dynamics of "Ca. Liberibacter asiaticus" in field populations of D. citri with experiments using field-collected insects to address how "Ca. Liberibacter asiaticus" infection density in the vector insect is relevant to pathogen transmission to citrus plants. Of 500 insects continuously collected from "Ca. Liberibacter asiaticus"-infected citrus trees with pathological symptoms in the spring and autumn of 2009, 497 (99.4%) were "Ca. Liberibacter asiaticus" positive. The infections were systemic across head-thorax and abdomen, ranging from 10(3) to 10(7) bacteria per insect. In spring, the infection densities were low in March, at ∼ 10(3) bacteria per insect, increasing up to 10(6) to 10(7) bacteria per insect in April and May, and decreasing to 10(5) to 10(6) bacteria per insect in late May, whereas the infection densities were constantly ∼ 10(6) to 10(7) bacteria per insect in autumn. Statistical analysis suggested that several factors, such as insect sex, host trees, and collection dates, may be correlated with "Ca. Liberibacter asiaticus" infection densities in field D. citri populations. Inoculation experiments with citrus seedlings using field-collected "Ca. Liberibacter asiaticus"-infected insects suggested that (i) "Ca. Liberibacter asiaticus"-transmitting insects tend to exhibit higher infection densities than do nontransmitting insects, (ii) a threshold level (∼ 10(6) bacteria per insect) of "Ca. Liberibacter asiaticus" density in D. citri is required for successful transmission to citrus plants, and (iii) D. citri attaining the threshold infection level transmits "Ca. Liberibacter asiaticus" to citrus plants in a stochastic manner. These findings provide

Towards Sustainable H2 Production: Rational Design of Hydrophobic Triphenylamine-based Dyes for Sensitized Ethanol Photoreforming.

Science.gov (United States)

Dessì, Alessio; Monai, Matteo; Bessi, Matteo; Montini, Tiziano; Calamante, Massimo; Mordini, Alessandro; Reginato, Gianna; Trono, Cosimo; Fornasiero, Paolo; Zani, Lorenzo

2018-02-22

Donor-acceptor dyes are a well-established class of photosensitizers, used to enhance visible-light harvesting in solar cells and in direct photocatalytic reactions, such as H 2 production by photoreforming of sacrificial electron donors (SEDs). Amines-typically triethanolamine (TEOA)-are commonly employed as SEDs in such reactions. Dye-sensitized photoreforming of more sustainable, biomass-derived alcohols, on the other hand, was only recently reported by using methanol as the electron donor. In this work, several rationally designed donor-acceptor dyes were used as sensitizers in H 2 photocatalytic production, comparing the efficiency of TEOA and EtOH as SEDs. In particular, the effect of hydrophobic chains in the spacer and/or the donor unit of the dyes was systematically studied. The H 2 production rates were higher when TEOA was used as SED, whereas the activity trends depended on the SED used. The best performance was obtained with TEOA by using a sensitizer with just one bulky hydrophobic moiety, propylenedioxythiophene, placed on the spacer unit. In the case of EtOH, the best-performing sensitizers were the ones featuring a thiazolo[5,4-d]thiazole internal unit, needed for enhancing light harvesting, and carrying alkyl chains on both the donor part and the spacer unit. The results are discussed in terms of reaction mechanism, interaction with the SED, and structural/electrochemical properties of the sensitizers. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Economic wealth and soil erosion in new Citrus plantations in Eastern Spain or how to explain the Land Degradation

Science.gov (United States)

Giménez-Morera, Antonio; Cerdà, Artemio; Pereira, Pauloq

2014-05-01

We use to accept the idea that the best oranges are coming from Valecia Region in Eastern Spain. Although the oranges are originally from Eastern Asia, Valencia is having a mild climate in winter, with a low recurrency of frost and is strategically located close to the largest market of citrus: Western Europe. This resulted in a continuous growth of production and trade of citrus, and contributed to make the Valencia Region the largest World exporter (Bono, 2010). This economical success reached the highest point after the EU and Spain agreement in 1986. This expansion of citrus plantations were done on steep slopes allowed by the drip irrigation systems that does not need leveling the land as it was done by new farmers with large properties. The traditional farming of oranges was done in small properties, flood irrigation and leveled land. Those changes are triggering intense soil erosion rates such were shown by previous researchers in Valencia (Cerdà et al., 2009). This impact is also shown in other regions with a similar citrus production evolution, and China is a clear example (Wang et al., 2010; Liu et al., 2012). Land This research evaluate the relations between the investment (economic wealth) of the owners of citrus plantations and the soil erosion rates on their orchards. The economic wealth of the onwers was measured on the size of their properties and after an interview. The soil erosion rates were measured by means of rainfall simulation experiments in each farm by means of thunderstorms of 10 years return period (55 mm h-1). The results show that the soil losses in the new plantations are extremely high (> 10 Mg ha-1 y-1), and that we can show three types of orchards: 10.1. The soil erosion rates where positively related to the size of the farms. The higher erosion rates are shown also by the scientific literature review. Chemically treated plantations (Cerdà, 2002) show high erosion rates due to the road construction too (Cerdà, 2007) and is

Insecticidal suppression of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae vector of huanglongbing pathogens.

Directory of Open Access Journals (Sweden)

Jawwad A Qureshi

Full Text Available Diaphorina citri vectors pathogens that cause 'huanglongbing' or citrus greening disease which poses a serious threat to citrus production worldwide. Vector suppression is critical to reduce disease spread. Efficacy is a main concern when choosing an insecticide. Insecticidal treatments of 49 products or 44 active ingredients (a.i labeled or experimental were field tested between 2005-2013 as foliar sprays (250 treatments, 39 a.i or soil applications (47 treatments, 9 a.i to control D. citri in citrus. A combined effect of nymphal and adult suppression in response to sprays of 23 insecticides representing 9 modes of action (MoA groups and 3 unknown MoA provided more than 90% reduction of adult D. citri over 24-68 days. Observable effects on nymphs were generally of shorter duration due to rapid maturation of flush. However, reduction of 76-100% nymphs or adults over 99-296 days was seen on young trees receiving drenches of the neonicotinoids imidacloprid, thiamethoxam or clothianidin (MoA 4A and a novel anthranilic diamide, cyantraniliprole (MoA 28. Effective products identified for foliar sprays to control D. citri provide sufficient MoA groups for rotation to delay evolution of insecticide resistance by D. citri and other pests. However, cyantraniliprole is now the only available alternative for rotation with neonicotinoids in soil application to young trees. Sprays of up to eight of the most effective insecticides could be rotated over a year without repetition of any MoA and little or no recourse to neonicotinoids or cyantraniliprole, so important for protection of young trees. Other considerations effecting decisions of what and when to spray include prevalence of huanglongbing, pest pressure, pre-harvest intervals, overall budget, equipment availability, and conservation of beneficial arthropods. Examples of spray programs utilizing broad-spectrum and relatively selective insecticides are provided to improve vector management and may vary

Insecticidal suppression of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae) vector of huanglongbing pathogens.

Science.gov (United States)

Qureshi, Jawwad A; Kostyk, Barry C; Stansly, Philip A

2014-01-01

Diaphorina citri vectors pathogens that cause 'huanglongbing' or citrus greening disease which poses a serious threat to citrus production worldwide. Vector suppression is critical to reduce disease spread. Efficacy is a main concern when choosing an insecticide. Insecticidal treatments of 49 products or 44 active ingredients (a.i) labeled or experimental were field tested between 2005-2013 as foliar sprays (250 treatments, 39 a.i) or soil applications (47 treatments, 9 a.i) to control D. citri in citrus. A combined effect of nymphal and adult suppression in response to sprays of 23 insecticides representing 9 modes of action (MoA) groups and 3 unknown MoA provided more than 90% reduction of adult D. citri over 24-68 days. Observable effects on nymphs were generally of shorter duration due to rapid maturation of flush. However, reduction of 76-100% nymphs or adults over 99-296 days was seen on young trees receiving drenches of the neonicotinoids imidacloprid, thiamethoxam or clothianidin (MoA 4A) and a novel anthranilic diamide, cyantraniliprole (MoA 28). Effective products identified for foliar sprays to control D. citri provide sufficient MoA groups for rotation to delay evolution of insecticide resistance by D. citri and other pests. However, cyantraniliprole is now the only available alternative for rotation with neonicotinoids in soil application to young trees. Sprays of up to eight of the most effective insecticides could be rotated over a year without repetition of any MoA and little or no recourse to neonicotinoids or cyantraniliprole, so important for protection of young trees. Other considerations effecting decisions of what and when to spray include prevalence of huanglongbing, pest pressure, pre-harvest intervals, overall budget, equipment availability, and conservation of beneficial arthropods. Examples of spray programs utilizing broad-spectrum and relatively selective insecticides are provided to improve vector management and may vary depending on

Space-time variability of citrus leprosis as strategic planning for crop management.

Science.gov (United States)

Andrade, Daniel J; Lorençon, José R; Siqueira, Diego S; Novelli, Valdenice M; Bassanezi, Renato B

2018-01-31

Citrus leprosis is the most important viral disease of citrus. Knowledge of its spatiotemporal structure is fundamental to a representative sampling plan focused on the disease control approach. Such a well-crafted sampling design helps to reduce pesticide use in agriculture to control pests and diseases. Despite the use of acaricides to control citrus leprosis vector (Brevipalpus spp.) populations, the disease has spread rapidly through experimental areas. Citrus leprosis has an aggregate spatial distribution, with high dependence among symptomatic plants. Temporal variation in disease incidence increased among symptomatic plants by 4% per month. Use of acaricides alone to control the vector of leprosis is insufficient to avoid its incidence in healthy plants. Preliminary investigation into the time and space variation in the incidence of the disease is fundamental to select a sampling plan and determine effective strategies for disease management. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Genome-wide comparative analysis reveals similar types of NBS genes in hybrid Citrus sinensis genome and original Citrus clementine genome and provides new insights into non-TIR NBS genes

Science.gov (United States)

In this study, we identified and compared nucleotide-binding site (NBS) domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China). Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approxima...

26 CFR 1.278-1 - Capital expenditures incurred in planting and developing citrus and almond groves.

Science.gov (United States)

2010-04-01

... developing citrus and almond groves. 1.278-1 Section 1.278-1 Internal Revenue INTERNAL REVENUE SERVICE... Capital expenditures incurred in planting and developing citrus and almond groves. (a) General rule. (1)(i... any citrus or almond grove (or part thereof), and which is incurred before the close of the fourth...

Resistance Management for Asian Citrus Psyllid, Diaphorina citri Kuwayama, in Florida.

Science.gov (United States)

Chen, Xue Dong; Stelinski, Lukasz L

2017-09-20

The Asian citrus psyllid, Diaphorina citri Kuwayma, is one of the most important pests in citrus production. The objective of this study was to evaluate D. citri resistance management with three insecticide rotations and compare them with no rotation and an untreated check. The different insecticides (modes of action) tested were: dimethoate, imidacloprid, diflubenzuron, abamectin 3% + thiamethoxam 13.9%, and fenpropathrin. Eggs, nymph, and adult psyllids were counted weekly. Five insecticide applications were made in 2016. Insecticide susceptibility was determined by direct comparison with a laboratory susceptible population and field populations before and after all treatments were applied. Rankings of eggs, nymphs, and adults counted in treated plots were significantly lower than in the untreated control plots after each application. Initially, the resistance ratio (RR 50 ) for each rotation model, as compared with laboratory susceptible strain and the field population before application, was less than 5.76 and 4.31, respectively. However, after five applications with dimethoate, the RR 50 using the laboratory and pre-treatment field populations was 42.34 and 34.74, respectively. Our results indicate that effectively rotating modes of action can delay and/or prevent development of insecticide resistance in populations of D. citri .

Misturas de herbicidas para o controle de plantas daninhas anuais na cultura de citrus (Citrus sinensis (L. Osbeck Herbicides mixtures for the control of annual weeds in citrus crop (Citrus sinensis (L, Osbeck

Directory of Open Access Journals (Sweden)

A.J.B. Galli

1985-12-01

Full Text Available Com o objetivo de se avaliar a eficiência das misturas de glyphosate com diuron ou simazine para o controle de plantas daninhas anuais na cultura de citrus, foram conduzidos dois experimentos durante o ano agrícola 83/84, sendo um em Jaguariúna e outro em Catanduva, ambos no estado de São Paulo. Os resultados obtidos mostraram que, embora todos os tratamentos tenham sido altamente eficientes, o controle de Digitaria horizontalis, Brachiaria plantaginea e portulaca oleracea aos 10 DAT foi um pouco inferior quando se aplicou as misturas de tanque (glyphosate + diuron ou simazine, em relação à aplicação seqüencial desses mesmos produtos. A adição do sulfato de amônio nas misturas de tanque minimizou esse problema, o qual não foi observado na avaliação realizada aos 30 DAT. Ainda com relação às misturas, o controle das gramíneas foi superior quando se utilizou diuron em relação à simazine. As misturas de herbicidas residuais com glyphosate proporcionaram melhor controle aos 60 DAT quando comparados às aplicações de glyphosate isoladamente.With the aim of evaluating the efficiency of glyphosate mixtures with diuron and simazine, in the control of annual weeds in citrus, two experiments were conducted in Catanduva and Jaguariúna, SP, during the 83/84 season. The results showed high efficiency of all treatments, but the control of Digitaria horizontalis, Brachiaria plantaginea and Portulaca oleracea at 10 DAT, has been slightly inferior when tank mistures were applied, in contrast with the sequencial application of these products. The addition of ammonium sulphate to the tank mixtures minimized the problem which was not observed at 30 DAT. Concerning mixtures, grass control was better with diuron than simazine. The use of glyphosate in mixtures with residuals offered better control at 60 DAT when compared to Glyphosate alone.

Study on excitation and fluorescence spectrums of Japanese citruses to construct machine vision systems for acquiring fluorescent images

Science.gov (United States)

Momin, Md. Abdul; Kondo, Naoshi; Kuramoto, Makoto; Ogawa, Yuichi; Shigi, Tomoo

2011-06-01

Research was conducted to acquire knowledge of the ultraviolet and visible spectrums from 300 -800 nm of some common varieties of Japanese citrus, to investigate the best wave-lengths for fluorescence excitation and the resulting fluorescence wave-lengths and to provide a scientific background for the best quality fluorescent imaging technique for detecting surface defects of citrus. A Hitachi U-4000 PC-based microprocessor controlled spectrophotometer was used to measure the absorption spectrum and a Hitachi F-4500 spectrophotometer was used for the fluorescence and excitation spectrums. We analyzed the spectrums and the selected varieties of citrus were categorized into four groups of known fluorescence level, namely strong, medium, weak and no fluorescence.The level of fluorescence of each variety was also examined by using machine vision system. We found that around 340-380 nm LEDs or UV lamps are appropriate as lighting devices for acquiring the best quality fluorescent image of the citrus varieties to examine their fluorescence intensity. Therefore an image acquisition device was constructed with three different lighting panels with UV LED at peak 365 nm, Blacklight blue lamps (BLB) peak at 350 nm and UV-B lamps at peak 306 nm. The results from fluorescent images also revealed that the findings of the measured spectrums worked properly and can be used for practical applications such as for detecting rotten, injured or damaged parts of a wide variety of citrus.

The effects of inter-crop cultivation Between rows of citrus crop on spreading of Guignardia citricarpa Ascospores and in the citrus black spot occurrence

Directory of Open Access Journals (Sweden)

José Antonio Miranda Bellotte

2013-03-01

Full Text Available This study highlighted the effect of planting coast-cross grass and forage peanut cv. Amarilis between rows of Natal oranges on spreading of Guignardia citricarpa ascospores and consequent citrus black spot control. Treatments evaluated were: 1- conventional cultivation, free of fungicides; 2- conventional cultivation, using protective fungicides; 3- inter-crop cultivation of coast-cross grass between rows of citrus crops and; 4- inter-cropping cultivation of forage peanut between the rows of citrus crops. Quest Volumetric Spore SystemTM traps were set in order to determine the number of ascospores released. A total of 33 inspections were conducted weekly, from the end of August until early September the following year. A diagrammatic scale was used to determine the severity of the disease as well as the percentage of fruits having a commercial standard. The coast-cross grass was more effective in reducing the number of ascospores produced, whose average statistics were lower than in the conventional treatments, free-fungicides. The inter-crop and conventional cultivation method coupled with fungicide treatment was more effective in reducing the severity of citrus black spot symptoms, and differs statistically from the fungicide-free control method. These methods also resulted in a higher percentage of fruits of a commercial standard, ranging from the 89% through the 91% percentile, and the cultivation, free of fungicides, fell within the 73%.

Effect of harvesting with a trunk shaker and an abscission chemical on fruit detachment and defoliation of citrus grown under Mediterranean conditions

Energy Technology Data Exchange (ETDEWEB)

Moreno, R.; Torregrosa, A.; Moltó, E.; Chueca, P.

2015-07-01

Spain ranks as the world’s leading exporter of citrus for fresh consumption. Manual harvest accounts for 50% of the total production costs. Mechanical harvest would increase labor productivity and benefits of growers. Efficiency of these machines depends on the varieties and operating conditions. Use of abscission chemicals has been promoted to increase the detachment rate of fruit without affecting its quality. This work is aimed at studying whether the mechanical harvest and/or the application of an abscission agent affect the quality and quantity of harvested fruit and tree defoliation under the conditions of citrus cultivation in Spain. Trials were made in a completely randomized experimental design. From 2008 to 2011, different orchards of mandarin and orange trees were sprayed with different doses of ethephon as abscission agent and harvested with a trunk shaker. Harvest related variables (detachment percentage, defoliation and fruit without calyx) were measured. The percentage of fruit detached by the trunk shaker ranged between 70 and 85% and it did not depend on the orchard. The shaker produced minimal damage to the bark when gripped incorrectly. Increased doses of ethephon increased fruit detachment except in ‘Clemenules’ orchard, but also increased the fruit without calyx in 1-9%. Moreover, ethephon promoted significant defoliation. Neither gummosis nor death of branches was observed. This work demonstrates that mechanical harvesting with trunk shakers may be a feasible solution for citrus cultivated in Spain for fresh market. Use of ethephon could only be recommended for citrus destined to industry and only for certain varieties. (Author)

Effect of harvesting with a trunk shaker and an abscission chemical on fruit detachment and defoliation of citrus grown under Mediterranean conditions

Directory of Open Access Journals (Sweden)

Rosana Moreno

2015-03-01

Full Text Available Spain ranks as the world’s leading exporter of citrus for fresh consumption. Manual harvest accounts for 50% of the total production costs. Mechanical harvest would increase labor productivity and benefits of growers. Efficiency of these machines depends on the varieties and operating conditions. Use of abscission chemicals has been promoted to increase the detachment rate of fruit without affecting its quality. This work is aimed at studying whether the mechanical harvest and/or the application of an abscission agent affect the quality and quantity of harvested fruit and tree defoliation under the conditions of citrus cultivation in Spain. Trials were made in a completely randomized experimental design. From 2008 to 2011, different orchards of mandarin and orange trees were sprayed with different doses of ethephon as abscission agent and harvested with a trunk shaker. Harvest related variables (detachment percentage, defoliation and fruit without calyx were measured. The percentage of fruit detached by the trunk shaker ranged between 70 and 85% and it did not depend on the orchard. The shaker produced minimal damage to the bark when gripped incorrectly. Increased doses of ethephon increased fruit detachment except in ‘Clemenules’ orchard, but also increased the fruit without calyx in 1-9%. Moreover, ethephon promoted significant defoliation. Neither gummosis nor death of branches was observed. This work demonstrates that mechanical harvesting with trunk shakers may be a feasible solution for citrus cultivated in Spain for fresh market. Use of ethephon could only be recommended for citrus destined to industry and only for certain varieties.

Ionization with accelerated high energy electrons as quarantine treatment against Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in citrus fruits

International Nuclear Information System (INIS)

Alonso, M.; Río, M.A. del; Jacas, J.

2002-01-01

Ceratitis capitata is a quarantine pest. Spanish citrus exports to countries such as the USA or Japan are subjected to a mandatory quarantine treatment consisting of exposure of fruits to a low temperatures. Some citrus (''Fino'' lemon, ''Fortune'' mandarin) are very sensitive to this kind of treatment and can not be treated this way. Therefore, alternative treatments are necessary. In this study, high energy electrons were investigated as an alternative quarantine treatment against C. capitata in citrus. Survival of the different instars (egg to old pupae) of C. capitata reared in an artificial medium was assessed when exposed to different doses between 0 and 1 kGy. Both pupariation and adult emergence were almost prevented at 0.25 kGy, and no viable adults were obtained at 0.50 kGy. When artificially infested fruits (in both ''Fino'' lemon and ''Fortune'' mandarin) were exposed to 1 kGy, 100% mortality was obtained. Finally, quality (texture, color index, maturity index, juice yield, ethanol and acetaldehyde contents, physiological alterations and organoleptic characteristics) of irradiated (1 kGy) and non irradiated fruit were compared. High energy electron irradiation resulted in unacceptable damage to ''Fortune'' mandarin, but quality of ''Fino'' lemon resulted unaltered even when evaluated one month after irradiation. Therefore high energy electrons could be a useful alternative to cold quarantine treatment for ''Fino'' lemons. (author) [es

Traditional Small-Size Citrus from Taiwan: Essential Oils, Bioactive Compounds and Antioxidant Capacity

Directory of Open Access Journals (Sweden)

Min-Hung Chen

2017-05-01

Full Text Available Background: The calamondin (Citrus microcarpa Bunge and the kumquat (Fortunella crassifolia Swingle are two small-size citrus fruits that have traditionally been consumed in Taiwan; however, there has been a lack of scientific research regarding the active compounds and functionalities of these fruits. Methods: Analysis of volatile composition of essential oil and phytosterol was carried out using Gas Chromatography–Mass Spectrometry (GC-MS. Flavonoid and limonoid were analyzed by High Performance Liquid Chromatography (HPLC. Moreover, antioxidant capacity from their essential oils and extracts were assessed in vitro. Results: The compositions of the essential oils of both fruits were identified, with the results showing that the calamondin and kumquat contain identified 43 and 44 volatile compounds, respectively. In addition, oxygenated compounds of volatiles accounted for 4.25% and 2.04%, respectively, consistent with the fact that oxygenated compounds are generally found in high content in citrus fruits. In terms of flavonoids, the calamondin exhibited higher content than the kumquat, with disomin-based flavonoids being predominant; on the other hand, phytosterol content of kumquat was higher than that of calamondin, with amyrin being the dominant phytosterol. Both of them contain high amounts of limonoids. The ethanol extracts and essential oils of small-sized citrus fruits have been shown to have antioxidant effects, with those effects being closely related to the flavonoid content of the fruit in question. Conclusions: The present study also reviewed antioxidant activity in terms of specific bioactive compounds in order to find the underlying biological activity of both fruits. The calamondin and kumquat have antioxidant effects, which are in turn very important for the prevention of chronic diseases.

Efficacy of an autodisseminator of an entomopathogenic fungus, Isaria fumosorosea, to suppress Asian citrus psyllid, Diaphorina citri, under greenhouse conditions

Science.gov (United States)

The Asian citrus psyllid (ACP), transmits the causative agents of citrus greening disease or huanglongbing (HLB), the most devastating disease of citrus trees in the world today. ACP dwelling in noncommercial citrus (neighborhoods, commercial landscapes, etc.) can stymie area-wide management program...

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis fruits in Vietnam.

Directory of Open Access Journals (Sweden)

Ivana Puglisi

Full Text Available Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis, a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana rootstocks grafted with 'King' mandarin (Citrus nobilis and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi, sweet orange (Citrus x sinensis and bergamot (Citrus x bergamia as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata. This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam.

Science.gov (United States)

Puglisi, Ivana; De Patrizio, Alessandro; Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano; Cacciola, Santa Olga

2017-01-01

Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with 'King' mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

Comparative evaluation of 12 immature citrus fruit extracts for the inhibition of cytochrome P450 isoform activities.

Science.gov (United States)

Fujita, Tadashi; Kawase, Atsushi; Niwa, Toshiro; Tomohiro, Norimichi; Masuda, Megumi; Matsuda, Hideaki; Iwaki, Masahiro

2008-05-01

In a previous study we found that 50% ethanol extracts of immature fruits of Citrus unshiu (satsuma mandarin) have anti-allergic effects against the Type I, II and IV allergic reactions. However, many adverse interactions between citrus fruit, especially grapefruit juice, and drugs have been reported due to the inhibition of cytochrome P450 (CYP) activities. The purpose of this study was to examine the competitive inhibitory effects of extracts from immature citrus fruit on CYP activity. Extracts were prepared from 12 citrus species or cultivars, and were tested against three kinds of major CYPs, CYP2C9, CYP2D6 and CYP3A4, in human liver microsomes. We also estimated the amounts of flavonoids (narirutin, hesperidin, naringin and neohesperidin) and furanocoumarins (bergapten, 6',7'-dihydroxybergamottin and bergamottin) in each extract using HPLC. Citrus paradisi (grapefruit) showed the greatest inhibition of CYP activities, while Citrus unshiu which has an antiallergic effect, showed relatively weak inhibitory effects. Extracts having relatively strong inhibitory effects for CYP3A4 tended to contain higher amounts of naringin, bergamottin and 6',7'-dihydroxybergamottin. These results, providing comparative information on the inhibitory effects of citrus extracts on CYP isoforms, suggest that citrus extracts containing high levels of narirutin and hesperidin and lower levels of furanocoumarins such as C. unshiu are favorable as antiallergic functional ingredients.

Fontes de amido de diferentes degradabilidades e sua substituição parcial por polpa de citrus em dietas para vacas leiteiras Starch sources with different degradabilities and their partial replacement by citrus pulp for lactating dairy cows

Directory of Open Access Journals (Sweden)

Alexandre Vaz Pires

2002-04-01

tract digestibility were high for FP, however F had a negative effect on fiber digestibility. The ruminal pH was low for FP. Ruminal ammonia and VFA were not affected by treatments. The F treatment reduced molar concentration of acetate and butyrate, while citrus pulp stimulated their ruminal production. Plasma glucose was not affected by treatments, however PUN was higher for MFP as compared to MG.

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.

Aspects of Salt Tolerance in a NaCl-Selected Stable Cell Line of Citrus sinensis1

Science.gov (United States)

Ben-Hayyim, Gozal; Kochba, Joshua

1983-01-01

A NaCl-tolerant cell line which was selected from ovular callus of `Shamouti' orange (Citrus sinensis L. Osbeck) proved to be a true cell line variant. This conclusion is based on the following observations. (a) Cells which have been removed from the selection pressure for at least four passages retain the same NaCl tolerance as do cells which are kept constantly on 0.2 molar NaCl. (b) Na+ and Cl− uptake are considerably lower in salt-tolerant cells (R-10) than in salt-sensitive cells (L-5) at a given external NaCl concentration. (c) Growth of salt-tolerant cells is markedly suppressed upon replacement of NaCl by KCl, whereas the growth of salt-sensitive cells is only slightly affected. Accumulation of K+ and Cl− accompanies the inhibition of growth. Experiments carried out with sodium and potassium sulfate suggest that the toxic effect is due to the accumulated Cl−. (d) Removal of Ca2+ from the growth medium severely inhibits the growth of salt-tolerant cells in the presence of NaCl, while it has a minor effect on growth of salt-sensitive cells in the presence of NaCl. (e) Electron micrographs show that the salt-tolerant cells have very big vacuoles when exposed to salt, while the size of the vacuoles of the salt-sensitive cells does not change. Images Fig. 3 PMID:16663067

Limited and time-delayed internal resource allocation generates oscillations and chaos in the dynamics of citrus crops

International Nuclear Information System (INIS)

Ye, Xujun; Sakai, Kenshi

2013-01-01

Alternate bearing or masting is a yield variability phenomenon in perennial crops. The complex dynamics in this phenomenon have stimulated much ecological research. Motivated by data from an eight-year experiment with forty-eight individual trees, we explored the mechanism inherent to these dynamics in Satsuma mandarin (Citrus unshiu Marc.). By integrating high-resolution imaging technology, we found that the canopy structure and reproduction output of individual citrus crops are mutually dependent on each other. Furthermore, it was revealed that the mature leaves in early season contribute their energy to the fruiting of the current growing season, whereas the younger leaves show a delayed contribution to the next growing season. We thus hypothesized that the annual yield variability might be caused by the limited and time-delayed resource allocation in individual plants. A novel lattice model based on this hypothesis demonstrates that this pattern of resource allocation will generate oscillations and chaos in citrus yield

Limited and time-delayed internal resource allocation generates oscillations and chaos in the dynamics of citrus crops

Energy Technology Data Exchange (ETDEWEB)

Ye, Xujun, E-mail: yexujun@cc.hirosaki-u.ac.jp [College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058 (China); Faculty of Agriculture and Life Sciences, Hirosaki University, Aomori 036-8561 (Japan); Sakai, Kenshi, E-mail: ken@cc.tuat.ac.jp [Environmental and Agricultural Engineering Department, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan)

2013-12-15

Alternate bearing or masting is a yield variability phenomenon in perennial crops. The complex dynamics in this phenomenon have stimulated much ecological research. Motivated by data from an eight-year experiment with forty-eight individual trees, we explored the mechanism inherent to these dynamics in Satsuma mandarin (Citrus unshiu Marc.). By integrating high-resolution imaging technology, we found that the canopy structure and reproduction output of individual citrus crops are mutually dependent on each other. Furthermore, it was revealed that the mature leaves in early season contribute their energy to the fruiting of the current growing season, whereas the younger leaves show a delayed contribution to the next growing season. We thus hypothesized that the annual yield variability might be caused by the limited and time-delayed resource allocation in individual plants. A novel lattice model based on this hypothesis demonstrates that this pattern of resource allocation will generate oscillations and chaos in citrus yield.

The effectiveness of weaver ant (Oecophylla smaragdina) biocontrol in Southeast Asian citrus and mango

DEFF Research Database (Denmark)

Offenberg, Joachim; Cuc, Nguyen Thi Thu; Wiwatwitaya, Decha

2013-01-01

Oecophylla ants may protect tropical plantation crops against pests. Cost-benefit studies comparing ant-based protection with conventional methods are needed to assess whether it is economically viable. Here we contrast profits in ant and chemically protected plots in a Thai and a Vietnamese citrus...

First Record of Diaphorina citri (Hemiptera: Psyllidae) in Ecuador Infesting Urban Citrus and Orange Jasmine Trees

Science.gov (United States)

Cornejo, J.F.; Chica, E.J.

2014-01-01

Abstract Adults and nymphs of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), were collected in the Guayaquil, Samborondón, and Durán cantons in coastal Ecuador. Psyllids were found in high numbers in citrus ( Citrus spp., Sapindales: Rutaceae) and orange jasmine ( Murraya exotica [L.] Jack, Sapindales: Rutaceae) trees within the Guayaquil-Samborondon-Duran conurbation; however, none was found during scoutings in the main citrus producing areas in coastal Ecuador. To the best of our knowledge, this is the first report of D. citri in Ecuador and the Pacific coastal plain of South America. PMID:25527601

The diversity of citrus endophytic bacteria and their interactions with Xylella fastidiosa and host plants

Science.gov (United States)

Azevedo, João Lúcio; Araújo, Welington Luiz; Lacava, Paulo Teixeira

2016-01-01

Abstract The bacterium Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC) and has been associated with important losses in commercial orchards of all sweet orange [Citrus sinensis (L.)] cultivars. The development of this disease depends on the environmental conditions, including the endophytic microbial community associated with the host plant. Previous studies have shown that X. fastidiosa interacts with the endophytic community in xylem vessels as well as in the insect vector, resulting in a lower bacterial population and reduced CVC symptoms. The citrus endophytic bacterium Methylobacterium mesophilicum can trigger X. fastidiosa response in vitro, which results in reduced growth and induction of genes associated with energy production, stress, transport, and motility, indicating that X. fastidiosa has an adaptive response to M. mesophilicum. Although this response may result in reduced CVC symptoms, the colonization rate of the endophytic bacteria should be considered in studies that intend to use this endophyte to suppress CVC disease. Symbiotic control is a new strategy that uses symbiotic endophytes as biological control agents to antagonize or displace pathogens. Candidate endophytes for symbiotic control of CVC must occupy the xylem of host plants and attach to the precibarium of sharpshooter insects to access the pathogen. In the present review, we focus on interactions between endophytic bacteria from sweet orange plants and X. fastidiosa, especially those that may be candidates for control of CVC. PMID:27727362

Soap production: A green prospective.

Science.gov (United States)

Félix, Sandra; Araújo, Joana; Pires, Ana Maria; Sousa, Ana Cláudia

2017-08-01

A green prospective based on the reuse of waste materials such as almond shells, orange peel and used cooking oil to manufacture soap is presented. In Portugal, thousands of tons of waste are generated from used cooking oil and production of nut shells' residues is growing every year. In addition, the high consumption of citrus fruits, oranges in particular, generates large amounts of citrus peel. Therefore, it is necessary to diversify reuse mechanisms of these wastes, in order to make them back into raw materials. Complying with this trend, this work was carried out by processing and grinding almond shells, treating used oil, processing orange peels and extracting limonene, formulating and producing soap, and performing an acceptance study of the final product. Results validated a high potential of the idea in the field of environmental education, so it can be replicated in practical classes. It can also be useful for waste management, and it can support the development of community projects on an ecological approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

Involvement of an ethylene response factor in chlorophyll degradation during citrus fruit degreening

Science.gov (United States)

Chlorophyll degradation naturally occurs during plant senescence. However, in fruit such as citrus, it is a positive characteristic, as degreening is an important colour development contributing to fruit quality. In the present work, Citrus sinensis Osbeck, cv. Newhall fruit was used as a model for ...

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

International Nuclear Information System (INIS)

Liu, C.Y.; Wu, Q.S.

2014-01-01

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)

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...

Combined use of a new SNP-based assay and multilocus SSR markers to assess genetic diversity of Xylella fastidiosa subsp. pauca infecting citrus and coffee plants.

Science.gov (United States)

Montes-Borrego, Miguel; Lopes, Joao R S; Jiménez-Díaz, Rafael M; Landa, Blanca B

2015-03-01

Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp-infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different isolates can be present in a single orchard or infect a single tree. This combined approach will be very useful in studies of the epidemiology of Xfp-induced diseases, host specificity of bacterial genotypes, the occurrence of Xfp host jumping, vector feeding habits, etc., in economically important cultivated plants or weed host reservoirs of Xfp in Brazil and elsewhere. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

DNA polymorphisms and biocontrol of Bacillus antagonistic to citrus bacterial canker with indication of the interference of phyllosphere biofilms.

Directory of Open Access Journals (Sweden)

Tzu-Pi Huang

Full Text Available Citrus bacterial canker caused by Xanthomonas axonopodis pv. citri is a devastating disease resulting in significant crop losses in various citrus cultivars worldwide. A biocontrol agent has not been recommended for this disease. To explore the potential of bacilli native to Taiwan to control this disease, Bacillus species with a broad spectrum of antagonistic activity against various phytopathogens were isolated from plant potting mixes, organic compost and the rhizosphere soil. Seven strains TKS1-1, OF3-16, SP4-17, HSP1, WG6-14, TLB7-7, and WP8-12 showing superior antagonistic activity were chosen for biopesticide development. The genetic identity based on 16S rDNA sequences indicated that all seven native strains were close relatives of the B. subtilis group and appeared to be discrete from the B. cereus group. DNA polymorphisms in strains WG6-14, SP4-17, TKS1-1, and WP8-12, as revealed by repetitive sequence-based PCR with the BOXA1R primers were similar to each other, but different from those of the respective Bacillus type strains. However, molecular typing of the strains using either tDNA-intergenic spacer regions or 16S-23S intergenic transcribed spacer regions was unable to differentiate the strains at the species level. Strains TKS1-1 and WG6-14 attenuated symptom development of citrus bacterial canker, which was found to be correlated with a reduction in colonization and biofilm formation by X. axonopodis pv. citri on leaf surfaces. The application of a Bacillus strain TKS1-1 endospore formulation to the leaf surfaces of citrus reduced the incidence of citrus bacterial canker and could prevent development of the disease.

Anti-Inflammatory Properties and Chemical Characterization of the Essential Oils of Four Citrus Species.

Science.gov (United States)

Amorim, Jorge Luis; Simas, Daniel Luiz Reis; Pinheiro, Mariana Martins Gomes; Moreno, Daniela Sales Alviano; Alviano, Celuta Sales; da Silva, Antonio Jorge Ribeiro; Fernandes, Patricia Dias

2016-01-01

Citrus fruits have potential health-promoting properties and their essential oils have long been used in several applications. Due to biological effects described to some citrus species in this study our objectives were to analyze and compare the phytochemical composition and evaluate the anti-inflammatory effect of essential oils (EO) obtained from four different Citrus species. Mice were treated with EO obtained from C. limon, C. latifolia, C. aurantifolia or C. limonia (10 to 100 mg/kg, p.o.) and their anti-inflammatory effects were evaluated in chemical induced inflammation (formalin-induced licking response) and carrageenan-induced inflammation in the subcutaneous air pouch model. A possible antinociceptive effect was evaluated in the hot plate model. Phytochemical analyses indicated the presence of geranial, limonene, γ-terpinene and others. EOs from C. limon, C. aurantifolia and C. limonia exhibited anti-inflammatory effects by reducing cell migration, cytokine production and protein extravasation induced by carrageenan. These effects were also obtained with similar amounts of pure limonene. It was also observed that C. aurantifolia induced myelotoxicity in mice. Anti-inflammatory effect of C. limon and C. limonia is probably due to their large quantities of limonene, while the myelotoxicity observed with C. aurantifolia is most likely due to the high concentration of citral. Our results indicate that these EOs from C. limon, C. aurantifolia and C. limonia have a significant anti-inflammatory effect; however, care should be taken with C. aurantifolia.

Anti-Inflammatory Properties and Chemical Characterization of the Essential Oils of Four Citrus Species.

Directory of Open Access Journals (Sweden)

Jorge Luis Amorim

Full Text Available Citrus fruits have potential health-promoting properties and their essential oils have long been used in several applications. Due to biological effects described to some citrus species in this study our objectives were to analyze and compare the phytochemical composition and evaluate the anti-inflammatory effect of essential oils (EO obtained from four different Citrus species. Mice were treated with EO obtained from C. limon, C. latifolia, C. aurantifolia or C. limonia (10 to 100 mg/kg, p.o. and their anti-inflammatory effects were evaluated in chemical induced inflammation (formalin-induced licking response and carrageenan-induced inflammation in the subcutaneous air pouch model. A possible antinociceptive effect was evaluated in the hot plate model. Phytochemical analyses indicated the presence of geranial, limonene, γ-terpinene and others. EOs from C. limon, C. aurantifolia and C. limonia exhibited anti-inflammatory effects by reducing cell migration, cytokine production and protein extravasation induced by carrageenan. These effects were also obtained with similar amounts of pure limonene. It was also observed that C. aurantifolia induced myelotoxicity in mice. Anti-inflammatory effect of C. limon and C. limonia is probably due to their large quantities of limonene, while the myelotoxicity observed with C. aurantifolia is most likely due to the high concentration of citral. Our results indicate that these EOs from C. limon, C. aurantifolia and C. limonia have a significant anti-inflammatory effect; however, care should be taken with C. aurantifolia.

Effects of soil-applied imidacloprid on Asian citrus psyllid (Hemiptera: Psyllidae) feeding behavior

Science.gov (United States)

The Asian citrus psyllid, Diaphorina citri Kuwayama is one of the most important pests of citrus due to its status as a vector of Candidatus Liberibacter asiaticus, the bacterium associated with huanglongbing (HLB) disease. The use of insecticides for vector control is the primary method of managing...

77 FR 41709 - Common Crop Insurance Regulations; Florida Citrus Fruit Crop Insurance Provisions

Science.gov (United States)

2012-07-16

... fees from limited resource farmers. FCIC believes this waiver helps to ensure that small entities are... farmers. FCIC is proposing to change the term ``citrus fruit crop'' to ``citrus fruit commodity'' and to.... Abandoned orchards harbor disease and insects, which without proper control measures and remediation efforts...

Citrus asymmetric somatic hybrids produced via fusion of gamma-irradiated and iodoacetamide-treated protoplasts

Energy Technology Data Exchange (ETDEWEB)

Bona, Claudine Maria de [Instituto Agronomico do Parana (IAPAR), Curitiba, PR (Brazil)], e-mail: debona@iapar.br; Gould, Jean Howe [Texas A and M University, College Station, TX (United States). Dept. of Ecosystem Science and Management], e-mail: gould@tamu.edu; Miller Junior, J. Creighton [Texas A and M University, College Station, TX (United States). Dept. of Horticultural Sciences], e-mail: jcmillerjr@tamu.edu; Stelly, David [Texas A and M University, College Station, TX (United States). Dept. of Soil and Crop Sciences], e-mail: stelly@tamu.edu; Louzada, Eliezer Silva [Texas A and M University, Kingsville, TX (United States). Citrus Center], e-mail: e-louzada@tamu.edu

2009-05-15

The objective of this study was to produce citrus somatic asymmetric hybrids by fusing gamma.irradiated protoplasts with iodoacetamide-treated protoplasts. Protoplasts were isolated from embryogenic suspension cells of grapefruit (Citrus paradisi Macfad.) cultivars Ruby Red and Flame, sweet oranges (C. sinensis Osbeck) 'Itaborai', 'Natal', Valencia', and 'Succari', from 'Satsuma' (C. unshiu Marcow.) and 'Changsha' mandarin (C. reticulata Blanco) and 'Murcott' tangor (C. reticulata x C. sinensis). Donor protoplasts were exposed to gamma rays and receptor protoplasts were treated with 3 mmol L{sup -1} iodoacetamide (IOA), and then they were fused for asymmetric hybridization. Asymmetric embryos were germinated, and the resulting shoots were either grafted onto sour orange, rough lemon or 'Swingle' (C. paradisi x Poncirus trifoliata) x 'Sunki' mandarin rootstock seedlings, or rooted after dipping their bases in indol.butyric acid (IBA) solution. The products were later acclimatized to greenhouse conditions. Ploidy was analyzed by flow cytometry, and hybridity was confirmed by amplified fragment length polymorphism (AFLP) analysis of plantlet DNA samples. The best treatment was the donor-recipient fusion combination of 80 Gy.irradiated 'Ruby Red' protoplasts with 20 min IOA.treated 'Succari' protoplasts. Tetraploid and aneuploid plants were produced. Rooting recalcitrance was solved by dipping shoots' stems in 3,000 mg L{sup -1} IBA solution for 10 min. (author)

Visitantes florais e produção de frutos em cultura de laranja ( Citrus sinensis L. Osbeck = Floral visitors and fruit production on sweet orange crop ( Citrus sinensis L. Osbeck

Directory of Open Access Journals (Sweden)

Lourdes Maria Gamito

2006-10-01

Full Text Available O presente experimento foi realizado em florada de laranja (Citrus sinensis L. Osbeck, variedade Pera-Rio, com os objetivos de estudar os insetos visitantes nas flores d e laranjeira, o seu comportamento nas flores, o tipo de coleta efetuada e o efeito dessas visitas na produção de frutos, em quantidade e qualidade. Os dados de freqüência foram obtidos por contagem nos primeiros 10 minutos de cada horário, das 8h às 18h, em três dias distintos, percorrendo-se as linhas da cultura. O comportamento forrageiro de cada espécie de inseto foi avaliado através de observações visuais, no decorrer do dia, no período experimental. Os insetos observados foram abelhas africanizadas Apis mellifera, Trigona spinipes e Tetragonisca angustula. As abelhas A. mellifera foram os visitantes florais maisfreqüentes e preferiram coletar néctar comparado ao pólen. Os botões florais descobertos produziram mais frutos que os botões florais cobertos. Os frutos decorrentes do tratamento coberto foram menores, mais ácidos e com menor quantidade de vitamina C que os frutos do tratamento descoberto. The present experiment was carried out in flowerage of sweet orange(Citrus sinensis L. Osbeck, Pera-rio variety, to study the insects involv ed in pollination, their behaviour in the flower (nectar or pollen collection and the effect of the pollination on fruit production (quantity and quality. More frequent insects were recorded daily (counted during ten minutes, every hour from 8:00 a.m. to 6:00 p.m., with three replications. The forage behaviour and nectar and/or pollen collect was also observed. The insect visitors onflowers were Africanized honey bee Apis mellifera, followed by stingless bees Trigona spinipes and Tetragonisca angustula. A. mellifera were the most frequent visitors and preferred to collectnectar than pollen. The uncovered flowers -buds produced more fruits than the covered ones. Another observation was that fruits derived from covered

Evaluation and public acceptance of irradiated strawberries and citrus fruits

International Nuclear Information System (INIS)

Del Mastro, Nelida L.; Kikuchi, Olivia K.; Villavicencio, Anna L.C.H.; Sabato, Susy F.; Rela, Paulo R.; Taipina, Magda S.; Mattiolo-Marchse, Sandra R.

1999-01-01

Irradiation is a physical process that can be applied to food in order to eliminate microorganisms, insects and other plagues as well as delay ripening or spoilage, thus lengthening its shelf life. In Brazil, the technique is only starting to be applied and is restricted to a few tons of dry or dehydrated food ingredients per year. Strawberry (Fragaria sp.) and citrus are usually attacked by various plagues. Both strawberry and citrus are included in the Brazilian legislation for irradiated foods. This work describes the first sensory trials of 2 varieties of strawberries and 3 varieties of citrus irradiated at IPEN. Irradiation was performed in a panoramic Co-60 source with doses ranging between 1.7 and 4 kGy. Untrained groups of panelists judged the quality of irradiated and non-irradiated control fruits. From the analysis of the results, it was concluded that there no significant differences in the characteristical properties of the fruits when they were irradiated with the doses recommended by the legislation. (author)

Differential expression of genes of Xylella fastidiosa in xylem fluid of citrus and grapevine.

Science.gov (United States)

Shi, Xiangyang; Bi, Jianlong; Morse, Joseph G; Toscano, Nick C; Cooksey, Donald A

2010-03-01

Xylella fastidiosa causes a serious Pierce's disease (PD) in grapevine. Xylella fastidiosa cells from a PD strain were grown in a pure xylem fluid of a susceptible grapevine cultivar vs. xylem fluid from citrus, which is not a host for this strain of X. fastidiosa. When grown in grapevine xylem fluid, cells of the PD strain formed clumps and biofilm formed to a greater extent than in citrus xylem fluid, although the PD strain did grow in xylem fluid of three citrus varieties. The differential expression of selected genes of a PD X. fastidiosa strain cultured in the two xylem fluids was analyzed using a DNA macroarray. Compared with citrus xylem fluid, grapevine xylem fluid stimulated the expression of X. fastidiosa genes involved in virulence regulation, such as gacA, algU, xrvA, and hsq, and also genes involved in the biogenesis of pili and twitching motility, such as fimT, pilI, pilU, and pilY1. Increased gene expression likely contributes to PD expression in grapevine, whereas citrus xylem fluid did not support or possibly suppressed the expression of these virulence genes.

Expression of Arabidopsis Hexokinase in Citrus Guard Cells Controls Stomatal Aperture and Reduces Transpiration.

Science.gov (United States)

Lugassi, Nitsan; Kelly, Gilor; Fidel, Lena; Yaniv, Yossi; Attia, Ziv; Levi, Asher; Alchanatis, Victor; Moshelion, Menachem; Raveh, Eran; Carmi, Nir; Granot, David

2015-01-01

Hexokinase (HXK) is a sugar-phosphorylating enzyme involved in sugar-sensing. It has recently been shown that HXK in guard cells mediates stomatal closure and coordinates photosynthesis with transpiration in the annual species tomato and Arabidopsis. To examine the role of HXK in the control of the stomatal movement of perennial plants, we generated citrus plants that express Arabidopsis HXK1 (AtHXK1) under KST1, a guard cell-specific promoter. The expression of KST1 in the guard cells of citrus plants has been verified using GFP as a reporter gene. The expression of AtHXK1 in the guard cells of citrus reduced stomatal conductance and transpiration with no negative effect on the rate of photosynthesis, leading to increased water-use efficiency. The effects of light intensity and humidity on stomatal behavior were examined in rooted leaves of the citrus plants. The optimal intensity of photosynthetically active radiation and lower humidity enhanced stomatal closure of AtHXK1-expressing leaves, supporting the role of sugar in the regulation of citrus stomata. These results suggest that HXK coordinates photosynthesis and transpiration and stimulates stomatal closure not only in annual species, but also in perennial species.

Comparative transcriptome analysis unveils the tolerance mechanisms of Citrus hystrix in response to 'Candidatus Liberibacter asiaticus' infection.

Directory of Open Access Journals (Sweden)

Yan Hu

Full Text Available Citrus Huanglongbing (HLB, a highly devastating citrus disease, is associated with 'Candidatus Liberibacter asiacitus' (CLas, a member of phloem-inhabiting α-proteobacteria. HLB can affect all cultivated citrus and no cure is currently available. Previous studies showed that Kaffir lime (Citrus hystrix, primarily grown in South Asia and Southeast Asia, was tolerant to HLB but the molecular mechanism remains unknown. In this study, gene expression profiling experiments were performed on HLB-tolerant C. hystrix and HLB-susceptible C. sinensis three months after inoculation with CLas using RNA-seq data. Differentially expressed genes (DEGs in the two citrus cultivars were mainly involved in diverse cellular functions including carbohydrate metabolism, photosynthesis, cell wall metabolism, secondary metabolism, hormone metabolism and oxidation/reduction processes. Notably, starch synthesis and photosynthesis process were not disturbed in CLas-infected C. hystrix. Most of the DEGs involved in cell wall metabolism and secondary metabolism were up-regulated in C. hystrix. In addition, the activation of peroxidases, Cu/Zn-SOD and POD4, may also enhance the tolerance of C. hystrix to CLas. This study provides an insight into the host response of HLB-tolerant citrus cultivar to CLas. C. hystrix is potentially useful for HLB-tolerant/resistant citrus breeding in the future.

The Evolutionary History and Spatiotemporal Dynamics of the NC Lineage of Citrus Tristeza Virus

Directory of Open Access Journals (Sweden)

María José Benítez-Galeano

2017-10-01

Full Text Available Citrus tristeza virus (CTV is a major pathogen affecting citrus trees worldwide. However, few studies have focused on CTV’s evolutionary history and geographic behavior. CTV is locally dispersed by an aphid vector and long distance dispersion due to transportation of contaminated material. With the aim to delve deeper into the CTV-NC (New Clade genotype evolution, we estimated an evolution rate of 1.19 × 10−3 subs/site/year and the most common recent ancestor in 1977. Furthermore, the place of origin of the genotype was in the United States, and a great expansion of the population was observed in Uruguay. This expansion phase could be a consequence of the increment in the number of naïve citrus trees in Uruguayan orchards encompassing citrus industry growth in the past years.

Evidence of behavior-based utilization by the Asian citrus psyllid of a combination of UV and green or yellow wavelengths.

Directory of Open Access Journals (Sweden)

Thomson M Paris

Full Text Available The Asian citrus psyllid, Diaphorina citri, vectors huanglongbing (HLB, the most serious disease affecting citrus globally. D. citri and HLB have spread to the major citrus growing regions of North America causing billions of dollars of damage in Florida alone. The visual behavior of D. citri is not well characterized and more knowledge is needed to improve attractive traps for monitoring and control of the D. citri. Bioassays were conducted to evaluate attraction to light transmitted through different colored filters. The addition of ultra-violet light (< 400 nm enhanced attraction of D. citri to transparent visual targets made of green or yellow filters. However, attraction to blue targets was unaffected by UV light. This is the first study to demonstrate a phytophagous insect responding to a hue that is a combination of long and short wavelengths. Further testing is needed to determine how D. citri uses such discriminatory powers in the field. Our results further imply that D. citri utilize color vision, as the less intense yellow and green hues were chosen over white light. In summary, this research provides an increased understanding of D. citri visual behavior and can be used for the development of a more attractive D. citri trap than those currently available.

CITRUS AS A COMPONENT OF THE MEDITERRANEAN DIET

Directory of Open Access Journals (Sweden)

Amilcar Duarte

2016-12-01

Full Text Available Citrus are native to southeastern Asia, but are present in the Mediterranean basin for centuries. This group of species has reached great importance in some of the Mediterranean countries and, in the case of orange, mandarin and lemon trees, they found here soil and climatic conditions which allows them to achieve a high level of fruit quality, even better than in the regions where they came from. Citrus fruits are present in the diet of the peoples living on the Mediterranean basin, at least since the time of the Roman Empire. In the 20th century they became the main crop in various agricultural areas of the Mediterranean, playing an important role in the landscape, in the diet of the overall population, and also in international trade. They are present in the gardens of palaces and monasteries, but also in the courtyards and orchards of the poorest families. Their fruits are not only a refreshing dessert, but also a condiment, or even a major component of many dishes. Citrus fruits have well-documented nutritional and health benefits. They can actually help prevent and cure some diseases and, above all, they are essential in a balanced and tasty diet.

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

Reference genes for accurate transcript normalization in citrus genotypes under different experimental conditions.