Transcriptome analysis of a spontaneous mutant in sweet orange [Citrus sinensis (L.) Osbeck] during fruit development.

Science.gov (United States)

Liu, Qing; Zhu, Andan; Chai, Lijun; Zhou, Wenjing; Yu, Keqin; Ding, Jian; Xu, Juan; Deng, Xiuxin

2009-01-01

Bud mutations often arise in citrus. The selection of mutants is one of the most important breeding channels in citrus. However, the molecular basis of bud mutation has rarely been studied. To identify differentially expressed genes in a spontaneous sweet orange [C. sinensis (L.) Osbeck] bud mutation which causes lycopene accumulation, low citric acid, and high sucrose in fruit, suppression subtractive hybridization and microarray analysis were performed to decipher this bud mutation during fruit development. After sequencing of the differentially expressed clones, a total of 267 non-redundant transcripts were obtained and 182 (68.2%) of them shared homology (E-value or = 2) in the bud mutation during fruit development. Self-organizing tree algorithm analysis results showed that 95.1% of the differentially expressed genes were extensively coordinated with the initiation of lycopene accumulation. Metabolic process, cellular process, establishment of localization, response to stimulus, and biological regulation-related transcripts were among the most regulated genes. These genes were involved in many biological processes such as organic acid metabolism, lipid metabolism, transport, and pyruvate metabolism, etc. Moreover, 13 genes which were differentially regulated at 170 d after flowering shared homology with previously described signal transduction or transcription factors. The information generated in this study provides new clues to aid in the understanding of bud mutation in citrus.

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...

Analysis of expressed sequence tags from Citrus sinensis L. Osbeck infected with Xylella fastidiosa

Directory of Open Access Journals (Sweden)

Alessandra A. de Souza

2007-01-01

Full Text Available In order to understand the genetic responses resulting from physiological changes that occur in plants displaying citrus variegated chlorosis (CVC symptoms, we adopted a strategy of comparing two EST libraries from sweet orange [Citrus sinensis (L. Osbeck]. One of them was prepared with plants showing typical CVC symptoms caused by Xylella fastidiosa and the other with non-inoculated plants. We obtained 15,944 ESTs by sequencing the two cDNA libraries. Using an in silico hybridization strategy, 37 genes were found to have significant variation at the transcriptional level. Within this subset, 21 were up-regulated and 16 were down-regulated in plants with CVC. The main functional categories of the down-regulated transcripts in plants with CVC were associated with metabolism, protein modification, energy and transport facilitation. The majority of the up-regulated transcripts were associated with metabolism and defense response. Some transcripts associated with adaptation to stress conditions were up-regulated in plants with CVC and could explain why plants remain alive even under severe water and nutritional stress. Others of the up-regulated transcripts are related to defense response suggesting that sweet orange plants activate their defense machinery. The genes associated with stress response might be expressed as part of a secondary response related to physiological alterations caused by the infection.

EFEITOS DE GIBERELINAS, CITOCININAS E DO NITRATO DE POTÁSSIO, NO PROCESSO GERMINATIVO DE SEMENTES DE LIMOEIRO `CRAVO' (Citrus limonia OSBECK)

OpenAIRE

Leonel,Sarita; Rodrigues,João Domingos

1999-01-01

Foram estudados os efeitos de reguladores vegetais do grupo das giberelinas e citocininas, bem como do nitrato de potássio na germinação de sementes do limoeiro `Cravo' (Citrus limonia Osbeck). O experimento foi realizado, contendo papel de filtro como substrato para a germinação das sementes, regulado à temperatura de 25oC. As sementes foram retiradas de frutos maduros no final da safra do limoeiro `Cravo', lavadas, secas à sombra e armazenadas durante 11 dias em câmara fria. Em seguida, rec...

Development of seedless fruits mutants in citrus including tangerine (C. reticulata) and pummelo (C. grandis) through induced mutations and biotechnology

Energy Technology Data Exchange (ETDEWEB)

Somsri, S. [Horticulture Research Institute, Department of Agriculture (DOA), Chatuchak, Bangkok (Thailand); Jompook, P. [Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Chatuchak, Bangkok (Thailand); Kanhom, P. [Phare Horticultural Research Center, Muang, Phare (Thailand); Thayamanont, P.; Meecharoen, S. [Pichit Horticultural Research Center, Muang, Pichit (Thailand); Kumcha, U. [Srisaket Horticultural Research Center, Muang, Srisaket (Thailand)

2009-05-15

The development of seedless fruit mutants in citrus, including Tangerine (C. reticulata) and Pummelo (C. grandis), through induced mutation and biotechnology was studied at the Gamma Irradiation Service and Nuclear Technology Center, Pichit and Phare Horticultural Research Center for 4 years (August 2000 to September 2004). The results showed successful induction of mutants with gamma irradiation using both chronic and acute procedures for pot plants, scions and in vitro plantlets of tangerine (Citrus reticulata var. Shogun and Sai Nam Puaeng) and pummelo (Citrus grandis viz. Kao Thong Dee). MS medium with 2 mgL{sup -1} of BA was found to be the most suitable medium for shoot proliferation. The seedlings were sub-cultured at least 4 times, and then they were treated with acute and chronic irradiation. Shoot induction from M{sub 1}V{sub 0} to M{sub 1}V{sub 4} generation was performed in basic MS medium with 2 mgL{sup -1} added BA. Rooting was induced in the M{sub 1}V{sub 4} in halfstrength MS enriched with BA 2 mgL{sup -1}. Later, the shoots were excised and grafted on mature plants or the plantlets directly transferred in the field and later the fruits from mature trees were evaluated for seedlessness in M{sub 1}V{sub 4} at Pichit and Phare Horticultural Research Center. (author)

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.

Unravelling molecular responses to moderate dehydration in harvested fruit of sweet orange (Citrus sinensis L. Osbeck) using a fruit-specific ABA-deficient mutant.

Science.gov (United States)

Romero, Paco; Rodrigo, María J; Alférez, Fernando; Ballester, Ana-Rosa; González-Candelas, Luis; Zacarías, Lorenzo; Lafuente, María T

2012-04-01

Water stress affects many agronomic traits that may be regulated by the phytohormone abscisic acid (ABA). Within these traits, loss of fruit quality becomes important in many citrus cultivars that develop peel damage in response to dehydration. To study peel dehydration transcriptional responsiveness in harvested citrus fruit and the putative role of ABA in this process, this study performed a comparative large-scale transcriptional analysis of water-stressed fruits of the wild-type Navelate orange (Citrus sinesis L. Osbeck) and its spontaneous ABA-deficient mutant Pinalate, which is more prone to dehydration and to developing peel damage. Major changes in gene expression occurring in the wild-type line were impaired in the mutant fruit. Gene ontology analysis revealed the ability of Navelate fruits to induce the response to water deprivation and di-, tri-valent inorganic cation transport biological processes, as well as repression of the carbohydrate biosynthesis process in the mutant. Exogenous ABA triggered relevant transcriptional changes and repressed the protein ubiquitination process, although it could not fully rescue the physiological behaviour of the mutant. Overall, the results indicated that dehydration responsiveness requires ABA-dependent and -independent signals, and highlight that the ability of citrus fruits to trigger molecular responses against dehydration is an important factor in reducing their susceptibility to developing peel damage.

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.

Populational fluctuation of vectors of Xylella fastidiosa, wells in sweet orange [Citrus sinensis (L. Osbeck] varieties of northwest Paraná State, Brazil

Directory of Open Access Journals (Sweden)

Rúbia de Oliveira Molina

2010-06-01

Full Text Available The aim of the present study was to assess the population flutuation of the sharpshooters species subfamily Cicadellinae belonging to the tribes Cicadellini and Proconiini, in sweet orange [Citrus sinensis( L. Osbeck] commercial orchards of the northwest region of Paraná State , Brazil. Samplings were carried out the employing every time 24 yellow sticky cards. Identification of the species showed that the most representative were Dilobopterus costalimai of the Cicadellini tribe and Acrogonia citrina of the Proconiini tribe.A Clorose variegada dos citros (CVC é uma importante doença que ocorre nos citros, cujo agente causal é a bactéria Xylella fastidiosa, Wells. A bactéria depende, obrigatoriamente, de insetos vetores para sua disseminação, que são as cigarrinhas sugadoras do xilema (Hemiptera: Cicadellidae, Cicadellinae. No presente estudo objetivou-se avaliar a flutuação populacional de espécies de cigarrinhas nas diferentes variedades de laranja doce [Citrus sinensis (L. Osbeck], Natal, Pêra, Valência e Folha Murcha, em um pomar comercial localizado na região Noroeste do Paraná, no período de janeiro de 2000 a dezembro de 2002. Amostragens quinzenais foram realizadas com o uso de armadilhas adesivas amarelas, num total de 24 armadilhas em cada avaliação. Após a identificação das espécies observou-se, que as mais representativas foram Dilobopterus costalimai da tribo Cicadellini e Acrogonia citrina da tribo Proconiini, sendo que a variedade de laranja Pêra apresentou o maior número de espécies vetoras durante os anos avaliados.

EFEITO DO ÁCIDO GIBERÉLICO SOBRE O COMPRIMENTO E DIÂMETRO DO CAULE DE PLÂNTULAS DE LIMÃO `CRAVO' (Citrus limonia Osbeck)

OpenAIRE

MODESTO J.C.; RODRIGUES J.D.; PINHO S.Z. de

1996-01-01

O presente trabalho foi instalado em condições de campo com plântulas de limão `Cravo'(Citrus limonia Osbeck), em delineamento inteiramente casualizado, com três repetições no esquema de parcelas sub-divididas, onde os tratamentos principais foram 5 concentrações de ácido giberélico: T1 = 0, T2 = 25, T3 = 50, T4 = 100 e T5 = 150 ppm, parceladas em quatro pulverizações. Os tratamentos secundários foram as coletas do material, realizadas dos 70 aos 210 dias, em intervalos de 14 dias. Pelos resu...

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.

[Research on the application of grey system theory in the pattern recognition for chromatographic fingerprints of traditional Chinese medicine].

Science.gov (United States)

Wei, Hang; Lin, Li; Zhang, Yuan; Wang, Lianjing; Chen, Qinqun

2013-02-01

A model based on grey system theory was proposed for pattern recognition in chromatographic fingerprints (CF) of traditional Chinese medicine (TCM). The grey relational grade among the data series of each testing CF and the ideal CF was obtained by entropy and norm respectively, then the principle of "maximal matching degree" was introduced to make judgments, so as to achieve the purpose of variety identification and quality evaluation. A satisfactory result in the high performance liquid chromatographic (HPLC) analysis of 56 batches of different varieties of Exocarpium Citrus Grandis was achieved with this model. The errors in the chromatographic fingerprint analysis caused by traditional similarity method or grey correlation method were overcome, as the samples of Citrus grandis 'Tomentosa' and Citrus grandis (L.) Osbeck were correctly distinguished in the experiment. Furthermore in the study on the variety identification of Citrus grandis 'Tomentosa', the recognition rates were up to 92.85%, although the types and the contents of the chemical compositions of the samples were very close. At the same time, the model had the merits of low computation complexity and easy operation by computer programming. The research indicated that the grey system theory has good applicability to pattern recognition in the chromatographic fingerprints of TCM.

Honey bee attractants and pollination in sweet orange, Citrus sinensis (L. Osbeck, var. Pera-Rio

Directory of Open Access Journals (Sweden)

D. T. Malerbo-Souza

2004-01-01

Full Text Available This experiment studied the frequency and behavior of insects on sweet orange flowers, Citrus sinensis (L. Osbeck, their effect on fruit production (quantity and quality, nectar and pollen collection, and the effectiveness of different attractants. Over three consecutive years, the most frequent visitor to the flowers was Apis mellifera (Africanized. Flowers visited less than ten times showed low fructification. Fruit production was 35.30% greater in uncovered flowers. Fruit mean weight was much greater in uncovered (180.2g than in covered flowers (168.5g. Fruits from the covered were more acid (1.411g of citric acid/100ml of juice than the uncovered flowers (1.164g of citric acid/100ml of juice. The number of seeds per bud was higher in the uncovered (1 seed/bud than in the covered treatment (0.8 seed/bud. Bee-HereR, eugenol, geraniol, citral, and lemon grass extract, mainly diluted in water, were effective in attracting honeybees to orchards. However, these compounds were less effective when diluted in sugar syrup. The same products had variable attractiveness to honeybees in different years.

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 ...

Flavonoid Composition of Tarocco (Citrus sinensis L. Osbeck) Clone "Lempso" and Fast Antioxidant Activity Screening by DPPH-UHPLC-PDA-IT-TOF.

Science.gov (United States)

Sommella, Eduardo; Pagano, Francesco; Pepe, Giacomo; Ostacolo, Carmine; Manfra, Michele; Chieppa, Marcello; Di Sanzo, Rosa; Carabetta, Sonia; Campiglia, Pietro; Russo, Mariateresa

2017-11-01

Clonal selection and hybridisation are valid strategies to obtain fruits with enhanced sensorial and nutraceutical properties. Within Citrus sinensis varieties, Tarocco clone "Lempso" is a typical product of the Calabria region (Italy) characterised by its red pulp. This is the first report concerning its accurate profiling. To characterise in detail the flavonoid composition of Lempso clone and to compare its antioxidant potential with other Citrus varieties by a fast screening method. Extracts were subjected to solid phase extraction and the qualitative/quantitative profile was elucidated through ultra-high performance liquid chromatography (UHPLC) coupled to photodiode array (PDA) and ion trap time-of-flight (IT-TOF) mass spectrometry detection, and compared to both Cleopatra mandarin (Citrus reticulata) and blood orange (Citrus sinensis (L.) Osbeck) Sanguinello varieties. The antioxidant activity was assessed by pre-column 2,2'-diphenyl-1-picrylhydrazyl (DPPH) reaction coupled to UHPLC-PDA. Lempso is characterised by flavonoids (17) and anthocyanins (8). Flavanones content (Hesperidin: 57.19 ± 0.49, Vicenin-2: 4.59 ± 0.03, Narirutin: 5.78 ± 0.13 mg/100 mL) was considerably higher than Cleopatra and Sanguinello varieties. The developed DPPH-UHPLC-PDA method provides information regarding the single contributions to antioxidant activity, highlighting how Ferulic acid, Quercetin and Cyanidin derivatives possess considerable radical scavenging activity (> 50%). The total antioxidant activity was also evaluated and compared with positive controls, showing higher scavenging activity than Cleopatra and Sanguinello (IC 50 : 333.76 ± 10.81 μg/mL vs. 452.62 ± 10.81 and 568.39 ± 26.98 μg/mL, respectively). These data evidence the nutraceutical potential of Lempso variety, which could be an ingredient for functional beverages. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Uso contínuo de herbicidas em citrus (Citrus sinensis L. osbeck : II. Efeitos no desenvolvimento, produção e qualidade dos frutos Continuos use of herbicides in citros (Citrus sinensis (L. osbeck: II - ffects ondevelopment, yield and fruit quality

Directory of Open Access Journals (Sweden)

Ricardo Victoria Filho

1991-01-01

Full Text Available A presente pesquisa foi conduzida no município de Conchal - SP, Brasil, em um Latossol Vermelho Amarelo com 1,75% de matéria orgânica com o objetivo de veri fic ar o efeito do uso cont inuo dos principais herbicidas no desenvolvimento, produção e qualidade dos frutos em um pomar de laranja 'Pera' Citrus sinensis (L. Osbeck, en xertada sobr e limão cravo (Citrus lionia Osbeck. O delineamento experimental adotado foi o de blocos ao acaso, com 12 tratamentos e 4 repetições. Os tratamentos utilizados com as respectivas doses do i. a. em kg/h a foram: terbacil a 3,2; simazine a 4,0; ametryne + secbumetone 4,5; dichlobenil a5,0 ; diuron a3,2 ; bromacila 3,2; bromacil + diuron a 3,2; paraquat a 0,6; glyphosate a 1,61 e MSMA a 1,77 alem de uma testemunha que recebia uma capina anualmente, e outra que era capinada sempre que a cobertura pelas plantas daninhas atingia 25% da área da parcela. O pomar foi plantado em meio/ 75 e a 1a aplicação dos herbicidas foi realizada em outubro de 1977. As parcelas continham 4 plantas em uma area de 3,0 x 18,0 m (54 m2. A última aplic ação foi realizada em 1992. O efeito no desenvolvimento foi feito pela medida do diâmetro do caule a 10 m acima do ponto de enxertia, pelo diâmetro da copa na altura mediana e pela altura das plantas. Todas essas medidas eram realizadas 2 vezes por ano. Para avaliação da produção, eram colhidos os frutos de quatro plantas por parcela. A qualidade dos frutos foi avaliada através das medidas do diâmetro longitudinal e transversal, albedo, peso e número de sementes, peso médio dos frutos, % de suco, % de sólidos solúveis e % de acidez. Pelos dados obtidos , verifica - se que não houve influência dos herbicidas no desenvolvimento das plantas de citros, e na produção. As influencias na qualidade dos frutos foram mínimas, e dependeram do ano de amostragem.The research reported in this paper was conducted at the Conchal county in Sao Paulo State, Brazil, in a Red

Use of the heat dissipation method for sap flow measurement in citrus nursery trees1

Directory of Open Access Journals (Sweden)

Eduardo Augusto Girardi

2010-12-01

Full Text Available Sap flow could be used as physiological parameter to assist irrigation of screen house citrus nursery trees by continuous water consumption estimation. Herein we report a first set of results indicating the potential use of the heat dissipation method for sap flow measurement in containerized citrus nursery trees. 'Valencia' sweet orange [Citrus sinensis (L. Osbeck] budded on 'Rangpur' lime (Citrus limonia Osbeck was evaluated for 30 days during summer. Heat dissipation probes and thermocouple sensors were constructed with low-cost and easily available materials in order to improve accessibility of the method. Sap flow showed high correlation to air temperature inside the screen house. However, errors due to natural thermal gradient and plant tissue injuries affected measurement precision. Transpiration estimated by sap flow measurement was four times higher than gravimetric measurement. Improved micro-probes, adequate method calibration, and non-toxic insulating materials should be further investigated.

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.

CARACTERIZAÇÃO QUÍMICA E AVALIAÇÃO DA ATIVIDADE LARVICIDA FRENTE AO Aedes aegypt do ÓLEO ESSENCIAL DA ESPÉCIE Citrus sinensis L. Osbeck (LARANJA DOCE)

OpenAIRE

GILSON VITORINO DE ASSUNÇÃO

2013-01-01

Estudos são desenvolvidos no sentido de encontrar substâncias de origem vegetal, como controle químico alternativo ao combate do vetor da dengue, uma vez em que até o presente momento não há vacina validada para a mesma. No referido trabalho, a partir da extração e do estudo analítico do óleo essencial das cascas frescas de Citrus sinensis L.Osbeck , foi possível analisar o efeito larvicida do óleo contra as larvas em terceiro estágio do mosquito Aedes aegypti (Linnaeus, 1762). Extraiu-se qua...

Visitantes florais e produção de frutos em cultura de laranja (Citrus sinensis L. Osbeck - DOI: 10.4025/actascianimsci.v28i4.612 Floral visitors and fruit production on sweet orange crop (Citrus sinensis L. Osbeck - DOI: 10.4025/actascianimsci.v28i4.612

Directory of Open Access Journals (Sweden)

Darclet Terezinha Malerbo Souza

2006-02-01

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 mais freqüentes 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 on flowers 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 collect nectar than pollen. The uncovered flowers -buds produced more fruits than the covered ones. Another observation was that fruits derived from covered

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

Exogenous applications of plant growth regulators influence the reproductive growth of citrus sinensis osbeck cv. blood red

International Nuclear Information System (INIS)

Khan, A.S.; Malik, A.U.; Ahmad, S.; Ahmad, I.

2014-01-01

To study the influence of exogenous applications of plant growth regulators on the reproductive behaviour of low bearing sweet orange (Citrus sinensis Osbeck) trees, three separate experiments were conducted on twelve years old 'Blood Red' Sweet orange trees budded on Rough Lemon (Citrus jambheri L.) root stock. In the first experiment, trees were sprayed with 20 mg L-1 2, 4-D and GA3 alone or in combination at mid bloom (MB) stage, whilst in the second and third experiments 20 mg L-1 2, 4-D and GA3 alone or in combination were sprayed at MB + 6 weeks after MB, and at MB + 22 and 28 weeks after MB stages, respectively. A single tree was selected as an experimental unit and each treatment was replicated four times. Data regarding the flowering intensity, flower drop, fruit set, fruit drop and fruit harvest percentages (%) were collected and analyzed statistically. In all experiments exogenous application of 20 mg L-1 2, 4-D and GA3 alone or in combination to Blood Red sweet orange trees reduced the flower drop % and increased the fruit set % as compared to untreated trees. Application 2, 4-D and GA3 alone or in combination at MB did not affect the fruit drop % and fruit harvest % in contrast to untreated trees. The trees sprayed with 20 mg L-1 GA3 alone or in combination with 2, 4-D at MB + 22 and 28 weeks after MB exhibited highest reduction in the fruit drop % compared to control trees. In conclusions application GA3 (20 mg L-1) alone or in combination of 2, 4-D (20 mg L-1) at MB + 22 and 28 weeks after MB can be used effectively to increase the fruit set and reduce the fruit drop in Blood Red sweet oranges. (author)

Systematic chemical profiling of Citrus grandis 'Tomentosa' by ultra-fast liquid chromatography/diode-array detector/quadrupole time-of-flight tandem mass spectrometry.

Science.gov (United States)

Li, Pan-lin; Liu, Meng-hua; Hu, Jie-hui; Su, Wei-wei

2014-03-01

Citrus grandis 'Tomentosa', as the original plant of the traditional Chinese medicine "Huajuhong", has been used as antitussive and expectorant in clinic for thousands of years. The fruit epicarp and whole fruit of this plant were both literarily recorded and commonly used. In the present study, an ultra-fast liquid chromatography coupled with diode-array detection and quadrupole/time-of-flight mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) based chemical profiling method was developed for rapid holistic quality evaluation of C. grandis 'Tomentosa', which laid basis for chemical comparison of two medicinal parts. As a result, forty-eight constituents, mainly belonging to flavonoids and coumarins, were unambiguously identified by comparison with reference standards and/or tentatively characterized by elucidating UV spectra, quasi-molecular ions and fragment ions referring to information available in literature. Both of the epicarp and whole fruit samples were rich in flavonoids and coumarins, but major flavonoids contents in whole fruit were significantly higher than in epicarp (P<0.5). The proposed method could be useful in quality control and standardization of C. grandis 'Tomentosa' raw materials and its products. Results obtained in this study will provide a basis for quality assessment and further study in vivo. Copyright © 2013 Elsevier B.V. All rights reserved.

Efeito de herbicidas residuais, aplicados por vários anos consecutivos, na distribuição do sistema radicular da laranjeira Natal (Citrus sinensis.(L. osbeck Effects of residual herbicides, applyed for several years son the root system distribution of 'Natal' orange (Citrus sinensis L. osbeck

Directory of Open Access Journals (Sweden)

R Victória Filho

1985-12-01

Full Text Available O presente trabalho foi desenvolvido com o objetivo de verificar a influência do uso contínuo de vários herbicidas residuais, sobre a distribuição das radicelas de laranjeiras Natal (Citrus sinensis (L. Osbeck enxertadas sobre limão Cravo (Cithus limonia Osbeck e plantadas em janeiro de 1970. O experimento foi instalado no pomar de produção da Faculdade de Ciências Agrárias e Veterinárias do Campus de Jaboticabal (UNESP, em Latossol Roxo distrófico, com 1,6% de matéria orgânica e 51% de argila. O delineamento experimental utilizado foi o de blocos ao acaso, dentro de um esquema fatorial 11x 3x2x2, com três repetições. Os tratamentos utilizados, com as respectivas doses em kg do i.a/ha foram: fluometuron a 4,2; simazíne a 4,8; atrazine a 4,8; bromacil a 3,2;bromacil (40% + diuron (40% a 4,8; bromacil (53,3% + diuron (27,6% a 4,8; terbacil a 3,2; oxadiazon a 1,5; dichlobenil a 3,0 e 6,0; além de uma testemunha capinada. O estudo das radicel as foi feito pelo "método do trado", tendo sido tomadas amostras de solo contendo radicelas, nas distâncias de 80, 160 e 240 cm do tronco, nas camadas de 0 a 15 cm e 15 a 30 cm de profundidade e em duas direções distintas (entrelinhas e entreplantas. Os resultados mostraram que as radicelas localizam-se superficialmente, com 70% delas nos primeiros 15 cm, do total encontrado na camada superficial de 0 a 30 cm de profundidade do solo. Cerca de 75% das radicelas situam-se até a distância de 160 cm do tronco. Na camada mais superficial do solo (0 a 15 cm, a quantidade de radicelas diminuiu de maneira acentuada, à medida que se afastou do tronco. Na camada de 15 a 30 cm de profundidade, ocorreu uma distribuição horizontal mais uniforme, comparada com a da camada de 0 a 15 cm. As radicelas das plantas do cultivar Natal distribuiram-se uniformemente, tanto na direção das plantas da linha vizinha, quanto nas das plantas de uma mesma linha, para o espaçamento de 7,0 m x 7,2 m. Não se

Sulfur-Mediated-Alleviation of Aluminum-Toxicity in Citrus grandis Seedlings

Directory of Open Access Journals (Sweden)

Peng Guo

2017-12-01

Full Text Available Limited data are available on the sulfur (S-mediated-alleviation of aluminum (Al-toxicity in higher plants. Citrus grandis seedlings were irrigated for 18 weeks with 0.5 mM MgSO4 or 0.5 mM MgSO4 + 0.5 mM Na2SO4, and 0 (−Al or 1 mM AlCl3·6H2O (+Al, Al-toxicity. Under Al-toxicity, S decreased the level of Al in leaves; increased the relative water content (RWC of roots and leaves, the contents of phosphorus (P, calcium (Ca and magnesium (Mg per plant, the dry weights (DW of roots and shoots, the ratios of root DW/shoot DW, and the Al-induced secretion of citrate from root; and alleviated the Al-induced inhibition of photosynthesis via mitigating the Al-induced decrease of electron transport capacity resulting from the impaired photosynthetic electron transport chain. In addition to decreasing the Al-stimulated H2O2 production, the S-induced upregulation of both S metabolism-related enzymes and antioxidant enzymes also contributed to the S-mediated-alleviation of oxidative damage in Al-treated roots and leaves. Decreased transport of Al from roots to shoots and relatively little accumulation of Al in leaves, and increased leaf and root RWC and P, Ca, and Mg contents per plant might also play a role in the S-mediated-alleviation of Al-toxicity.

Caracterización mediante microsatélites de 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de Corpoica-Palmira Genetic characterization using microsatellites of 34 accessions of the orange, Citrus sinensis L. Osbeck from the Germplasm bank of Corpoica-Palmira

Directory of Open Access Journals (Sweden)

Yacenia Morillo Coronado

2010-01-01

Full Text Available Se utilizaron 19 marcadores microsatélites para caracterizar 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de la Corporación Colombiana de Investigación Agropecuaria (Corpoica-Palmira. Seis marcadores fueron polimórficos, los de mayor heterocigosidad fueron CCSM- 19 (0.4097 y CCSM-3 (0.3254. Se diferenciaron 33 accesiones y al 85% de similitud, con el índice de Nei-Li y el método de agrupamiento UPGMA, se conformaron cuatro grupos. En el primero se situaron dos accesiones blancas (Lerma y Valencia Olinda 2, en el segundo la mayoría de las blancas (Indian River, Valencia Olinda, Wialua, Lima Dulce, Pera del Río, St. Michael, Enterprise, Cafetera No. 1 junto con García Valencia y Navel (Lane Late, Valle Washington, New Hall y dos sanguinas (Rudy Blood, Moro Blood, en el tercero accesiones blancas (Joppa, Salerma, Cuban Queen, Rico, Galicia, Star Calyx, Valencia Cutter, Valencia Frost, Valencia Campbell y Valencia Variegado y una sola accesión sanguina (Morocco Blood. En el cuarto grupo se situaron dos accesiones blancas, (Jaffa y Valencia 1-D-E. Finalmente, la variedad Sanguinella no hizo parte de grupos. Con los marcadores microsatélites no se encontró relación entre los grupos genéticos, formación y las características morfológicas del grupo.To characterize 34 orange accessions Citrus sinensis L. Osbeck from the Germplasm bank Corpoica- Palmira, 19 microsatellite markers were used. Six markers were polymorphic; the highest heterozygosity was obtained by CCSM-19 (0.4097 and CCSM-3 (0.3254. Thirty-three accessions were differentiated; with 85% of similarity, Nei-Li´s index and the UPGMA clustering method were formed fi ve groups. In the first one, two accessions were white (Lerma and Valencia Olinda 2, in the second one most of the white (Indian River, Valencia Olinda, Wialua, Lima Dulce, Pera del Río, St. Michael, Enterprise, Cafetera No. 1, García Valencia and Navel (Lane Late, Valle Washington

Cloning and characterization of two 9-cis-epoxycarotenoid dioxygenase genes, differentially regulated during fruit maturation and under stress conditions, from orange (Citrus sinensis L. Osbeck).

Science.gov (United States)

Rodrigo, María-Jesús; Alquezar, Berta; Zacarías, Lorenzo

2006-01-01

There is now biochemical and genetic evidence that oxidative cleavage of cis-epoxycarotenoids by 9-cis-epoxycarotenoid dioxygenase (NCED) is the critical step in the regulation of abscisic acid (ABA) synthesis in higher plants. The peel of Citrus fruit accumulates large amounts of ABA during maturation. To understand the regulation of ABA biosynthesis in Citrus, two full-length cDNAs (CsNCED1 and CsNCED2) encoding NCEDs were isolated and characterized from the epicarp of orange fruits (Citrus sinensis L. Osbeck). Expression of the CsNCED1 gene increased in the epicarp during natural and ethylene-induced fruit maturation, and in water-stressed leaves, in a pattern consistent with the accumulation of ABA. The second gene, CsNCED2, was not detected in dehydrated leaves and, in fruits, exhibited a differential expression to that of CsNCED1. Taken together, these results suggests that CsNCED1 is likely to play a primary role in the biosynthesis of ABA in both leaves and fruits, while CsNCED2 appears to play a subsidiary role restricted to chromoplast-containing tissue. Furthermore, analysis of 9-cis-violaxanthin and 9'-cis-neoxanthin, as the two possible substrates for NCEDs, revealed that the former was the main carotenoid in the outer coloured part of the fruit peel as the fruit ripened or after ethylene treatment, whereas 9'-cis-neoxanthin was not detected or was in trace amounts. By contrast, turgid and dehydrated leaves contained 9'-cis-neoxanthin but 9-cis-violaxanthin was absent. Based on these results, it is suggested that 9-cis-violaxanthin may be the predominant substrate for NCED in the peel of Citrus fruits, whereas 9'-cis-neoxanthin would be the precursor of ABA in photosynthetic tissues.

Época da indução e evocação floral em Citrus sinensis (L. Osbeck cv. Pêra Rio The flower induction and evocation period in Citrus sinensis (L. Osbeck cv. Pêra Rio

Directory of Open Access Journals (Sweden)

Iara Alvarenga Mesquita Pereira

2003-10-01

Full Text Available A produção do estímulo floral (indução e emissão das primeiras sépalas, na gema floralmente determinada (evocação floral em Citrus sinensis (L. Osbeck cv. Pêra Rio pôde ser acompanhada pelas variações anatômicas nos meristemas apicais e axilares. Com objetivo de determinar a época na qual ocorre a indução e evocação floral, cortes longitudinais de gemas apicais e axilares, corados com pironina Y-methylgreen foram efetuados em períodos regulares de maio a agosto. Através das mudanças no formato da gema, principalmente diâmetro, que aumentou com a indução, foi possível determinar a época do ano na qual gemas vegetativas são induzidas a florescerem. Foram detectadas variações nos diâmetros das gemas no período de início da morfogênese floral (meados até o final de julho. A medição do diâmetro das gemas mostra-se um procedimento eficiente para acompanhar os fenômenos decorrentes da indução, evocação e morfogênese florais. Gemas vegetativas apresentam diâmetro médio de 100µm, com túnica composta por três camadas, de formato cônico, recobrindo o corpo, ao passo que a reprodutiva é mais achatada, após a iniciação do primeiro primórdio de sépala, exibindo diâmetro médio de 200µm. Coloração com pironina Y-methylgreen proporciona a captação do fenômeno da evocação floral, pela detecção de regiões mais concentradas em RNA, nas zonas periféricas das gemas; alteração bioquímica esta que precede a emissão das sépalas.The research aims to determine the time in which the inflorescence induction and evocation occurs. The production of inflorescence stimulus (induction and emission of first sepals in a bud determined as a flower bud (floral evocation in Citrus sinensis (L. Osbeck cv. Pêra Rio could be observed through the anatomic variations of the apical and lateral meristems. Longitudinal sections, stained with pironina Y-methylgreen were done in regular periods from May to August. The

Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

Science.gov (United States)

Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

2010-03-24

To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

A Comparison of the Volatile Components of Cold Pressed Hamlin and Valencia (Citrus sinensis (L. Osbeck Orange Oils Affected by Huanglongbing

Directory of Open Access Journals (Sweden)

Brittany M. Xu

2017-01-01

Full Text Available Volatiles from huanglongbing (HLB symptomatic and asymptomatic cold pressed orange oils from Florida Hamlin and Valencia fruit were assessed. Qualitative gas-liquid chromatography studies showed the presence of several compounds (β-longifolene, perillene, and 4-decenal which are not commonly identified in Citrus sinensis (L. Osbeck oils. Oils derived from huanglongbing symptomatic fruit had lower concentrations of linalool, decanal, citronellol, neral, geranial, carvone, dodecanal, and 2-decenal and higher concentrations of citronellal compared to asymptomatic fruit. A comparison to historic literature of orange oil investigations before HLB was of issue in Florida orange crops showed lower levels of linalool, decanal, neral, and geranial in Hamlin peel oil samples, as well as higher levels of dodecanal. Valencia peel oil samples showed lower concentrations of linalool and increased concentration of citronellol and dodecanal. As a result of huanglongbing (HLB phenomena, the concentrations of several important volatiles found in Hamlin and Valencia peel oil profiles have changed compared to historic values. Differences in volatile concentrations of symptomatic and asymptomatic HLB affected peel oil compounds in orange fruit are identified.

Efficient micropropagation of Citrus sinensis (L.) Osbeck from ...

African Journals Online (AJOL)

sunny t

2016-08-24

Aug 24, 2016 ... 2Plant Tissue Culture Laboratory, Department of Botany, D.S.B. Campus, Kumaun University, ... 2007 data, India is the largest producer of lemons .... Values represent mean±SE, values within each column followed by the same letters are not significantly ..... ICALTD Asian Citrus rehabilitation conference.

Cadmium induces changes in sucrose partitioning, invertase activities, and membrane functionality in roots of Rangpur lime (Citrus limonia L. Osbeck).

Science.gov (United States)

Podazza, G; Rosa, M; González, J A; Hilal, M; Prado, F E

2006-09-01

Cadmium (Cd) uptake effects on sucrose content, invertase activities, and plasma membrane functionality were investigated in Rangpur lime roots ( CITRUS LIMONIA L. Osbeck). Cadmium accumulation was significant in roots but not in shoots and leaves. Cadmium produced significant reduction in roots DW and increment in WC. Leaves and shoots did not show significant differences on both parameters. Sucrose content was higher in control roots than in Cd-exposed ones. Apoplastic sucrose content was much higher in Cd-exposed roots than in control ones. Cd-exposed roots showed a significant decrease in both cell wall-bound and cytoplasmic (neutral) invertase activities; while the vacuolar isoform did not show any change. Alterations in lipid composition and membrane fluidity of Cd-exposed roots were also observed. In Cd-exposed roots phospholipid and glycolipid contents decreased about 50 %, while sterols content was reduced about 22 %. Proton extrusion was inhibited by Cd. Lipid peroxidation and proton extrusion inhibition were also detected by histochemical analysis. This work's findings demonstrate that Cd affects sucrose partitioning and invertase activities in apoplastic and symplastic regions in Rangpur lime roots as well as the plasma membrane functionality and H (+)-ATPase activity.

Agrobacterium-mediated transformation of Citrus sinensis and Citrus limonia epicotyl segments Transformação genética em Citrus sinensis e Citrus limonia mediada por Agrobacterium tumefaciens a partir de segmentos de epicótilo

Directory of Open Access Journals (Sweden)

Weliton Antonio Bastos de Almeida

2003-02-01

Full Text Available 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 as explants. These were co-cultivated with Agrobacterium tumefaciens strain EHA-105 and different experiments were done to evaluate the transformation efficiency: explants were co-cultivated with Agrobacterium for one, three or five days; explants were incubated with Agrobacterium suspension for 5, 10, 20 or 40 minutes; co-cultivation medium was supplemented with acetosyringone at 0, 100 or 200 µmol L-1; Explants ends had a longitudinal terminal incision (2-3 mm; co-cultivation temperatures of 19, 23 or 27°C were imposed. The experimental design was completely randomized in all experiments with five replications, each consisted of a Petri dish (100 x 15 mm with 30 explants and resulted in a total of 150 explants per treatment. Longitudinal terminal incision in the explant ends did not improve shoot regeneration. However, transgenic plants of all three cultivars were confirmed from explants that had been subjected to inoculation time of 20 minutes, co-culture of three days at 23-27°C, in the absence of acetosyringone.A transformação genética permite produzir cultivares com características específicas e pode, dessa forma ser associada a programas de melhoramento de citros. O objetivo deste trabalho foi estabelecer protocolos de transformação genética para as laranjas doce 'Valência' e 'Natal' (Citrus sinensis L. Osbeck, bem como para o limão 'Cravo'(Citrus limonia L. Osbeck. Segmentos de epicótilo de plântulas germinadas in vitro (três semanas no

Leaf cDNA-AFLP analysis reveals novel mechanisms for boron-induced alleviation of aluminum-toxicity in Citrus grandis seedlings.

Science.gov (United States)

Wang, Liu-Qing; Yang, Lin-Tong; Guo, Peng; Zhou, Xin-Xing; Ye, Xin; Chen, En-Jun; Chen, Li-Song

2015-10-01

Little information is available on the molecular mechanisms of boron (B)-induced alleviation of aluminum (Al)-toxicity. 'Sour pummelo' (Citrus grandis) seedlings were irrigated for 18 weeks with nutrient solution containing different concentrations of B (2.5 or 20μM H3BO3) and Al (0 or 1.2mM AlCl3·6H2O). B alleviated Al-induced inhibition in plant growth accompanied by lower leaf Al. We used cDNA-AFLP to isolate 127 differentially expressed genes from leaves subjected to B and Al interactions. These genes were related to signal transduction, transport, cell wall modification, carbohydrate and energy metabolism, nucleic acid metabolism, amino acid and protein metabolism, lipid metabolism and stress responses. The ameliorative mechanisms of B on Al-toxicity might be related to: (a) triggering multiple signal transduction pathways; (b) improving the expression levels of genes related to transport; (c) activating genes involved in energy production; and (d) increasing amino acid accumulation and protein degradation. Also, genes involved in nucleic acid metabolism, cell wall modification and stress responses might play a role in B-induced alleviation of Al-toxicity. To conclude, our findings reveal some novel mechanisms on B-induced alleviation of Al-toxicity at the transcriptional level in C. grandis leaves. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Caipira sweet orange + Rangpur lime: a somatic hybrid with potential for use as rootstock in the Brazilian citrus industry

Directory of Open Access Journals (Sweden)

Fernanda Januzzi Mendes-da-Glória

2000-09-01

Full Text Available Protoplast culture following polyethylene glycol-induced fusion resulted in the regeneration of somatic hybrid plants between Caipira sweet orange (Citrus sinensis L. Osbeck and Rangpur lime (C. limonia L. Osbeck. The plants were confirmed as somatic hybrids by leaf morphology, chromosome number and RAPD profile. All regenerated plants were tetraploid (2n = 4x = 36, with intermediate leaf morphology and complementary RAPD banding profile of both parents. This combination may be useful as a rootstock for the citrus industry in Southeastern Brazil since this somatic hybrid could combine the drought tolerance and vigor of Rangpur lime with the blight tolerance of Caipira sweet orange.Híbridos somáticos de laranja doce (Citrus sinensis L. Osbeck e limão Cravo (C. limonia L. Osbeck foram regenerados após a fusão (polietileno glicol e cultura de protoplastos. Os híbridos somáticos foram confirmados pela análise da morfologia das folhas, determinação do número de cromossomos e marcadores moleculares (RAPD. Todas as plantas analisadas revelaram-se tetraplóides (2n = 4x = 36, possuíam folhas de morfologia intermediária e uma combinação do padrão de bandas de RAPD de ambos os parentais. Esta combinação pode se tornar útil como porta-enxerto para a Região Sudeste da indústria citrícola brasileira. Este híbrido somático potencialmente combinará as características de tolerância à seca e o vigor do limão Cravo com a tolerância ao declínio da laranja Caipira.

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

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

Rare Earth Element Transfer from Soil to Navel Orange Pulp (Citrus sinensis Osbeck cv. Newhall) and the Effects on Internal Fruit Quality

Science.gov (United States)

Cheng, Jinjin; Ding, Changfeng; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

2015-01-01

The effects of soil rare earth element (REE) on navel orange quality and safety in rare earth ore areas have gained great attention. This study investigated the transfer characteristics of REE from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and examined the effects of soil REE on internal fruit quality in Xinfeng County, Jiangxi province, China. Path analysis showed that soil REE, pH, cation exchange capacity (CEC), and Fe oxide (Feox) significantly affected pulp REE concentrations. A Freundlich-type prediction model for pulp REE was established: log[REEpulp] = -1.036 + 0.272 log[REEsoil] - 0.056 pH - 0.360 log[CEC] + 0.370 log[Feox] (n = 114, R2 = 0.60). From the prediction model, it was inferred that even when soil REE and Feox were as high as 1038 mg kg-1 and 96.4 g kg-1, respectively, and pH and CEC were as low as 3.75 and 5.08 cmol kg-1, respectively, pulp REE concentrations were much lower than the food limit standard. Additionally, soil REE levels were significantly correlated with selected fruit quality indicators, including titratable acidity (r = 0.52, P fruit quality. PMID:25806821

EFEITOS DE GIBERELINAS, CITOCININAS E DO NITRATO DE POTÁSSIO, NO PROCESSO GERMINATIVO DE SEMENTES DE LIMOEIRO `CRAVO' (Citrus limonia OSBECK

Directory of Open Access Journals (Sweden)

Leonel Sarita

1999-01-01

Full Text Available Foram estudados os efeitos de reguladores vegetais do grupo das giberelinas e citocininas, bem como do nitrato de potássio na germinação de sementes do limoeiro `Cravo' (Citrus limonia Osbeck. O experimento foi realizado, contendo papel de filtro como substrato para a germinação das sementes, regulado à temperatura de 25oC. As sementes foram retiradas de frutos maduros no final da safra do limoeiro `Cravo', lavadas, secas à sombra e armazenadas durante 11 dias em câmara fria. Em seguida, receberam tratamento com os fitorreguladores e KNO3 por 24 horas, de acordo com os tratamentos: KNO3 0,1% e 0,2%; GA3 50, 100 e 250 mg.L-1; GA4 + GA7 + fenilmetilaminopurina 100 mg.L-1; fenilmetilaminopurina 20 mg.L-1 e água destilada (testemunha. As avaliações foram iniciadas 15 dias após a semeadura, em intervalos de 5 dias. Conclui-se que os reguladores vegetais utilizados não afetaram o processo germinativo das sementes e que os tratamentos com nitrato de potássio 0,1% e 0,2% exerceram efeito inibitório sobre a germinação.

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.

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).

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)

Volatile constituents of the fruit peel oil of Citrus maxima (J. Burman) Merrill. from Northeast India

NARCIS (Netherlands)

Bordoloi, A.K.; Pathak, M.G.; Sperkova, S.; Leclercq, P.A.

1999-01-01

The oil obtained by steam distillation of the fruit peels of cultivated Citrus maxima (T. Burman) Merrill [syn. C. decumana Linn.; syn. C. grandts (1.) Osbeck] was investigated by GC and GC/MS. Thirty-five compounds were identified accounting for 98.90/0 of the oil. The major constituent was

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

cDNA-AFLP analysis reveals the adaptive responses of citrus to long-term boron-toxicity.

Science.gov (United States)

Guo, Peng; Qi, Yi-Ping; Yang, Lin-Tong; Ye, Xin; Jiang, Huan-Xin; Huang, Jing-Hao; Chen, Li-Song

2014-10-28

Boron (B)-toxicity is an important disorder in agricultural regions across the world. Seedlings of 'Sour pummelo' (Citrus grandis) and 'Xuegan' (Citrus sinensis) were fertigated every other day until drip with 10 μM (control) or 400 μM (B-toxic) H3BO3 in a complete nutrient solution for 15 weeks. The aims of this study were to elucidate the adaptive mechanisms of citrus plants to B-toxicity and to identify B-tolerant genes. B-toxicity-induced changes in seedlings growth, leaf CO2 assimilation, pigments, total soluble protein, malondialdehyde (MDA) and phosphorus were less pronounced in C. sinensis than in C. grandis. B concentration was higher in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. Here we successfully used cDNA-AFLP to isolate 67 up-regulated and 65 down-regulated transcript-derived fragments (TDFs) from B-toxic C. grandis leaves, whilst only 31 up-regulated and 37 down-regulated TDFs from B-toxic C. sinensis ones, demonstrating that gene expression is less affected in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. These differentially expressed TDFs were related to signal transduction, carbohydrate and energy metabolism, nucleic acid metabolism, protein and amino acid metabolism, lipid metabolism, cell wall and cytoskeleton modification, stress responses and cell transport. The higher B-tolerance of C. sinensis might be related to the findings that B-toxic C. sinensis leaves had higher expression levels of genes involved in photosynthesis, which might contribute to the higher photosyntheis and light utilization and less excess light energy, and in reactive oxygen species (ROS) scavenging compared to B-toxic C. grandis leaves, thus preventing them from photo-oxidative damage. In addition, B-toxicity-induced alteration in the expression levels of genes encoding inorganic pyrophosphatase 1, AT4G01850 and methionine synthase differed between the two species, which might play a role in the B-tolerance of C. sinensis. C. sinensis

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.

An evaluation of sequence tagged microsatellite site markers for genetic analysis within Citrus and related species.

Science.gov (United States)

Kijas, J M; Fowler, J C; Thomas, M R

1995-04-01

Microsatellites, also called sequence tagged microsatellite sites (STMSs), have become important markers for genome analysis but are currently little studied in plants. To assess the value of STMSs for analysis within the Citrus plant species, two example STMSs were isolated from an intergeneric cross between rangpur lime (Citrus x limonia Osbeck) and trifoliate orange (Poncirus trifoliata (L.) Raf.). Unique flanking primers were constructed for polymerase chain reaction amplification both within the test cross and across a broad range of citrus and related species. Both loci showed length variation between test cross parents with alleles segregating in a Mendelian fashion to progeny. Amplification across species showed the STMS flanking primers to be conserved in every genome tested. The traits of polymorphism, inheritance, and conservation across species mean that STMS markers are ideal for genome mapping within Citrus, which contains high levels of genetic variability.

An investigation of boron-toxicity in leaves of two citrus species differing in boron-tolerance using comparative proteomics.

Science.gov (United States)

Sang, Wen; Huang, Zeng-Rong; Qi, Yi-Ping; Yang, Lin-Tong; Guo, Peng; Chen, Li-Song

2015-06-18

Limited data are available on boron (B)-toxicity-responsive proteins in plants. We first applied 2-dimensional electrophoresis (2-DE) to compare the effects of B-toxicity on leaf protein profiles in B-tolerant Citrus sinensis and B-intolerant Citrus grandis seedlings, and identified 27 (20) protein species with increased abundances and 23 (25) protein species with decreased abundances from the former (latter). Generally speaking, B-toxicity increased the abundances of protein species involved in antioxidation and detoxification, proteolysis, cell transport, and decreased the abundances of protein species involved in protein biosynthesis in the two citrus species. The higher B-tolerance of C. sinensis might include following several aspects: (a) protein species related to photosynthesis and energy metabolism in C. sinensis leaves were more adaptive to B-toxicity than in C. grandis ones, which was responsible for the higher photosynthesis and for the better maintenance of energy homeostasis in the former; and (b) the increased requirement for detoxification of reactive oxygen species and cytotoxic compounds due to decreased photosynthesis was less in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. B-toxicity-responsive protein species involved in coenzyme biosynthesis differed between the two species, which might also contribute to the higher B-tolerance of C. sinensis. B-toxicity occurs in many regions all over the world, especially in arid and semiarid regions due to the raising of B-rich water tables with high B accumulated in topsoil. In China, B-toxicity often occurs in some citrus orchards. However, the mechanisms of citrus B-tolerance are still not fully understood. Here, we first used 2-DE to identify some new B-toxicity-responsive-proteins involved in carbohydrate and energy metabolism, antioxidation and detoxification, signal transduction and nucleotide metabolism. Our results showed that proteins involved in photosynthesis and energy metabolism

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...

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 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

An in silico analysis of the key genes involved in flavonoid biosynthesis in Citrus sinensis

Directory of Open Access Journals (Sweden)

Adriano R. Lucheta

2007-01-01

Full Text Available Citrus species are known by their high content of phenolic compounds, including a wide range of flavonoids. In plants, these compounds are involved in protection against biotic and abiotic stresses, cell structure, UV protection, attraction of pollinators and seed dispersal. In humans, flavonoid consumption has been related to increasing overall health and fighting some important diseases. The goals of this study were to identify expressed sequence tags (EST in Citrus sinensis (L. Osbeck corresponding to genes involved in general phenylpropanoid biosynthesis and the key genes involved in the main flavonoids pathways (flavanones, flavones, flavonols, leucoanthocyanidins, anthocyanins and isoflavonoids. A thorough analysis of all related putative genes from the Citrus EST (CitEST database revealed several interesting aspects associated to these pathways and brought novel information with promising usefulness for both basic and biotechnological applications.

Synergistic Effect of Sodium Chlorite and Edible Coating on Quality Maintenance of Minimally Processed Citrus grandis under Passive and Active MAP.

Science.gov (United States)

Ban, Zhaojun; Feng, Jianhua; Wei, Wenwen; Yang, Xiangzheng; Li, Jilan; Guan, Junfeng; Li, Jiang

2015-08-01

Edible coating has been an innovation within the bioactive packaging concept. The comparative analysis upon the effect of edible coating, sodium chlorite (SC) and their combined application on quality maintenance of minimally processed pomelo (Citrus grandis) fruits during storage at 4 °C was conducted. Results showed that the combination of edible coating and SC dipping delayed the microbial development whereas the sole coating or dipping treatment was less efficient. The synergetic application of edible coating and SC treatment under modified atmosphere packaging (MAP, 10% O2 , 10% CO2 ) was able to maintain the total soluble solids level and ascorbic acid content, while reduce the weight loss as well as development of mesophiles and psychrotrophs. Nonetheless, the N, O-carboxymethyl chitosan solely coated samples showed significantly higher level of weight loss during storage with comparison to the untreated sample. Furthermore, the combined application of edible coating and SC dipping under active MAP best maintained the sensory quality of minimally processed pomelo fruit during storage. © 2015 Institute of Food Technologists®

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.

In vitro organogenesis optimization and plantlet regeneration in Citrus sinensis and C. limonia

Directory of Open Access Journals (Sweden)

Almeida Weliton Antonio Bastos de

2002-01-01

Full Text Available Exogenous genes can be introduced in plants by genetic transformation techniques. However, an efficient tissue culture system with high rates of plant recovery is necessary for gene introduction. This work aimed to define organogenesis and plant regeneration protocols for sweet orange varieties Natal, Valencia and Hamlin (Citrus sinensis L. Osbeck and Rangpur lime (Citrus limonia L. Osbeck which can be used in plant transformation experiments. Seeds of which teguments were removed, were germinated in vitro and maintained in the dark for three weeks, followed by one week at 16-h photoperiod (40 µmol m-2 s-1 and 27 ± 2°C. Organogenesis induction was done by introducing epicotyl segments in MT medium with 25 g L-1 sucrose and different BAP concentrations. After adventitious bud growth, the shoots were transferred to MT medium with either NAA or IBA (1 mg L-1, or absence of auxin, for rooting. The best results were obtained with 1 mg L-1 BAP for bud induction and 1 mg L-1 IBA for rooting for all three sweet orange cultivars. The use of 0.5-2.5 mg L-1 BAP, followed by 1 mg L-1 IBA were the best growth regulator combinations for bud induction and rooting, respectively, for 'Rangpur' lime. The protocols presented in this work are suitable for associations with genetic transformation experiments for these cultivars.

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.

Caracterización mediante microsatélites de 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de Corpoica-Palmira

Directory of Open Access Journals (Sweden)

Yacenia Morillo Coronado

2010-01-01

Full Text Available Se utilizaron 19 marcadores microsatélites para caracterizar 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de la Corporación Colombiana de Investigación Agropecuaria (Corpoica-Palmira. Seis marcadores fueron polimórficos, los de mayor heterocigosidad fueron CCSM- 19 (0.4097 y CCSM-3 (0.3254. Se diferenciaron 33 accesiones y al 85% de similitud, con el índice de Nei-Li y el método de agrupamiento UPGMA, se conformaron cuatro grupos. En el primero se situaron dos accesiones blancas (Lerma y Valencia Olinda 2, en el segundo la mayoría de las blancas (Indian River, Valencia Olinda, Wialua, Lima Dulce, Pera del Río, St. Michael, Enterprise, Cafetera No. 1 junto con García Valencia y Navel (Lane Late, Valle Washington, New Hall y dos sanguinas (Rudy Blood, Moro Blood, en el tercero accesiones blancas (Joppa, Salerma, Cuban Queen, Rico, Galicia, Star Calyx, Valencia Cutter, Valencia Frost, Valencia Campbell y Valencia Variegado y una sola accesión sanguina (Morocco Blood. En el cuarto grupo se situaron dos accesiones blancas, (Jaffa y Valencia 1-D-E. Finalmente, la variedad Sanguinella no hizo parte de grupos. Con los marcadores microsatélites no se encontró relación entre los grupos genéticos, formación y las características morfológicas del grupo.

Caracterización mediante microsatélites de 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de Corpoica-Palmira

Directory of Open Access Journals (Sweden)

Morillo Coronado Yacenia

2010-03-01

Full Text Available Se utilizaron 19 marcadores microsatélites para caracterizar 34 accesiones de naranja Citrus sinensis L. Osbeck del Banco de Germoplasma de la Corporación Colombiana de Investigación Agropecuaria (Corpoica-Palmira. Seis marcadores fueron polimórficos, los de mayor heterocigosidad fueron CCSM- 19 (0.4097 y CCSM-3 (0.3254. Se diferenciaron 33 accesiones y al 85% de similitud, con el índice de Nei-Li y el método de agrupamiento UPGMA, se conformaron cuatro grupos. En el primero se situaron dos accesiones blancas (Lerma y Valencia Olinda 2, en el segundo la mayoría de las blancas (Indian River, Valencia Olinda, Wialua, Lima Dulce, Pera del Río, St. Michael, Enterprise, Cafetera No. 1 junto con García Valencia y Navel (Lane Late, Valle Washington, New Hall y dos sanguinas (Rudy Blood, Moro Blood, en el tercero accesiones blancas (Joppa, Salerma, Cuban Queen, Rico, Galicia, Star Calyx, Valencia Cutter, Valencia Frost, Valencia Campbell y Valencia Variegado y una sola accesión sanguina (Morocco Blood. En el cuarto grupo se situaron dos accesiones blancas, (Jaffa y Valencia 1-D-E. Finalmente, la variedad Sanguinella no hizo parte de grupos. Con los marcadores microsatélites no se encontró relación entre los grupos genéticos, formación y las características morfológicas del grupo.

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)

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.

Illumina microRNA profiles reveal the involvement of miR397a in Citrus adaptation to long-term boron toxicity via modulating secondary cell-wall biosynthesis.

Science.gov (United States)

Huang, Jing-Hao; Qi, Yi-Ping; Wen, Shou-Xing; Guo, Peng; Chen, Xiao-Min; Chen, Li-Song

2016-03-10

The mechanisms underlying tolerance to B-toxicity in plants are still controversial. Our previous studies indicated that B-toxicity is mainly limited to leaves in Citrus and that alternations of cell-wall structure in vascular bundles are involved in tolerance to B-toxicity. Here, miRNAs and their expression patterns were first identified in B-treated Citrus sinensis (tolerant) and C. grandis (intolerant) leaves via high-throughput sequencing. Candidate miRNAs were then verified with molecular and anatomical approaches. The results showed that 51 miRNAs in C. grandis and 20 miRNAs in C. sinensis were differentially expressed after B-toxic treatment. MiR395a and miR397a were the most significantly up-regulated miRNAs in B-toxic C. grandis leaves, but both were down-regulated in B-toxic C. sinensis leaves. Four auxin response factor genes and two laccase (LAC) genes were confirmed through 5'-RACE to be real targets of miR160a and miR397a, respectively. Up-regulation of LAC4 resulted in secondary deposition of cell-wall polysaccharides in vessel elements of C. sinensis, whereas down-regulation of both LAC17 and LAC4, led to poorly developed vessel elements in C. grandis. Our findings demonstrated that miR397a plays a pivotal role in woody Citrus tolerance to B-toxicity by targeting LAC17 and LAC4, both of which are responsible for secondary cell-wall synthesis.

Structure and composition of the assemblage of parasitoids associated to Phyllocnistis citrella pupae Stainton (Lepidoptera: Gracillariidae) in citrus orchards in Southern Brazil

International Nuclear Information System (INIS)

Jahnke, Simone M.; Redaelli, Luiza R.; Soglio, Fabio K. Dal

2007-01-01

The structure and composition of the assemblage of pupal parasitoids of Phyllocnistis citrella Stainton, the citrus leaf miner, were studied in two citrus orchards (Citrus deliciosa Tenore cv. Montenegrina and Citrus sinensis (L.) Osbeck x Citrus reticulata Blanco hybrid Murcott), in Montenegro County (29 deg 68S and 51 deg 46W), southern Brazil. At fortnightly samplings, from July 2001 to June 2003, all the new shoots from 24 randomly selected trees were inspected. The species richness reached five native species in the Murcott orchard, and six in Montenegrina. In Murcott, the presence of Ageniaspis citricola (Hymenoptera: Encyrtidae), an exotic species, was detected in the first year of sampling, probably migrating from the nearby areas where it had been released for the miner control. In Montenegrina, its presence was only registered in the second year. A. citricola in both areas was dominant and changed the community structure of parasitoid complex of P. citrella in both orchards. (author)

Two-dimensional gel electrophoresis data in support of leaf comparative proteomics of two citrus species differing in boron-tolerance

Directory of Open Access Journals (Sweden)

Wen Sang

2015-09-01

Full Text Available Here, we provide the data from a comparative proteomics approach used to investigate the response of boron (B-tolerant ‘Xuegan’ (Citrus sinensis and B-intolerant ‘Sour pummelo’ (Citrus grandis leaves to B-toxicity. Using two-dimensional gel electrophoresis (2-DE technique, we identified 50 and 45 protein species with a fold change of more than 1.5 and a P-value of less than 0.05 from B-toxic C. sinensis and C. grandis leaves. These B-toxicity-responsive protein species were mainly involved in carbohydrate and energy metabolism, antioxidation and detoxification, stress responses, coenzyme biosynthesis, protein and amino acid metabolism, signal transduction, cell transport, cytoskeleton, nucleotide metabolism, and cell cycle and DNA processing. A detailed analysis of this data may be obtained from Sang et al. (J. Proteomics 114 (2015[1].

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.

Use of the heat dissipation method for sap flow measurement in citrus nursery trees1 Uso do método de dissipação de calor para a medição do fluxo de seiva em mudas cítricas

Directory of Open Access Journals (Sweden)

Eduardo Augusto Girardi

2010-12-01

Full Text Available Sap flow could be used as physiological parameter to assist irrigation of screen house citrus nursery trees by continuous water consumption estimation. Herein we report a first set of results indicating the potential use of the heat dissipation method for sap flow measurement in containerized citrus nursery trees. 'Valencia' sweet orange [Citrus sinensis (L. Osbeck] budded on 'Rangpur' lime (Citrus limonia Osbeck was evaluated for 30 days during summer. Heat dissipation probes and thermocouple sensors were constructed with low-cost and easily available materials in order to improve accessibility of the method. Sap flow showed high correlation to air temperature inside the screen house. However, errors due to natural thermal gradient and plant tissue injuries affected measurement precision. Transpiration estimated by sap flow measurement was four times higher than gravimetric measurement. Improved micro-probes, adequate method calibration, and non-toxic insulating materials should be further investigated.O fluxo de seiva poderia ser utilizado como parâmetro fisiológico para fomentar a irrigação de mudas cítricas em cultivo protegido pela estimação do consumo contínuo de água. Neste trabalho, reportam-se os primeiros resultados, indicando o uso potencial e as limitações iniciais do método de dissipação de calor para medição do fluxo de seiva em mudas cítricas em recipientes. Mudas de laranjeira-doce 'Valência' [Citrus sinensis (L. Osbeck] enxertadas sobre limoeiro 'Cravo' (Citrus limonia Osbeck foram avaliadas por 30 dias, durante o verão. Sondas de dissipação de calor e sensores do tipo termopar foram construídos a partir de materiais prontamente disponíveis e de baixo custo para favorecer o acesso ao método por viveiristas. O fluxo de seiva apresentou alta correlação com a temperatura do ar dentro da estufa telada. Contudo, erros inerentes ao gradiente térmico natural e a injúrias nos tecidos do caule afetaram a

Fita plástica e fita degradável na enxertia de citros Plastic and degradable tape on citrus budding

Directory of Open Access Journals (Sweden)

Roberto Pedroso de Oliveira

2004-12-01

Full Text Available Este trabalho foi realizado com o objetivo de avaliar o efeito de fitas plástica e degradável no pegamento e no desenvolvimento de enxertos de citros, em viveiro telado. Borbulhas certificadas de 6-8 mm das cultivares de laranjeira-de-umbigo 'Navelina' (Citrus sinensis (L. Osbeck, tangerineira 'Marisol' (C. reticulata Blanco e do híbrido 'Nova' [C. clementina x (C. paradisi x C. tangerina ] foram enxertadas em limoeiro 'Cravo' (C. limonia Osbeck, com 10 meses de idade, em fevereiro de 2003. A fixação das borbulhas nos porta-enxertos foi feita com fitas de dois tipos: fita plástica de polietileno transparente e fita degradável de parafilme. Os tratamentos foram dispostos em esquema fatorial (3 cultivares x 2 tipos de fita, em delineamento inteiramente ao acaso, com quatro repetições, sendo as unidades experimentais constituídas por dez plantas. A média geral de pegamento dos enxertos foi elevada (99,6%, em razão das condições propícias à enxertia fornecidas no viveiro telado. Não houve efeito do tipo de fita no pegamento dos enxertos nem das cultivares no pegamento e desenvolvimento dos enxertos. No entanto, o desenvolvimento dos enxertos foi sensivelmente maior quando a enxertia foi realizada com fita degradável em relação à fita plástica.The aim of this work was to evaluate the effect of the plastic and degradable tape on budding efficiency and scion development of citrus in nursery under screenhouse. Certificated 6-8 mm buds of the cultivars navel orange 'Navelina' (Citrus sinensis (L. Osbeck, mandarin 'Marisol' (C. reticulata Blanco and the hybrid 'Nova' [C. clementina x (C. paradisi x C. tangerina ] were budded on 10 months rangpur lime (C. limonia Osbeck, in February 2003. The buds were attached to the rootstocks using either one of two types of tape: plastic polyethylene transparent tape and parafilm degradable tape. The experimental design was a factorial entirely randomized with 3 cultivars, 2 tape types and four

Collection and chemical composition of phloem sap from Citrus sinensis L. Osbeck (sweet orange).

Science.gov (United States)

Hijaz, Faraj; Killiny, Nabil

2014-01-01

Through utilizing the nutrient-rich phloem sap, sap feeding insects such as psyllids, leafhoppers, and aphids can transmit many phloem-restricted pathogens. On the other hand, multiplication of phloem-limited, uncultivated bacteria such as Candidatus Liberibacter asiaticus (CLas) inside the phloem of citrus indicates that the sap contains all the essential nutrients needed for the pathogen growth. The phloem sap composition of many plants has been studied; however, to our knowledge, there is no available data about citrus phloem sap. In this study, we identified and quantified the chemical components of phloem sap from pineapple sweet orange. Two approaches (EDTA enhanced exudation and centrifugation) were used to collect phloem sap. The collected sap was derivatized with methyl chloroformate (MCF), N-methyl-N- [tert-butyl dimethylsilyl]-trifluroacetamide (MTBSTFA), or trimethylsilyl (TMS) and analyzed with GC-MS revealing 20 amino acids and 8 sugars. Proline, the most abundant amino acid, composed more than 60% of the total amino acids. Tryptophan, tyrosine, leucine, isoleucine, and valine, which are considered essential for phloem sap-sucking insects, were also detected. Sucrose, glucose, fructose, and inositol were the most predominant sugars. In addition, seven organic acids including succinic, fumaric, malic, maleic, threonic, citric, and quinic were detected. All compounds detected in the EDTA-enhanced exudate were also detected in the pure phloem sap using centrifugation. The centrifugation technique allowed estimating the concentration of metabolites. This information expands our knowledge about the nutrition requirement for citrus phloem-limited bacterial pathogen and their vectors, and can help define suitable artificial media to culture them.

Transformation of sweet orange [Citrus sinensis (L.) Osbeck] with pthA-nls for acquiring resistance to citrus canker disease.

Science.gov (United States)

Yang, Li; Hu, Chunhua; Li, Na; Zhang, Jiayin; Yan, Jiawen; Deng, Ziniu

2011-01-01

The COOH terminal of pthA encoding three nuclear localizing signals (NLS) was amplified by polymerase chain reaction (PCR) from the plasmid of Xanthomonas axonopodis pv. citri, the pathogen of citrus canker disease. Then the sense and antisense strands of the nls were cloned into pBI121 vector. pthA-nls driven by the CaMV35 s promoter was transferred into sweet orange via Agrobacterium -mediated transformation. Successful integration was confirmed by PCR and Southern blotting, and 12 sense-nls (nls (+)) and 9 antisense-nls (nls (-)) transgenic clones were obtained. The expression of nls fragment was analyzed by RT-PCR, Real time q-PCR and Western blotting, in which the specific NLS protein was detected only in nls (+) transgenic clones. In an in vitro assay, when pin-puncture inoculation was performed with 2.5 × 10(7) cfu/ml of bacterial solution, the nls (+) transgenic clones showed no typical lesion development, while typical symptoms were observed in the wild types and the nls (-) transgenic clones. In vivo assay results indicated that the nls (+) transgenic clones showed less disease incidence, in comparison with the wild types and the nls (-) transgenic clones, when pin-puncture inoculation was performed with 10(4)-10(5) cfu/ml. The minimum disease incidence was 23.3% for 'Sucarri' sweet orange and 33.3% for 'Bingtang' sweet orange. When 10(4)-10(7) cfu/ml of pathogen was spray inoculated, the nls (+) transgenic clones did not show any symptom, and even the concentration raised to 10(9) cfu/ml, the disease incidence was 20-80%, while the wild types and the nls (-) transgenic clones had 100% disease development with whatever concentration of inoculum. Two transgenic clones were confirmed to be resistant to citrus canker disease in the repeated inoculation. The results suggested that the transformation of nls sense strands may offer an effective way to acquire resistance to citrus canker disease.

Concentrations of p-synephrine in fruits and leaves of Citrus species (Rutaceae) and the acute toxicity testing of Citrus aurantium extract and p-synephrine.

Science.gov (United States)

Arbo, M D; Larentis, E R; Linck, V M; Aboy, A L; Pimentel, A L; Henriques, A T; Dallegrave, E; Garcia, S C; Leal, M B; Limberger, R P

2008-08-01

Dietary supplements containing bitter orange unripe fruit extract/p-synephrine are consumed worldwide for lose weight. This study were conducted to determine the concentration of p-synephrine in unripe fruits and leaves from Citrus aurantium Lin, C. sinensis Osbeck, C. deliciosa Ten, C. limon Burm and C. limonia Osbeck, collected in Southern Brazil, and to evaluate the acute toxicity of C. aurantium extract and p-synephrine. A high performance liquid chromatographic method with diode array detector (HPLC-DAD) was optimized and validated for determination of p-synephrine. The results indicate that all of analyzed samples present p-synephrine in amounts that range from 0.012% to 0.099% in the unripe fruits and 0.029 to 0.438% in the leaves. Acute oral administration of C. aurantium extracts (2.5% p-synephrine, 300-5,000 mg/kg) in mice produced reduction of locomotor activity, p-synephrine (150-2,000 mg/kg) produced piloerection, gasping, salivation, exophtalmia and reduction in locomotor activity, which was confirmed in spontaneous locomotor activity test. All the effects were reversible and persisted for 3-4h. The toxic effects observed seem to be related with adrenergic stimulation and should alert for possible side effects of p-synephrine and C. aurantium.

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.

[Parasitism in Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Citrus orchards in Montenegro, RS, Brazil].

Science.gov (United States)

Jahnke, Simone M; Redaelli, Luiza R; Diefenbach, Lúcia M G

2006-01-01

Phyllocnistis citrella Stainton, the citrus-leafminer, is an important pest of citrus worldwide. Knowledge of natural parasitism levels is fundamental to the establishment of tactics of management and control of this species. This work aimed to evaluate the parasitism in two citrus orchards, one of 'Montenegrina' (Citrus deliciosa Ten.) and the other of 'Murcott' (C. sinensis (L.) Osbeck x C. reticulata Blanco), located in Montenegro, RS. In fortnightly samplings, from July/2001 to June/2003, all leaves containing P. citrella pupae from randomly selected plants were collected and maintained individually until emergence of the parasitoids or the citrus-leafminer. Parasitism was calculated considering the number of emerged parasitoids relative to the total number of emerged individuals. Correlation and linear regression tests were done to evaluate the relationship and the influence of biotic and abiotic factors upon the parasitism index. In both orchards the greatest parasitism percentage was registered on autumn in both years. The total percentage was 36.2% in 'Murcott' and 26.4% in 'Montenegrina' in the first year, and 30.2% and 37.6%, respectively, in the second year. In 'Murcott', this index did not differed between the years (chi2 = 2.06; df = 1; P > 0.05), in 'Montenegrina' the parasitism was significantly higher in the second year (chi2 = 7.36; df = 1; P < 0.05). The correlation and linear regression tests indicated a strong influence, in the parasitism index, of the host populational density registered in the previous 45 and 135 days.

Differences between elemental composition of orange juices and leaves from organic and conventional production systems

International Nuclear Information System (INIS)

Turra, C.; Fernandes, E.A.N.; Bacchi, M.A.; Tagliaferro, F.S.; Franca, E.J.

2006-01-01

A comprehensive sampling of organic and conventional oranges was carried out in Bebedouro, an important citrus producing region of Brazil. The soils, leaves and fruits of the variety Valencia (Citrus sinensis [L.] Osbeck) budded on Rangpur lime (Citrus limonia Osbeck) were analyzed. The chemical characterization was accomplished by instrumental neutron activation analysis (INAA). Indications for a difference between organic and conventional orange juices and leaves were obtained by applying univariate and multivariate statistical analysis. There were differences between samples for Br, Co, Cs, La and Rb from both systems. (author)

Efecto del déficit hídrico en el crecimiento y desarrollo de frutos de naranja Valencia (Citrus sinensis Osbeck en el piedemonte del Meta, Colombia

Directory of Open Access Journals (Sweden)

Diana Lucía Garzón Correa

2013-04-01

Full Text Available En Colombia el área sembrada con cítricos es marginal, si se compara con el área potencial de cultivo, debido a factores como déficit de agua, nutrición y eficiencia de la formación de frutos. El objetivo del presente estudio fue evaluar el efecto del déficit hídrico mediante la aplicación controlada de láminas de riego en el cultivo de naranja Valencia (Citrus sinensis Osbeck en el piedemonte del Meta (departamento del Meta, Colombia. Los tratamientos (T de riego fueron: T1 = 100% de la evapotranspiración del cultivo (ETc; T2 = 50% ETc; T3 = testigo = 0% ETc. El riego se aplicó desde el inicio de la floración en febrero hasta la formación del fruto en abril de 2011. El diseño experimental fue bloques completamente al azar con tres repeticiones por tratamiento. Las variables evaluadas fueron: humedad del suelo (q g, estado hídrico de la planta (Ytallo, fenología, brotación, floración, formación, crecimiento y calidad del fruto. Los árboles en el T1 presentaron un mayor número y tamaño de fruto, pero no se encontraron diferencias (P > 0.05 en producción y calidad respecto al testigo; la q g y el Ytallo fueron diferentes (P < 0.05 entre tratamientos y el testigo mostró los menores valores, 13.82% y -2.5 MPa, lo cual indica un estrés moderado.

Relation of carbohydrate reserves with the forthcoming crop, flower formation and photosynthetic rate, in the alternate bearing Salustiana sweet orange (Citrus sinensis L.)

OpenAIRE

Monerri Huguet, Mª Consuelo; Fortunato De Almeida, Ambrosio; Molina Romero, Rosa Victoria; González Nebauer, Sergio; García Luís, Mª Desamparados; Guardiola Barcena, José Luís

2011-01-01

[EN] The aim of this work was to assess the relation between carbohydrate levels and flower and fruit production, as well as the role of carbohydrates on CO(2) fixation activity, by analysis of leaves, twigs and roots from the alternate bearing 'Salustiana' cultivar of sweet orange (Citrus sinensis [L.] Osbeck). A heavy crop load (on year) did not affect photosynthesis activity when compared to non-fruiting trees (off year). Fruiting trees accumulated most of the fixed carbon in mature fruits...

Phenolic Composition and Antioxidant Capacities of Chinese Local Pummelo Cultivars' Peel

Directory of Open Access Journals (Sweden)

Zefang Lü

2016-05-01

Full Text Available China is one of the main production areas of pummelo [Citrus grandis (L. Osbeck.] in the world and has lots of distinctive local cultivars. Systematic research on the detection of phenolics and antioxidant capacity of peels of mature local cultivars pummelo  fruits is rare. In the current study, phenolic composition and content in peels (flavedo and albedo of ten Chinese local pummelo cultivars were determined using Ultraviolet Spectrophotometer and High Performance Liquid Chromatography (HPLC, and their antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH radicals, ferric reducing antioxidant power (FRAP, and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS methods in the current study. The research not only provides data that support making full use of the resources of Chinese local pummelo cultivars, but also lays the theoretical basis for research of pummelo fruit nutrition and health values. The results showed that the total phenolic (TP content in albedo was significantly higher than that in flavedo; on the contrary, the total flavonoid (TF content was lower in the albedo than in the flavedo. C. grandis ‘Hongxinyou’ flavedo contained the highest TP contents, C. grandis ‘Liangpingyou 78-8’ flavedo contained the highest TF contents, and C. grandis ‘Guanxi Miyou’ albedo contained the highest TP and TF contents. Naringenin, hesperetin, diosmin, and gallic acid were the predominant phenolics in the flavedo, whereas hesperetin, diosmin, rutin, chlorogenic acid, and gallic acid were the primary phenolics in the albedo. The flavedo of C. grandis ‘Yubei Shatianyou’ and the albedo of C. grandis ‘Dianjiang Baiyou’ had the highest antioxidant potency composite (APC indexes. Overall, the ‘Yubei Shatianyou’ flavedo and the ‘Dianjiang Baiyou’ albedo are excellent sources of antioxidants and have the greatest potential value for exploitation and utilization.

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.

Mechanisms on boron-induced alleviation of aluminum-toxicity in Citrus grandis seedlings at a transcriptional level revealed by cDNA-AFLP analysis.

Directory of Open Access Journals (Sweden)

Xin-Xing Zhou

Full Text Available The physiological and biochemical mechanisms on boron (B-induced alleviation of aluminum (B-toxicity in plants have been examined in some details, but our understanding of the molecular mechanisms underlying these processes is very limited. In this study, we first used the cDNA-AFLP to investigate the gene expression patterns in Citrus grandis roots responsive to B and Al interactions, and isolated 100 differentially expressed genes. Results showed that genes related to detoxification of reactive oxygen species (ROS and aldehydes (i.e., glutathione S-transferase zeta class-like isoform X1, thioredoxin M-type 4, and 2-alkenal reductase (NADP+-dependent-like, metabolism (i.e., carboxylesterases and lecithin-cholesterol acyltransferase-like 4-like, nicotianamine aminotransferase A-like isoform X3, thiosulfate sulfurtransferase 18-like isoform X1, and FNR, root isozyme 2, cell transport (i.e., non-specific lipid-transfer protein-like protein At2g13820-like and major facilitator superfamily protein, Ca signal and hormone (i.e., calcium-binding protein CML19-like and IAA-amino acid hydrolase ILR1-like 4-like, gene regulation (i.e., Gag-pol polyprotein and cell wall modification (i.e., glycosyl hydrolase family 10 protein might play a role in B-induced alleviation of Al-toxicity. Our results are useful not only for our understanding of molecular processes associated with B-induced alleviation of Al-toxicity, but also for obtaining key molecular genes to enhance Al-tolerance of plants in the future.

Mechanisms on boron-induced alleviation of aluminum-toxicity in Citrus grandis seedlings at a transcriptional level revealed by cDNA-AFLP analysis.

Science.gov (United States)

Zhou, Xin-Xing; Yang, Lin-Tong; Qi, Yi-Ping; Guo, Peng; Chen, Li-Song

2015-01-01

The physiological and biochemical mechanisms on boron (B)-induced alleviation of aluminum (B)-toxicity in plants have been examined in some details, but our understanding of the molecular mechanisms underlying these processes is very limited. In this study, we first used the cDNA-AFLP to investigate the gene expression patterns in Citrus grandis roots responsive to B and Al interactions, and isolated 100 differentially expressed genes. Results showed that genes related to detoxification of reactive oxygen species (ROS) and aldehydes (i.e., glutathione S-transferase zeta class-like isoform X1, thioredoxin M-type 4, and 2-alkenal reductase (NADP+-dependent)-like), metabolism (i.e., carboxylesterases and lecithin-cholesterol acyltransferase-like 4-like, nicotianamine aminotransferase A-like isoform X3, thiosulfate sulfurtransferase 18-like isoform X1, and FNR, root isozyme 2), cell transport (i.e., non-specific lipid-transfer protein-like protein At2g13820-like and major facilitator superfamily protein), Ca signal and hormone (i.e., calcium-binding protein CML19-like and IAA-amino acid hydrolase ILR1-like 4-like), gene regulation (i.e., Gag-pol polyprotein) and cell wall modification (i.e., glycosyl hydrolase family 10 protein) might play a role in B-induced alleviation of Al-toxicity. Our results are useful not only for our understanding of molecular processes associated with B-induced alleviation of Al-toxicity, but also for obtaining key molecular genes to enhance Al-tolerance of plants in the future.

ORGANOGÊNESE IN VITRO DE Citrus EM FUNÇÃO DE CONCENTRAÇÕES DE BAP E SECCIONAMENTO DO EXPLANTE CITRUS IN VITRO ORGANOGENESIS RELATED TO BAP CONCENTRATIONS AND EXPLANT SECTION

Directory of Open Access Journals (Sweden)

THAÍS LACAVA DE MOURA

2001-08-01

Full Text Available O sucesso de técnicas biotecnológicas no melhoramento in vitro de Citrus depende diretamente do desenvolvimento de protocolos eficientes para regeneração de plantas. Objetivou-se avaliar o efeito de concentrações de 6-benzilaminopuria (BAP na organogênese in vitro de limão-'Cravo' e laranja-'Pêra', bem como o efeito do seccionamento do explante em laranja-'Valência'. Para o limão-'Cravo', foram utilizados como explante, segmentos internodais de plântulas germinadas in vitro, cultivados em meio MT e variando-se as concentrações de BAP em 0; 2,5; 5; 7,5 e 10 mg.L-1. Nas laranjas-'Pêra' e 'Valência' os explantes foram segmentos do epicótilo de plântulas germinadas in vitro. Os explantes de laranja-'Pêra' foram cultivados em meio MT variando-se as concentrações de BAP em 0; 1; 2; 3 e 4 mg.L-1. Para a laranja-'Valência', metade dos explantes foram seccionados e cultivados em meio MT acrescido de 1,0 mg.L-1 de BAP. Todas as brotações obtidas foram alongadas no meio de cultura MT + 25 g.L-1 de sacarose + 1 mg.L-1 de ácido giberélico (GA3 e enraizadas no meio MT + 25 g.L-1 de sacarose + 0,5 g.L-1 de carvão ativado + 1 mg.L-1 de ácido naftaleno acético (ANA. O melhor resultado para o número de brotações adventícias foi obtido na concentração 2,5 mg.L-1 de BAP para limão-'Cravo', e nas concentrações 1,0 e 2,0 mg.L-1 de BAP para laranja-'Pêra'. O seccionamento dos explantes favoreceu a organogênese in vitro da laranja-'Valência', porém as brotações apresentaram menor índice de enraizamento.The establishment of efficient plant regeneration protocols is essential for the success and application of in vitro breeding biotechnologies in Citrus. The objective of this work was to verify the effect of 6-benzilaminopurine (BAP on the in vitro organogenesis of Rangpur lime (Citrus limonia (L. Osbeck and 'Pera' sweet orange (Citrus sinensis (L. Osbeck, and the effect of cutting the explant on the in vitro organogenesis of

Transcriptome Profiling to Understand the Effect of Citrus Rootstocks on the Growth of 'Shatangju' Mandarin.

Science.gov (United States)

Liu, Xiang-Yu; Li, Juan; Liu, Meng-Meng; Yao, Qing; Chen, Jie-Zhong

2017-01-01

To obtain insight into potential mechanisms underlying the influence of rootstock on scion growth, we performed a comparative analysis of 'Shatangju' mandarin grafted onto 5 rootstocks: Fragrant orange (Citrus junons Sieb. ex. Tanaka), Red tangerine (Citrus reticulata Blanco), 'Shatangju' mandarin (Citrus reticulata Blanco), Rough lemon (Citrus jambhiri Lush) and Canton lemon (Citrus limonia Osbeck). The tree size of 'Shatangju' mandarin grafted onto Canton lemon and Rough lemon were the largest, followed by self-rooted rootstock trees, and the lowest tree sizes correspond to ones grafted on Red tangerine and Fragrant orange rootstocks. The levels of indoleacetic acid (IAA) and gibberellin (GA) were significantly and positively related to growth vigor. The differences of gene expression in leaves of trees grafted onto Red tangerine, Canton lemon and 'Shatangju' mandarin were analyzed by RNA-Seq. Results showed that more differentially expressed genes involved in oxidoreductase function, hormonal signal transduction and the glycolytic pathway were enriched in 'Red tangerine vs Canton lemon'. qRT-PCR analysis showed that expression levels of ARF1, ARF8, GH3 and IAA4 were negatively correlated with the growth vigor and IAA content. The metabolism of GA was influenced by the differential expression of KO1 and GA2OX1 in grafted trees. In addition, most of antioxidant enzyme genes were up-regulated in leaves of trees grafted onto Red tangerine, resulting in a higher peroxidase activity. We concluded that different rootstocks significantly affected the expression of genes involved in auxin signal transduction pathway and GA biosynthesis pathway in the grafted plants, and then regulated the hormone levels and their signal pathways.

Starvation-induced morphological responses of the boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae)

Science.gov (United States)

Status of the boll weevil, Anthonomus grandis grandis Boheman, as a pest of cotton (Gossypium spp.) in the United States has diminished because of progress by eradication programs. However, this pest remains of critical importance in South America, and intractable populations in extreme South Texas ...

The possible allelopathic effects of Brachiaria decumbens on initial development of root stock of Citrus limonia

OpenAIRE

Souza, L. S.; Velini, E. D.; Martins, D.; Rosolem, C. A.

1997-01-01

Foram estudados os possíveis efeitos alelopáticos da incorporação da matéria seca da parte aérea de Brachiaria decumbens, ao substrato, nas concentrações de 0, 1,5 e 3,0% (p/p) sobre o crescimento inicial de limão cravo (Citrus limonia Osbeck), em casa-de-vegetação. Foram determinados os parâmetros biométrico s e algumas propriedades físico-químicas da solução do solo. A maior quantidade de matéria seca incorporada causou redução de 44, 42, 57 e 55% das médias da altura, teor de clorofila, ár...

Transcriptome Profiling to Understand the Effect of Citrus Rootstocks on the Growth of ‘Shatangju’ Mandarin

Science.gov (United States)

Liu, Meng-Meng; Yao, Qing; Chen, Jie-Zhong

2017-01-01

To obtain insight into potential mechanisms underlying the influence of rootstock on scion growth, we performed a comparative analysis of ‘Shatangju’ mandarin grafted onto 5 rootstocks: Fragrant orange (Citrus junons Sieb. ex. Tanaka), Red tangerine (Citrus reticulata Blanco), ‘Shatangju’ mandarin (Citrus reticulata Blanco), Rough lemon (Citrus jambhiri Lush) and Canton lemon (Citrus limonia Osbeck). The tree size of ‘Shatangju’ mandarin grafted onto Canton lemon and Rough lemon were the largest, followed by self-rooted rootstock trees, and the lowest tree sizes correspond to ones grafted on Red tangerine and Fragrant orange rootstocks. The levels of indoleacetic acid (IAA) and gibberellin (GA) were significantly and positively related to growth vigor. The differences of gene expression in leaves of trees grafted onto Red tangerine, Canton lemon and ‘Shatangju’ mandarin were analyzed by RNA-Seq. Results showed that more differentially expressed genes involved in oxidoreductase function, hormonal signal transduction and the glycolytic pathway were enriched in ‘Red tangerine vs Canton lemon’. qRT-PCR analysis showed that expression levels of ARF1, ARF8, GH3 and IAA4 were negatively correlated with the growth vigor and IAA content. The metabolism of GA was influenced by the differential expression of KO1 and GA2OX1 in grafted trees. In addition, most of antioxidant enzyme genes were up-regulated in leaves of trees grafted onto Red tangerine, resulting in a higher peroxidase activity. We concluded that different rootstocks significantly affected the expression of genes involved in auxin signal transduction pathway and GA biosynthesis pathway in the grafted plants, and then regulated the hormone levels and their signal pathways. PMID:28081213

Influencia de 46 porta-injertos para cítricos en la precocidad o retardo de maduración de la naranja "Frost valencia" (Citrus sinensis (L. Osbeck

Directory of Open Access Journals (Sweden)

Caselles N. Álvaro A.

1987-03-01

Full Text Available Of 46 graft carrier influence in citrics on ripe precocity or retardation from "Frost Valencia" Citrus sinensis (L Osbeck was studied looking for to guaranter a fruit constant supply toward market. Graft carrier influence was tested in orange blosson, fruiting ripeness season. Stock influence to induce early intermediate or later blossoms was observed, related with period and intensity so them same ocurr. Stock influence on solubles solids content, juici volume, ripeness index, ripe fruit, mantenence on tree also was found . Early of later yields are feasible to obtain using trifoliado x Ruby Or (1437 and "Garcia Valencia" stock markedly, or which highly significant ripeness gains were found with "Frost Valencia" Orange respectively.Se estudió la influencia de los portainjertos para cítricos buscando la obtención de producciones tempranas o tardías para garantizar un suministro continuo de fruta fresca al mercado. Se analizó por espacio de dos años la influencia de los porta-injertos en el período de floración, fructificación y maduración de la naranja. Se observó influencia del patrón para inducir floraciones precoces, intermedias o tardías haciendo referencia al período de intensidad con que ocurren las mismas. También se encontró influencia del patrón en contenido de sólidos solubles, volumen de jugo, acidez, índice de marez y mantenimiento de la fruta madura en el árbol. Es posible obtener producciones tempranas o tardías con la utilización de los patrones trifoliados x Ruby Or (1437 Y García Valencia, sobre las cuales se encontró adelantos altamente significativos de maduración de la naranja "Frost Valencia" respectivamente.

Comportamento de catorze porta-enxertos para o limão eureka km 47 na região de Araraquara-SP Behaviour of fourteen rootstocks for eureka lemon [Citrus limon (L Burm. F. ] cv. km 47, in Araraquara, SP, Brazil

Directory of Open Access Journals (Sweden)

José Orlando de Figueiredo

2005-04-01

Full Text Available Foi avaliado o comportamento de 14 porta-enxertos para o limão 'Eureka km 47' [Citrus limon (L. Burm. f.], clone nucelar, em experimento instalado em 1991, na Fazenda Fittipaldi, Araraquara-SP. Os porta-enxertos foram: tangelos 'Orlando' e 'Seminole' (C. reticulata Blanco x C. paradisi Macfad., tangerinas 'Cleópatra' (C. reshni hort. ex Tanaka e 'Sunki' [C. sunki (Hayata hort. ex Tanaka], limões 'Cravo' (C. limonia Osbeck, 'Rugoso da África' (C. jambhiri Lush. e 'Volkameriano Catania 2' (C. volkameriana V. Ten. & Pasq., laranja 'Caipira DAC' [C. sinensis (L. Osbeck], laranja 'Azeda Doble Cálice' (C. aurantium L., trifoliatas 'EEL'e 'Kryder 8-5' [Poncirus trifoliata (L. Raf.], citrange 'Morton' [P. trifoliata (L. Raf. x C. sinensis (L. Osbeck], C. karna Raf. e C. pennivesiculata (Lush. Tanaka. As produções foram avaliadas no período de 1998 a 2002. As maiores produções médias em peso de frutos estiveram relacionadas aos porta-enxertos C. pennivesiculata e tangerina 'Cleópatra' (>220 kg/planta. Entre os porta-enxertos que induziram as mais baixas produções, estão C. karna, os dois tangelos, os dois trifoliatas e a 'Caipira DAC' (Fourteen rootstocks were compared in a trial started in 1991, for Eureka lemon cv. km 47, nucellar clone, in Araraquara, Brazil. The rootstocks tested were Orlando and Seminole tangelos (C. reticulata Blanco x C. paradisi Macfad., Cleopatra mandarin (C. reshni hort. ex Tanaka, Sunki mandarin [C. sunki (Hayata hort. ex Tanaka], Rangpur Lime (C. limonia Osbeck, Rough Lemon cv. African (C. jambhiri Lush., and Volkamerican cv Catania 2 (C. volkameriana V. Ten. & Pasq., sweet orange [C. sinensis (L. Osbeck] cv. Caipira DAC, sour orange (C. aurantium L., Poncirus trifoliata (L. Raf. cv. EEL, P. trifoliata (L. Raf. cv. Kryder 8-5, Morton citrange [P. trifoliata (L. Raf. x C. sinensis (L. Osbeck], C. karna Raf. and C. pennivesiculata (Lush. Tanaka. Yield was measured by weight of fruits per tree, for a period of

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.

Dispersion patterns and sampling plans for Diaphorina citri (Hemiptera: Psyllidae) in citrus.

Science.gov (United States)

Sétamou, Mamoudou; Flores, Daniel; French, J Victor; Hall, David G

2008-08-01

The abundance and spatial dispersion of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) were studied in 34 grapefruit (Citrus paradisi Macfad.) and six sweet orange [Citrus sinensis (L.) Osbeck] orchards from March to August 2006 when the pest is more abundant in southern Texas. Although flush shoot infestation levels did not vary with host plant species, densities of D. citri eggs, nymphs, and adults were significantly higher on sweet orange than on grapefruit. D. citri immatures also were found in significantly higher numbers in the southeastern quadrant of trees than other parts of the canopy. The spatial distribution of D. citri nymphs and adults was analyzed using Iowa's patchiness regression and Taylor's power law. Taylor's power law fitted the data better than Iowa's model. Based on both regression models, the field dispersion patterns of D. citri nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. For the average density of each life stage obtained during our surveys, the minimum number of flush shoots per tree needed to estimate D. citri densities varied from eight for eggs to four flush shoots for adults. Projections indicated that a sampling plan consisting of 10 trees and eight flush shoots per tree would provide density estimates of the three developmental stages of D. citri acceptable enough for population studies and management decisions. A presence-absence sampling plan with a fixed precision level was developed and can be used to provide a quick estimation of D. citri populations in citrus orchards.

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

Directory of Open Access Journals (Sweden)

João P.R. Marques

2010-06-01

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

Seasonal Population Dynamics of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) in Sweet Orange Trees Maintained under Continuous Deficit Irrigation

Science.gov (United States)

A two-year study was conducted in a citrus orchard [Citrus sinensis (L.) Osbeck cv. ‘Valencia’] to determine influence of plant water stress on population dynamics of glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop...

Growth of citrus rootstocks under aluminium stress in hydroponics Crescimento de porta-enxertos de citros submetidos a estresse por alumínio, em cultivo hidropônico

Directory of Open Access Journals (Sweden)

Walter Esfrain Pereira

2003-02-01

Full Text Available Plants present different degrees of adaptation to aluminium (Al concentrations in the soil, and the understanding of this characteristic can lead to a viable option for the utilization of acid soils. The objective of this experiment was to evaluate the effects of five Al concentrations (0, 50, 100, 200, and 400 mumol L-1 on the growth of 'Rangpur' lime (Citrus limonia Osbeck and 'Volkamer' lemon (Citrus volkameriana Hort. ex Tan., and tangerine rootstocks 'Cleópatra' (Citrus reshni Hort. ex Tan and 'Sunki' (Citrus sunki Hort. ex Tan., in hydroponic culture. The treatments were arranged in a randomized block design, with four replications. For all rootstocks, the relative growth rate in terms of plant total fresh matter increased under low and, decreased under large Al concentrations. Growth of the shoot, leaf area ratio and leaf weight ratio decreased for all rootstocks in the presence of Al. The 'Rangpur' lime had a decrease of the root system growth, starting from 23 mumol L-1 of Al. For the remaining rootstocks, this growth reached maximum values at 91 to 117 mumol L-1 of Al, respectively. Considering all the evaluated characteristics of plant growth, the 'Rangpur' lime was the most susceptible to Al.As plantas apresentam diferentes graus de tolerância aos efeitos tóxicos do alumínio (Al, e a exploração dessa característica pode ser uma opção viável para a utilização dos solos ácidos. Este experimento teve como objetivo avaliar os efeitos de cinco concentrações de alumínio (0, 50, 100, 200 e 400 mimol L-1 de Al sobre o crescimento dos porta-enxertos limoeiros 'Cravo' (Citrus limonia Osbeck e 'Volkameriano' (Citrus volkameriana Hort. ex Tan., e tangerineiras 'Cleópatra' (Citrus reshni Hort. ex Tan e 'Sunki' (Citrus sunki Hort. ex Tan. em cultivo hidropônico. Os tratamentos foram distribuídos no delineamento de blocos casualizados, com quatro repetições e duas plantas por parcela. Em todos os porta-enxertos, a taxa relativa

greening

African Journals Online (AJOL)

Utpal

orange (Citrus Sinensis osbeck) and acid lime (Citrus aurantifolia Swingle) ... Moreover, these are not practically feasible methods for handling a ... ease by conventional procedures viz., electron microsco- py examination of ultra thin sections, bioassay on indicator plants. Therefore, the present study was attempted with a ...

Unravelling molecular responses to moderate dehydration in harvested fruit of sweet orange (Citrus sinensis L. Osbeck) using a fruit-specific ABA-deficient mutant

OpenAIRE

Romero, Paco; Rodrigo, María J.; Alférez, Fernando; Ballester, Ana-Rosa; González-Candelas, Luis; Zacarías, Lorenzo; Lafuente, María T.

2012-01-01

Water stress affects many agronomic traits that may be regulated by the phytohormone abscisic acid (ABA). Within these traits, loss of fruit quality becomes important in many citrus cultivars that develop peel damage in response to dehydration. To study peel dehydration transcriptional responsiveness in harvested citrus fruit and the putative role of ABA in this process, this study performed a comparative large-scale transcriptional analysis of water-stressed fruits of the wild-type Navelate ...

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

Full Text Available Os citros são as frutas mais produzidas e consumidas no mundo. O Brasil ocupa primeiro lugar na produção mundial e na exportação de suco de laranja, sendo o Estado do Rio Grande do Sul um importante produtor. Ao longo do cultivo e do processamento dos citros, são geradas toneladas de resíduos de baixo valor comercial, mas com grande potencial de aproveitamento dentro da indústria de alimentos. Esses resíduos possuem elevados teores de nutrientes, pigmentos e componentes bioativos, bem como possuem baixa toxicidade e baixo custo. Há evidências de que a casca de diferentes espécies de citros possui princípios ativos antibacterianos e antifúngicos. O objetivo deste trabalho, portanto, foi verificar a atividade antibacteriana de extratos alcoólicos da casca de citros na perspectiva da desinfecção e da conservação de alimentos, propondo alternativas sustentáveis e naturais voltadas a consumidores cada vez mais preocupados com sua saúde. Foram obtidos extratos alcoólicos da casca crua de bergamota-ponkan (Citrus reticulata Blanco, pomelo (Citrus maxima (Burm. Merr. e limão-bergamota (Citrus limonia Osbeck ou limão-cravo maduros, provenientes de cultivo agroecológico, cujas atividades antibacterianas foram avaliadas quanto à Concentração Inibitória Mínima (CIM e à Concentração Bactericida Mínima (CBM frente a cinco diferentes bactérias. O extrato de limão-bergamota apresentou a melhor atividade antibacteriana, apresentando CIM em torno de 24 mg.mL-1 e CBM de 42 mg.mL-1 para as bactérias mais resistentes. A bactéria mais sensível a todos os extratos foi Pseudomonas aeruginosa, com CIM entre 16 e 36 mg.mL-1 e CBM entre 28 e 49 mg.mL-1. Os extratos inibiram ou inativaram na sua totalidade as bactérias testadas, indicando a possibilidade de se tornarem alternativas naturais na desinfecção e na conservação de alimentos.Citrus are the most produced fruits in the world. Brazil ranks first in global production and

Cytotoxicity and anti-Leishmania amazonensis activity of Citrus sinensis leaf extracts.

Science.gov (United States)

Garcia, Andreza R; Amaral, Ana Claudia F; Azevedo, Mariana M B; Corte-Real, Suzana; Lopes, Rosana C; Alviano, Celuta S; Pinheiro, Anderson S; Vermelho, Alane B; Rodrigues, Igor A

2017-12-01

Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease characterized by lesional polymorphism and the commitment of skin surface. Previous reports demonstrated that the Citrus genus possess antimicrobial activity. This study evaluated the anti-L. amazonensis activity of Citrus sinensis (L.) Osbeck (Rutaceae) extracts. Citrus sinensis dried leaves were subjected to maceration with hexane (CH), ethyl acetate (CEA), dichloromethane/ethanol (CD/Et - 1:1) or ethanol/water (CEt/W - 7:3). Leishmania amazonensis promastigotes were treated with C. sinensis extracts (1-525 μg/mL) for 120 h at 27 °C. Ultrastructure alterations of treated parasites were evaluated by transmission electron microscopy. Cytotoxicity of the extracts was assessed on RAW 264.7 and J774.G8 macrophages after 48-h treatment at 37 °C using the tetrazolium assay. In addition, Leishmania-infected macrophages were treated with CH and CD/Et (10-80 μg/mL). CH, CD/Et and CEA displayed antileishmanial activity with 50% inhibitory activity (IC 50 ) of 25.91 ± 4.87, 54.23 ± 3.78 and 62.74 ± 5.04 μg/mL, respectively. Parasites treated with CD/Et (131.2 μg/mL) presented severe alterations including mitochondrial swelling, lipid body formation and intense cytoplasmic vacuolization. CH and CD/Et demonstrated cytotoxic effects similar to that of amphotericin B in the anti-amastigote assays (SI of 2.16, 1.98 and 1.35, respectively). Triterpene amyrins were the main substances in CH and CD/Et extracts. In addition, 80 μg/mL of CD/Et reduced the number of intracellular amastigotes and the percentage of infected macrophages in 63% and 36%, respectively. The results presented here highlight C. sinensis as a promising source of antileishmanial agents.

Microdissection and molecular manipulation of single chromosomes in woody fruit trees with small chromosomes using pomelo (Citrus grandis) as a model. I. Construction of single chromosomal DNA libraries.

Science.gov (United States)

Huang, D; Wu, W; Zhou, Y; Hu, Z; Lu, L

2004-05-01

Construction of single chromosomal DNA libraries by means of chromosome microdissection and microcloning will be useful for genomic research, especially for those species that have not been extensively studied genetically. Application of the technology of microdissection and microcloning to woody fruit plants has not been reported hitherto, largely due to the generally small sizes of metaphase chromosomes and the difficulty of chromosome preparation. The present study was performed to establish a method for single chromosome microdissection and microcloning in woody fruit species using pomelo as a model. The standard karyotype of a pomelo cultivar ( Citrus grandis cv. Guanxi) was established based on 20 prometaphase photomicrographs. According to the standard karyotype, chromosome 1 was identified and isolated with fine glass microneedles controlled by a micromanipulator. DNA fragments ranging from 0.3 kb to 2 kb were acquired from the isolated single chromosome 1 via two rounds of PCR mediated by Sau3A linker adaptors and then cloned into T-easy vectors to generate a DNA library of chromosome 1. Approximately 30,000 recombinant clones were obtained. Evaluation based on 108 randomly selected clones showed that the sizes of the cloned inserts varied from 0.5 kb to 1.5 kb with an average of 860 bp. Our research suggests that microdissection and microcloning of single small chromosomes in woody plants is feasible.

Balanço hídrico no solo para porta-enchertos de citros em ecossistema de tabuleiro costeiro Water balance in soil for citrus rootstocks in the brazilian coastal tableland ecosystem

Directory of Open Access Journals (Sweden)

Fernando Luis Dultra Cintra

2000-04-01

Full Text Available A má distribuição das chuvas e a existência de camadas coesas em muitos solos dos tabuleiros promovem, muitas vezes, alterações importantes no regime hídrico do solo e nas taxas de evapotranspiração das culturas exploradas nesse ecossistema. Objetivou-se, com este trabalho, conhecer, através do balanço hídrico, como esses processos ocorrem e, também, contribuir para o estabelecimento de práticas de manejo visando ao melhor uso das reservas de água no solo. Todos os componentes do balanço foram medidos, à exceção da evapotranspiração, que foi calculada. Os resultados obtidos permitiram concluir que a maior demanda hídrica da laranjeira aconteceu nos meses de outubro e novembro e que, com base na taxa de evapotranspiração, a Tangerina Cleópatra (Citrus reshni Hort. ex Tan. foi o porta-enxerto menos adaptado e o Limão Cravo (Citrus limonia Osbeck o que apresentou as melhores características de adaptação à área estudada.The irregular rain distribution and the existence of hardened layers in several soils of the tablelands promote, sometimes, important changes in the soil water regime and in the rates of evapotranspiration of the crops utilized in that ecosystem. The objective of this work was to know, by means of the water balance, how these processes occur in the studied area and to contribute to the establishment of management practices in order to make better use of the soil water. All components of the equations were measured, with exception of the evapotranspiration which was calculated. According to the results, it could be concluded that the orange tree had the maximum water consumption during the months of October and November and that, in terms of the rootstocks during these periods of great water consumption, the "Tangerina Cleópatra" (Citrus reshni Hort. former Tan. was the less adapted and the "Limão Cravo" (Citrus limonia Osbeck presented the best adaptation characteristics to the studied area.

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...

Weedy hosts and prevalence of potential leafhopper vectors (Hemiptera: Cicadellidae) of a phytoplasma (16SrIX group) associated with Huanglongbing symptoms in citrus groves.

Science.gov (United States)

Marques, R N; Teixeira, D C; Yamamoto, P T; Lopes, J R S

2012-04-01

Huanglongbing (HLB) is a severe citrus (Citrus spp.) disease associated with the bacteria genus Candidatus Liberibacter, detected in Brazil in 2004. Another bacterium was found in association with HLB symptoms and characterized as a phytoplasma belonging to the 16SrIX group. The objectives of this study were to identify potential leafhopper vectors of the HLB-associated phytoplasma and their host plants. Leafhoppers were sampled every other week for 12 mo with sticky yellow cards placed at two heights (0.3 and 1.5 m) in the citrus tree canopy and by using a sweep net in the ground vegetation of two sweet orange, Citrus sinensis (L.) Osbeck, groves infected by the HLB-phytoplasma in São Paulo state. Faunistic analyses indicated one Agalliinae (Agallia albidula Uhler) and three Deltocephalinae [Balclutha hebe (Kirkaldy), Planicephalus flavicosta (Stål), and Scaphytopius (Convelinus) marginelineatus (Stål)] species, as the most abundant and frequent leafhoppers (Hemiptera: Cicadellidae). Visual observations indicated an association of leafhopper species with some weeds and the influence of weed species composition on leafhopper abundance in low-lying vegetation. S. marginelineatus and P. flavicosta were more frequent on Sida rhombifolia L. and Althernantera tenella Colla, respectively, whereas A. albidula was observed more often on Conyza bonariensis (L.) Cronq. and B. hebe only occurred on grasses. DNA samples of field-collected S. marginelineatus were positive by polymerase chain reaction and sequencing tests for the presence of the HLB-phytoplasma group, indicating it as a potential vector. The association of leafhoppers with their hosts may be used in deciding which management strategies to adopt against weeds and diseases in citrus orchards.

Micropropagation of Eucalyptus grandis and nitens using tissue culture techniques

Energy Technology Data Exchange (ETDEWEB)

Furze, M.J.; Creswell, C.F.

1985-01-01

Experiments with nodal explants of E. grandis and E. nitens seedlings and E. grandis coppice shoots showed that a large number of plants can be produced from a single explant using micropropagation. The percentage of micropropagated shoots that formed roots was about 90% for E. grandis and 80% for E. nitens. For both species, about 90% of the rooted shoots survived after hardening off. 9 references.

Actividad antianémica de la Cassia grandis L. The antianemic activity of Cassia grandis L.

Directory of Open Access Journals (Sweden)

Juana Tillán Capó

2004-12-01

Full Text Available La población de la zona oriental de Cuba refiere los efectos beneficiosos del uso tradicional de la Cassia grandis L. en la anemia, con la utilización del polvo seco obtenido del fruto como un suplemento nutricional. El objetivo fue evaluar dicho efecto en un modelo experimental de anemia ferropénica en ratas, inducido por sucesivas extracciones de sangre y administración de una dieta carente de hierro. Todos los animales fueron sometidos durante 15 días a una dieta semisintética deficiente en hierro y a extracciones de sangre 3 veces por semana hasta lograr concentraciones de hemoglobina en sangre menores de 9 g/dL. Se formaron 3 grupos y se mantuvo la misma dieta: grupo I sin suplementar, grupo II suplementado con 15 mg de hierro/kg de dieta y grupo III la misma cantidad de hierro más 750 mg/kg de peso corporal de polvo seco de Cassia grandis L. durante otros 15 días. Al finalizar se determinaron las concentraciones de hierro, hemoglobina y hematócrito en sangre. Las concentraciones medias de hemoglobina al cabo de los 15 días de tratamiento fueron significativamente diferentes en los 3 grupos experimentales, con resultados mayores en el grupo suplementado con hierro y Cassia grandis L.; también en este grupo se observó un incremento significativo de los valores medios de hierro en plasma en relación con los valores obtenidos en los animales no suplementados y en los animales que recibieron solamente hierro en la dieta. El porcentaje de hematócrito no mostró diferencia significativa entre tratamiento. Los resultados corroboran el uso popular y tradicional de la Cassia grandis L. en los estados anémicos, al mejorar la utilización del hiero y la producción de hemoglobina.The population of the eastern zone of Cuba refers to the benefitial effects of the traditional use of Cassia grandis L. in anemia by using dry powder obtained from the fruit as a nutritional supplement. The objective was to evaluate this effect in an

'Valencia' sweet orange tree flowering evaluation under field conditions Avaliação do florescimento de laranjeiras valência em condição de campo

Directory of Open Access Journals (Sweden)

Rafael Vasconcelos Ribeiro

2008-01-01

Full Text Available Since citrus flowering is a key process in citriculture and its evaluation is often difficult due to the canopy structure and field sampling, the aim of this research was to give some directions regarding the evaluation of flowering in field-grown sweet orange plants. This study was conducted in a citrus orchard of sweet orange plants cv. 'Valencia' [Citrus sinensis (L. Osbeck] grafted on 'Cleopatra' mandarin (Citrus reshni hort. ex Tanaka or 'Rangpur' lime (Citrus limonia Osbeck rootstocks, with North-South orientation. Generative structures [buds, flowers and fruitlets (diameter O florescimento dos citros é um processo chave na citricultura e sua avaliação é dificultada devido à estrutura da copa e amostragem em campo. O objetivo desse artigo foi fornecer algumas indicações de como avaliar o florescimento de laranjeiras em condição de campo. Esse estudo foi conduzido em um pomar de laranjeiras 'Valência' [Citrus sinensis (L. Osbeck] enxertadas em tangerineira 'Cleópatra' (Citrus reshni hort. ex Tanaka ou limoeiro 'Cravo' (Citrus limonia Osbeck, com orientação Norte-Sul. As estruturas reprodutivas [botões florais, flores e frutos (diâmetro < 3 cm] foram quantificadas semanalmente entre agosto e novembro de 2005, utilizando guias de 1 m² posicionadas no terço médio da copa das plantas, amostrando aproximadamente um volume de 1 m³. As guias foram divididas em duas partes para que duas pessoas pudessem realizar as avaliações, e posicionadas nas orientações sudeste, sudoeste, nordeste e noroeste, em sete plantas. Alguns aspectos do florescimento dos citros foram avaliados: (i quantas plantas são necessárias para uma amostragem representativa do florescimento; (ii em qual orientação deve ser feita a medida e (iii qual volume da copa das plantas que deve ser amostrado. Ao se considerar os aspectos práticos da produção dos citros, um método rápido, simples e representativo é necessário para avaliar o florescimento

Mudas de laranjeira 'valência' sobre dois porta-enxertos e sob diferentes manejos de adubação 'Valencia' sweet orange nursery trees on two rootstocks under different fertilizer managements

Directory of Open Access Journals (Sweden)

Eduardo Augusto Girardi

2010-09-01

Full Text Available O manejo da adubação é uma das principais práticas culturais para a produção de mudas cítricas em cultivo protegido. Avaliou-se o efeito de seis tipos de manejo das adubações comercialmente recomendadas na produção de mudas de laranjeira 'Valência' [Citrus sinensis (L. Osbeck] enxertada sobre os porta-enxertos limoeiro 'Cravo' (Citrus limonia Osbeck e citrumeleiro 'Swingle' [Citrus paradisi Macf. x Poncirus trifoliata (L. Raf.]. As avaliações foram conduzidas a partir da transplantação dos porta-enxertos até 180 dias após a enxertia, em viveiro empresarial, em Conchal-SP. Os manejos corresponderam a duas soluções de fertilizantes solúveis aplicadas isoladamente, soluções de fertilizante solúveis associadas a fertilizante de liberação controlada e aplicação exclusiva de fertilizante de liberação controlada. O delineamento experimental adotado foi o fatorial 2 x 6 (porta-enxerto x manejo da adubação, em blocos casualizados, com três repetições e 12 mudas na parcela. O limoeiro 'Cravo' induziu maior crescimento ao enxerto. O crescimento vegetativo das mudas foi similar após o uso de fertilizantes solúveis ou de liberação controlada, apesar da grande variação de quantidades totais de nutrientes fornecidas às plantas. Desta forma, o viveirista poderá optar pelo manejo mais econômico ou prático, conforme as condições locais.The fertilizer program is a major practice for screened citrus nursery tree production. The effect of six fertilizer programs commercially recommended was evaluated on the production of 'Valência' sweet orange [Citrus sinensis (L. Osbeck] nursery trees budded on rootstocks 'Rangpur' lime (Citrus limonia Osbeck and 'Swingle' citrumelo [Citrus paradisi Macf. x Poncirus trifoliata (L. Raf.]. Experimental work was carried out from rootstock transplant until 180 days after budding, in a citrus nursery in Conchal, SP, Brazil. Fertilizer managements consisted of two soluble fertilizers

Different adaptation strategies of two citrus scion/rootstock combinations in response to drought stress.

Science.gov (United States)

Dutra de Souza, Joadson; de Andrade Silva, Edson Mario; Coelho Filho, Mauricio Antônio; Morillon, Raphaël; Bonatto, Diego; Micheli, Fabienne; da Silva Gesteira, Abelmon

2017-01-01

Scion/rootstock interaction is important for plant development and for breeding programs. In this context, polyploid rootstocks presented several advantages, mainly in relation to biotic and abiotic stresses. Here we analyzed the response to drought of two different scion/rootstock combinations presenting different polyploidy: the diploid (2x) and autotetraploid (4x) Rangpur lime (Citrus limonia, Osbeck) rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis) scions, named V/2xRL and V/4xRL, respectively. Based on previous gene expression data, we developed an interactomic approach to identify proteins involved in V/2xRL and V/4xRL response to drought. A main interactomic network containing 3,830 nodes and 97,652 edges was built from V/2xRL and V/4xRL data. Exclusive proteins of the V/2xRL and V/4xRL networks (2,056 and 1,001, respectively), as well as common to both networks (773) were identified. Functional clusters were obtained and two models of drought stress response for the V/2xRL and V/4xRL genotypes were designed. Even if the V/2xRL plant implement some tolerance mechanisms, the global plant response to drought was rapid and quickly exhaustive resulting in a general tendency to dehydration avoidance, which presented some advantage in short and strong drought stress conditions, but which, in long terms, does not allow the plant survival. At the contrary, the V/4xRL plants presented a response which strong impacts on development but that present some advantages in case of prolonged drought. Finally, some specific proteins, which presented high centrality on interactomic analysis were identified as good candidates for subsequent functional analysis of citrus genes related to drought response, as well as be good markers of one or another physiological mechanism implemented by the plants.

Estimativa do tempo de vaporização de toras de Eucalyptus grandis Steaming times estimates for Eucalyptus grandis logs

Directory of Open Access Journals (Sweden)

Fred Willians Calonego

2006-06-01

Full Text Available O objetivo deste estudo foi adequar o modelo geral de determinação do tempo de vaporização de toras, proposto por Steinhagen et al. (1980, para a madeira de Eucalyptus grandis. Para tanto, foram coletadas toras de 20 a The aim this study was to adjust the general model for determining log steaming time, proposed by Steinhagen et al. (1980, for Eucalyptus grandis wood. In order to do so, logs with diameter from 20 to <25, 25 to <30 and 30 to <35 cm were collected from 14 trees of Eucalyptus grandis derived from the `Horto Florestal' nursery, Manduri, São Paulo. A thermocouple was inserted into each log near its center. The logs were steamed during 20 hours at 90ºC and 100% relative humidity. A data logger recorded the temperatures during the thermal treatment. It was concluded that the Steinhagen et al. (1980 model cannot be directly used for this species in study and corrections factors are proposed for the utilization of the general model for log steaming time, developed by Steinhagen et al. (1980, for Eucalyptus grandis wood.

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)

Wood Permeability in Eucalyptus grandis and Eucalyptus dunnii

Directory of Open Access Journals (Sweden)

Raphael Nogueira Rezende

2017-12-01

Full Text Available ABSTRACT The objective of this study was to evaluate the flow of air and water in Eucalyptus grandis and Eucalyptus dunnii wood. Wood was collected from four trees aged 37 years in an experimental plantation of the Federal University of Lavras, Brazil. Planks were cut off the basal logs to produce specimens for air and water permeability testing. Results indicated that the longitudinal permeability to air and water of E. grandis wood were, on average, 5% and 10% higher, respectively, than that of E. dunnii wood. E. grandis and E. dunnii wood showed neither air nor water flow in the test for permeability transversal to the fibers, and longitudinal permeability to air exceeded that to water by approximately 50 fold in both species.

Possíveis efeitos alelopaticos de Brachiaria decumbens sobre o crescimento inicial de limão cravo (Citrus limonia The possible allelopathic effects of Brachiaria decumbens on initial development of root stock of Citrus limonia

Directory of Open Access Journals (Sweden)

L. S. Souza

1997-01-01

Full Text Available Foram estudados os possíveis efeitos alelopáticos da incorporação da matéria seca da parte aérea de Brachiaria decumbens, ao substrato, nas concentrações de 0, 1,5 e 3,0% (p/p sobre o crescimento inicial de limão cravo (Citrus limonia Osbeck, em casa-de-vegetação. Foram determinados os parâmetros biométrico s e algumas propriedades físico-químicas da solução do solo. A maior quantidade de matéria seca incorporada causou redução de 44, 42, 57 e 55% das médias da altura, teor de clorofila, área foliar e acúmulo de matéria seca total, respectivamente. O potencial osmótico, pH, condutividade elétrica e os teores de nutrientes da solução do solo foram alterados. Provavelmente, a redução do crescimento observada seja devida a deficiência de N causada por alterações na dinâmica do N-solo em função da incorporação de B. decumbens.It was studied the possible allelopathic effect of Brachiaria decumbens on initial development of Citrus limonia in greenhouse. The dry matter was incorporated into the soil in 0, 1,5, 3,0% (w/w-proportion. Biometric parameters and physic propert ies of soil were determined by soil solutio n. Greatest propotion reduced all the biometric parameters analyse d. Physical properties of nutrient levels (except N of soil did not observed significantly alterations. Greatest proportion reduced the average stem diameter of Citrus limonia at 57%. Probably, these results were due to lack in nitrogen level observed in soil solution.

Hea õpetamise grandi saajad

Index Scriptorium Estoniae

2016-01-01

Õpetamise uurimist alustavad grandi toel Andrus Org, Riina Oruaas, Natalja Zagura (humanitaar- ja kunstide valdkond), Stefano Braghiroli, Aet Kiisla, Tiiu Taur (sotsiaalteadused), Marje Oona, Oivi Uibo, Daisy Volmer (meditsiinitead.), Svetlana Ganina, Natalja Lepik ja Raivo Raid (loodus- ja täppistead.)

Natural and synthetic oviposition stimulants forCatolaccus grandis (Burks) females.

Science.gov (United States)

Guerra, A A; Martinez, S; Sonia Del Rio, H

1994-07-01

Oviposition behavior was elicited fromCatolaccus grandis (Burks) (Hymenoptera: Pteromalidae) females, an ectoparasitoid of the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae), by smears of freshly cut cotton bolls or smears of extracts prepared with boll weevil damaged or undamaged cotton boll tissues. Oviposition behavior was also elicited fromC. grandis females by smears made withn-pentane,n-hexane,n-heptane, and isooctane. This is the first report of oviposition behavior elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behavior during host selection. Oviposition behavior was also elicited fromC. grandis females by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination ofn-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.

The Effect of Designated Pollutants on Plant Species

Science.gov (United States)

1981-01-01

L.) Burm. J. Roughlemon seedling 12 Citrus C. limo, Lisbon lemon graft 80 Citrus C. sinensis (L.) Osbeck Valencia orange graft 80 Dudleya Dudleya...CALIFORNIA UNIVERSITY OF CALIFORNIA, IR VINE IR VINE, ORANGE COUNTY, CALIFORNIA 92664 JANUARY 1981 S Approved for public release; distribution...California poppy, indigenous to the Vandenberg Air Force Base area, blooms in the spring. Since flowering of individual plants could not be closely

Large changes in anatomy and physiology between diploid Rangpur lime (Citrus limonia) and its autotetraploid are not associated with large changes in leaf gene expression.

Science.gov (United States)

Allario, Thierry; Brumos, Javier; Colmenero-Flores, Jose Manuel; Tadeo, Francisco; Froelicher, Yann; Talon, Manuel; Navarro, Luis; Ollitrault, Patrick; Morillon, Raphaël

2011-05-01

Very little is known about the molecular origin of the large phenotypic differentiation between genotypes arising from somatic chromosome set doubling and their diploid parents. In this study, the anatomy and physiology of diploid (2x) and autotetraploid (4x) Rangpur lime (Citrus limonia Osbeck) seedlings has been characterized. Growth of 2x was more vigorous than 4x although leaves, stems, and roots of 4x plants were thicker and contained larger cells than 2x that may have a large impact on cell-to-cell water exchanges. Leaf water content was higher in 4x than in 2x. Leaf transcriptome expression using a citrus microarray containing 21 081 genes revealed that the number of genes differentially expressed in both genotypes was less than 1% and the maximum rate of gene expression change within a 2-fold range. Six up-regulated genes in 4x were targeted to validate microarray results by real-time reverse transcription-PCR. Five of these genes were apparently involved in the response to water deficit, suggesting that, in control conditions, the genome expression of citrus autotetraploids may act in a similar way to diploids under water-deficit stress condition. The sixth up-regulated gene which codes for a histone may also play an important role in regulating the transcription of growth processes. These results show that the large phenotypic differentiation in 4x Rangpur lime compared with 2x is not associated with large changes in genome expression. This suggests that, in 4x Rangpur lime, subtle changes in gene expression may be at the origin of the phenotypic differentiation of 4x citrus when compared with 2x.

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...

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...

Prospects of Tectona Grandis as a Feedstock for Biodiesel

International Nuclear Information System (INIS)

Sarin, Amit; Singh, Meetu; Sharma, Neerja; Singh, N. P.

2017-01-01

The limited availability of fossil fuels has encouraged the need of replacement fuels of renewable nature. Among the renewable fuels, biodiesel produced from oil seeds and food wastes has been favored by the majority of researchers. In this study, Tectona Grandis seed oil has been investigated as a non-edible feedstock for biodiesel. The oil content of seed is 43% which makes it suitable for commercial production of biodiesel. The synthesis of biodiesel from T. Grandis oil was done with transesterification reaction giving high percentage yield of biodiesel which reached to 89%. The T. Grandis biodiesel was subjected to determine various physicochemical parameters by standard testing methods and found in agreement with the ASTM D-6751 and EN-14214 standards. The fatty-acid methyl ester composition for the biodiesel is composed of 42.71% oleic acid, 13.1% palmitic acid, and 31.51% linoleic acid. The biodiesel showed low oxidation stability which is attributed to high percentage of unsaturation. To address this issue, synthetic antioxidants were added to increase its resistance towards oxidation. By considering all the parameters, the present study reveals that T. Grandis seed oil is reliable for the production of biodiesel with encouraging probability in future.

Prospects of Tectona Grandis as a Feedstock for Biodiesel

Energy Technology Data Exchange (ETDEWEB)

Sarin, Amit, E-mail: amit.sarin@yahoo.com [Department of Physical Sciences, I.K. Gujral Punjab Technical University, Kapurthala (India); Singh, Meetu [Department of Applied Sciences, I.K. Gujral Punjab Technical University, Kapurthala (India); Sharma, Neerja [PG Department of Physics and Electronics, DAV College, Amritsar (India); Singh, N. P. [Department of Planning and External Development, I.K. Gujral Punjab Technical University, Kapurthala (India)

2017-10-26

The limited availability of fossil fuels has encouraged the need of replacement fuels of renewable nature. Among the renewable fuels, biodiesel produced from oil seeds and food wastes has been favored by the majority of researchers. In this study, Tectona Grandis seed oil has been investigated as a non-edible feedstock for biodiesel. The oil content of seed is 43% which makes it suitable for commercial production of biodiesel. The synthesis of biodiesel from T. Grandis oil was done with transesterification reaction giving high percentage yield of biodiesel which reached to 89%. The T. Grandis biodiesel was subjected to determine various physicochemical parameters by standard testing methods and found in agreement with the ASTM D-6751 and EN-14214 standards. The fatty-acid methyl ester composition for the biodiesel is composed of 42.71% oleic acid, 13.1% palmitic acid, and 31.51% linoleic acid. The biodiesel showed low oxidation stability which is attributed to high percentage of unsaturation. To address this issue, synthetic antioxidants were added to increase its resistance towards oxidation. By considering all the parameters, the present study reveals that T. Grandis seed oil is reliable for the production of biodiesel with encouraging probability in future.

Clonal differences in log end splitting in Eucalyptus grandis in ...

African Journals Online (AJOL)

This paper discusses the juvenile–mature correlation of log end splitting among Eucalyptus grandis clones from two trials and how differences in splitting relate to differences in wood density, pith-to-bark gradient and growth rate. Two approximately 20-year-old Eucalyptus grandis clonal trials at Bergvliet plantation were ...

Variety and Harvesting Season Effects on Antioxidant Activity and Vitamins Content of Citrus sinensis Macfad.

Directory of Open Access Journals (Sweden)

Vanessa Cardeñosa

2015-05-01

Full Text Available Five sweet orange (Citrus sinensis Osbeck varieties cultivated in Huelva (Spain and picked at two seasons during two consecutive years, were characterized for their antioxidant activity (free radicals scavenging activity, reducing power and lipid peroxidation inhibition and vitamin content (vitamin E and vitamin C. The effects induced by sweet orange variety and stage of maturity were comprehensively compared by applying 2-way ANOVA and linear discriminant analysis. The results indicated higher differences in antioxidant activity and vitamin contents in response to the effect of the harvesting season, when compared to the effect of sweet orange variety. Nevertheless, the results observed in 2012 showed less marked differences among the assayed sweet orange varieties. Either way, it might be concluded that oranges sampled in January show the highest antioxidant activity and vitamin contents. Furthermore, concerning the properties evaluated in this work, all sweet orange varieties represent good alternatives, except for Rhode Summer, which would not be the preferable choice as a target to enhance sweet orange overall characteristics.

Different adaptation strategies of two citrus scion/rootstock combinations in response to drought stress.

Directory of Open Access Journals (Sweden)

Joadson Dutra de Souza

Full Text Available Scion/rootstock interaction is important for plant development and for breeding programs. In this context, polyploid rootstocks presented several advantages, mainly in relation to biotic and abiotic stresses. Here we analyzed the response to drought of two different scion/rootstock combinations presenting different polyploidy: the diploid (2x and autotetraploid (4x Rangpur lime (Citrus limonia, Osbeck rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis scions, named V/2xRL and V/4xRL, respectively. Based on previous gene expression data, we developed an interactomic approach to identify proteins involved in V/2xRL and V/4xRL response to drought. A main interactomic network containing 3,830 nodes and 97,652 edges was built from V/2xRL and V/4xRL data. Exclusive proteins of the V/2xRL and V/4xRL networks (2,056 and 1,001, respectively, as well as common to both networks (773 were identified. Functional clusters were obtained and two models of drought stress response for the V/2xRL and V/4xRL genotypes were designed. Even if the V/2xRL plant implement some tolerance mechanisms, the global plant response to drought was rapid and quickly exhaustive resulting in a general tendency to dehydration avoidance, which presented some advantage in short and strong drought stress conditions, but which, in long terms, does not allow the plant survival. At the contrary, the V/4xRL plants presented a response which strong impacts on development but that present some advantages in case of prolonged drought. Finally, some specific proteins, which presented high centrality on interactomic analysis were identified as good candidates for subsequent functional analysis of citrus genes related to drought response, as well as be good markers of one or another physiological mechanism implemented by the plants.

Growth and yield models for Eucalyptus grandis grown in Swaziland ...

African Journals Online (AJOL)

The aim of this study was to develop a stand-level growth and yield model for short-rotationEucalyptus grandis grown for pulp wood production at Piggs Peak in Swaziland. The data were derived from a Nelder 1a spacing trial established with E. grandis clonal cuttings in 1998 and terminated in 2005. Planting density ...

A proteomic analysis of the chromoplasts isolated from sweet orange fruits [Citrus sinensis (L.) Osbeck].

Science.gov (United States)

Zeng, Yunliu; Pan, Zhiyong; Ding, Yuduan; Zhu, Andan; Cao, Hongbo; Xu, Qiang; Deng, Xiuxin

2011-11-01

Here, a comprehensive proteomic analysis of the chromoplasts purified from sweet orange using Nycodenz density gradient centrifugation is reported. A GeLC-MS/MS shotgun approach was used to identify the proteins of pooled chromoplast samples. A total of 493 proteins were identified from purified chromoplasts, of which 418 are putative plastid proteins based on in silico sequence homology and functional analyses. Based on the predicted functions of these identified plastid proteins, a large proportion (∼60%) of the chromoplast proteome of sweet orange is constituted by proteins involved in carbohydrate metabolism, amino acid/protein synthesis, and secondary metabolism. Of note, HDS (hydroxymethylbutenyl 4-diphosphate synthase), PAP (plastid-lipid-associated protein), and psHSPs (plastid small heat shock proteins) involved in the synthesis or storage of carotenoid and stress response are among the most abundant proteins identified. A comparison of chromoplast proteomes between sweet orange and tomato suggested a high level of conservation in a broad range of metabolic pathways. However, the citrus chromoplast was characterized by more extensive carotenoid synthesis, extensive amino acid synthesis without nitrogen assimilation, and evidence for lipid metabolism concerning jasmonic acid synthesis. In conclusion, this study provides an insight into the major metabolic pathways as well as some unique characteristics of the sweet orange chromoplasts at the whole proteome level.

Production of haploid plant of 'Banpeiyu' pummelo [Citrus maxima (Burm.) Merr.] by pollination with soft X-ray-irradiated pollen

International Nuclear Information System (INIS)

Yahata, Masaki; Yasuda, Kiichi; Kunitake, Hisato; Nagasawa, Kohji; Harusaki, Seiichi; Komatsu, Haruki

2010-01-01

To induce haploid plants in Citrus maxima (Burm.) Merr. 'Banpeiyu', we evaluated the effect of pollination with soft X-ray-irradiated pollen on fruit set and seed development, and carried out ovule culture. When 'Banpeiyu' pummelo pistils were pollinated with X-ray-irradiated pollen of 'Fukuhara' sweet orange [C. sinensis (L.) Osbeck], the exposure doses affected the fruit set. The number of seeds per fruit was also affected by the exposure dose, and tended to decrease as the dose increased; however, all developed seeds obtained from these crosses were diploid. In the ovule culture of 'Banpeiyu' pummelo, six embryoids shown haploidy were obtained in all treatments. One haploid plantlet with 9 chromosomes was regenerated from an embryoid in a culture of ovules established 40 days after pollination with 400 Gray (Gy)-irradiated pollen of 'Tosa-buntan' pummelo (C. maxima). This haploid was suggested to be derived from 'Banpeiyu' pummelo by random amplified polymorphic DNA (RAPD) and cleaved amplified polymorphic sequence (CAPS) analysis. (author)

Optimal management and productivity of Eucalyptus grandis on former phosphate mined and citrus lands in central and southern Florida: influence of genetics and spacing

Science.gov (United States)

Kyle W. Fabbro; Donald L. Rockwood

2016-01-01

Eucalyptus short rotation woody crops (SRWC) with superior genotypes are promising in central and south Florida due to their fast growth, freeze resilience, coppicing ability, and site tolerance. Four Eucalyptus grandis cultivars, E.nergy™ G1, G2, G3, and/or G5, were established in 2009 at varying planting densities on a...

[Study and comparison on HPLC fingerprints of flavonoids of frequently used Chinese materia medica in citrus].

Science.gov (United States)

Chen, Yonggang; Lin, Li

2011-10-01

To establish the HPLC fingerprint of flavonoids of the six clinical frequently used Chinese materia medica for regulating Qi flow,such as Citri grandis, C. grands, Citri Reticulatae Pericarpium, Citri Reticulatae Pericarpium Viride, Aurantii Fructus, and Aurantii Fructus Immaturus from Citrus, and analysis differences in the fingerprints to provide scientific basis for profile-effect research and clinical reasonable use. HPLC was performed on a C18 column with methanol-water (with acetic acid), to establish HPLC fingerprints of the six kinds of medicinal herbs on the same chromatograph condition. The six frequently used Chinese materia medica were divided into naringin type and hesperidin type according to the method of phytochemotaxonomy. Based on the retention time of chromatograph peaks, C. grandis and C. grands had fifteen common peaks; Citri Reticulatae Pericarpium, Citri Reticulatae Pericarpium Viride, Aurantii Fructus and Aurantii Fructus Immaturus had ten common peaks. All herbs had five common peaks. Compared with mutual model, the holistic similarity of chromatograms of C. grandis and C. grands was in the range of 0.9285 - 0.9962. The degree of similarity was high. For Citri Reticulatae Pericarpium, Citri Reticulatae Pericarpium Viride and Aurantii Fructus Immaturus, it was in the range of 0.9221 - 0.9973 and high. But the similarity of Aurantii Fructus was only in 0.4547 - 0.7733 with the mutual model. The established fingerprints of flavonoids of the six common traditional Chinese medicines can be used to compare the differences intuitively. Meanwhile, the peak height and peak areas of characteristic peaks are different remarkably, but whether it is connected with the different function of regulating Qi flow of the six medical materials in clinical use, is still needed to be studied.

Long-Term Effects of Exotic Tree Species ( Tectona grandis Linn. F ...

African Journals Online (AJOL)

Long-Term Effects of Exotic Tree Species ( Tectona grandis Linn. F.) on the Status of Extractable Micronutrients in the ... The study therefore implied that Tectona grandis has an extractive property on micronutrient particularly on soils that are low in these nutrients. Nigerian Journal of Soil and Environmental Research Vol.

Vigor, produtividade e qualidade de frutos de quatro tangerineiras e híbridos sobre quatro porta-enxertos Vegetative growth, yield and fruit quality of four mandarin and hybrid cultivars on four rootstocks

Directory of Open Access Journals (Sweden)

Eduardo Sanches Stuchi

2008-09-01

Full Text Available Avaliaram-se o desenvolvimento vegetativo, a produção e a qualidade de frutos das cultivares-copa 'Swatow' (Citrus reticulata Blanco, 'Ellendale' [C. reticulata x C. sinensis (L. Osbeck], 'Fortune' (C. clementina hort. ex Tanaka x C. tangerina hort. ex Tanaka e 'Nova' [C. clementina x (C. paradisi Macfad. x C. reticulata] sobre limoeiro 'Cravo' (C. limonia Osbeck, citrumeleiro 'Swingle' (C. paradisi x P. trifoliata (L. Raf., tangelereiro 'Orlando' (C. reticulata x C. paradisi e tangerineira 'Cleópatra' (C. reshni hort. ex Tanaka, de 2000 a 2006. O experimento foi instalado em Bebedouro-SP, em outubro de 1997. As variáveis analisadas foram: produção anual e produção acumulada de todas as cultivares para todos os anos (2000 a 2006, qualidade de frutos em 2005 e 2006 (massa, sólidos solúveis totais, acidez total, ratio, volume da copa, diâmetro do tronco da copa, eficiência de produção (Kg frutos/m³ copa e índice de alternância de produção. A produção acumulada e a qualidade de frutos das cultivares testadas não foram influenciadas pelos porta-enxertos. O citrumelo 'Swingle' induziu menor porte às plantas das cultivares-copa. O tangelo 'Nova' apresentou características adequadas à comercialização in natura. A tangerineira 'Swatow' produziu frutos de qualidade semelhante aos de tangerineira 'Ponkan'. O tangor 'Ellendale' e a tangerineira 'Fortune' apresentaram produção de frutos baixa e irregular.Plant growth, yield, and fruit quality of 'Swatow' (Citrus reticulata Blanco, 'Ellendale' (C. reticulata x Citrus sinensis L. Osbeck, 'Fortune' (Citrus clementina Hort. ex Tan. x Citrus tangerina Hort. ex Tan. e 'Nova' [(C. clementina x (Citrus paradisi Macf. x C. reticulata] mandarins budded on 'Rangpur' lime (C. limonia Osbeck, 'Swingle' citrumelo (P. trifoliata Raf. x C. paradisi Macf., 'Orlando' tangelo (C. reticulata Blanco x C. paradisi Macf., and 'Cleopatra' mandarin (Citrus reshni Hort. ex Tan. were evaluated, from 2000

Zeuxine grandis Seidenf. (Orchidaceae - an Addition to the Orchid Flora of India

Directory of Open Access Journals (Sweden)

Avishek Bhattacharjee

2010-09-01

Full Text Available Zeuxine grandis Seidenf., is being reported for the first time from India. We provide line drawing and color photo of specimen of Z. grandis in support of our treatment and to facilitate identification of the species.

Effects of heat treatment on antioxidative and anti-inflammatory properties of orange by-products

Science.gov (United States)

This study investigated the changes in functional components, antioxidative activities, antibacterial activities, anti-inflammatory activities of orange (Citrus sinensis (L.) Osbeck) by-products (OBP) by heat treatment at 50 and 100 degrees C (hereafter, 50D and 100D extracts, respectively). Optimal...

Antibacterial, antioxidant and cell proliferative properties of Coccinia grandis fruits

Directory of Open Access Journals (Sweden)

Prashant Sakharkar

2017-06-01

Full Text Available Objective: Little knowledge is available on the antimicrobial and antioxidant properties of Coccina grandis fruits and no study has reported on its cell proliferative property. The aim of this study was to examine the antimicrobial, antioxidant and cell proliferative property of fruits of C. grandis. Material and Methods: Fruits of C. grandis were extracted using water; ethanol and acetone by cold and hot Soxhlet extraction. The antibacterial activities of the extracts were tested against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa using the modified Kirby-Bauer diffusion method and compared against erythromycin. The antioxidant property was determined using Cayman's antioxidant assay; whereas cell proliferation/cytotoxic properties were evaluated using the Cell Titer 96 Aqueous One Solution Cell MTS assay with MDA-MB 321 breast cancer cells. Data were analyzed for correlation and differences using unpaired student's t-test and one-way ANOVA. A p value of Results: Both cold and hot ethanol and acetone extracts of C. grandis fruits showed some degree of bacterial growth inhibition. Acetone extracts exhibited higher antibacterial activity. Both ethanol extracts showed antioxidant property when compared with standard Trolox. In contrary to cytotoxicity, all four extracts showed cell proliferation compared to controls at different concentrations. However, acetone extracts exhibited greater cell proliferation compared to ethanol extracts and cold extracts performed better than the hot extracts. Conclusion: C. grandis fruits exhibited some degree of antimicrobial, antioxidant and cell proliferative properties. Further investigation is warranted to isolate, confirm and characterize phytochemicals that are responsible for the medicinal properties observed.

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.

Multielement determination in orange juice by ICP-MS associated with data mining for the classification of organic samples

Directory of Open Access Journals (Sweden)

Christian Turra

2017-09-01

Full Text Available The aim of this study was to discriminate organic from conventional orange juice based on chemical elements and data mining applications. A comprehensive sampling of organic and conventional oranges was carried out in Borborema, state of São Paulo, Brazil. The fruits of the variety Valencia (Citrus sinensis (L. Osbeck budded on Rangpur lime (Citrus limonia Osbeck were analyzed. Eleven chemical elements were determined in 57 orange samples grown in organic and conventional systems. In order to classify these samples, data mining techniques (Support Vector Machine (SVM and Multilayer Perceptron (MLP were combined with feature selection (F-score and chi-squared. SVM with chi-squared had a better performance compared with the other techniques because it reached 93.00% accuracy using only seven chemical components (Cu, Cs, Zn, Al, Mn, Rb and Sr, and correctly classified 96.73% of the samples grown in an organic system.

[Habitat factor analysis for Torreya grandis cv. Merrillii based on spatial information technology].

Science.gov (United States)

Wang, Xiao-ming; Wang, Ke; Ao, Wei-jiu; Deng, Jin-song; Han, Ning; Zhu, Xiao-yun

2008-11-01

Torreya grandis cv. Merrillii, a tertiary survival plant, is a rare tree species of significant economic value and expands rapidly in China. Its special habitat factor analysis has the potential value to provide guide information for its planting, management, and sustainable development, because the suitable growth conditions for this tree species are special and strict. In this paper, the special habitat factors for T. grandis cv. Merrillii in its core region, i.e., in seven villages of Zhuji City, Zhejiang Province were analyzed with Principal Component Analysis (PCA) and a series of data, such as IKONOS image, Digital Elevation Model (DEM), and field survey data supported by the spatial information technology. The results showed that T. grandis cv. Merrillii exhibited high selectivity of environmental factors such as elevation, slope, and aspect. 96.22% of T. grandis cv. Merrillii trees were located at the elevation from 300 to 600 m, 97.52% of them were found to present on the areas whose slope was less than 300, and 74.43% of them distributed on sunny and half-sunny slopes. The results of PCA analysis indicated that the main environmental factors affecting the habitat of T. grandis cv. Merrillii were moisture, heat, and soil nutrients, and moisture might be one of the most important ecological factors for T. grandis cv. Merrillii due to the unique biological and ecological characteristics of the tree species.

Inotropic effect of Citrus sinensis (L. Osbeck leaf extracts on the guinea pig atrium

Directory of Open Access Journals (Sweden)

Oliveira E.D.

2005-01-01

Full Text Available The objective of the present investigation was to determine the contractile effect of crude and acetone leaf extracts of Citrus sinensis (L. Osb. on mammalian myocardium. Crude leaf extracts have been used in folk medicine to treat neurological disorders. Some flavonoids isolated from this plant presented a positive inotropic effect on myocardium. This motivated us to test the extracts on the atria of guinea pigs of both sexes (300-500 g and surprisingly we observed inotropic depression instead of an increase in force. The maximum effect of the crude extract was 79.4 ± 8.1% of the control force amplitude (N = 5 hearts, 10 trials, 27 ± 0.1ºC, stimulus: 2 Hz, 400 V, 0.5 ms. The EC50 for crude, ethanol, acetic, aqueous, and acetone extracts was 300, 300, 600, 1000, and 140 µg/ml, respectively, with a Hill constant of 1.8, 2.0, 2.5, 2.0, and 1.4, respectively. Blockade of cholinergic, beta-adrenergic, or opioid membrane receptors with 1.5 µM atropine sulfate, 1 µM propranolol, and 10 µM naloxone, respectively, did not change the effect of the crude extract. The acetone extract abolished the Bowditch positive staircase phenomenon (N = 5 hearts, 10 trials, 27 ± 0.1ºC, suggesting a possible reduction of the calcium inward current, and also promoted the so-called Woodworth phenomenon. The effect was concentration-dependent and indicated the existence of another inhibitory contractile mechanism such as the simultaneous activation of some of the membrane potassium channels reducing the myocardial action potential duration and further decreasing the cellular calcium entry.

Crescimento vegetativo de porta-enxertos de citros produzidos em substratos comerciais Vegetative growth of citrus rootstocks producing in distinct commercials substrates

Directory of Open Access Journals (Sweden)

Mário Luís Fochesato

2007-08-01

husks and expanded vermiculite (Commercial 3] and three rootstocks (Trifoliate orange - Poncirus trifoliata [ L. ] Raf.; "C13" citrange - Citrus sinensis [ L. ] Osbeck x P. trifoliata, and Rangpur lime - C. limonia Osbeck were tested in randomized blocks under dripping irrigation. The following variables were evaluated: stem height and diameter; leaf number and area; root, aerial and total dry mass; leaf nutrient content and relative number of available rootstocks for grafting. The substrate with processed and enriched husks, expanded vermiculite, expanded perlite and peat provided greater vegetative development of rootstocks due to higher nutrient availability. The rootstocks showed diverse development. The "C13" citrange may be offered to the citrus industry as a choice for diversification of rootstocks, due its vegetative growth.

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.

Biology of Anastrepha grandis (Diptera: Tephritidae) in Different Cucurbits.

Science.gov (United States)

Bolzan, Anderson; Nava, Dori E; Garcia, Flávio R M; Valgas, Ricardo A; Smaniotto, Giovani

2015-06-01

Anastrepha grandis (Macquart) (Diptera: Tephritidae) is one of the main pests of cucurbits in Brazil. Losses occur due to the damage caused to the fruits and the embargo on exports, as A. grandis is considered a quarantine pest in countries that import Brazilian cucurbits. This study aimed to evaluate the development of A. grandis in hosts of the Cucurbitaceae family. The hosts used were stem squash (Cucurbita pepo L.), squash (Cucurbita moschata Duchesne), chayote [Sechium edule (Jacq.) Swartz], mini watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai], Spanish melon (Cucumis melo L.), hybrid squash "Tetsukabuto" (C. moschata×Cucurbita maxima Duchesne), and salad cucumber (Cucumis sativus L.). We evaluated the viability and duration of egg-to-pupa period, pupal weight, sex ratio, and average number of pupae per fruit under controlled conditions of temperature, relative humidity, and photophase. The preoviposition and oviposition periods, fecundity, fertility, and longevity of females were determined for adults. Hosts of the genus Cucurbita provided a better development of A. grandis in comparison with other hosts, and presented a greater number of insects on fruit as well as higher infestation rate. Fecundity and longevity were also higher for females that developed in hosts of the genus Cucurbita, although values of these biological parameters varied between stem squash, squash, hybrid squash "Tetsukabuto." © 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.

In silico analysis of ESTs from roots of Rangpur lime (Citrus limonia Osbeck under water stress

Directory of Open Access Journals (Sweden)

Raquel L. Boscariol-Camargo

2007-01-01

Full Text Available CitEST project resulted in the construction of cDNA libraries from different Citrus sp. tissues under various physiological conditions. Among them, plantlets of Rangpur lime were exposed to hydroponic conditions with and without water stress using PEG6000. RNA from roots was obtained and generated a total of 4,130 valid cDNA reads, with 2,020 from the non-stressed condition and 2,110 from the stressed set. Bioinformatic analyses measured the frequency of each read in the libraries and yielded an in silico transcriptional profile for each condition. A total of 40 contigs were differentially expressed and allowed to detect up-regulated homologue sequences to well known genes involved in stress response, such as aquaporins, dehydrin, sucrose synthase, and proline-related synthase. Some sequences could not be classified by using FunCat and remained with an unknown function. A large number of sequences presented high similarities to annotated genes involved with cell energy, protein synthesis and cellular transport, suggesting that Rangpur lime may sustain active cell growth under stressed condition. The presence of membrane transporters and cell signaling components could be an indication of a coordinated morphological adaptation and biochemical response during drought, helping to explain the higher tolerance of this rootstock to water stress.

Effect of gamma irradiation treatment at phytosanitary dose levels on the quality of ‘Lane Late’ navel oranges

Science.gov (United States)

The objectives of this study were to determine the dose tolerance of ‘Lane Late’ navel oranges (Citrus sinensis L. Osbeck) to irradiation for phytosanitary purposes, identify the sensory attributes that may be affected by the treatment, and determine which changes, if any, influence consumer liking....

Alterações das características químicas de três substratos comerciais na produção de mudas cítricas Change of the chemical characteristics of three commercial substrates in the production of citric seedlings

Directory of Open Access Journals (Sweden)

Mário Luís Fochesato

2008-08-01

Full Text Available Avaliou-se a dinâmica dos nutrientes em três substratos comerciais em que cultivaram-se mudas cítricas, desde o momento da repicagem dos porta-enxertos até a fase final de produção das mesmas. O experimento foi conduzido em ambiente protegido, sendo as mudas cultivadas em citropotes de 4L. O experimento foi desenvolvido na Estação Experimental Agronômica da UFRGS em Eldorado do Sul, RS, no período de junho/2003 a novembro/2004, e obedeceu ao delineamento experimental de blocos casualizados, em esquema fatorial 3 x 3 x 2, sendo: 3 substratos comerciais de cultivo (Comercial 1, 2 e 3 - composto de turfa preta; cascas processadas e enriquecidas, perlita, vermiculita expandida e turfa; e, casca de pinus compostada e vermiculita, respectivamente, 3 porta-enxertos (Trifoliata - Poncirus trifoliata [L.] Raf.; citrangeiro 'C13' - Citrus sinensis [L.] Osbeck x P. trifoliata [L.] Raf.; e limoeiro 'Cravo' - C. limonia Osbeck e 2 variedades copa (laranjeira 'Valência' C. sinensis [L.] Osbeck e a tangerineira 'Montenegrina' - C. deliciosa Tenore. Empregou-se o sistema de irrigação por gotejamento. Avaliou-se a caracterização química dos substratos e conteúdo nutricional foliar e a massa seca da raiz e da parte aérea. Nas condições deste experimento, os substratos apresentam perdas consideráveis de nutrientes, especialmente de fósforo e potássio. No entanto, observa-se que o substrato Comercial 2 apresenta maior aporte de nutrientes, quando comparado com os outros substratos, proporcionando maior acúmulo de massa seca nos porta-enxertos, no momento da enxertia e nas mudas cítricas no final do experimento.The dynamics of nutrients in three commercial substrates were evaluated, from the transplanting until final nursery. The rootstocks were cultivated in 4L containers under greenhouse conditions. The experiment was developed at Estação Experimental Agronômica of UFRGS from June/2003 to November/2004, with the experimental design of

Description and Phylogeny of Urostyla grandis wiackowskii subsp. nov. (Ciliophora, Hypotricha) from an Estuarine Mangrove in Brazil.

Science.gov (United States)

Paiva, Thiago da Silva; Shao, Chen; Fernandes, Noemi Mendes; Borges, Bárbara do Nascimento; da Silva-Neto, Inácio Domingos

2016-01-01

Interphase specimens, aspects of physiological reorganization and divisional morphogenesis were investigated in a strain of a hypotrichous ciliate highly similar to Urostyla grandis Ehrenberg, (type species of Urostyla), collected from a mangrove area in the estuary of the Paraíba do Sul river (Rio de Janeiro, Brazil). The results revealed that albeit interphase specimens match with the known morphologic variability in U. grandis, morphogenetic processes have conspicuous differences. Parental adoral zone is entirely renewed during morphogenesis, and marginal cirri exhibit a unique combination of developmental modes, in which left marginal rows originate from multiple anlagen arising from innermost left marginal cirral row, whereas right marginal ciliature originates from individual within-row anlagen. Based on such characteristics, a new subspecies, namely U. grandis wiackowskii subsp. nov. is proposed, and consequently, U. grandis grandis Ehrenberg, stat. nov. is established. Bayesian and maximum-likelihood analyses of the 18S rDNA unambiguously placed U. grandis wiackowskii as adelphotaxon of a cluster formed by other U. grandis sequences. The implications of such findings to the systematics of Urostyla are discussed. © 2015 The Author(s) Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

Application of Sensory Evaluation, HS-SPME GC-MS, E-Nose, and E-Tongue for Quality Detection in Citrus Fruits.

Science.gov (United States)

Qiu, Shanshan; Wang, Jun

2015-10-01

In this study, electronic tongue (E-tongue), headspace solid-phase microextraction gas chromatography-mass spectrometer (GC-MS), electronic nose (E-nose), and quantitative describe analysis (QDA) were applied to describe the 2 types of citrus fruits (Satsuma mandarins [Citrus unshiu Marc.] and sweet oranges [Citrus sinensis {L.} Osbeck]) and their mixing juices systematically and comprehensively. As some aroma components or some flavor molecules interacted with the whole juice matrix, the changes of most components in the fruit juice were not in proportion to the mixing ratio of the 2 citrus fruits. The potential correlations among the signals of E-tongue and E-nose, volatile components, and sensory attributes were analyzed by using analysis of variance partial least squares regression. The result showed that the variables from the sensor signals (E-tongue system and E-nose system) had significant and positive (or negative) correlations to the most variables of volatile components (GC-MS) and sensory attributes (QDA). The simultaneous utilization of E-tongue and E-nose obtained a perfect classification result with 100% accuracy rate based on linear discriminant analysis and also attained a satisfying prediction with high coefficient association for the sensory attributes (R(2) > 0.994 for training sets and R(2) > 0.983 for testing sets) and for the volatile components (R(2) > 0.992 for training sets and R(2) > 0.990 for testing sets) based on random forest. Being easy-to-use, cost-effective, robust, and capable of providing a fast analysis procedure, E-nose and E-tongue could be used as an alternative detection system to traditional analysis methods, such as GC-MS and sensory evaluation by human panel in the fruit industry. Being easy-to-use, cost-effective, robust, and capable of providing a fast analysis procedure, E-nose and E-tongue could be used as an alternative detection system to traditional analysis methods for characterizing food flavors. Based on those

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.

High-resolution genetic maps of Eucalyptus improve Eucalyptus grandis genome assembly.

Science.gov (United States)

Bartholomé, Jérôme; Mandrou, Eric; Mabiala, André; Jenkins, Jerry; Nabihoudine, Ibouniyamine; Klopp, Christophe; Schmutz, Jeremy; Plomion, Christophe; Gion, Jean-Marc

2015-06-01

Genetic maps are key tools in genetic research as they constitute the framework for many applications, such as quantitative trait locus analysis, and support the assembly of genome sequences. The resequencing of the two parents of a cross between Eucalyptus urophylla and Eucalyptus grandis was used to design a single nucleotide polymorphism (SNP) array of 6000 markers evenly distributed along the E. grandis genome. The genotyping of 1025 offspring enabled the construction of two high-resolution genetic maps containing 1832 and 1773 markers with an average marker interval of 0.45 and 0.5 cM for E. grandis and E. urophylla, respectively. The comparison between genetic maps and the reference genome highlighted 85% of collinear regions. A total of 43 noncollinear regions and 13 nonsynthetic regions were detected and corrected in the new genome assembly. This improved version contains 4943 scaffolds totalling 691.3 Mb of which 88.6% were captured by the 11 chromosomes. The mapping data were also used to investigate the effect of population size and number of markers on linkage mapping accuracy. This study provides the most reliable linkage maps for Eucalyptus and version 2.0 of the E. grandis genome. © 2014 CIRAD. New Phytologist © 2014 New Phytologist Trust.

Evaluation of central nervous system effects of Citrus limon essential oil in mice

Directory of Open Access Journals (Sweden)

Lidianne Mayra Lopes Campêlo

2011-05-01

Full Text Available The central nervous system (CNS depressant and anticonvulsant activities of Citrus limon (L. Osbeck, Rutaceae, essential oil (EO were investigated in animal models. The EO (50, 100 and 150 mg/kg injected by oral route (p.o. in mice caused a significant decrease in the motor activity of animals when compared with the control group, up to thirty days after the administration and the dose of 150 mg/kg significantly reduced the remaining time of the animals on the Rota-rod apparatus. Additionally, C. limon essential oil was also capable to promote an increase of latency for development of convulsions induced by pentylenetetrazole (PTZ. The administration of FLU (10 mg/kg, i.p., GABA A-benzodiazepine (GABA-BZD receptor antagonist, antagonized the effect of C. limon essential oil at higher dose. This C. limon essential oil was also capable to promote an increase of latency for development of convulsions induced by picrotoxin (PIC at higher dose. In the same way, the anticonvulsant effect of the EO was affected by pretreatment with flumazenil, a selective antagonist of benzodiazepine site of GABA A receptor. These results suggest a possible CNS depressant and anticonvulsant activities in mice that needs further investigation.

Eucalyptus grandis AND Eucalyptus dunnii USE FOR WOOD-CEMENT PANELS MANUFACTURING

Directory of Open Access Journals (Sweden)

Setsuo Iwakiri

2008-03-01

Full Text Available This research evaluated the potential use of Eucalyptus grandis and Eucalyptus dunnii wood for wood-cement panelsmanufacturing. The boards were manufactured at the density of 1,20 g/cm³, using portland cement as mineral bonding and woodfurnish without treatment, treated in cold water and hot water. The wood furnish of Pinus taeda was used as control. The resultsindicated that it is not necessary to treat E. grandis and E. dunni wood for wood-cement board manufacturing. In relation to woodspecies, the board manufactured with E. dunnii showed lower values of mechanical properties. However, boards manufactured of E.grandis wood showed satisfactory results in comparison to boards of P. taeda and the referenced values of BISON process and otherproducts cited in the pertnent literature, indicating the high potential for wood-cement board manufacture of this tree species.

Boll weevil (Anthonomus grandis) population genomics as a tool for monitoring and management

Science.gov (United States)

Despite the success of eradication efforts across most of the cotton-producing regions of the U.S., the cotton boll weevil (Anthonomus grandis grandis Boheman) remains a major pest of cotton in much of the New World. The area along the Texas border with northern Mexico has been a particularly troub...

Competition between Catolaccus grandis (Hymenoptera: Pteromalidae and Bracon vulgaris (Hymenoptera: Braconidae, parasitoids of the Boll Weevil

Directory of Open Access Journals (Sweden)

Francisco de Sousa Ramalho

2007-05-01

Full Text Available The competition between populations of the parasitoids C. grandis and B. vulgaris was studied using larvae of Euscepes postfasciatus (Fairmaire as an alternative host. A series of biological parameters was observed and related to the competitive abilities of both parasitoid species. They were capable of colonizing and maintaining their populations regardless of host location. The population growth of C. grandis and B. vulgaris, based on fecundity was not affected by the competition. The parasitism and survivorship to the adult stage were affected by competition, except when the host was located at the bottom of the rearing cage. C. grandis performed better than B. vulgaris independently of the competition and host location, but it did not exclude the other species.Catolaccus grandis (Burks e Bracon vulgaris Ashmead são os principais parasitóides do bicudo-do-algodoeiro Anthonomus grandis Boheman no Nordeste do Brasil. É importante que se determinem as interações entre esses parasitóides e o seu efeito em programas de controle biológico dessa praga com os mesmos. A competição entre os parasitóides C. grandis e B. vulgaris foi estudada, utilizando-se larvas de Euscepes postfasciatus Fairmaire como hospedeiro alternativo. A fecundidade de C. grandis e B. vulgaris baseada na produção de ovos, não foi afetada pela competição, mas o parasitismo e a produção de adultos desses parasitóides foram afetados pela competição, exceto quando o hospedeiro se encontrava na base da caixa de criação. Independentemente da competição e da localização do hospedeiro, C. grandis apresentou melhor desempenho que B. vulgaris, mas não excluiu as populações da outra espécie de parasitóide.

Sanitary and nutritional characterization of honeybee colonies in Eucalyptus grandis plantations

OpenAIRE

Invernizzi, C.; Santos, E.; García, E.; Daners, G.; Di Landro, R.; Saadoun, A.; Cabrera, C.

2011-01-01

In Uruguay, many beekeepers transport their colonies to Eucalyptus grandis plantations at the end of the summer and autumn, obtaining important honey harvests. However, at the end of the flowering period the colonies become extremely weakened undergoing high levels of mortality. Nutritional and health problems could explain the weakening of colonies. In order to find out the causes for this weakening, colonies of the same size were taken to an E. grandis plantation, split up in three groups d...

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.

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

Multiplicação in vitro de Eucalyptus grandis sob estímulo com benzilaminopurina In vitro multiplication of Eucalyptus grandis under BAP pulse

Directory of Open Access Journals (Sweden)

Wirifran Fernandes de Andrade

2006-12-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos do estímulo com benzilaminopurina (BAP na multiplicação in vitro de Eucalyptus grandis. Foram avaliadas as interações entre concentrações de BAP (0, 200, 400 e 600 mg L-1, tempo de exposição (1, 2 e 3 horas, pH (3 e 5,8 da solução e alterações morfológicas dos explantes. Semanalmente, foi determinada a massa da matéria fresca dos explantes. Aos 21 dias de cultura, foram avaliados: o número de brotações por tratamento, o número de brotações obtidas por explante (taxa de multiplicação, e foi realizado o resgate das plântulas para avaliação histológica. O pH não apresentou interação com os demais fatores estudados. Os tratamentos com BAP a 200 mg L-1, durante 1 e 2 horas, apresentaram-se como os mais indicados na multiplicação do E. grandis. Houve intensificação da divisão celular, no parênquima cortical e no procâmbio, representada pelo surgimento de meristemóides, em resposta aos tratamentos com 200 mg L-1 de BAP, durante 1 e 2 horas. O estímulo com BAP na multiplicação in vitro de E. grandis é viável.The objective of this work was to evaluate the effect of pulse on in vitro multiplication of Eucalyptus grandis. Interactions were evaluated among BAP concentrations (0, 200, 400 and 600 mg L-1, exposure time (1, 2 and 3 hours, pH values (3 and 5.8, and explant morphological changes. Fresh weight of the explants was determined weekly. At 21 days of culture, valuations were made of the number of shootings per treatment, number of shootings obtained per explant (multiplication rate, and seedlings rescue was accomplished for histological analysis. The pH values did not present any interaction with the other factors. The most significant treatments on E. grandis shoot multiplications were 200 mg L-1 of 6-BAP during 1 and 2 hours. There was an intensification of cell division in the cortical parenchyma and procambium, represented by the arising of meristems in

Antibacterial Activity of Emulsified Pomelo (Citrus grandis Osbeck Peel Oil and Water-Soluble Chitosan on Staphylococcus aureus and Escherichia coli

Directory of Open Access Journals (Sweden)

Guan-Wen Chen

2018-04-01

Full Text Available This study utilized pomelo steam distillation to isolate pomelo peel essential oil. The constituents were then analyzed through gas chromatography-mass spectrometry (GC-MS, and the antibacterial activity of the essential oil emulsions at different homogenizer speed conditions and concentrations of water-soluble chitosan (degree of acetylation, DA = 54.8% against S. aureus and E. coli was examined. Analysis of the essential oil composition identified a total of 33 compounds with the main constituent, limonene accounting for 87.5% (940.07 mg/g of the total. The pomelo peel oil was emulsified through homogenization at 24,000 rpm, resulting in a minimal inhibitory concentration (MIC for E. coli that was 1.9 times lower than that of the essential oil without homogenization. In addition, a mixture of 0.4% essential oil emulsion and 0.03% water-soluble chitosan had the strongest synergetic antibacterial effect on S. aureus and E. coli at pH 7.4. In comparison with chitosan alone, the MIC value of this mixture was significantly 2.4 and 2.5 times lower. Hence, this study suggests using a mixture of emulsified pomelo peel oil and water-soluble chitosan to develop a novel natural food preservative, and that the processability of food, as well as the economic value of the byproducts of the Taiwan Matou pomelo and chitosan, could be increased.

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...

Seed viability constants for Eucalyptus grandis Constantes de viabilidade para sementes de Eucalyptus grandis

Directory of Open Access Journals (Sweden)

Jussara Bertho Fantinatti

2007-01-01

Full Text Available This work aimed to analyse Eucalyptus grandis W.Hill ex Maiden seed behaviour, under controlled deterioration, and to estimate viability equation constants for the species. Seeds were harvested in the growing season of 1999, and the moisture contents were adjusted from 11.3% to a range between 1.2 and 18.1% at 25ºC. The subsamples were sealed into laminate aluminium-foil packets, for storage in incubators at 40, 50 and 65±0.5ºC. The seeds presented orthodox performance, in which the constants for predicting seed longevity of E. grandis were K E = 9.661, C W = 6.467, C H = 0.03498 and C Q = 0.0002330. The usual and inverse relationship between water content and seed longevity was also observed. The lowest moisture content limit for application of the viability equation at 65ºC was 4.9%, estimated under hygroscopic equilibrium with 23% of relative humidity in the storage environment.Este trabalho teve como objetivos verificar o desempenho de sementes de Eucalyptus grandis W.Hill ex Maiden, após a deterioração em condições controladas, e obter as constantes da equação de viabilidade. As sementes foram colhidas na safra de 1999, e a umidade foi ajustada de 11,3% para valores entre 1,2 e 18,1% a 25ºC As subamostras foram acondicionadas em embalagens de alumínio termossoldadas, armazenadas a 40, 50 e 65±0,5ºC. As sementes apresentaram um desempenho ortodoxo em relação ao armazenamento. As constantes para a predição da longevidade foram K E = 9,661, C W = 6,467, C H = 0,03498 e C Q = 0,0002330. Foi observada a relação inversa entre teor de água e longevidade. O limite inferior de grau de umidade, calculado para aplicação da equação a 65ºC, foi de 4,9%, estimativa obtida sob equilíbrio higroscópico com umidade relativa de 23% no ambiente de armazenamento.

Comportamento de 16 porta-enxertos para o tangor Murcott na região de Itirapina-SP Behavior of sixteen rootstocks for Murcott in Itirapina, SP, Brazil

Directory of Open Access Journals (Sweden)

José Orlando de Figueiredo

2006-04-01

Full Text Available Foi monitorado o comportamento de 16 porta-enxertos para o tangor Murcott [Citrus reticulata Blanco x C. sinensis (L. Osbeck], do clone nucelar J, em experimento instalado em 1990, na Fazenda Raio de Sol, Itirapina-SP. Os porta-enxertos foram: tangelo 'Orlando' (C. reticulata Blanco x C. paradisi Macf., laranja 'Caipira DAC' [C. sinensis (L. Osbeck], limão 'Cravo'(C. limonia Osbeck, os trifoliatas 'Kryder 8-5'e 'EEL'[Poncirus trifoliata (L. Raf.] e as tangerinas 'Cleópatra' (C. reshni hort. ex. Tanaka, 'Sunki' [C. sunki (Hayata hort. ex. Tanaka], 'Batangas', 'Oneco', 'Swatow', 'Szinkon', 'Satsuma', 'Cravo', 'Dancy', 'Suen Kat' e 'Pook Ling Ming' (C. reticulata Blanco. As produções foram avaliadas de 1996 a 2003 e as maiores médias foram proporcionadas pelas plantas enxertadas nas tangerinas 'Cleópatra', 'Suen Kat', 'Pook Ling Ming' e 'Sunki' (>40 kg planta-1. Dentre os porta-enxetos que induziram as mais baixas produções, estão os dois trifoliatas, a 'Caipira DAC' e a tangerina 'Cravo' (Sixteen rootstocks were compared in a trial started in 1990, for Murcott tangor, nucellar clone "J", in Itirapina, Brazil. The rootstocks tested were Orlando tangelo (Citrus reticulata Blanco x C. paradisi Macf., sweet orange [C. sinensis (L. Osbeck] cv. Caipira DAC, Rangpur lime (C. limonia Osbeck, Poncirus trifoliata (L. Raf. cv. Kryder 8-5, P. trifoliata (L. Raf. cv. EEL and the mandarins Cleopatra (C. reshni hort. ex. Tanaka, Sunki [C. sunki (Hayata hort. ex. Tanaka] and Batangas, Oneco, Swatow, Szinkon, Satsuma, Cravo, Dancy, Suen Kat and Pook Ling Ming (C. reticulata Blanco. Fruit yield was measured per plant, in a period of seven years (1996-2003. The best yielding rootstocks were Cleopatra, Suen Kat, Pook Ling Ming and Sunki mandarins (> 40 kg tree-1. The two Trifoliate, sweet orange cv. Caipira DAC and Cravo mandarin presented the lowest yields (< 25 kg tree-1. No significant variation was observed for fruit quality characteristics of trees on

The genome of Eucalyptus grandis

Energy Technology Data Exchange (ETDEWEB)

Myburg, Alexander A.; Grattapaglia, Dario; Tuskan, Gerald A.; Hellsten, Uffe; Hayes, Richard D.; Grimwood, Jane; Jenkins, Jerry; Lindquist, Erika; Tice, Hope; Bauer, Diane; Goodstein, David M.; Dubchak, Inna; Poliakov, Alexandre; Mizrachi, Eshchar; Kullan, Anand R. K.; Hussey, Steven G.; Pinard, Desre; van der Merwe, Karen; Singh, Pooja; van Jaarsveld, Ida; Silva-Junior, Orzenil B.; Togawa, Roberto C.; Pappas, Marilia R.; Faria, Danielle A.; Sansaloni, Carolina P.; Petroli, Cesar D.; Yang, Xiaohan; Ranjan, Priya; Tschaplinski, Timothy J.; Ye, Chu-Yu; Li, Ting; Sterck, Lieven; Vanneste, Kevin; Murat, Florent; Soler, Marçal; Clemente, Hélène San; Saidi, Naijib; Cassan-Wang, Hua; Dunand, Christophe; Hefer, Charles A.; Bornberg-Bauer, Erich; Kersting, Anna R.; Vining, Kelly; Amarasinghe, Vindhya; Ranik, Martin; Naithani, Sushma; Elser, Justin; Boyd, Alexander E.; Liston, Aaron; Spatafora, Joseph W.; Dharmwardhana, Palitha; Raja, Rajani; Sullivan, Christopher; Romanel, Elisson; Alves-Ferreira, Marcio; Külheim, Carsten; Foley, William; Carocha, Victor; Paiva, Jorge; Kudrna, David; Brommonschenkel, Sergio H.; Pasquali, Giancarlo; Byrne, Margaret; Rigault, Philippe; Tibbits, Josquin; Spokevicius, Antanas; Jones, Rebecca C.; Steane, Dorothy A.; Vaillancourt, René E.; Potts, Brad M.; Joubert, Fourie; Barry, Kerrie; Pappas, Georgios J.; Strauss, Steven H.; Jaiswal, Pankaj; Grima-Pettenati, Jacqueline; Salse, Jérôme; Van de Peer, Yves; Rokhsar, Daniel S.; Schmutz, Jeremy

2014-06-11

Eucalypts are the world s most widely planted hardwood trees. Their broad adaptability, rich species diversity, fast growth and superior multipurpose wood, have made them a global renewable resource of fiber and energy that mitigates human pressures on natural forests. We sequenced and assembled >94% of the 640 Mbp genome of Eucalyptus grandis into its 11 chromosomes. A set of 36,376 protein coding genes were predicted revealing that 34% occur in tandem duplications, the largest proportion found thus far in any plant genome. Eucalypts also show the highest diversity of genes for plant specialized metabolism that act as chemical defence against biotic agents and provide unique pharmaceutical oils. Resequencing of a set of inbred tree genomes revealed regions of strongly conserved heterozygosity, likely hotspots of inbreeding depression. The resequenced genome of the sister species E. globulus underscored the high inter-specific genome colinearity despite substantial genome size variation in the genus. The genome of E. grandis is the first reference for the early diverging Rosid order Myrtales and is placed here basal to the Eurosids. This resource expands knowledge on the unique biology of large woody perennials and provides a powerful tool to accelerate comparative biology, breeding and biotechnology.

Different processing of CAPA and pyrokinin precursors in the giant mealworm beetle Zophobas atratus (Tenebrionidae) and the boll weevil Anthonomus grandis grandis (Curculionidae).

Science.gov (United States)

Neupert, Susanne; Marciniak, Pawel; Köhler, Rene; Nachman, Ronald J; Suh, Charles P-C; Predel, Reinhard

2018-03-01

Capa and pyrokinin (pk) genes in hexapods share a common evolutionary origin. Using transcriptomics and peptidomics, we analyzed products of these genes in two beetles, the giant mealworm beetle (Zophobas atratus; Tenebrionidae) and the boll weevil (Anthonomus grandis grandis; Curculionidae). Our data revealed that even within Coleoptera, which represents a very well-defined group of insects, highly different evolutionary developments occurred in the neuropeptidergic system. These differences, however, primarily affect the general structure of the precursors and differential processing of mature peptides and, to a lesser degree, the sequences of the active core motifs. With the differential processing of the CAPA-precursor in Z. atratus we found a perfect example of completely different products cleaved from a single neuropeptide precursor in different cells. The CAPA precursor in abdominal ganglia of this species yields primarily periviscerokinins (PVKs) whereas processing of the same precursor in neurosecretory cells of the subesophageal ganglion results in CAPA-tryptoPK and a novel CAPA-PK. Particularly important was the detection of that CAPA-PK which has never been observed in the CNS of insects before. The three different types of CAPA peptides (CAPA-tryptoPK, CAPA-PK, PVK) each represent potential ligands which activate different receptors. In contrast to the processing of the CAPA precursor from Z. atratus, no indications of a differential processing of the CAPA precursor were found in A. g. grandis. These data suggest that rapid evolutionary changes regarding the processing of CAPA precursors were still going on when the different beetle lineages diverged. The sequence of the single known PVK of A. g. grandis occupies a special position within the known PVKs of insects and might serve asa basis to develop lineage-specific peptidomimetics capable of disrupting physiological processes regulated by PVKs. Copyright © 2017 Elsevier Inc. All rights reserved.

Spatial distribution of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae larvae in three scales Distribuição espacial das larvas de Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae em três escalas

Directory of Open Access Journals (Sweden)

CR. Jesus

2008-02-01

Full Text Available The spatial distribution of larvae of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae, the citrus leaf miner, in leaves, shoots, and tree crowns of Montenegrina tangerine (Citrus deliciosa Tenore and Murcott tangor (Citrus sinensis L. Osbeck x Citrus reticulata Blanco was determined. Fortnightly samplings from July/2001 to June/2003, in orchards located in Montenegro (29º 68’ S and 51º 46’ W, RS, Brazil, were carried out. At each sampling occasion eighth shoots randomly selected were collected. The spatial distribution pattern of P. citrella larvae between tree crowns and in the shoots was aggregated in most sampling occasions in both citrus species. Nevertheless, on the leaves, this pattern followed a random distribution, as indicated by the indices I, Idelta and k parameter.Com o objetivo de determinar a distribuição espacial das larvas de Phyllocnistis citrella Stainton, (Lepidoptera: Gracillariidae, o minador-dos-citros, nas folhas, nos brotos e nas copas das plantas de tangerineira ‘Montenegrina’ (Citrus deliciosa Tenore e de tangor ‘Murcott’ (Citrus sinensis L. Osbeck x Citrus reticulata Blanco, foram realizadas amostragens quinzenais de julho de 2001 a junho de 2003 em pomares localizados em Montenegro (29º 68’ S e 51º 46’ W, RS, Brasil. Em cada ocasião de amostragem foram coletados aleatoriamente oito brotos. Através da análise, pelos índices de dispersão I e Idelta, o padrão de distribuição espacial das larvas de P. citrella entre as plantas e nos brotos de ‘Montenegrina’ e ‘Murcott’ foi agregado na maioria das ocasiões de amostragem. O padrão de distribuição espacial das larvas do minador-dos-citros nas folhas mostrou-se diferente do registrado em copas das plantas e brotos, os índices I, Idelta e o parâmetro k indicaram distribuição aleatória.

Efeitos de algumas práticas de cultivo do solo, na nutrição mineral dos citros Effect of soil management practices on mineral nutrition of citrus tree

Directory of Open Access Journals (Sweden)

J. Romano Gallo

1960-01-01

Full Text Available Diferentes sistemas de cultivo do solo no pomar cítrico foram comparados no presente trabalho, por meio da análise foliar. Os tratamentos estudados fazem parte de um experimento com plantas da variedade Hamlin sôbre laranjeira caipira (Citrus sinensis Osbeck instalodo no Estação Experimental de Limeira, do Instituto Agronômico. Amostras de fôlhas do ciclo vegetativo da primavera foram colhidas a intervalos regulares, desde outubro de 1957 a março de 1959 e analisadas para os seguintes elementos: N, P, K, Ca, Mg, Fe e Mn. São apresentados os tendências das curvas de concentração dos elementos nutritivos nas fôlhas e os resultados de produção correspondentes a quatro onos de colheita. Como observação mais importante foi verificado que a cobertura morta de capim e a adubação verde de mucuna aumentaram de modo sensível o teor de fósforo nas fôlhas dos citros. As produções de laranja acompanharam a ordem dos níveis dêsse elemento na folhagem.The influence of several soil management systems on the mineral nutrition and production of citrus trees was studied. This study was mode in an experimental orchard installed in 1949 with Hamlin orange on sweet orange (Citrus sinensis Osbeck. Differential treatments were started in 1953. Since 1956 all plots received uniform fertilizer applications and liming. The cultural treatments employed are as follows: clean cultivation with herbicide; clean cultivation plus a cover crop of velvet bean (Stizolobium aterrimum Pip. & Trac. planted in the spring and cut down in the fall; clean cultivation plus a cover crop of pigeon pea (Cajanus cajan (L. Millsp. planted in the spring and cut down in the fall; molasses grass (Melinis minutiflora Béauv. mulch; and superficial soil plowing. Leaf samples of the spring cycle were collected from each treatment at regular intervals, from October, 1957 to March, 1959, and analysed for N, P, K, Ca, Mg, Fe, and Mn. The seasonal variations in mineral

Cafe Grandis kõlab lautomuusika / Anneli Remme

Index Scriptorium Estoniae

Remme, Anneli, 1968-

2008-01-01

Corelli Musicu salongiõhtutel festivali "Fiesta de la Guitarra" raames esineb trio koosseisus Stewart McCoy (lautomängija), Robert Staak (lautomängija) ja Maria Staak (laulja), esinejatest. Esitatakse renessansiaja autorite lautoduette ja -laule. Kontsert 8. nov. Pärnu hotellis sarjas "Café Grandi muusikasalong"

Revisión taxonómica de Alytes grandis Brunner (Amphibia, Anura

Directory of Open Access Journals (Sweden)

Sanchiz, B.

1986-12-01

Full Text Available The holotype and only existing remain referred to Alytes grandis Brunner, 1957, presumably a discoglossid frog from the German Pleistocene, is examined and compared with other living and fossil Palaearctic anurans. The analysis rejects its validity as an independent extinct species, as The material is clearly within the known variability of living Rana temporaria Linnaeus, 1758, of which it should be considered merely a sinonym.

Se examina el holotipo y único resto atribuido de Alytes grandis Brunner, 1957, un supuesto discoglósido del Pleistoceno alemán, comparándose con otros anuros actuales y fósiles del Paleártico. El análisis permite desechar su pertenencia a una especie extinta independiente, siendo en cambio atribuible con toda claridad a la viviente Rana temporaria Linnaeus, 1758, de la que debe considerarse sinónimo.
Zum systematischen Status von Alytes grandis Brunner, 1957 (Amphibia, Anura. Der bislang einzig bekannte und von Brunner (1957 beschriebene Rest zu Alytes grandis aus pleistozänen Ablagerungen der Breitenberghöhle bei Gössweinstein (Fränk, Alb wird beschrieben und aufgrund ausführlicher Vergleichsuntersuchungen der rezenten Art Rana temporaria Linnaeus, 1758, zugeordnet, Alytes grandis Brunner, 1957, ist somit als synonyrn zu Rana temporaria zu betrachten.

Produção e qualidade de frutos de cultivares de laranja-doce no norte do Paraná Fruit production and quality of sweet orange cultivars in northern Paraná state, Brazil

Directory of Open Access Journals (Sweden)

Zuleide Hissano Tazima

2009-06-01

Full Text Available O objetivo do trabalho foi a caracterização de acessos de laranja-doce [Citrus sinensis (L. Osbeck] do Banco Ativo de Germoplasma de Citros (BAG Citros do IAPAR, em Londrina-PR. Foram estudados os acessos I-02 'Piralima'; I-03 'Barão'; I-11 'Natal', I-16 'Hamlin', I-17 'Seleta-Vermelha', I-60 'Natal', enxertados sobre limão- 'Cravo' (Citrus limonia Osbeck. As plantas foram conduzidas em espaçamento de 7,0 m x 7,0 m e sem irrigação. Os dados de produção (de 1983 a 1997 e as características físico-químicas dos frutos (de 1984 a 2000, como massa (MF, sólidos solúveis totais (SST, acidez titulável total (ATT, ratio (SST/ATT, rendimento em suco (Suco e índice tecnológico (IT foram submetidos à análise de variância, complementada pelo teste de Tukey, a 5% de probabilidade. O acesso I-16 'Hamlin' foi o mais produtivo (218,1 kg por planta e diferiu-se dos demais. Para a massa do fruto, destacaram-se os acessos I-17 'Seleta-Vermelha' (208,8 g e I-11 'Natal' (142,0 g, sem diferença entre si. Com relação às características químicas dos frutos, os acessos apresentaram resultados semelhantes, dentro dos padrões considerados adequados para as cultivares, exceto o acesso I-17, 'Seleta- Vermelha', que teve índice tecnológico menor que 2,0 kg.caixa-1 de SST.The aim of this work was to characterize sweet orange [Citrus sinensis (L. Osbeck] accessions from the IAPAR Active Citrus Germplasm Bank (AGB Citrus in Londrina, Paraná, Brazil. The accessions studied were: I-02 'Piralima', I-03 'Barão', I-11 'Natal', I-16 'Hamlin', I-17 'Seleta Vermelha', I-60 'Natal', I-67 budded on Rangpur lime (Citrus limonia Osbeck. The plants had 7.0 m x 7.0 m spacing, and were carried out without irrigation. Data of yield (from 1983 to 1997 and fruit physical-chemical characteristics (from 1984 to 2000, like fruit mass (FM, total soluble solids (TSS, total titratable acidity (TTA, ratio (TSS/TTA, juice content and technological index (TI were submitted

[Community structure of soil fauna in Eucalyptus grandis plantations at different slope locations].

Science.gov (United States)

Zhao, Yu; Zhong, Yu; Zhang, Jian; Yang, Wan-qin

2010-09-01

To understand the effects of slope location on the community structure of soil fauna in Eucalyptus grandis plantation, an investigation was made on the soil fauna in 3 E. grandis plantations at different slope locations in the hilly area of Sichuan Province from January to October 2009. A total of 39,2762 individuals were observed, belonging to 146 groups, 7 phyla, 16 classes, and 31 orders. The community composition, trophic group, diversity, and seasonal dynamics of soil fauna in the plantations all varied with slope. The abundance of macro-fauna, xeric meso- and micro-fauna, saprophagous macro-fauna, and omnivorous xeric meso- and micro-fauna increased with the decrease of slope, indicating that soil fauna had sensitive responses to the soil environmental factors affected by slope. Significant differences in the diversity of soil saprophagous macro-fauna and hygrophilous meso- and micro-fauna were observed at different slope locations, suggesting that these two faunal groups could be used as the indicators of the habitat heterogeneity of E. grandis plantations at different slope. Overall, slope location had definite effects on the community structure and distribution of soil fauna in the E. grandis plantations, but the effects were not statistically significant.

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...

Transcriptome analysis in cotton boll weevil (Anthonomus grandis and RNA interference in insect pests.

Directory of Open Access Journals (Sweden)

Alexandre Augusto Pereira Firmino

Full Text Available Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

Transcriptome analysis in cotton boll weevil (Anthonomus grandis) and RNA interference in insect pests.

Science.gov (United States)

Firmino, Alexandre Augusto Pereira; Fonseca, Fernando Campos de Assis; de Macedo, Leonardo Lima Pepino; Coelho, Roberta Ramos; Antonino de Souza, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

2013-01-01

Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

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

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.

Transcriptomic survey of the midgut of Anthonomus grandis (Coleoptera: Curculionidae).

Science.gov (United States)

Salvador, Ricardo; Príncipi, Darío; Berretta, Marcelo; Fernández, Paula; Paniego, Norma; Sciocco-Cap, Alicia; Hopp, Esteban

2014-01-01

Anthonomus grandis Boheman is a key pest in cotton crops in the New World. Its larval stage develops within the flower bud using it as food and as protection against its predators. This behavior limits the effectiveness of its control using conventional insecticide applications and biocontrol techniques. In spite of its importance, little is known about its genome sequence and, more important, its specific expression in key organs like the midgut. Total mRNA isolated from larval midguts was used for pyrosequencing. Sequence reads were assembled and annotated to generate a unigene data set. In total, 400,000 reads from A. grandis midgut with an average length of 237 bp were assembled and combined into 20,915 contigs. The assembled reads fell into 6,621 genes models. BlastX search using the NCBI-NR database showed that 3,006 unigenes had significant matches to known sequences. Gene Ontology (GO) mapping analysis evidenced that A. grandis is able to transcripts coding for proteins involved in catalytic processing of macromolecules that allows its adaptation to very different feeding source scenarios. Furthermore, transcripts encoding for proteins involved in detoxification mechanisms such as p450 genes, glutathione-S-transferase, and carboxylesterases are also expressed. This is the first report of a transcriptomic study in A. grandis and the largest set of sequence data reported for this species. These data are valuable resources to expand the knowledge of this insect group and could be used in the design of new control strategies based in molecular information. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Development during indirect organogenesis in Eucalyptus grandis x ...

African Journals Online (AJOL)

BQWUPC1

isolation or from a region of the stem immediately above the callus. Roots developed ... In this study, the same clone (Eucalyptus grandis urophylla hybrid) was used and .... strands and they linked these with shoot formation, whilst. Arvore et al.

Citrus Waste Biomass Program

Energy Technology Data Exchange (ETDEWEB)

Karel Grohman; Scott Stevenson

2007-01-30

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

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.

Mites (Arachnida, Acari on Citrus sinensis L. Osbeck orange trees in the state of Amazonas, Northern Brazil Ácarofauna de Citrus sinensis L. Osbeck no estado do Amazonas, Brasil

Directory of Open Access Journals (Sweden)

Teiamar da Encarnação Bobot

2011-01-01

Full Text Available Despite the importance of citriculture in Brazil, very little is known about mite populations in citrus crops in the Northern Region. In the municipality of Manaus, 12 sprayed sweet orange orchards were surveyed every two weeks during seven months to record mite species amount, and to describe the abundance and distribution of the most important species. The size and age of the orchards varied from 3,360 to 88,080 m² and seven to 25 years, respectively. In the fourteen sampling period, leaves, twigs and fruits were collected from 12 trees, one per orchard. In total, 3,360 leaves, 672 twigs and 1,344 fruits were sampled from 168 trees. Mites were manually extracted from the fruits, and by the washing method on leaves and twigs. We identified pests with the potential to cause economic loss. Fourteen species of phytophagous and mycophagous mites from Eriophyidae, Tarsonemidae, Tenuipalpidae, and Tetranychidae were recorded. Brevipalpus phoenicis (Geijskes 1939 and Phyllocoptruta oleivora (Ashm., 1879, the two commonest phytophagous mites in other Brazilian regions were dominant, showing that local orchards are susceptible to their infestation. Eleven predatory mites were recorded, comprising 10% of the mite population, belonging to Phytoseiidae and Ascidae. Phytoseiidae was the richest family, with ten species. The results are discussed in relation to the temporal variation aspects and habitat use of the most important species. Long-term research encompassing chemical applications followed by evaluations of the mite community are necessary for a better management of the orchards, taking into consideration the seasonal phenology of key pests.Apesar da importância da citricultura no Brasil, pouco se conhece sobre as populações de ácaros em plantações de citros no norte do país. No município de Manaus, 12 pomares de laranja doce pulverizados foram avaliados a cada duas semanas, durante sete meses, para o registro de ácaros plantícolas e

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.

Migration and dispersal of Anthonomus grandis (Coleoptera: Curculionidae in South America Migración y dispersión de Anthonomus grandis (Coleoptera: Curculionidae en América del Sur

Directory of Open Access Journals (Sweden)

Teodoro Stadler

2007-12-01

Full Text Available This study discusses the dispersal of Anthonomus grandis Boheman, the cotton boll weevil, in Argentina, Brazil, Paraguay and Bolivia, exploring the ecological and physiological factors that have made the dispersal and establishment of this insect in South America so successful. The boll weevil's phenotypic plasticity is represented by its flexible developmental time, its multivoltine life cycle with several overlapping generations, its capacity to feed on pollen from diverse botanical families as well as from non pollen food sources and its ability to migrate and disperse aided by winds. These characteristics make it a key pest for cotton. Probable overwintering «hot spots» for the boll weevil were identified in Misiones-Argentina, where large numbers of prediapausing weevils concentrate after arrival from newly harvested cotton fields in Paraguay, probably attracted by citrus orchards volatiles. The boll weevil's facultative quiescence is always relative to environmental adverse conditions. This suggests that overwintering in the boll weevil can be defined as «oligopause», an intermediate form of diapause. Since its introduction to Brazil in 1983, until 2006, it has spread southwest at an average of 61 km year-1 towards Argentina. However, it took the boll weevil approximately ten years to move 250 km between Paraguay and the main cotton growing area in Argentina. This slower progress is probably due to the actions taken by the Argentine government through the boll weevil eradication program. The arrival of the boll weevil at the cotton cropping areas in Paraguay and Argentina reinforces the fact that the boll weevil should finally be included in an integrated cotton pest management program jointly with other major cotton pests.El presente estudio sobre la dispersión de Anthonomus grandis Boheman, el picudo del algodonero, en Argentina, Brasil, Paraguay y Bolivia, explora las características ecológicas y fisiológicas que han permitido a

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.

MODIFICACIÓN AL PROCESO DE PRODUCCIÓN MASIVA DE LOS PARASITOIDES Catolaccus grandis Y Catolaccus hunteri

Directory of Open Access Journals (Sweden)

Marco Antonio Reyes-Rosas

2010-01-01

Full Text Available El presente estudio se realizó con el objetivo de modificar la tecnología de producción masiva de Catolaccus grandis y Catolaccus hunteri, himenópteros parasitoides de Anthonomus grandis el picudo del algodonero en Tamaulipas, México en el 2002. Se determinó la eficiencia del papel toalla para el secado de manos, en el sellamiento de cápsulas moldeadas en cera de hidrocarburos y poliolefina (LCHP, donde se confina al huésped, y evaluar la efectividad del gorgojo del garbanzo Callosobruchus maculatus como hospedante facticio para la cría de ambos parasitoides. Hubo producción masiva de C. grandis y C. hunteri utilizando C. maculatus como huésped y el papel toalla fue efectivo para sellar los orificios de las cápsulas moldeadas en LCHP. La producción masiva de C. grandis y C. hunteri mediante C. maculatus, contribuyó a incrementar la seguridad y facilidad del proceso, además de una significativa reducción de costos. El papel toalla en el sellado de los orificios de las cápsulas moldeadas en LCHP, redujo en un 50% por m2 los costos del proceso, sin afectar la eficiencia del parasitismo y emergencia de C. grandis.

Regeneration and transformation of Eucalyptus grandis

OpenAIRE

Esteki, Leila

2013-01-01

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas Eucalyptus grandis is the most widely used species in planted forests in tropical and subtropical areas. The traits of interest underlying Eucalyptus breeding programs concern productivity and wood quality for the pulp and paper industry, as well as biotic and abiotic stress tolerance. The development of an efficient transformation protocol is necessary to explore eucalypt resources th...

Lethal and sublethal effects of selected insecticides and an insect growth regulator on the boll weevil (Coleoptera: Curculionidae) ectoparasitoid Catolaccus grandis (Hymenoptera: Pteromalidae).

Science.gov (United States)

Elzen, G W; Maldonado, S N; Rojas, M G

2000-04-01

A laboratory culture of Catolaccus grandis (Burks), an ectoparasitoid of the boll weevil, Anthonomus grandis grandis Boheman, was exposed to lethal and sublethal doses of insecticides and an insect growth regulator using a spray chamber bioassay. Materials tested were azinphos-methyl, endosulfan, fipronil, malathion, cyfluthrin, dimethoate, spinosad, methyl parathion, acephate, oxamyl, and tebufenozide. At full rates, spinosad was significantly less toxic to female C. grandis than other treatments except endosulfan. Fipronil and malathion were significantly more toxic to females than other treatments. Most of the chemicals tested were highly toxic to male C. grandis; spinosad was least toxic. At reduced rates, most of 4 selected chemicals tested were low in toxicity to C. grandis; however, a reduced rate of malathion was significantly more toxic to females than other treatments. No C. grandis pupae developed from parasitism during a 24-h treatment period with malathion or spinosad. The sex ratio of progeny from sprayed adults appeared to be unaffected by the treatments.

Monitoramento populacional das cigarrinhas vetoras de Xylella fastidiosa, através de armadilhas adesivas amarelas em pomares comerciais de citros Population monitoring of leafhopper vectors of Xylella fastidiosa, through yellow sticky traps in commercial citrus orchards

Directory of Open Access Journals (Sweden)

Rúbia de Oliveira Molina

2010-12-01

Full Text Available A Clorose variegada dos citros (CVC é uma doença causada pela bactéria de xilema Xylella fastidiosa Wells. A disseminação ocorre por meio de insetos vetores pertencente à ordem Hemiptera, família Cicadellidae (subfamília Cicadellinae, os quais transmitem a bactéria depois de se alimentarem em plantas contaminadas. Neste trabalho, objetivou-se identificar e monitorar as espécies de cigarrinhas vetoras em um pomar comercial no município de Paranavaí, Paraná. O experimento foi realizado em um talhão comercial de laranja doce (Citrus sinensis (L. Osbeck, variedade Pera, com 1.000 plantas de dez anos de idade. A amostragem foi realizada por meio de armadilhas adesivas amarelas, distribuídas na área periférica e central do pomar, com duas repetições por rua amostrada. As etiquetas foram distribuídas entre a 5ª e 30ª plantas em 10 ruas, totalizando 20 armadilhas que foram renovadas no pomar, a cada trinta dias, durante o período de avaliação que foi entre junho de 2005 e setembro de 2006. As principais espécies de Cicadellinae capturadas foram Acrogonia citrina Marucci & Cavichioli, Dilobopterus costalimai Young e Macugonalia cavifrons Stal. Essas espécies apresentaram ocorrência constante e frequência de 3,97%, 4,2%, 13,0% respectivamente, em relação ao total de cigarrinhas coletadas.Citrus variegated chlorosis (CVC is the disease caused by the bacteria Xylella fastidiosa Wells. Dissemination occurs through insect vectors belonging to the order Hemiptera, family Cicadellidae (subfamily Cicadellinae, which transmit the bacteria after feeding on infected plants. The objective of this study was to identify the species of insect vectors in an orchard in the municipality of Paranavaí, in the State of Paraná. The experiment was conducted in a commercial stand of sweet orange (Citrus sinensis (L. Osbeck, Pêra variety with 1,000 10-year-old plants. Monitoring was performed using yellow sticky traps, distributed in the central

Anthraquinones and naphtoquinones from the bark of Tectona grandis (Verbenaceae) reforestation specimen

OpenAIRE

Moreira, Rafael Y.O.; Arruda, Mara S.P.; Arruda, Alberto C.; Santos, Lourivaldo S.; Müller, Adolfo H.; Guilhon, Giselle M.S.P.; Santos, Alberdan S.; Terezo, Evaristo

2006-01-01

O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae), através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o o...

Stomatal characteristics of Eucalyptus grandis clonal hybrids in ...

African Journals Online (AJOL)

This study describes the stomatal response occurring during water stress and subsequent recovery of three Eucalyptus grandis clonal hybrids. The aim was to investigate the degree to which stomatal conductance (gs) and stomatal density differ between the clonal hybrids across seasons and in response to water stress.

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.

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...

Morphology, diet, and temperature dependent host-free survival of the boll weevil, Anthonomus grandis (Coleoptera: Curculionidae)

Science.gov (United States)

The boll weevil, Anthonomus grandis grandis Boheman, is an important pest of cotton (Gossypium spp.) in South America, Mexico, and southernmost Texas in the United States. A key factor in the persistence of the boll weevil is its ability to survive the non-cotton season. Mechanisms facilitating this...

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...

Contenido de los nutrientes básicos en Catolaccus grandis Burks criados sobre larvas del picudo del algodon Basic nutrients content of Catolaccus grandis Burks reared in cotton boll weevil larvae

Directory of Open Access Journals (Sweden)

LÚCIA HELENA AVELINO ARAUJO

2000-09-01

Full Text Available El objetivo del trabajo fue determinar los niveles de carbohidratos, proteínas solubles y aminoácidos libres de larvas, pupas hembras y adultos hembras de Catolaccus grandis (Burks (Hymenoptera: Pteromalidae criados sobre larvas del picudo del algodón envenenadas por hembras del parasitoide y por larvas de primer instar del parasitoide. Esto estudio fue conducido en la Unidade de Investigación de Control Biologico de Plagas del Departamento de Agricultura de los Estados Unidos de la América, en Weslaco, Texas. Las 20 muestras de cada uno de los tres estados de desarrollo: tercer instar larval, pupas hembra y adultos hembra del parasitoide C. grandis, fueron separadas y pesadas individualmente y se cuantió el contenido de carbohidratos totales, proteínas solubles totales y aminoácidos libres criados en diferentes sustratos. Los resultados obtenidos confirman la existencia de patrones metabólicos significativamente distintos de estos nutrientes básicos.The aim of this work was to determine the levels of carbohydrate, soluble proteins and free amino acids of larvae, pupae and adult females Catolaccus grandis Burks (Hymenoptera: Pteromalidae which were reared in cotton (Gossypium hirsutum L. r. latifolium Hutch boll weevil (Anthonomus grandis larvae venomized by ectoparasitoid of female and 1st instar ectoparasitoid larvae. This study was carried out at the Biological Control of Pests Research Unit, Weslaco, Texas. The twenty samples of each one of three stages of development: 3rd instar larval, female pupae and female adult of parasitoid C. grandis were separated and individually weighted, and levels of carbohydrates, proteins and amino acids were quantified when reared in different substrates. The results confirmed the existence of metabolic patterns significantly distinct from the basic nutrient model.

Intercropping Acacia mangium stimulates AMF colonization and soil phosphatase activity in Eucalyptus grandis

Directory of Open Access Journals (Sweden)

Daniel Bini

Full Text Available ABSTRACT: Arbuscular mycorrhizal fungi (AMF are very important to plant nutrition, mostly in terms of acquisition of P and micronutrients. While Acacia mangium is closely associated with AMF throughout the whole cycle, Eucalyptus grandis presents this symbiosis primarily at the seedling stage. The aim of this study was to evaluate the dynamics of AMF in these two tree species in both pure and mixed plantations during the first 20 months after planting. We evaluated the abundance, richness and diversity of AMF spores, the rate of AMF mycorrhizal root colonization, enzymatic activity and soil and litter C, N and P. There was an increase in AMF root colonization of E. grandis when intercropped with A. mangium as well as an increase in the activity of acid and alkaline phosphatase in the presence of leguminous trees. AMF colonization and phosphatase activities were both involved in improvements in P cycling and P nutrition in soil. In addition, P cycling was favored in the intercropped plantation, which showed negative correlation with litter C/N and C/P ratios and positive correlation with soil acid phosphatase activity and soil N and P concentrations. Intercropping A. mangium and E. grandis maximized AMF root colonization of E. grandis and phosphatase activity in the soil, both of which accelerate P cycling and forest performance.

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...

Genetic improvement of Eucalyptus grandis using breeding seedling ...

African Journals Online (AJOL)

Eucalyptus grandis is commercially important in Zimbabwe and a breeding program has been in progress since 1962. A classical breeding strategy was used initially but, in 1981, the Multiple Population Breeding Strategy (MPBS) was implemented and the concept of the Breeding Seedling Orchard (BSO) became central to ...

Primeiro registro de Oligonychus yothersi (McGregor (Acari: Tetranychidae em Eucalyptus grandis Hill ex Maiden no Brasil First record of Oligonychus yothersi (McGregor (Acari: Tetranychidae on Eucalyptus grandis Hill ex Maiden in Brazil

Directory of Open Access Journals (Sweden)

Fabrício Fagundes Pereira

2005-08-01

Full Text Available Relata-se a infestação de um ácaro-vermelho em mudas clonais de Eucalyptus grandis Hill ex Maiden, mantidas em casa de vegetação no município de Martinho Campos, Minas Gerais. O ácaro foi observado na parte superior das folhas que exibiam sinais de sucção de seiva e bronzeamento. Essas injúrias causaram desenvolvimento anormal e morte de plantas. O ácaro foi identificado como Oligonychus yothersi (McGregor (Acari: Tetranychidae, e isso representa o primeiro registro dessa espécie em mudas clonais de E. grandis no Brasil.An infestation of the red spider mite was reported in clone seedlings of Eucalyptus grandis Hill ex Maiden under greenhouse conditions, in the municipality of Martinho Campos, Minas Gerais State. The spider mite was found on the leaf upper faces with signs of sap suction and bronzing. Such injuries caused abnormal development and plant death. The spider mite was identified as Oligonychus yothersi (McGregor (Acari: Tetranychidae. This is the first record of O. yothersi on E. grandis seedlings in Brazil.

EFFECT OF FERTILIZATION ON MECHANICAL PROPERTIES OF THE WOOD OF Eucalyptus grandis

Directory of Open Access Journals (Sweden)

Israel Luiz de Lima

2011-09-01

Full Text Available The effect of the fertilization in the amount and quality of the produced wood is one of the questions to be considered in the research of the Eucalyptus grandis. The present work aimed to evaluate the fertilization effect in the mechanical properties of Eucalyptus grandis. The population of Eucalyptus grandis was 21 years old and was managed under the system of selective thinning, with application of fertilizers. The factors used in this study were: presence or absence of fertilizers, two positions of log and five radial positions. The influences of the factors and of their combinations were evaluated regarding to compression strength, shear strength, modulus of rupture and modulus of elasticity in static banding. The compressive strength and the modulus of elasticity had been influenced by the factors: fertilizer and radial positions of the log. There was also an increase in the direction of the pith-bark in all studied properties. A good positive relationship was found to exist among the compression strength, the shear, the modulus of rupture and the modulus of elasticity with radial position.

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.

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.

Diagnosing foliar nutrient dynamics of Eucalyptus grandis in ...

African Journals Online (AJOL)

Fertilisation is one of the most cost-effective methods of increasing and maintaining the productivity of Eucalyptus grandis plantations in South Africa. This silvicultural practice can be optimised by using the foliar nutrient ratios measured in plants at maximum growth as a guideline for fertiliser application. The foliar nutrient ...

[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.

β-cyclodextrin inclusion complexes containing Citrus sinensis (L.) Osbeck essential oil: An alternative to control Aedes aegypti larvae

Energy Technology Data Exchange (ETDEWEB)

Galvão, J.G., E-mail: julianaggalvao@gmail.com [Pharmacy Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Silva, V.F.; Ferreira, S.G. [Pharmacy Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); França, F.R.M. [Chemical Engineering Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Santos, D.A.; Freitas, L.S.; Alves, P.B. [Chemistry Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil); Araújo, A.A.S.; Cavalcanti, S.C.H.; Nunes, R.S. [Pharmacy Department, Federal University of Sergipe, 49100-000 São Cristóvão, SE (Brazil)

2015-05-20

Highlights: • Thermal analysis was useful to determine the formation of inclusion complexes by paste and co-precipitation methods. • HS/GC-FID quantitative analysis revealed that the best method of obtaining a CSEO/β-CD complex was the PWE, with the largest inclusion content [78.5%]. • The inclusion complex revealed LC{sub 50} of 23.01 ppm, close to CSEO LC{sub 50} 21.5 ppm. - Abstract: The development of β-cyclodextrin (β-CD) complexes is an interesting way for increasing the aqueous solubility of essential oils. The aim of this study was to prepare inclusion complexes of Citrus sinensis essential oil (CSEO) with β-CD using paste complexation (with and without co-solvent) and co-precipitation methods. Additionally, the physicochemical properties of the inclusion complexes using thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were evaluated. Furthermore, CSEO content (%) and solubility of complexes were measured. The biological activity against the Aedes aegypti Linn. larvae was further evaluated. For comparison purposes, a physical mixture between β-CD and CSEO was prepared and evaluated. Thermal analysis clearly indicated the formation of complexes by paste and co-precipitation methods. The headspace/gas chromatography quantitative analysis showed inclusions contents higher than 50%. On the other hand, the product revealed LC{sub 50} of 23.01 ppm, close to CSEO LC{sub 50} 21.5 ppm.

β-cyclodextrin inclusion complexes containing Citrus sinensis (L.) Osbeck essential oil: An alternative to control Aedes aegypti larvae

International Nuclear Information System (INIS)

Galvão, J.G.; Silva, V.F.; Ferreira, S.G.; França, F.R.M.; Santos, D.A.; Freitas, L.S.; Alves, P.B.; Araújo, A.A.S.; Cavalcanti, S.C.H.; Nunes, R.S.

2015-01-01

Highlights: • Thermal analysis was useful to determine the formation of inclusion complexes by paste and co-precipitation methods. • HS/GC-FID quantitative analysis revealed that the best method of obtaining a CSEO/β-CD complex was the PWE, with the largest inclusion content [78.5%]. • The inclusion complex revealed LC 50 of 23.01 ppm, close to CSEO LC 50 21.5 ppm. - Abstract: The development of β-cyclodextrin (β-CD) complexes is an interesting way for increasing the aqueous solubility of essential oils. The aim of this study was to prepare inclusion complexes of Citrus sinensis essential oil (CSEO) with β-CD using paste complexation (with and without co-solvent) and co-precipitation methods. Additionally, the physicochemical properties of the inclusion complexes using thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy were evaluated. Furthermore, CSEO content (%) and solubility of complexes were measured. The biological activity against the Aedes aegypti Linn. larvae was further evaluated. For comparison purposes, a physical mixture between β-CD and CSEO was prepared and evaluated. Thermal analysis clearly indicated the formation of complexes by paste and co-precipitation methods. The headspace/gas chromatography quantitative analysis showed inclusions contents higher than 50%. On the other hand, the product revealed LC 50 of 23.01 ppm, close to CSEO LC 50 21.5 ppm

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.

Modelos de predição para sobrevivência de plantas de Eucalyptus grandis Prediction models of Eucalyptus grandis plant survival

Directory of Open Access Journals (Sweden)

Telde Natel Custódio

2009-01-01

Full Text Available Objetivou-se com este trabalho comparar modelos de predição de plantas sobreviventes de Eucalyptus grandis. Utilizaram-se os seguintes modelos: modelo linear misto com os dados transformados, utilizando-se as transformações angular e BOX-COX; modelo linear generalizado misto com distribuição binomial e funções de ligação logística, probit e complemento log-log; modelo linear generalizado misto com distribuição Poisson e função de ligação logarítmica. Os dados são provenientes de um experimento em blocos ao acaso, para avaliação de progênies maternas de Eucalyptus grandis, aos 5 anos de idade, em que a variável resposta são plantas sobreviventes. Para comparação dos efeitos entre os modelos foram estimadas as correlações de Spearman e aplicado o teste de permutação de Fisher. Foi possível concluir que, o modelo linear generalizado misto com distribuição Poisson e função de ligação logarítmica se ajustou mal aos dados e que as estimativas para os efeitos fixos e predição para os efeitos aleatórios, não se diferenciaram entre os demais modelos estudados.The objective of this work was to compare models for prediction of the survival of plants of Eucalyptus grandis. The following models were used: linear mixed model with the transformed data, by utilizing the angular transformations and BOX-COX; generalized linear mixed model with binomial distribution and logistic functions, probit and complement log-log links; generalized linear mixed model with Poisson distribution and logarithmic link function. The data came from a randomized block experiment for evaluation of Eucalyptus grandis maternal progenies at five years old, in which the variable response are surviving plants. For comparison of the effects among the models the correlations of Spearman were estimated and the test of permutation of Fisher was applied. It was possible to conclude that: the generalized linear mixed model with Poisson distribution and

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...

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.

Molecular cloning of alpha-amylases from cotton boll weevil, Anthonomus grandis and structural relations to plant inhibitors: an approach to insect resistance.

Science.gov (United States)

Oliveira-Neto, Osmundo B; Batista, João A N; Rigden, Daniel J; Franco, Octávio L; Falcão, Rosana; Fragoso, Rodrigo R; Mello, Luciane V; dos Santos, Roseane C; Grossi-de-Sá, Maria F

2003-01-01

Anthonomus grandis, the cotton boll weevil, causes severe cotton crop losses in North and South America. Here we demonstrate the presence of starch in the cotton pollen grains and young ovules that are the main A. grandis food source. We further demonstrate the presence of alpha-amylase activity, an essential enzyme of carbohydrate metabolism for many crop pests, in A. grandis midgut. Two alpha-amylase cDNAs from A. grandis larvae were isolated using RT-PCR followed by 5' and 3' RACE techniques. These encode proteins with predicted molecular masses of 50.8 and 52.7kDa, respectively, which share 58% amino acid identity. Expression of both genes is induced upon feeding and concentrated in the midgut of adult insects. Several alpha-amylase inhibitors from plants were assayed against A. grandis alpha-amylases but, unexpectedly, only the BIII inhibitor from rye kernels proved highly effective, with inhibitors generally active against other insect amylases lacking effect. Structural modeling of Amylag1 and Amylag2 showed that different factors seem to be responsible for the lack of effect of 0.19 and alpha-AI1 inhibitors on A. grandis alpha-amylase activity. This work suggests that genetic engineering of cotton to express alpha-amylase inhibitors may offer a novel route to A. grandis resistance.

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)

Timing of the inhibitory effect of fruit on return bloom of 'Valencia' sweet orange (Citrus sinensis (L.) Osbeck).

Science.gov (United States)

Martínez-Fuentes, Amparo; Mesejo, Carlos; Reig, Carmina; Agustí, Manuel

2010-08-30

In Citrus the inhibitory effect of fruit on flower formation is the main cause of alternate bearing. Although there are some studies reporting the effect on flowering of the time of fruit removal in a well-defined stage of fruit development, few have investigated the effect throughout the entire fruit growth stage from early fruitlet growth to fruit maturity. The objective of this study was to determine the phenological fruit developmental stage at which the fruit begins its inhibitory effect on flowering in sweet orange by manual removal of fruits, and the role of carbohydrates and nitrogen in the process. Fruit exerted its inhibitory effect from the time it was close to reaching its maximum weight, namely 90% of its final size (November) in the present experiments, to bud sprouting (April). The reduction in flowering paralleled the reduction in bud sprouting. This reduction was due to a decrease in the number of generative sprouted buds, whereas mixed-typed shoots were largely independent of the time of fruit removal, and vegetative shoots increased in frequency. The number of leaves and/or flowers per sprouted shoot was not significantly modified by fruit load. In 'Valencia' sweet orange, fruit inhibits flowering from the time it completes its growth. Neither soluble sugar content nor starch accumulation in leaves due to fruit removal was related to flowering intensity, but some kind of imbalance in nitrogen metabolism was observed in trees tending to flower scarcely. Copyright (c) 2010 Society of Chemical Industry.

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...

Shoot and root morphogenesis from Eucalyptus grandis x urophylla ...

African Journals Online (AJOL)

Eucalyptus grandis x urophylla plantlets were regenerated via indirect organogenesis. Histological assessment of their development focused on identifying the calli, the differentiation of shoots from the calli and the shoot-root junction from the nascent shoots. Vascular tissue formation within the callus preceded that 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.

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

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.

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

A Newly Identified Passive Hyperaccumulator Eucalyptus grandis × E. urophylla under Manganese Stress.

Science.gov (United States)

Xie, Qingqing; Li, Zhenji; Yang, Limin; Lv, Jing; Jobe, Timothy O; Wang, Qiuquan

2015-01-01

Manganese (Mn) is an essential micronutrient needed for plant growth and development, but can be toxic to plants in excess amounts. However, some plant species have detoxification mechanisms that allow them to accumulate Mn to levels that are normally toxic, a phenomenon known as hyperaccumulation. These species are excellent candidates for developing a cost-effective remediation strategy for Mn-polluted soils. In this study, we identified a new passive Mn-hyperaccumulator Eucalyptus grandis × E. urophylla during a field survey in southern China in July 2010. This hybrid can accumulate as much as 13,549 mg/kg DW Mn in its leaves. Our results from Scanning Electron Microscope (SEM) X-ray microanalysis indicate that Mn is distributed in the entire leaf and stem cross-section, especially in photosynthetic palisade, spongy mesophyll tissue, and stem xylem vessels. Results from size-exclusion chromatography coupled with ICP-MS (Inductively coupled plasma mass spectrometry) lead us to speculate that Mn associates with relatively high molecular weight proteins and low molecular weight organic acids, including tartaric acid, to avoid Mn toxicity. Our results provide experimental evidence that both proteins and organic acids play important roles in Mn detoxification in Eucalyptus grandis × E. urophylla. The key characteristics of Eucalyptus grandis × E. urophylla are an increased Mn translocation facilitated by transpiration through the xylem to the leaves and further distribution throughout the leaf tissues. Moreover, the Mn-speciation profile obtained for the first time in different cellular organelles of Eucalyptus grandis × E. urophylla suggested that different organelles have differential accumulating abilities and unique mechanisms for Mn-detoxification.

Soil carbon estimation from eucalyptus grandis using canopy spectra

African Journals Online (AJOL)

Mapping soil fertility parameters, such as soil carbon (C), is fundamentally important for forest management and research related to forest growth and climate change. This study seeks to establish the link between Eucalyptus grandis canopy spectra and soil carbon using raw and continuum-removed spectra. Canopy-level ...

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,...

Population structure and genetic diversity of the boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), on Gossypium in North America

Science.gov (United States)

While the boll weevil, Anthonomus grandis, has been identified as one of the most devastating pests in U.S. history, its origin and activity in Mexico, both on wild and cultivated cotton hosts (genus Gossypium), is poorly understood. Three forms (geographical or host-associated races) of A. grandis ...

Site of pheromone biosynthesis and isolation of HMG-CoA reductase cDNA in the cotton boll weevil, Anthonomus grandis.

Science.gov (United States)

Taban, A Huma; Fu, Jessica; Blake, Jacob; Awano, Ami; Tittiger, Claus; Blomquist, Gary J

2006-08-01

Isolated gut tissue from male cotton boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), incorporated radiolabeled acetate into components that co-eluted with monoterpenoid pheromone components on HPLC. This demonstrates that pheromone components of male A. grandis are produced de novo and strongly suggests that pheromone biosynthesis occurs in gut tissue. A central enzyme in isoprenoid biosynthesis is 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-R), and a full-length HMG-R cDNA was isolated from A. grandis. The predicted translation product was 54 and 45% identical to HMG-R from Ips paraconfusus and Drosophila melanogaster, respectively. HMG-R gene expression gradually increased with age in male A. grandis, which correlates with pheromone production. However, topical application of JH III did not significantly increase HMG-R mRNA levels.

Water relations of Eucalyptus nitens x Eucalyptus grandis : is there ...

African Journals Online (AJOL)

Water relations of Eucalyptus nitens x Eucalyptus grandis : is there interclonal variation in response to experimentally imposed water stress? ... Southern Forests: a Journal of Forest Science ... However, water stress reduced shoot hydraulic conductance and stem hydraulic conductivity with significant interclonal effects.

Nonlinear models for describing the Citrus Variegated Chlorosis in groves of two counties at northwestern Paraná state, Brazil = Modelo não-linear para a curva de progresso de incidência da Clorose Variegada dos Citros (CVC em dois municípios da região noroeste do Estado do Paraná

Directory of Open Access Journals (Sweden)

Clara Matiko Ueda

2010-10-01

Full Text Available In Brazil, the production of sweet oranges has been threatened by the Citrus Variegated Chlorosis (CVC incited by the gram-negative bacterium Xylella fastidiosa (Wells. Commercial citrus groves in two counties at the Northwestern Paraná state were evaluated to estimate the disease progression by using parameterizations of nonlinear models. Groves of Citrus sinensis Osbeck, variety “Pêra”, “Valência”, “Natal” and “Folha Murcha” had all the plants evaluated for the presence of disease symptoms. Thereafter, different parameterizations of the Logistic and Gompertz models were fitted to these data. The goodness of fit was evaluated by the intrinsic (IN and parameter-effects (PE curvatures of Bates and Watts, the bias of Box and the Hougaard measures of skewness. In Loanda, the best model was the Fermi-Dirac, and in Nova Esperança the data were best fitted to the parameterization L5, which is also a parameterization from the Logistic model.A citricultura é afetada por diversas doenças, dentre as quais a Clorose Variegada dos Citros (CVC causada pela bactéria Xylella fastidiosa (Wells. Para a região noroeste do Estado do Paraná, onde foi avaliada a CVC, propõe-se encontrar modelos não-lineares de curvas de progresso de incidência da CVC que representem o percentual de plantas acometidas pela doença. Para avaliar o comprometimento dos pomares com relação à doença, foram escolhidos pomares comerciais em dois municípios, onde foi determinada a proporção de plantas doentes. Foram selecionados talhões de laranja doce (Citrus sinensis Osbeck nas variedades “Pêra”, “Valência”, “Natal” e “Folha Murcha” e a avaliação de todas as plantas do talhão foi realizada visualmente em relação à presença ou à ausência de sintomas de CVC. Para estimar o modelo que melhor se ajustou aos dados de progresso da proporção da doença em cada talhão, foram considerados modelos não-lineares decrescimento sigmoidal

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.

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...

Salicylic acid alleviates the adverse effects of salt stress in Torreya grandis cv. Merrillii seedlings by activating photosynthesis and enhancing antioxidant systems.

Directory of Open Access Journals (Sweden)

Tingting Li

Full Text Available BACKGROUND: Salt stress is a major factor limiting plant growth and productivity. Salicylic acid (SA has been shown to ameliorate the adverse effects of environmental stress on plants. To investigate the protective role of SA in ameliorating salt stress on Torreya grandis (T. grandis trees, a pot experiment was conducted to analyze the biomass, relative water content (RWC, chlorophyll content, net photosynthesis (Pn, gas exchange parameters, relative leakage conductivity (REC, malondialdehyde (MDA content, and activities of superoxide dismutase (SOD and peroxidase (POD of T. grandis under 0.2% and 0.4% NaCl conditions with and without SA. METHODOLOGY/PRINCIPAL FINDINGS: The exposure of T. grandis seedlings to salt conditions resulted in reduced growth rates, which were associated with decreases in RWC and Pn and increases in REC and MDA content. The foliar application of SA effectively increased the chlorophyll (chl (a+b content, RWC, net CO2 assimilation rates (Pn, and proline content, enhanced the activities of SOD, CAT and POD, and minimized the increases in the REC and MDA content. These changes increased the capacity of T. grandis in acclimating to salt stress and thus increased the shoot and root dry matter. However, when the plants were under 0% and 0.2% NaCl stress, the dry mass of the shoots and roots did not differ significantly between SA-treated plants and control plants. CONCLUSIONS: SA induced the salt tolerance and increased the biomass of T. grandis cv. by enhancing the chlorophyll content and activity of antioxidative enzymes, activating the photosynthetic process, and alleviating membrane injury. A better understanding about the effect of salt stress in T. grandis is vital, in order gain knowledge over expanding the plantations to various regions and also for the recovery of T. grandis species in the future.

Recombinant Cry1Ia protein is highly toxic to cotton boll weevil (Anthonomus grandis Boheman) and fall armyworm (Spodoptera frugiperda).

Science.gov (United States)

Martins, E S; Aguiar, R W D S; Martins, N F; Melatti, V M; Falcão, R; Gomes, A C M M; Ribeiro, B M; Monnerat, R G

2008-05-01

To evaluate the activity of cry1Ia gene against cotton pests, Spodoptera frugiperda and Anthonomus grandis. Had isolated and characterized a toxin gene from the Bacillus thuringiensis S1451 strain which have been previously shown to be toxic to S. frugiperda and A. grandis. The toxin gene (cry1Ia) was amplified by PCR, sequenced, and cloned into the genome of a baculovirus. The Cry1Ia protein was expressed in baculovirus infected insect cells, producing protein inclusions in infected cells. The Cry1Ia protein has used in bioassays against to S. frugiperda and A. grandis. Bioassays using the purified recombinant protein showed high toxicity to S. frugiperda and A. grandis larvae. Molecular modelling of the Cry1Ia protein translated from the DNA sequence obtained in this work, showed that this protein possibly posses a similar structure to the Cry3A protein. Ultrastructural analysis of midgut cells from A. grandis incubated with the Cry1Ia toxin, showed loss of microvilli integrity. The results indicate that the cry1Ia is a good candidate for the construction of transgenic plants resistant to these important cotton pests.

A Newly Identified Passive Hyperaccumulator Eucalyptus grandis × E. urophylla under Manganese Stress.

Directory of Open Access Journals (Sweden)

Qingqing Xie

Full Text Available Manganese (Mn is an essential micronutrient needed for plant growth and development, but can be toxic to plants in excess amounts. However, some plant species have detoxification mechanisms that allow them to accumulate Mn to levels that are normally toxic, a phenomenon known as hyperaccumulation. These species are excellent candidates for developing a cost-effective remediation strategy for Mn-polluted soils. In this study, we identified a new passive Mn-hyperaccumulator Eucalyptus grandis × E. urophylla during a field survey in southern China in July 2010. This hybrid can accumulate as much as 13,549 mg/kg DW Mn in its leaves. Our results from Scanning Electron Microscope (SEM X-ray microanalysis indicate that Mn is distributed in the entire leaf and stem cross-section, especially in photosynthetic palisade, spongy mesophyll tissue, and stem xylem vessels. Results from size-exclusion chromatography coupled with ICP-MS (Inductively coupled plasma mass spectrometry lead us to speculate that Mn associates with relatively high molecular weight proteins and low molecular weight organic acids, including tartaric acid, to avoid Mn toxicity. Our results provide experimental evidence that both proteins and organic acids play important roles in Mn detoxification in Eucalyptus grandis × E. urophylla. The key characteristics of Eucalyptus grandis × E. urophylla are an increased Mn translocation facilitated by transpiration through the xylem to the leaves and further distribution throughout the leaf tissues. Moreover, the Mn-speciation profile obtained for the first time in different cellular organelles of Eucalyptus grandis × E. urophylla suggested that different organelles have differential accumulating abilities and unique mechanisms for Mn-detoxification.

Interspecific hybridization and inbreeding effect in seed from a Eucalyptus grandis x E. urophylla clonal orchard in Brazil

Directory of Open Access Journals (Sweden)

Campinhos Eduardo N.

1998-01-01

Full Text Available We used allozyme markers to estimate the amount of natural hybridization between Eucalyptus grandis and E. urophylla in a 7.4-hectare commercial hybrid-seed orchard planted in Espírito Santo, Brazil. This orchard was planted in 1982 using a honeycomb design, with each hexagonal plot containing one E. grandis tree surrounded by six E. urophylla trees. There were 267 replicated hexagonal plots in the orchard. Seeds were harvested from the E. grandis clone only. The multilocus outcrossing rate estimated for the E. grandis clone averaged 70.2%, ranging from 33.0 to 99.0% among individual trees. Contaminant pollination, inferred from progeny genotypes containing alleles not present in the seven parental clones, accounted for 14.4% of the hybrid seed. Contaminant pollen was attributed to neighboring eucalyptus stands isolated from the orchard by a 400-m wide belt of native forest. Inbred and hybrid progenies were identified by their allozyme genotypes and transplanted to the field. Field growth of inbred progeny was 30% lower than that of hybrid plants at two and three years of age.

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...

ECONOMIC ROTATION OF Eucalyptus grandis PLANTATIONS FOR PULP PRODUCTION

Directory of Open Access Journals (Sweden)

Thais Cunha Ferreira

2004-07-01

Full Text Available The objectives of the research were: to determine the economic impact of several minimum diameter and length of logs in economic rotation age, economic feasibility of Eucalyptus grandis plantation for cellulose production; to determine the economic loss of cutting the stand before or after the optimal economic rotation age. A biometric model for making wood volume prognosis was developed using data of a trial of Eucalyptus grandis plantation envisaging pulp production. Eucalyptus grandis stands of 19 and 103 months old, in the spacing 3 x 2 and 3 x 3 m in site index of 30; 28; 26 and 24 m were used. Theprognosis started at the age zero, considering logs of 2.5; 2.8; 4.0 and 6.0 m of length for minimum diameter varying from 4 to 10 cm, in intervals of 2 cm. Net Present Worth (VPL was used the economic criterion, considering an infinite horizon and a cost relation including reestablishment, yearly maintenance, logging and wood transportation costs. The main conclusions were: increases in the minimum diameter and or in logs length increase the rotation age; harvesting the stands in ages different from the optimal one cause large economic loss mainly in the better sites; the economic loss is larger if the harvest is made before the optimal economic rotation than if it is make after; economic feasibility increases when the minimum diameter is smaller and when the length of the logs is shorter. Any way, before making any decision it is necessary to take into account possible technical restrictions and effect on harvest and transportation costs caused by changer in the length of logs and in the size of the minimum commercial diameter.

Dry mass allocation, water use efficiency and delta C-13 in clones of Eucalyptus grandis, E-grandis x camaldulensis and E-grandis x nitens grown under two irrigation regimes

CSIR Research Space (South Africa)

Le Roux, D

1996-05-01

Full Text Available - cial clones of Eucalyptus grandis W. Hill ex Maiden. implying that less water-use-efficient trees were more productive (Bond and Stock 1990). Similarly, growing season WUE and delta13C were positively correlated in western larch and Eucalyptus globulus... regimes DEBBIE LE ROUX,1,2 WILLIAM D. STOCK,3 WILLIAM J. BOND3 and DAVID MAPHANGA4 1 Division of Forest Science and Technology, CSIR, Pretoria, South Africa 2 Present address: Department of Botany, University of Kansas, Lawrence, KS 66045, USA 3 Department...

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

[Distribution pattern of meso-micro soil fauna in Eucalyptus grandis plantation].

Science.gov (United States)

Huang, Yumei; Zhang, Jian; Yang, Wanqin

2006-12-01

In this paper, meso-micro soil fauna were extracted and collected by Baermann's and Tullgren' s method, and their distribution pattern in the Eucalyptus grandis plantation of Hongya County, Sichuan Province was studied. A total of 13 550 specimens were collected, belonging to 6 phyla, 13 classes, and 26 orders. Acarina, Nematoda, Collembola were the dominant groups, and Enchytraeidae was the frequent one. The group and individual numbers of meso-micro soil fauna varied with seasons, being the maximum in autumn or winter, fewer in summer, and the minimum in spring. The density of meso-micro soil fauna in soil profile decreased rapidly with increasing soil depth, but a converse distribution was observed from time to time in 5 - 10 cm and 10 - 15 cm soil layers. The meso-micro soil fauna collected by Baermann's and Tullgren's method had a density of 3. 333 x 10(3) - 2. 533 x 10(5) ind x m(-2) and 1.670 x 10(2) - 2.393 x 10(5) ind x m(-2), respectively, and the decreasing rate of the density with the increase of soil depth was higher for those collected by Tullgren's method. The density-group index of meso-micro soil fauna in the E. grandis plantation was the lowest in spring, but the highest in autumn or summer. There were no significant differences in the density of meso-micro soil fauna and in the density-group index between E. grandis plantation and Quercus acutissima secondary forest.

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.

The potential of young, green finger-jointed Eucalyptus grandis ...

African Journals Online (AJOL)

Drying will occur naturally while the lumber is fixed within the roof truss structure. The objectives of this study were (1) to investigate the strength and stiffness variation of the finger-jointed E. grandis product in both the green and dry state for different age and dimension lumber, (2) to investigate the variation in density, warp ...

Produtividade e qualidade dos frutos da laranjeira 'Pêra' clone IAC em 16 porta-enxertos na região de Bebedouro-SP Yield and fruit quality of 'Pêra' sweet orange clone IAC on 16 rootstocks in Bebedouro region, State of São Paulo, Brazil

Directory of Open Access Journals (Sweden)

Eduardo Sanches Stuchi

2004-08-01

Full Text Available Avaliou-se a influência de 16 porta-enxertos na produtividade, nas características físicas e químicas (sólidos solúveis totais-°Brix; acidez; ratio; porcentagem de suco; índice tecnológico e tamanho dos frutos dos frutos da laranjeira 'Pêra' [Citrus sinensis (L. Osbeck] e na incidência e severidade da clorose variegada dos citros (CVC. O plantio do experimento foi realizado em julho de 1993, com espaçamento de 6,0 m entre linhas e 3,5 m entre plantas (476 plantas/ha. O experimento foi conduzido sem irrigação. O delineamento experimental foi em blocos ao acaso, duas plantas por parcela, três repetições e 16 tratamentos, constituídos pelas seguintes cultivares porta-enxertos: tangerineira 'Sun Chu Sha Kat' (Citrus reticulata Blanco, tangerineira 'Pectinífera' (C. reticulata, 'Shekwasha' (C. depressa Hayata, tangerineira 'Pectinífera/Shekwasha' (C. depressa Hayata, tangerineira 'Batangas' (C. reticulata, tangerineira 'Oneco' (C. reticulata, citrangor [citrange (Poncirus trifoliata Raf. x C. sinensis x C. sinensis], citrandarin [C.sunki hort. Ex Tanaka x Poncirus trifoliata (L. Raf. cv. English, tangerineira 'Sunki' (C. sunki, tangerineira 'Suen-Kat' (C. sunki, tangerineira 'Nasnaran' (C. amblycarpa Ochse, tangerineira 'Venezuela' (C. reticulata, tangerineira Heen Naran (C. lycopersicaeformis hort. ex Tan. , limoeiro 'Cravo' (C. limonia Osbeck x tangerineira 'Cleópatra' (C. reshni hort ex Tanaka, limoeiro 'Cravo' (C. limonia, tangerineira 'Cleópatra' (C. reshni. A intensidade da clorose variegada dos citros variou em função dos porta-enxertos e não se relacionou com a produção de frutos até a quarta safra. Os porta-enxertos estudados, com exceção da tangerineira Nasnaran, proporcionaram qualidade e produções iniciais de frutos similares aos do limoeiro 'Cravo'.An experiment was set up in July 1993, at Bebedouro city, São Paulo state, Brazil, aiming to evaluate the rootstock influence on the yield and several physical

Efficient micropropagation of Citrus sinensis (L.) Osbeck from ...

African Journals Online (AJOL)

... shoots/explant) in comparison to control (0.00±0.00 shoots/explant). Microshoots were rooted best (75.00±14.43%) under the treatment 100μM NAA for 48 hrs. and rooted plantlets were transferred to soil, following acclimatization were taken to maturity in the polyhouse. Keywords: Malta, Himalaya, benzyl adenine (BA), ...

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...

A Multivariate Study on Genetic Variation in Teak (Tectona grandis (L.))

DEFF Research Database (Denmark)

Kjær, Erik Dahl; Siegismund, Hans Redlef; Suangtho, V.

1996-01-01

Genetic differentiation between populations of teak (Tectona grandis (L.)) was examined in 9 quantitative characters and 10 allozyme loci. Large differences between populations were revealed in the quantitative traits. Regional patterns were revealed by multivariate analysis of the data, but ther...

Establishment of Eucalyptus grandis W. Hill ex Maiden in vitro using ...

African Journals Online (AJOL)

Establishment of Eucalyptus grandis W. Hill ex Maiden in vitro using commercial products for seed treatment. Moacir Ribeiro Neto, Cíntia de Oliveira Martendal, Flávia Dionísio Pereira, Edson Luiz Souchie, Fabiano Guimarães Silva ...

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...

Grandi Eventi: indicatori di classificazione e incidenza sui sistemi urbani

Directory of Open Access Journals (Sweden)

Giuseppe Mazzeo

2008-08-01

Full Text Available I grandi eventi sono ritenuti una opportunità per le città in quanto sono uno straordinario catalizzatore di investimenti mirati alla trasformazione della città. L’azione dei grandi eventi non è confinata solo nel periodo di svolgimento dell’evento stesso ma si estende ad un periodo molto più ampio, prima e, soprattutto, dopo il suo termine. Nell’organizzazione delle manifestazioni più recenti le trasformazioni urbane hanno interessato in modo sempre maggiore parti già in precedenza urbanizzate, al punto che l’evento diviene l’occasione per trasformare la città costruita e per modificarne il profilo. Il paper approfondisce l’argomento della classificazione degli eventi e del loro impatto sul sistema urbano sviluppandosi in tre parti. Nella prima si analizzano due tipologie di grandi eventi (le esposizioni internazionali e i giochi olimpici con l’obiettivo di pervenire ad una definizione condivisa. Nella seconda parte si identificano i più importanti fattori ed indicatori per l’analisi di questa specifica categoria di avvenimenti. Infine, nella terza parte, si approfondiscono i fattori connessi all’impatto sul sistema urbano e all’organizzazione della sua mobilità. In particolare, viene approfondito il concetto di “effetto pulsar”, ossia gli effetti moltiplicativi sulla evoluzione urbana dipendenti dalla organizzazione di eventi multipli in parallelo o in sequenza. Uno degli elementi più negativi connessi alla organizzazione di un grande evento è la dispersione nel tempo dei benefici acquisiti grazie ad esso; per evitare ciò è necessario che l’evento sia seguito da politiche strategiche continue in modo da preservare i vantaggi acquisiti.

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...

Dependence of rate of germination of teak ( Tectona grandis ) seeds ...

African Journals Online (AJOL)

A study was conducted to determine suitable sources of teak (Tectona grandis) seeds and methods of treating the seeds to promote higher rate of germination, with the objective to supply large quantities of seedlings for developing commercial teak plantations in Ghana. The field work involved seed collection, seed pericarp ...

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

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.

Ingestão de seiva do xilema de laranjeiras 'Pêra' e 'Valência' (Citrus sinensis (L. Osbeck sadias e infectadas por Xylella fastidiosa, pelas cigarrinhas vetoras Oncometopia facialis e Dilobopterus costalimai (Hemiptera: Cicadellidae Xylem sap ingestion form healthy "Pera" and "Valencia" sweet orange (Citrus sinensis (L. Osbeck and infected ones by Xylella fastidiosa, Oncometopia facialis and Dilobopterus costalimai (Hemiptera: Cicadellidae

Directory of Open Access Journals (Sweden)

Luiz Henrique Montesino

2006-08-01

Full Text Available Estudou-se o efeito da infecção pela bactéria Xylella fastidiosa, agente causal da Clorose Variegada dos Citros (CVC, sobre a taxa de ingestão de seiva do xilema de plantas cítricas por duas espécies de cigarrinhas vetoras (Hemiptera: Cicadellidae. Foram utilizados pés-francos de laranjeira-doce (Citrus sinensis das variedades 'Pêra' e 'Valência', infectadas por X. fastidiosa da linhagem 9a5c, por meio de inoculação mecânica. Os insetos utilizados nos experimentos foram coletados em campo, sendo um representante da Tribo Cicadellini (Dilobopterus costalimai e um da Proconiini (Oncometopia facialis. A taxa de ingestão de seiva do xilema por O. facialis foi quantificada nos ramos das plantas e a de D. costalimai nas folhas e ramos, por meio da avaliação do volume do líquido (honeydew excretado por unidade de tempo. O consumo pela cigarrinha O. facialis nas plantas doentes foi menor do que nas plantas sadias. Na variedade 'Pêra' doente, o consumo foi baixo, não permitindo a quantificação da seiva eliminada. Na 'Pêra' sadia e na 'Valência' doente e sadia, O. facialis apresentou valores expressivos de excreção, com maior alimentação no período diurno. Nas plantas sadias das duas variedades, o consumo pela cigarrinha D. costalimai foi maior do que nas plantas com CVC. Comparando-se as variedades, o consumo foi superior na variedade 'Valência', e, em relação às partes da planta, folha e ramo, a taxa de ingestão foi maior no ramo das duas variedades, apresentando consumo maior no período diurno.It was studied the effect of Xylella fastidiosa infection, causal agent of Citrus Variegated Chlorosis (CVC, on the xylem sap ingestion rate of citrus plants by two sharpshooters species (Hemiptera: Cicadellidae. Seedlings of sweet orange Pera and Valencia (Citrus sinensis were used and infected by X. fastidiosa, strain 9a5c, obtained by mechanical inoculation. The insects used in the experiments were collected in the field, one

Durabilidad natural de madera de Eucalyptus grandis Hill ex Maiden de plantaciones de rápido crecimiento

Directory of Open Access Journals (Sweden)

Silvia Böthig

2011-05-01

Full Text Available Una de las especies forestales de rápido crecimiento cultivadas en Uruguay de mayor importancia económica es el Eucalyptus grandis. Trabajos anteriores reportan propiedades físicas y mecánicas de la madera juvenil y adulta proveniente de plantaciones de esta especie en diferentes regiones del país. Sin embargo, dado que no se dispone de datos científicos nacionales sobre su durabilidad natural, en este trabajo fue evaluada madera de E. grandis obtenida de dos plantaciones de 16 años de edad con semilla del mismo origen, de dos sitios, Rivera y Río Negro. Se estudió la durabilidad natural del duramen externo e interno siguiendo los métodos de la norma EN 350-1, tomando Populus deltoides x euroamericana cv I-214 como especie de referencia. Se realizaron ensayos de laboratorio para determinar la resistencia a la descomposición fúngica (Gloeophyllum trabeum, Trametes versicolor y Serpula lacrymans y a las termites (Reticulitermes spp. siguiendo las normas EN 113 y EN 118, respectivamente. Se realizaron ensayos de campo de estacas, de doble capa y cámara fúngica, los cuales aún están en curso, por lo que en el presente trabajo se presentan resultados parciales. Los perfiles radiales de densidad básica revelaron que la madera del duramen externo no era adulta, sino madera de transición. En general, el duramen de E. grandis mostró una mayor durabilidad que el híbrido Populus.El E. grandis se clasificó como moderadamente o seriamente atacado por Reticulitermes spp. Según EN 350-1, la madera juvenil de E. grandis puede considerarse como “moderadamente durable” ante la pudrición parda provocada por G. trabeum, mientras que la madera de transición puede describirse como “durable”. La madera de transición mostró en relación a la madera juvenil una mayor resistencia al G. trabeum, una susceptibilidad levemente menor a las termites y mejor desempeño en el campo luego de 17 meses de exposición. El sitio de la plantación no

Effect of thermal modification on the physical properties of juvenile and mature woods of Eucalyptus grandis

Directory of Open Access Journals (Sweden)

Fred Willians Calonego

Full Text Available This study aimed to evaluate the effect of thermal treatment on the physical properties of juvenile and mature woods of Eucalyptus grandis. Boards were taken from 30-year-old E. grandis trees. The boards were thermally modified at 180 °C in the Laboratory of Wood Drying and Preservation at UNESP, Botucatu, Sao Paulo state, Brazil. The results showed that thermal modification caused: (1 decrease of 6.8% in the density at 0% equilibrium moisture content of mature wood; (2 significant decreases of 14.7% and 35.6% in the maximum volumetric swellings of juvenile and mature woods, respectively; (3 significant decreases of 13.7% and 21.3% in the equilibrium moisture content of juvenile and mature woods, respectively. The influence of thermal modification in juvenile wood was lower than in mature wood and caused greater uniformity in the physical variations between these types of wood in E. grandis.

Development and assessment of microarray-based DNA fingerprinting in Eucalyptus grandis.

Science.gov (United States)

Lezar, Sabine; Myburg, A A; Berger, D K; Wingfield, M J; Wingfield, B D

2004-11-01

Development of improved Eucalyptus genotypes involves the routine identification of breeding stock and superior clones. Currently, microsatellites and random amplified polymorphic DNA markers are the most widely used DNA-based techniques for fingerprinting of these trees. While these techniques have provided rapid and powerful fingerprinting assays, they are constrained by their reliance on gel or capillary electrophoresis, and therefore, relatively low throughput of fragment analysis. In contrast, recently developed microarray technology holds the promise of parallel analysis of thousands of markers in plant genomes. The aim of this study was to develop a DNA fingerprinting chip for Eucalyptus grandis and to investigate its usefulness for fingerprinting of eucalypt trees. A prototype chip was prepared using a partial genomic library from total genomic DNA of 23 E. grandis trees, of which 22 were full siblings. A total of 384 cloned genomic fragments were individually amplified and arrayed onto glass slides. DNA fingerprints were obtained for 17 individuals by hybridizing labeled genome representations of the individual trees to the 384-element chip. Polymorphic DNA fragments were identified by evaluating the binary distribution of their background-corrected signal intensities across full-sib individuals. Among 384 DNA fragments on the chip, 104 (27%) were found to be polymorphic. Hybridization of these polymorphic fragments was highly repeatable (R2>0.91) within the E. grandis individuals, and they allowed us to identify all 17 full-sib individuals. Our results suggest that DNA microarrays can be used to effectively fingerprint large numbers of closely related Eucalyptus trees.

Comparisons between two economically valuable forest species (Eucalyptus grandis and Pinus taeda in relation to seed behaviour under controlled deterioration

Directory of Open Access Journals (Sweden)

Jussara Bertho Fantinatti

2011-02-01

Full Text Available The objectives of this work were to analyze seed behaviour under controlled deterioration and estimate viability equations for forest species Eucalyptus grandis and Pinus taeda. Desired moisture content levels were achieved from initial values after either rehydration over water or drying over silica gel, both at 25 ºC. Seed sub samples with 8 moisture contents each for E. grandis (1.2 to 18.1%, initial value of 11.3% and P. taeda (1.5 to 19.5%, initial value of 12.9% were sealed in laminate aluminium-foil packets and stored in incubators maintained at 40, 50 and 65 ºC. The seeds from these species exhibited true orthodox and sub-orthodox storage behaviour, respectively, however E. grandis showed higher seed storability, probably due to a different seed chemical composition. Lowest moisture content limits estimated for application of the viability equations at 65 ºC were 4.9 and 4.1 mc for E. grandis and P. taeda, on equilibrium with ±20% RH. The viability equation estimated quantified the response of seed longevity to storage environment well with K E = 9.661 and 8.838; C W = 6.467 and 5.981; C H = 0.03498 and 0.10340; C Q = 0.0002330 and 0.0005476, for E. grandis and P. taeda, respectively.

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.

Effects of autohydrolysis of Eucalyptus urograndis and Eucalyptus grandis on influence of chemical components and crystallinity index.

Science.gov (United States)

da Silva Morais, Alaine Patrícia; Sansígolo, Cláudio Angeli; de Oliveira Neto, Mario

2016-08-01

Samples of Eucalyptus urograndis and Eucalyptus grandis sawdust were autohydrolyzed in aqueous conditions to reach temperatures in the range 110-190°C and reaction times of 0-150min in a minireactor. In each minireactor were used a liquor:wood ratio (10:1 L:kg dry wood), in order to assess the effects of the autohydrolysis severity and the crystalline properties of cellulose. The content of extractives, lignin, holocellulose, cellulose, hemicelluloses and crystallinity index obtained from the solid fraction after autohydrolysis of sawdust were determined. This study demonstrated that the hemicelluloses were extensively removed at 170 and 190°C, whereas cellulose was partly degraded to Eucalyptus urograndis and Eucalyptus grandis sawdust. The lignin content decreased, while the extractives content increased. It was defined that during autohydrolysis, had a slight decreased on crystalline structure of cellulose of Eucalyptus urogandis and Eucalyptus grandis. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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.

Relações entre a produção de laranjeira 'Westin' e as precipitações em Botucatu, SP Relationships between production of 'Westin' sweet orange trees and rainfall at Botucatu, São Paulo State, Brazil

Directory of Open Access Journals (Sweden)

Antonio Tubelis

1999-05-01

Full Text Available O trabalho estuda a correlação entre a produção de um pomar de laranja, plantado no altiplano de Botucatu, SP, com as precipitações que ocorrem dezesseis meses antes da colheita e a idade do pomar. As plantas eram de laranjeira doce (Citrus sinensis (L. Osbeck, variedade Westin, de clone nucelar, enxertadas em porta-enxerto de limoeiro 'Cravo' (Citrus limonia Osbeck, plantadas em solo Terra Roxa Estruturada, a 810 m de altitude e em região de clima do tipo Cwb. A cultura foi conduzida de modo convencional e sem irrigação. Coletaram-se dados de produção, nos períodos entre o 3º e o 17º e entre o 21º e o 27º ano de idade do pomar, para análise do comportamento da produção e o efeito da idade e das precipitações na produção. Calcularam-se equações lineares múltiplas de regressão, entre a produção, idade do pomar e as precipitações mensais, nos períodos de pomar juvenil, adulto, senescente e adulto-senescente. A produção correlacionou-se com a idade e com valores mensais de precipitação. Os pequenos desvios observados entre os valores medidos e estimados de produção revelaram que as equações de regressão poderiam ser usadas na previsão de safra ou no controle de irrigação suplementar do pomar.This paper deals with the existence of correlation between the production of a sweet orange orchard, planted at the plateau of Botucatu, São Paulo State, Brazil, with the orchard age and the rainfall that occurred in the sixteen months before the picking season. The plants were of sweet orange trees (Citrus sinensis (L. Osbeck, variety Westin, budded on 'Rangpur' lime (Citrus limonia Osbeck rootstock, grown on "Terra Roxa Estruturada" soil, at an altitude of 810 m above sea level and in a region with Cwb climatic type. The orchard was conducted by conventional ways and no irrigation was applied. The production of the orchard was recorded, during the period from the 3rd until the 17th and from the 21st until the 27th

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

Antraquinonas e naftoquinonas do caule de um espécime de reflorestamento de Tectona grandi (Verbenaceae)

OpenAIRE

Moreira,Rafael Y.O.; Arruda,Mara S.P.; Arruda,Alberto C.; Santos,Lourivaldo S.; Müller,Adolfo H.; Guilhon,Giselle M.S.P.; Santos,Alberdan S.; Terezo,Evaristo

2006-01-01

O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae), através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o o...

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...

Mechanical Damage Detection of Indonesia Local Citrus Based on Fluorescence Imaging

Science.gov (United States)

Siregar, T. H.; Ahmad, U.; Sutrisno; Maddu, A.

2018-05-01

Citrus experienced physical damage in peel will produce essential oils that contain polymethoxylated flavone. Polymethoxylated flavone is fluorescence substance; thus can be detected by fluorescence imaging. This study aims to study the fluorescence spectra characteristic and to determine the damage region in citrus peel based on fluorescence image. Pulung citrus from Batu district, East Java, as a famous citrus production area in Indonesia, was used in the experiment. It was observed that the image processing could detect the mechanical damage region. Fluorescence imaging can be used to classify the citrus into two categories, sound and defect citruses.

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...

Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis).

Science.gov (United States)

Oliveira, Gustavo R; Silva, Maria C M; Lucena, Wagner A; Nakasu, Erich Y T; Firmino, Alexandre A P; Beneventi, Magda A; Souza, Djair S L; Gomes, José E; de Souza, José D A; Rigden, Daniel J; Ramos, Hudson B; Soccol, Carlos R; Grossi-de-Sa, Maria F

2011-09-09

The cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro directed molecular evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis. Bioassays carried out with A. grandis larvae revealed that the LC50 of the screened mutant Cry8Ka5 toxin was 3.15-fold higher than the wild-type Cry8Ka1 toxin. Homology modelling of Cry8Ka1 and the Cry8Ka5 mutant suggested that both proteins retained the typical three-domain Cry family structure. The mutated residues were located mostly in loops and appeared unlikely to interfere with molecular stability. The improved toxicity of the Cry8Ka5 mutant obtained in this study will allow the generation of a transgenic cotton event with improved potential to control A. grandis.

Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis

Directory of Open Access Journals (Sweden)

Gomes José E

2011-09-01

Full Text Available Abstract Background The cotton boll weevil (Anthonomus grandis is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro directed molecular evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis. Results Bioassays carried out with A. grandis larvae revealed that the LC50 of the screened mutant Cry8Ka5 toxin was 3.15-fold higher than the wild-type Cry8Ka1 toxin. Homology modelling of Cry8Ka1 and the Cry8Ka5 mutant suggested that both proteins retained the typical three-domain Cry family structure. The mutated residues were located mostly in loops and appeared unlikely to interfere with molecular stability. Conclusions The improved toxicity of the Cry8Ka5 mutant obtained in this study will allow the generation of a transgenic cotton event with improved potential to control A. grandis.

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)

Citrus asymmetric somatic hybrids produced via fusion of gamma-irradiated and iodoacetamide-treated protoplasts Híbridos somáticos assimétricos de citros produzidos pela fusão de protoplastos irradiados e tratados com iodoacetamida

Directory of Open Access Journals (Sweden)

Claudine Maria de Bona

2009-05-01

Full Text Available 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 'Itaboraí', '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-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 DNAsamples. 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-1 IBA solution for 10 min.O objetivo deste trabalho foi produzir híbridos somáticos assimétricos de citros pela fusão de protoplastos irradiados com raios gama e protoplastos tratados com iodoacetamida. Protoplastos foram isolados de suspensões celulares embriogênicas de pomelo (Citrus paradisi Macfad., cultivares Ruby Red e Flame, de laranja doce (C. sinensis Osbeck 'Itaboraí', 'Natal', Valencia' e 'Succari', de tangerinas 'Satsuma' (C. unshiu Marcow. e 'Changsha' (C. reticulata Blanco e de tangor 'Murcott' (C. reticulata x C. sinensis

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.

Tolerance of Anadenanthera peregrina to Eucalyptus camaldulensis and Eucalyptus grandis essential oil as condition for mixed plantation

Directory of Open Access Journals (Sweden)

Neimar de Freitas Duarte

2012-06-01

Full Text Available With the purpose of selecting the species of woody Caatinga for mixed plantations with Eucalyptus spp., the allelophatic effects of E. camaldulensis and E. grandis essential oil were studied on the growth activities of Anadenanthera peregrina. The plants were closed in glass chambers in the presence of volatile oil of E. camaldulensis or E. grandis at the concentration of 13 nl.cm-3. The number of leaves, height and diameter at soil lever were compared before, immediately after and after 30 days. Chlorophyll a and b, carotenoids and dry mass were evaluated after the treatment application. There was no inhibitory effect of E. camaldulensis and E. grandis oils on A. peregrina. E. camaldulensis, which was more adapted to semi-arid conditions, was planted in mixture stands with two native legume species, inoculated with Rhizobium and arbuscular mycorrhizal fungi. E. camaldulensis did not inhibit native species growth after two years of cultivation.

MANEJO DO SOLO E CRESCIMENTO INICIAL DE Eucalyptus grandis Hill ex Maiden EM ARGISSOLO

Directory of Open Access Journals (Sweden)

Juliana Prevedello

2013-01-01

Full Text Available The forest species cultivation with rapid growth in Brazil has increased, mainly due to the diverse use of its wood and climate adaptation. The cultivation with minimum tillage in the forest sector stands out a way to increase productivity, combined with the maintenance of biodiversity and soil conservation. This study was conducted at the experimental area of State Foundation for Agricultural Research - Research Center for Forestry in Santa Maria - RS, with aimed to evaluate the effect of the soil tillage methods on soil physical properties and on initial development of Eucalyptus grandis, in a sandy loam Typic Hapludalf. Four soil management practices were compared: no-tillage; chisel tillage; chisel tillage plus harrowing and; rotary tillage (rotary tiller, installed in a randomized block design with three replications. The soil under no-tillage conditioned lower initial growth of eucalyptus due higher soil penetration resistance and bulk density, when compared with treatments with mobilization. The root distribution analysis in soil, despite being a qualitative method, was effective in demonstrating the effect of soil tillage for the Eucalyptus grandis plantation. The soil tillage with mobilization resulted in a higher initial growth of Eucalyptus grandis. The chisel tillage effects in the soil physical properties persisted after one year of soil tillage.

Gas Exchange Characteristics in Tectona grandis L. Clones under Varying Concentrations of CO2 Levels

Directory of Open Access Journals (Sweden)

S. Saravanan

2014-08-01

Full Text Available The Institute of Forest Genetics and Tree Breeding, Coimbatore, India functioning under the Indian Council of Forestry Research and Education, Dehara Dun, has a long term systematic tree improvement program for Tectona grandis aimed to enhancing productivity and screening of clones for site specific. In the process, twenty clones of T. grandis L. were studied for the physiological parameters and water use efficiency with reference to the elevated CO2 levels. CO2 enrichment studies in special chambers help in understanding the changes at individual level, and also at physiological, biochemical and genetic level. It also provides valuable information for establishing plantations at different geographic locations. Considerable variations were observed when the selected 20 clones of T. grandis were subjected to physiological studies under elevated CO2 conditions (600 and 900 mol mol-1. Eight clones exhibited superior growth coupled with favorable physiological characteristics including high photosynthetic rate, carboxylation and water use efficiency under elevated CO2 levels. Clones with minimal variation in physiological characteristics under elevated levels of CO2 suggest their ability to overcome physiological stresses and adapt to varying climatic conditions.

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.

Propriedades térmicas e de pasta de misturas de fécula de mandioca e polpa cítrica

OpenAIRE

Leonel, Magali; Souza, Luciana Bronzi de; Mischan, Martha Maria

2011-01-01

Instant mixtures are easy to prepare and frequently present functional appeals. A quality parameter for instant mixtures is their rheological behavior. This study aimed at evaluating the effects of extrusion parameters on the pasting properties of cassava (Manihot esculenta L.) starch and dehydrated orange (Citrus sinensis (L.) Osbeck) pulp mixtures. The variable parameters were moisture of mixtures (12.5 to 19%), barrel temperature (40 to 90ºC) and screw rotation (170 to 266 rpm). The extrud...

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,.

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...

Effects of black-eyed pea trypsin/chymotrypsin inhibitor on proteolytic activity and on development of Anthonomus grandis.

Science.gov (United States)

Franco, Octávio L; dos Santos, Roseane C; Batista, João A N; Mendes, Ana Cristina M; de Araújo, Marcus Aurélio M; Monnerat, Rose G; Grossi-de-Sá, Maria Fátima; de Freitas, Sonia M

2003-06-01

The cotton boll weevil Anthonomus grandis (Boheman) is one of the major pests of cotton (Gossypium hirsutum L.) in tropical and sub-tropical areas of the New World. This feeds on cotton floral fruits and buds causing severe crop losses. Digestion in the boll weevil is facilitated by high levels of serine proteinases, which are responsible for the almost all proteolytic activity. Aiming to reduce the proteolytic activity, the inhibitory effects of black-eyed pea trypsin/chymotrypsin inhibitor (BTCI), towards trypsin and chymotrypsin from bovine pancreas and from midguts of A. grandis larvae and adult insects were analyzed. BTCI, purified from Vigna unguiculata (L.) seeds, was highly active against different trypsin-like proteinases studied and moderately active against the digestive chymotrypsin of adult insects. Nevertheless, no inhibitory activity was observed against chymotrypsin from A. grandis larval guts. To test the BTCI efficiency in vivo, neonate larvae were reared on artificial diet containing BTCI at 10, 50 and 100 microM. A reduction of larval weight of up to approximately 54% at the highest BTCI concentration was observed. At this concentration, the insect mortality was 65%. This work constitutes the first observation of a Bowman-Birk type inhibitor active in vitro and in vivo toward the cotton boll weevil A. grandis. The results of bioassays strongly suggest that BTCI may have potential as a transgene protein for use in engineered crop plants modified for heightened resistance to the cotton boll weevil.

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...

Mycorrhizal symbionts of Pisonia grandis and P. sechellarum in Seychelles: identification of mycorrhizal fungi and description of new Tomentella species.

Science.gov (United States)

Suvi, Triin; Tedersoo, Leho; Abarenkov, Kessy; Beaver, Katy; Gerlach, Justin; Kõljalg, Urmas

2010-01-01

Nyctaginaceae includes species that are predominantly non-mycorrhizal or form arbuscular or ectomycorrhiza. Root-associated fungi were studied from P. grandis and P. sechellarum roots collected respectively on the islands of Cousin and Silhouette in Seychelles. In addition fungal sporocarps were collected from the sampling area. Fungal symbionts were identified from the roots by anatomotyping and rDNA sequencing; sporocarps collected were examined microscopically and sequenced. Three distantly related ectomycorrhizal fungal species belonging to Thelephoraceae were identified from the roots of P. grandis. Sporocarps also were found for two symbionts and described as new Tomentella species. In addition Tomentella species collected from other Seychelles islands were studied and described as new species if there was no close resemblance to previously established species. P. sechellarum was determined to be an arbuscular mycorrhizal plant; three arbuscular mycorrhizal fungal species were detected from the roots. P. grandis is probably associated only with species of Thelephoraceae throughout its area. Only five Tomentella species are known to form ectomycorrhiza with P. grandis and they never have been found to be associated with another host, suggesting adaptation of these fungi to extreme environmental conditions in host's habitat.

Ectopic accumulation of linalool confers resistance to Xanthomonas citri subsp. citri in transgenic sweet orange plants.

Science.gov (United States)

Shimada, Takehiko; Endo, Tomoko; Rodríguez, Ana; Fujii, Hiroshi; Goto, Shingo; Matsuura, Takakazu; Hojo, Yuko; Ikeda, Yoko; Mori, Izumi C; Fujikawa, Takashi; Peña, Leandro; Omura, Mitsuo

2017-05-01

In order to clarify whether high linalool content in citrus leaves alone induces strong field resistance to citrus canker caused by Xanthomonas citri subsp. citri (Xcc), and to assess whether this trait can be transferred to a citrus type highly sensitive to the bacterium, transgenic 'Hamlin' sweet orange (Citrus sinensis L. Osbeck) plants over-expressing a linalool synthase gene (CuSTS3-1) were generated. Transgenic lines (LIL) with the highest linalool content showed strong resistance to citrus canker when spray inoculated with the bacterium. In LIL plants inoculated by wounding (multiple-needle inoculation), the linalool level was correlated with the repression of the bacterial titer and up-regulation of defense-related genes. The exogenous application of salicylic acid, methyl jasmonate or linalool triggered responses similar to those constitutively induced in LIL plants. The linalool content in Ponkan mandarin leaves was significantly higher than that of leaves from six other representative citrus genotypes with different susceptibilities to Xcc. We propose that linalool-mediated resistance might be unique to citrus tissues accumulating large amounts of volatile organic compounds in oil cells. Linalool might act not only as a direct antibacterial agent, but also as a signal molecule involved in triggering a non-host resistance response against Xcc. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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)

Long-term boron-deficiency-responsive genes revealed by cDNA-AFLP differ between Citrus sinensis roots and leaves

Science.gov (United States)

Lu, Yi-Bin; Qi, Yi-Ping; Yang, Lin-Tong; Lee, Jinwook; Guo, Peng; Ye, Xin; Jia, Meng-Yang; Li, Mei-Li; Chen, Li-Song

2015-01-01

Seedlings of Citrus sinensis (L.) Osbeck were supplied with boron (B)-deficient (without H3BO3) or -sufficient (10 μM H3BO3) nutrient solution for 15 weeks. We identified 54 (38) and 38 (45) up (down)-regulated cDNA-AFLP bands (transcript-derived fragments, TDFs) from B-deficient leaves and roots, respectively. These TDFs were mainly involved in protein and amino acid metabolism, carbohydrate and energy metabolism, nucleic acid metabolism, cell transport, signal transduction, and stress response and defense. The majority of the differentially expressed TDFs were isolated only from B-deficient roots or leaves, only seven TDFs with the same GenBank ID were isolated from the both. In addition, ATP biosynthesis-related TDFs were induced in B-deficient roots, but unaffected in B-deficient leaves. Most of the differentially expressed TDFs associated with signal transduction and stress defense were down-regulated in roots, but up-regulated in leaves. TDFs related to protein ubiquitination and proteolysis were induced in B-deficient leaves except for one TDF, while only two down-regulated TDFs associated with ubiquitination were detected in B-deficient roots. Thus, many differences existed in long-term B-deficiency-responsive genes between roots and leaves. In conclusion, our findings provided a global picture of the differential responses occurring in B-deficient roots and leaves and revealed new insight into the different adaptive mechanisms of C. sinensis roots and leaves to B-deficiency at the transcriptional level. PMID:26284101

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.

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.

Detection of Citrus psorosis virus in the northwestern citrus production area of Argentina by using an improved TAS-ELISA.

Science.gov (United States)

Zanek, Maria Cecilia; Peña, Eduardo; Reyes, Carina Andrea; Figueroa, Julia; Stein, Beatriz; Grau, Oscar; Garcia, Maria Laura

2006-11-01

Citrus Psorosis in Argentina is a serious disease. Citrus is produced in two regions located in the northeast (NE) and northwest (NW) area of the country. These two areas have different climates and soil types, and therefore different citrus species and varieties are cultivated. In the NE region, Psorosis is epidemic, and in the NW region, the disease was described on several occasions since 1938, but it is not observed commonly in the orchards. Recently, trees with symptoms of Psorosis were observed in the Tucumán and Salta Provinces located in the NW region. Epidemiological studies in Argentina and Texas suggested that the disease is spread naturally by an unknown vector. The causal agent of the disease is the Citrus psorosis virus (CPsV), which can be detected by TAS-ELISA, RT-PCR and indicator plants. A new more rapid TAS-ELISA-HRP (horseradish peroxidase) is described which is more reliable, faster and more sensitive than the currently used for this virus, the TAS-ELISA-AP (alkaline phosphatase). Psorosis was detected by this improved method in few trees in the orchards of the Tucumán Province, in the NW citrus region, although natural spread does not seem to occur.

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.

Semiochemicals from herbivory induced cotton plants enhance the foraging behavior of the cotton boll weevil, Anthonomus grandis.

Science.gov (United States)

Magalhães, D M; Borges, M; Laumann, R A; Sujii, E R; Mayon, P; Caulfield, J C; Midega, C A O; Khan, Z R; Pickett, J A; Birkett, M A; Blassioli-Moraes, M C

2012-12-01

The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by cotton plants enhanced the attractiveness of the aggregation pheromone emitted by male boll weevils. Behavioral responses of A. grandis to VOCs from conspecific-damaged, heterospecific-damaged (Spodoptera frugiperda and Euschistus heros) and undamaged cotton plants, at different phenological stages, were assessed in Y-tube olfactometers. The results showed that volatiles emitted from reproductive cotton plants damaged by conspecifics were attractive to adults boll weevils, whereas volatiles induced by heterospecific herbivores were not as attractive. Additionally, addition of boll weevil-induced volatiles from reproductive cotton plants to aggregation pheromone gave increased attraction, relative to the pheromone alone. The VOC profiles of undamaged and mechanically damaged cotton plants, in both phenological stages, were not different. Chemical analysis showed that cotton plants produced qualitatively similar volatile profiles regardless of damage type, but the quantities produced differed according to the plant's phenological stage and the herbivore species. Notably, vegetative cotton plants released higher amounts of VOCs compared to reproductive plants. At both stages, the highest rate of VOC release was observed in A. grandis-damaged plants. Results show that A. grandis uses

Sequential Sampling Plan of Anthonomus grandis (Coleoptera: Curculionidae) in Cotton Plants.

Science.gov (United States)

Grigolli, J F J; Souza, L A; Mota, T A; Fernandes, M G; Busoli, A C

2017-04-01

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is one of the most important pests of cotton production worldwide. The objective of this work was to develop a sequential sampling plan for the boll weevil. The studies were conducted in Maracaju, MS, Brazil, in two seasons with cotton cultivar FM 993. A 10,000-m2 area of cotton was subdivided into 100 of 10- by 10-m plots, and five plants per plot were evaluated weekly, recording the number of squares with feeding + oviposition punctures of A. grandis in each plant. A sequential sampling plan by the maximum likelihood ratio test was developed, using a 10% threshold level of squares attacked. A 5% security level was adopted for the elaboration of the sequential sampling plan. The type I and type II error used was 0.05, recommended for studies with insects. The adjustment of the frequency distributions used were divided into two phases, so that the model that best fit to the data was the negative binomial distribution up to 85 DAE (Phase I), and from there the best fit was Poisson distribution (Phase II). The equations that define the decision-making for Phase I are S0 = -5.1743 + 0.5730N and S1 = 5.1743 + 0.5730N, and for the Phase II are S0 = -4.2479 + 0.5771N and S1 = 4.2479 + 0.5771N. The sequential sampling plan developed indicated the maximum number of sample units expected for decision-making is ∼39 and 31 samples for Phases I and II, respectively. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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)

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...

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 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.

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.

Assessment of wood density of seven clones of Eucalyptus grandis ...

African Journals Online (AJOL)

With the objective of evaluating the correlation of wood basic density with age in seven Eucalyptus grandis clones planted in Brazil, five trees in each clone were sampled at the ages of 0, 5, 1, 5, 2, 5, 3, 5, 4, 5 and 7, 5 years. The analysis of these samples showed that the intraclonal variation of the basic density (except for 0, ...

Molecular cloning of a cysteine proteinase cDNA from the cotton boll weevil Anthonomus grandis (Coleoptera: Curculionidae).

Science.gov (United States)

De Oliveira Neto, Osmundo Brilhante; Batista, João Aguiar Nogueira; Rigden, Daniel John; Franco, Octávio Luiz; Fragoso, Rodrigo Rocha; Monteiro, Ana Carolina Santos; Monnerat, Rose Gomes; Grossi-De-Sa, Maria Fátima

2004-06-01

The cotton boll weevil (Anthonomus grandis) causes severe cotton crop losses in North and South America. This report describes the presence of cysteine proteinase activity in the cotton boll weevil. Cysteine proteinase inhibitors from different sources were assayed against total A. grandis proteinases but, unexpectedly, no inhibitor tested was particularly effective. In order to screen for active inhibitors against the boll weevil, a cysteine proteinase cDNA (Agcys1) was isolated from A. grandis larvae using degenerate primers and rapid amplification of cDNA ends (RACE) techniques. Sequence analysis showed significant homologies with other insect cysteine proteinases. Northern blot analysis indicated that the mRNA encoding the proteinase was transcribed mainly in the gut of larvae. No mRNA was detected in neonatal larvae, pupae, or in the gut of the adult insect, suggesting that Agcys1 is an important cysteine proteinase for larvae digestion. The isolated gene will facilitate the search for highly active inhibitors towards boll weevil larvae that may provide a new opportunity to control this important insect pest.

The oropharyngeal morphology in the semiaquatic giant Asian pond turtle, Heosemys grandis, and its evolutionary implications.

Directory of Open Access Journals (Sweden)

Monika Lintner

Full Text Available The oropharynx as a functional entity plays a fundamental role in feeding. Transitions from aquatic to terrestrial lifestyles in vertebrates demanded major changes of the oropharynx for the required adaptations to a different feeding environment. Extant turtles evolved terrestrial feeding modes in three families (testudinids, emydids, geoemydids-independently from other amniotes-and are therefore important model organisms to reconstruct morpho-functional changes behind aquatic-terrestrial transitions. In this study we hypothesized that the oropharyngeal morphology in semiaquatic turtles of the geoemydid family shows parallels to testudinids, the only purely terrestrial extant lineage. We provide an in-depth description of the oropharynx in the semiaquatic geoemydid Heosemys grandis by using a combination of micro computed tomography (micro-CT and subsequent digital in situ 3-D reconstruction, scanning electron microscopy (SEM, and histology. We show that H. grandis has a large tongue with rough papillose surface and well-developed lingual muscles. The attachment sites of the lingual muscles on the hyolingual skeleton and their courses within the tongue are nearly identical with testudinids. The hyolingual skeleton itself is mainly cartilaginous and shows distinct-but compared to testudinids rather small-anterior extensions of the hyoid body and hypoglossum. Oral glands are well developed in H. grandis but are smaller and simpler than in testudinids. Similarly, oropharyngeal keratinization was minimal and found only in the anterior palate, regions close to the beak, and tongue tip. We conclude that H. grandis shows distinct oropharyngeal morpho-functional adaptations for a terrestrial lifestyle but still retains characters typical for aquatic forms. This makes this species an important example showing the oropharyngeal adaptations behind aquatic-terrestrial transitions in turtles.

Citrus orchard planted with no tillage and conventional systemsHuerto de cítricos plantado con sistema de cero labranza y sistema convencional

Directory of Open Access Journals (Sweden)

Carmen Silvia Vieira Janeiro Neves

2010-02-01

Full Text Available No tillage system has brought many advantages to soil protection, without reducing the yield of annual crops. This system has been adapted for Citrus orchards, with the plantation of trees in furrows opened in areas previously occupied by pastures. This work had as objective to evaluate tree development, root system, yield, and soil characteristics in an orchard planted in two systems. The study was made in Parana State, Brazil, in a medium texture oxisol with ‘Valência’ orange (Citrus sinensis L. trees with Rangpur lime rootstock (Citrus limonia Osbeck. The treatments were no tillage (furrowing and plantation and conventional plantation (hole area plowing and disk harrowing before furrowing and plantation. The yield was 86 - 129 kg of fruits per plant, without significant difference between treatments. The plantation systems either do not affect the development of the plants, the amount of roots and the fruit quality. In the conventional plantation system the soil has greater resistance to penetration in inter rows than in the zero tillage system plantation.El sistema de cero labranza ha traído muchas ventajas en la protección del suelo, sin perjudicar el rendimiento de los cultivos anuales. Este sistema ha sido adaptado para los huertos citrícolas, realizándose la plantación en surcos abiertos en terrenos anteriormente ocupados por pastizales. El trabajo tuvo como objetivo evaluar el desarrollo de las plantas y del sistema radicular, producción, características del suelo en un huerto plantado en dos sistemas de labranza. El estudio fue realizado en el Noroeste de Paraná, en un oxisol con textura media, en plantas de naranja ‘Valência’ con patrón de lima Rangpur. Los tratamientos evaluados fueron: cero labranza (apertura de surcos y plantación y plantación convencional (arado de discos y grada, seguido de apertura de surcos y plantación. La producción fue de 86 a 129 kg de frutos por planta, sin diferencia significativa

Efeitos de ácido giberélico e carvão ativado no cultivo in vitro de Citrus limonia Osbeck chiPoncirus trifoliata (L. Raf Effects of gibberellic acid (GA3 and activated coal on in vitro culture of Citrus limonia Osbeck chi Poncirus trifoliata L. Raf. Embryos

Directory of Open Access Journals (Sweden)

Valtemir Gonçalves Ribeiro

2000-01-01

Full Text Available Pesquisou-se o desenvolvimento in vitro de embriões de um híbrido do cruzamento Citrus limonia Osb. chi Poncirus trifoliata (L. Raf. em meio MS, acrescido de GA3 (0,0, 0,01, 0,1 e 1,0 mg/L e carvão ativado (0,0, 0,5, 1,0 e 2,0 g/L, em todas as combinações possíveis. Após a excisão das sementes os embriões obtidos, independentemente dos estádios, foram inoculados nos respectivos meios de cultura. Cada tratamento permaneceu por 48 horas no escuro e 40 dias em sala de crescimento à temperatura de 27 ± 1ºC, com 16 horas de luminosidade. Após esse período, as plântulas foram avaliadas, considerando-se o porcentual de sobrevivência e comprimento da haste caulinar e do sistema radicular. Verificou-se que a concentação de 0,1 mg/L de GA3 interagiu antagonicamente em meio de cultivo contendo até 2,0 g/L de carvão ativado. O GA3 a 0,01 mg/L associado a concentrações de carvão ativado a partir de 0,5 g/L até 2,0 g/L, maximizou o porcentual de sobrevivência dos em- briões. Os embriões apresentaram o maior comprimento de raiz (4,5 cm e da haste caulinar (2,1 cm com carvão ativado na concentração de 0,5 g/L e 2,0 g/L, respectivamente.This work utilized fruits of a single plant obtained from the cross between Citrus limonia Osb. chi Poncirus trifoliata L. Raf. Seeds were removed and after excision, all the embryos, regardless their development stages, were inoculated in MS medium added with GA3 (0.0, 0.01, 0.1 and 1.0 mg/L and activated coal (0.0, 0.5, 1.0 and 2.0 g/L in every possible combination. These treatments remained for 48 hours in the dark and afterwards in growth room at the temperature of 27 ± 1ºC with 16 hours lighting. After 40 days, seedlings were evaluated by the lengths of the aerial part and root system and percent of survival. The concentration of 0.1 mg/L of GA3 interacts negatively in culture medium containing up to 2.0 g/L of activated coal. The concentration of 0.01 mg/L of GA3 associated to activated coal

In vitro antioxidant activities of the fractions of Coccinia grandis l. leaf ...

African Journals Online (AJOL)

The present study was aimed at investigating the antioxidant activities of the various fractions of the hydromethanolic extract of the leaves of Coccinia grandis L. Voigt. (Cucurbitaceae). The antioxidant activities of the fractions have been evaluated by using nine in vitro assays and were compared to standard antioxidants ...

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.

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 ...

Produção e qualidade dos frutos de clones de laranjeira-'Pera' no norte do Paraná Yield and fruit quality of 'Pêra' orange tree accessions in northern Paraná, Brazil

Directory of Open Access Journals (Sweden)

Zuleide Hissano Tazima

2010-03-01

Full Text Available Na implantação dos pomares cítricos, é importante o uso de cultivares adaptadas às condições locais, de forma a assegurar boa produtividade. A laranjeira-'Pera' [Citrus sinensis (L. Osbeck] é a cultivar mais importante da citricultura brasileira. O objetivo deste trabalho foi avaliar três clones de laranjeira-'Pera' do Banco Ativo de Germoplasma de Citros (BAG-Citros do Instituto Agronômico do Paraná - IAPAR (acessos I-58 'Pera Vacinada 3', I-59 'Pera Vacinada 4' e I-89 'Pera Bianchi' enxertados sobre o limoeiro-'Cravo' (Citrus limonia Osbeck, nas condições edafoclimáticas de Londrina-PR. As plantas cultivadas no espaçamento 7,0 m x 6,0 m foram conduzidas sem irrigação e avaliadas em relação à produção por planta e às características físico-químicas dos frutos. Os clones de laranjeira I-58 'Pera Vacinada 3', I-59 'Pera Vacinada 4' e I-89 'Pera Bianchi' apresentaram em nove safras, produção média anual por planta de 164,10 kg, 133,96 kg e 131,03 kg, respectivamente. Não houve diferença estatística entre os clones para as variáveis estudadas nas 14 safras. A qualidade dos frutos foi a seguinte: para I-58 'Pera Vacinada 3' e I-59 'Pêra Vacinada 4' e I-89 'Pera Bianchi', respectivamente: 159,6 g, 149,9 g e 150,9 g para massa de fruto; sólidos solúveis de 11,16 ºBrix, 10,98 ºBrix e 10,65 ºBrix; acidez titulável de 1,07%, 1,12% e 0,99%; teor de suco de 50,8%, 52,9% e 49,7%; ratio de 10,6; 10,0 e 10,9 e índice tecnológico de 2,31; 2,34 e 2,15 kg de sólidos solúveis por caixa.The use of adapted cultivars to the local conditions is important when establishing citrus orchards to ensure good yield. The sweet orange 'Pêra' [Citrus sinensis (L. Osbeck] is the most important cultivar to the Brazilian citriculture. The aim of this study was to evaluate three clones of 'Pêra' orange trees from the Citrus Active Germplasm Bank of the Instituto Agronômico do Paraná - IAPAR ('Pêra Vacinada 3' accession I-58, 'Pêra

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...

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.

(TECTONA GRANDIS LEAF POWDER

Directory of Open Access Journals (Sweden)

Yash Mishra

2015-01-01

Full Text Available In this study, the adsorption potential of Teak (Tectona grandis leaf powder (TLP toremove Methylene blue (MB and Malachite Green (MG dye molecules from aqueoussolution was investigated. Batch experiments were conducted to evaluate the influenceof operational parameters such as, pH (2−9, adsorbent dosage (1−7 g/L, contact time(15−150 minutes and initial dye concentration (20−120 mg/L at stirring speed of 150rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4%and 95.1% was achieved for MB and MG dye, respectively. The experimentalequilibrium data were analysed using Langmuir, Freundlich and Temkin isothermmodels and it was found that, it fitted well to the Freundlich isotherm model. Thesurface structure and morphology of the adsorbent was characterized using scanningelectron microscopy (SEM and the presence of functional groups and its interactionwith the dye molecules were analysed using Fourier transform infrared spectroscopy(FTIR. Based on the investigation, it has been demonstrated that the teak leaf powderhas good potential for effective adsorption of methylene blue and malachite green dye.

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 ...

Dynamic transcriptome profiling of the floral buds in the dioecious cucurbit Coccinia grandis using RNA-Seq

Directory of Open Access Journals (Sweden)

Jatindra Nath Mohanty

2017-10-01

Full Text Available Angiosperms exhibits diversified sexual systems encompassing bisexual, monoecious and dioecious conditions. Dioecy offers opportunities to explore separately, the male and female systems giving an insight into the evolutionary, developmental and molecular processes of sex expression in plants. Coccinia grandis (Family: Cucurbitaceae with small genome size and heteromorphic sex chromosomes is often considered a model dioecious plant for sex evolution. However, the information relating to its genetic orientation, physical state and sex determining factors is highly ambiguous and limited. In the present study we have attempted to identify the molecular basis of sex determination in C. grandis through genome wide transcriptome profiling of the floral buds. About 75 million clean reads were generated resulting in 72,479 unigenes for male library and 63,308 unigenes for female library with a mean length of 736 bp. 1410 unigenes were differentially expressed (DEGs between the male and female buds as identified from the RNA-Seq pattern and qRT-PCR validation. Functional annotation using BLAST2GO and KEGG revealed high enrichment of DEGs in phytohormone biosynthesis, hormone signaling and transduction, transcriptional regulation and methyl transferase activity. Manifold up-regulation of genes phytohormone responsive genes such as ARF6, ACC synthase1, SNRK2 and BRI1-associated receptor kinase 1 (BAK1 suggest that a signaling crosstalk is implicated in the sex determination of this species. Besides, a wide range of transcription factors including zinc fingers, homeodomain leucine zippers and MYBs were recognized as major determinants of male specific expression in the dioecious plant. Additionally, C. grandis transcriptome revealed 48 target genes for many miRNAs sequences with established role in floral development and sex determination. Overall, our study resulted in the identification of a large amount of molecular resources that could be critical to

PARASITISM OF BOLL WEEVIL (Anthonomus grandis IN FLOWER BUDS OF COTTON PLANT, IN THE MUNICIPAL DISTRICT OF GOIÂNIA-GO PARASITISMO DO BICUDO DO ALGODOEIRO (Anthonomus grandis EM BOTÕES FLORAIS DO ALGODOEIRO, NO MUNICÍPIO DE GOIÂNIA-GO

Directory of Open Access Journals (Sweden)

Paulo Marçal Fernandes

2007-09-01

Full Text Available

This work studied the indexes of parasitism of A. grandis in floral buttons of the cotton plants, collected in the soil and in the plants, in an area not treat with insecticides, located in the School of Agronomy of the Universidade Federal de Goiás, municipal district of Goiânia-GO. Floral buttons were collected with and without sign of oviparousness of the beaked ones. They presented larger parasitism occurrence in those collected in the soil. The parasites were identified as: Chelonus sp. (Microchelonus, Bracon sp. and Pteromalidae.

KEY-WORDS: Insecta; parasitism; cotton plant; Anthonomus grandis.

Estudou-se o índice de parasitismo de A. grandis em botões florais de algodoeiro coletados no solo e nas plantas, em uma área não tratada com inseticidas, localizada na Escola de Agronomia da Universidade Federal de Goiás, no município de Goiânia (GO. Foram coletados botões florais com e sem puncturas de oviposição dos bicudos. Verificou-se um maior parasitismo nos botões florais coletados no solo. Os parasitóides foram identificados como Chelonus sp. (Microchelonus, Bracon sp. e Pteromalidae.

PALAVRAS-CHAVE: Insecta; parasitismo; algodoeiro; Anthonomus grandis.

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 ...

Performance of Australian provenances of Eucalyptus grandis and Eucalyptus saligna in Hawaii

Science.gov (United States)

Roger G. Skolmen

1986-01-01

Australian provenances of Eucalyptus grandis and E. saligna were compared at four locations on the island of Hawaii to seek seed sources better than those in current use which were introduced earlier from unrecorded locations in Australia. A broad range of latitude and elevation was represented among the provenances. At all four...

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.

Monitoring Citrus Soil Moisture and Nutrients Using an IoT Based System

Directory of Open Access Journals (Sweden)

Xueyan Zhang

2017-02-01

Full Text Available Chongqing mountain citrus orchard is one of the main origins of Chinese citrus. Its planting terrain is complex and soil parent material is diverse. Currently, the citrus fertilization, irrigation and other management processes still have great blindness. They usually use the same pattern and the same formula rather than considering the orchard terrain features, soil differences, species characteristics and the state of tree growth. With the help of the ZigBee technology, artificial intelligence and decision support technology, this paper has developed the research on the application technology of agricultural Internet of Things for real-time monitoring of citrus soil moisture and nutrients as well as the research on the integration of fertilization and irrigation decision support system. Some achievements were obtained including single-point multi-layer citrus soil temperature and humidity detection wireless sensor nodes and citrus precision fertilization and irrigation management decision support system. They were applied in citrus base in the Three Gorges Reservoir Area. The results showed that the system could help the grower to scientifically fertilize or irrigate, improve the precision operation level of citrus production, reduce the labor cost and reduce the pollution caused by chemical fertilizer.

Toxicity to cotton boll weevil Anthonomus grandis of a trypsin inhibitor from chickpea seeds.

Science.gov (United States)

de P G Gomes, Angélica; Dias, Simoni C; Bloch, Carlos; Melo, Francislete R; Furtado, José R; Monnerat, Rose G; Grossi-de-Sá, Maria F; Franco, Octávio L

2005-02-01

Cotton (Gossypium hirsutum L.) is an important agricultural commodity, which is attacked by several pests such as the cotton boll weevil Anthonomus grandis. Adult A. grandis feed on fruits and leaf petioles, reducing drastically the crop production. The predominance of boll weevil digestive serine proteinases has motivated inhibitor screenings in order to discover new ones with the capability to reduce the digestion process. The present study describes a novel proteinase inhibitor from chickpea seeds (Cicer arietinum L.) and its effects against A. grandis. This inhibitor, named CaTI, was purified by using affinity Red-Sepharose Cl-6B chromatography, followed by reversed-phase HPLC (Vydac C18-TP). SDS-PAGE and MALDI-TOF analyses, showed a unique monomeric protein with a mass of 12,877 Da. Purified CaTI showed significant inhibitory activity against larval cotton boll weevil serine proteinases (78%) and against bovine pancreatic trypsin (73%), when analyzed by fluorimetric assays. Although the molecular mass of CaTI corresponded to alpha-amylase/trypsin bifunctional inhibitors masses, no inhibitory activity against insect and mammalian alpha-amylases was observed. In order to observe CaTI in vivo effects, an inhibitor rich fraction was added to an artificial diet at different concentrations. At 1.5% (w/w), CaTI caused severe development delay, several deformities and a mortality rate of approximately 45%. These results suggested that CaTI could be useful in the production of transgenic cotton plants with enhanced resistance toward cotton boll weevil.

Antraquinonas e naftoquinonas do caule de um espécime de reflorestamento de Tectona grandi (Verbenaceae

Directory of Open Access Journals (Sweden)

Rafael Y.O. Moreira

Full Text Available O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae, através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o objetivo principal deste trabalho a comprovação da presença de tectoquinona em espécimes cultivados.

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 ...

Cover crop with Teramnus labialis in a citrus orchard: effects on some physical properties of the soil / Cubierta vegetal con Teramnus labialis en plantaciones citrícolas: efectos sobre algunas propiedades físicas del suelo Cubierta vegetal con Teramnus labialis en plantaciones citrícolas: efectos sobre algunas propiedades físicas del suelo

Directory of Open Access Journals (Sweden)

Leydis Castellano Rodríguez

2009-03-01

Full Text Available The use of leguminous cover crops in citrus orchards constitutes a viable alternative for the improvement of soil properties, whenever they are appropriately managed. In Ciego de Avila University, Cuba, it was evaluated the effect of a leguminous cover crop on some properties of an orchard soil. The work was carried out during four years in an orange plantation of Valencia late (Citrus sinensis L. Osbeck in a 22 years-old orchard, with a plantation frame of 8 X 4 m, planted on a typical red Ferralitic soil, belonging to the CPA ¨José Martí¨, in Ciego de Avila. It was used a random block design with three treatments: one with covering of Teramnus labialis (T1, one with expontaneous vegetation (T2 and the third with no vegetation (T3. The functional structure properties of the soil were determined, and also the composition of macroaggregates expressed in the structure coefficient and the percentage of stable added in water, soil density, humidity and porosity. The increments in the humidity of the soil, the specific volume of pores and air, the structure coefficient, as well as the percentage of stable added in water, in the soil where the covering of Teramnus labialis was stablished, show the efficiency of cover crops in these citrus orchards.El uso de coberturas vivas de leguminosas en plantaciones citrícolas constituye una alternativa viable para el mejoramiento de las propiedades de los suelos, siempre que ellas se manejan adecuadamente en estas áreas. En la universidad de Ciego de Ávila, Cuba se viene trabajando en la evaluación del efecto de coberturas vivas de leguminosas en plantaciones citrícolas en producción, con el objetivo de evaluar el efecto que ejerce la cobertura de leguminosa sobre algunas propiedades del suelo. El trabajo se realizó durante cuatro años (2001-2005 en una plantación de naranja Valencia Late ( Citrus sinensis L. Osbeck en producción de 22 años, con marco de plantación de 8 X 4 m, plantada sobre un

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...

Utilização de madeiras de Eucalyptus grandis E Eucalyptus dunnii para produção de painéis de partículas orientadas – OSB

Directory of Open Access Journals (Sweden)

Setsuo Iwakiri

2008-01-01

Full Text Available This study was developed to evaluate the feasibility of OSB manufacturing using woods of Eucalyptus grandis and Eucalyptus dunnii. Boards with nominal density of 0,70 g/cm³ and 1,0 g/cm³ were manufactured in laboratory, using 100% of wood particles from Pinus taeda, Eucalyptus grandis and Eucalyptus dunnii, and mixtures of 50% of Pinus taeda in the internal layer of the board, with 50% of Eucalyptus grandis and 50% of Eucalyptus dunnii. The boards of Eucalyptus grandis with density of 0,70 g/cm³, as standard board density, showed the values of properties compatible with the requirements of the Canadian and European Standards and also in relation of boards manufactured from Pinus taeda. The results of the mechanical properties showed an increase in the MOE and MOR in static bending with the increase in the board density, opening the possibility to use the high density OSB for applications requiring higher strength. The results of this research indicate that wood of Eucalyptus grandis can be used as alternative specie to OSB manufacturing in the Brazil.

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...

Citrus Production, Constraints and Management Practices in Ethiopia

African Journals Online (AJOL)

Citrus is economically important fruit crop in Ethiopia. However, its production is seriously constrained by various diseases including Pseudocercospora leaf and fruit spot. Surveys were conducted between June 2012 and May 2013 in the main citrus production areas of the country to assess the spread of the disease, and to ...

Tectona grandis L. f (the teak tree; Hindi: Sagallll or Segllll) (~r ...

Indian Academy of Sciences (India)

Tectona grandis L. f (the teak tree; Hindi: Sagallll or Segllll) (~r Verhell({Ceae is a large deciduous tree cllitivatedfor its timber. Leaves are large; flmvers are small, white, svveet-scented and borne on highly branched inflorescences. Fruit is hard and enveloped by bladder-like cal.vx. The timber is one of the best for all wood ...

Locais e período de alimentação da cigarrinha vetora de Xylella fastidiosa, Bucephalogonia xanthophis (Berg (Hemiptera: Cicadellidae, em mudas cítricas Feeding sites and food intake of Bucephalogonia xanthophis (Berg (Hemiptera: Cicadellidae, a sharpshooter vector of Xylella fastidiosa, on citrus plants

Directory of Open Access Journals (Sweden)

Marcelo Pedreira de Miranda

2008-12-01

Full Text Available A cigarrinha Bucephalogonia xanthophis (Berg (Hemiptera: Cicadellidae é um importante vetor da bactéria Xylella fastidiosa, agente causal da clorose variegada dos citros. Este trabalho teve como objetivo identificar o local preferido de alimentação e o período de maior atividade alimentar desta cigarrinha em citros, no sentido de elucidar o comportamento alimentar relacionado à transmissão da bactéria. O local de alimentação foi estudado em ensaio de escolha, no qual 30 insetos adultos foram liberados em gaiolas de observação (n = 10 contendo uma muda de laranja-doce [Citrus sinensis (L. Osbeck]. Após 1; 15; 21; 25; 39; 45 e 49 h da liberação, contaram-se os insetos na parte superior (ramos com brotações e inferior (haste principal, até H"40 cm de altura da muda. Nos ramos da parte superior, avaliou-se a preferência entre a haste, o pecíolo e o limbo foliar. Em um segundo ensaio, 20 machos e 20 fêmeas de B. xanthophis foram confinados individualmente sobre a haste de 'seedlings' de laranja-doce para determinar os períodos de alimentação, quantificando-se a excreção de 'honeydew' (medida indireta da ingestão em períodos sucessivos de dia e noite, durante 48 h. A maioria dos indivíduos de B. xanthophis preferiu a haste dos ramos novos (62%, na parte superior da muda cítrica (91%. Nos 'seedlings', observou-se maior volume de excreção e proporção de indivíduos excretando durante a fotofase, independentemente do sexo. Portanto, em estudos de transmissão de X. fastidiosa, deve-se considerar a preferência de B. xanthophis pela haste de brotações cítricas e sua maior atividade alimentar durante a fotofase.The sharpshooter Bucephalogonia xanthophis (Berg (Hemiptera: Cicadellidae is an important vector of Xylella fastidiosa, a bacterium that causes citrus variegated chlorosis. This study aimed to identify the preferred feeding sites and periods of this vector on citrus, in order to improve our understanding of the

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.

Genetic and environmental factors affecting rooting in Eucalyptus Grandis X Eucalyptus Longistrata hybrid cuttings

CSIR Research Space (South Africa)

Naidoo, N

2012-03-01

Full Text Available An investigation was undertaken to study the rooting ability of E. grandis x E. longirostrata hybrid cuttings. The plant material was sourced from five families in seedling derived hedges at two nurseries, as well as five families coppiced from...

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...

Avaliação do teor de umidade da madeira de Eucalyptus grandis por medidores elétricos resistivos. Evaluation of the Eucalyptus grandis lumber moisture content by resistancetype moisture meters.

Directory of Open Access Journals (Sweden)

João Eduardo Guarnetti dos SANTOS

2006-01-01

Full Text Available O presente estudo teve como objetivoverificar a precisão de dois tipos de medidoreselétricos de teor de umidade durante o processo desecagem da madeira de Eucalyptus grandis. Foramretiradas amostras representativas de 14 tábuas deEucalyptus grandis e secas em estufa elétrica a40 ºC de temperatura, até que o material atingisse10% de umidade. Durante a secagem foramdeterminados, periodicamente, o teor de umidadeatravés do método de massas correntes e deverificações simultâneas com um medidor elétricoportátil (EMM e com o sistema de controle de umsecador convencional (KCS. Os resultados mostraramque: (1 o sensor de umidade KCS pode substituiro método gravimétrico durante a secagem damadeira; (2 o medidor do teor de umidade EMMsubestima os reais teores de umidade durante asecagem da madeira e não é indicado parasubstituir o método gravimétrico de determinação de umidade.The aim of the study was to evaluate theprecision of two types of electric moisture metersduring the drying process of Eucalyptus grandisboards. Samples were obtained from 14 boards ofEucalyptus grandis and they were dried in electriclaboratory oven at 40 ºC of temperature, until thewood achieve 10% of moisture content. During thedrying, the moisture content was determined bygravimetric method and simultaneous checks by anelectric moisture meter (EMM and by kilncontrol system (KCS. The results showed that:(1 the KCS can replace the gravimetric methodduring the wood drying; (2 the EMMunderestimate the real moisture content during thedrying of boards and it is not indicate as substituteof the gravimetric method.

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 ...

Adubos foliares quelatizados e sais na absorção de boro, manganês e zinco em laranjeira ?Pera?

Directory of Open Access Journals (Sweden)

Santos Carlos Henrique dos

1999-01-01

Full Text Available O presente trabalho teve como objetivo comparar a eficiência de formulações de adubos foliares quelatizados na absorção dos micronutrientes boro, manganês e zinco, com a aplicação convencional de sais em plantas de laranjeira ?Pera? (Citrus sinensis (L. Osbeck. Para tanto foi conduzido experimento nas dependências do Departamento de Ciência do Solo da Faculdade de Ciências Agronômicas UNESP/Campus de Botucatu, Estado de São Paulo. Utilizaram-se plantas de laranjeira ?Pera? (Citrus sinensis (L. Osbeck enxertadas sobre limoeiro ?Cravo? (Citrus limonia Osbeck, com 2 anos de idade, plantadas em caixas de 250 litros. Os adubos foliares utilizados foram: Grex Citros na dose de 1,0 mL L-1; Copas citros 2,0 mL L-1; Plantin Citros 1,0 mL L-1; Citrolino 2,0 mL L-1; Fertamin Citros 1,75 mL L-1; Yogen Citros 2,0 mL L-1; MS-2 1,0 mL L-1; Sais, Sais + 1,0 g L-1 de KCl e Sais substituindo o ZnSO4 pelo ZnCl2. O volume de aplicação, foi de 1 litro de calda planta-1. Em todos os tratamentos adicionou-se o espalhante adesivo do grupo químico dos alquifenoletoxilados a 0,03%. A amostragem das folhas foi realizada 30 dias após a aplicação dos tratamentos, coletando-se a 3a ou 4a folha de ramos vegetativos no início do florescimento, dos 4 quadrantes, localizados na região mediana da planta, totalizando 10 folhas por planta. A aplicação foliar de micronutrientes, favoreceu a absorção e resultou no aumento do teor foliar de Mn e Zn mas não de B, sendo que a presença de cloreto aumentou os teores de Zn na folhas de laranjeira ?Pera?, proporcionando maior absorção do que o sulfato e sulfato adicionado ao cloreto de potássio. Os resultados mostram, também, que os produtos quelatizados Yogen e MS-2, para as condições deste estudo, não foram eficientes como fontes fornecedoras de Mn.

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...

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...

Método de diagnóstico para el monitoreo de resistencia a insecticidas en poblaciones de "picudo del algodonero", Anthonomus grandis (Coleoptera: Curculionidae A diagnostic test for insecticide resistance monitoring in "cotton boll weevil" Anthonomus grandis (Coleoptera: Curculionidae populations

Directory of Open Access Journals (Sweden)

Teodoro Stadler

2009-06-01

Full Text Available El control de las poblaciones de Anthonomus grandis Boheman, por debajo de su umbral de daño económico durante el ciclo del cultivo del algodón, se realiza en forma efectiva hasta el momento, a través de insecticidas de síntesis. La presión selectiva de las aplicaciones extensivas e intensivas de insecticidas hace imperativa la detección temprana de focos de resistencia a los mismos, en función de un correcto manejo del fenómeno. Se desarrolló un método de diagnóstico de resistencia para A. grandis a partir de la técnica "vial test", que fue adaptada en forma de "kit" para el monitoreo rápido y sencillo de los focos de resistencia en el campo. La toxicidad (CL99, para calcular la concentración discriminante (CD del insecticida y la preparación del "kit", se obtiene a partir de bioensayos de laboratorio con una cepa normal susceptible de A. grandis. Se determinó la vida media de los insecticidas dentro de los viales por CIPAC MT 46, para establecer una fecha de vencimiento del "kit". La CD y el método en su conjunto fueron validados a través de ensayos a campo. El "kit", usado en el monitoreo de resistencia en el campo, fue especialmente diseñado para ser utilizado en las condiciones geográficas, económicas y socio-culturales presentes en la región algodonera argentina. La implementación de esta técnica permitirá conseguir la información necesaria, y así obtener una apropiada alternancia de insecticidas. Como consecuencia, se prevé una reducción de impacto ambiental de las prácticas agronómicas en el control de plagas en algodón.The in-season control of the cotton boll weevil Anthonomus grandis Boheman is done by insecticide application, which so far is the only effective way to reduce boll weevil populations to levels below economic significance. The extensive and intensive control actions with insecticides cause selective pressure on pest populations. Thus, to achieve an accurate insecticide resistance

Antagonistic actions of boron against inhibitory effects of aluminum toxicity on growth, CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase, and photosynthetic electron transport probed by the JIP-test, of Citrus grandis seedlings

Directory of Open Access Journals (Sweden)

Tang Ning

2009-08-01

Full Text Available Abstract Background Little information is available on the amelioration of boron (B on aluminum (Al-induced photosynthesis inhibition. Sour pummelo (Citrus grandis seedlings were irrigated for 18 weeks with nutrient solution containing 4 B levels (2.5, 10, 25 and 50 μM H3BO3 × 2 Al levels (0 and 1.2 mM AlCl3·6H2O. The objectives of this study were to determine how B alleviates Al-induced growth inhibition and to test the hypothesis that Al-induced photosynthesis inhibition can be alleviated by B via preventing Al from getting into shoots. Results B had little effect on plant growth, root, stem and leaf Al, leaf chlorophyll (Chl, CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, Chl a fluorescence (OJIP transient and related parameters without Al stress except that root, stem and leaf B increased with increasing B supply and that 50 μM B decreased slightly root dry weight. Al-treated roots, stems and leaves displayed a higher or similar B. B did not affect root Al under Al stress, but decreased stem and leaf Al level. Shoot growth is more sensitive to Al stress than root growth, CO2 assimilation, Chl, Rubisco, OJIP transient and most related parameters. Al-treated leaves showed decreased CO2 assimilation, but increased or similar intercellular CO2 concentration. Both initial and total Rubisco activity in Al-treated leaves decreased to a lesser extent than CO2 assimilation. Al decreased maximum quantum yield of primary photochemistry and total performance index, but increased minimum fluorescence, K-band, relative variable fluorescence at J- and I-steps. B could alleviate Al-induced increase or decrease for all these parameters. Generally speaking, the order of B effectiveness was 25 μM > 10 μM ≥ 50 μM (excess B > 2.5 μM. Conclusion We propose that Al-induced photosynthesis inhibition was mainly caused by impaired photosynthetic electron transport chain, which may be associated with growth inhibition. B

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.

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.

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.

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.

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.

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...

Diversidade genética entre híbridos de laranja-doce e tangor 'Murcott' avaliada por fAFLP e RAPD Genetic diversity among hybrids of sweet orange and 'Murcott' tangor evaluated by fAFLP and RAPD markers

Directory of Open Access Journals (Sweden)

Marinês Bastianel

2006-05-01

Full Text Available O objetivo deste trabalho foi avaliar a diversidade genética em uma população de 148 híbridos de tangor 'Murcott' (Citrus reticulata Blanco x C. sinensis L. Osbeck e laranja 'Pêra' (C. sinensis L. Osbeck obtidos por polinização controlada, pelo uso de marcadores fAFLP e RAPD. Marcadores polimórficos (416 marcadores fAFLP e 33 RAPD foram utilizados para avaliar a similaridade genética entre os híbridos, calculada com o coeficiente Jaccard pelo método UPGMA. A consistência de cada agrupamento foi determinada pelo programa BOOD. Houve alta similaridade genética entre os parentais. A laranja 'Pêra' apresentou maior número (132 de loci em heterozigose em relação ao tangor 'Murcott' (105, corroborando a teoria de origem híbrida para a laranja-doce. Observaram-se dois grupos distintos de plantas, e um deles abrangeu 80% dos híbridos com maior similaridade com a laranja 'Pêra'. A análise bootstrap não revelou consistência estatística entre esses grupos. Marcadores fAFLP são mais eficientes na avaliação do polimorfismo, sendo indicados para seleção de indivíduos híbridos mais próximos a um dos parentais.The objective of this work was to evaluate the genetic diversity in a population of 148 hybrids of 'Murcott' tangor (Citrus reticulata Blanco x C. sinensis L. Osbeck and 'Pêra' sweet orange (C. sinensis L. Osbeck, obtained by controlled polination, using fAFLP and RAPD markers. Polymorphic markers (416 fAFLP and 33 RAPD markers were used to evaluate genetic similarity among the hybrids, calculated by the coefficient of Jaccard, using the UPGMA method. The consistency of each group was determined by software BOOD. There was high genetic similarity within the parents. 'Pêra' sweet orange had a higher number of loci in heterozygosis (132 compared to 'Murcott' tangor (105, supporting the theory of hybrid origin for sweet oranges. Two distinct groups of plants were observed: one group had 80% of the hybrids that displayed

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.

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.

Temporal dynamics of the response to Al stress in Eucalyptus grandis × Eucalyptus camaldulensis

Directory of Open Access Journals (Sweden)

Berenice K. de Alcântara

2015-06-01

Full Text Available Lipid peroxidation and root elongation of Eucalyptus grandis × Eucalyptus camaldulensis were studied under stress conditions in response to aluminum (Al, a metal known to limit agricultural productivity in acidic soils primarily due to reduced root elongation. In Brazil, the Grancam 1277 hybrid (E. grandis × E. camaldulensis has been planted in the "Cerrado", a region of the country with a wide occurrence of acidic soils. The present study demonstrated that the hybrid exhibited root growth reduction and increased levels of lipid peroxidation after 24h of treatment with 100 µM of Al, which was followed by a reduction in lipid peroxidation levels and the recovery of root elongation after 48h of Al exposure, suggesting a rapid response to the early stressful conditions induced by Al. The understanding of the temporal dynamics of Al tolerance may be useful for selecting more tolerant genotypes and for identifying genes of interest for applications in bioengineering.

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.

Acción Bactericida del Jugo de Limón Sobre el Staphylococcus Aureus Rosenbach

Directory of Open Access Journals (Sweden)

Obregón Botero. Rafael

1946-04-01

Full Text Available El objeto de este experimento fue el determinar la influencia que pudiera tener el jugo de limón común (citrus limonia Osbeck sobre el Staphylococcus; aureus Rosenbach. Esta bacteria se encuentra con frecuencia en la piel y el pelo del hombre y de los animales, también en el pus y con frecuencia asociados a muchas otras causantes de abcesos, forúnculos, nacidos, etc. Ocasionalmente pueden causar osteomielitis y endocarditis. En individuos tuberculosos las infecciones causadas por esta bacteria pueden ocasionar la muerte.

Induction and identification of somatic mutations with particular reference to perennial plants. Part of a coordinated programme on improvement of vegetatively propagated crops and tree crops through radiation-induced mutations

International Nuclear Information System (INIS)

Zubrzycki, H.M.

1980-06-01

An attempt was made to obtain resistance of oranges (Citrus sinensis L. Osbeck) and grapefruit (C. paradisi Macf.) to Tristeza virus by induced mutation breeding. Two methods were used. In one, buds were treated with X or gamma radiation. The detached sprouts were subsequently grafted. In the other, a number of chemical mutagens were used: diethyl sulfate or propylenoxide on buds; diethyl sulfate or nitrosemethylurethane on seeds (2400). The selection and isolation of mutants from treated buds and seeds, respectively, are described. Intermediate results only are given and discussed

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.

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.

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

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) ...

Midgut GPI-anchored proteins with alkaline phosphatase activity from the cotton boll weevil (Anthonomus grandis) are putative receptors for the Cry1B protein of Bacillus thuringiensis.

Science.gov (United States)

Martins, Erica Soares; Monnerat, Rose Gomes; Queiroz, Paulo Roberto; Dumas, Vinicius Fiuza; Braz, Shélida Vasconcelos; de Souza Aguiar, Raimundo Wagner; Gomes, Ana Cristina Menezes Mendes; Sánchez, Jorge; Bravo, Alejandra; Ribeiro, Bergmann Morais

2010-02-01

Cry toxins from Bacillus thuringiensis (Bt) are used for insect control. They interact with specific receptors located on the host cell surface and are activated by host proteases following receptor binding resulting in midgut epithelial cells lysis. In this work we had cloned, sequenced and expressed a cry1Ba toxin gene from the B thuringiensis S601 strain which was previously shown to be toxic to Anthonomus grandis, a cotton pest. The Cry1Ba6 protein expressed in an acrystaliferous B. thuringiensis strain was toxic to A. grandis in bioassays. The binding of Cry1Ba6 toxin to proteins located in the midgut brush border membrane of A. grandis was analyzed and we found that Cry1Ba6 binds to two proteins (62 and 65kDa) that showed alkaline phosphatase (ALP) activity. This work is the first report that shows the localization of Cry toxin receptors in the midgut cells of A. grandis. 2009. Published by Elsevier Ltd.

Efeito da hidrólise ácida dos taninos de Eucalyptus grandis w. hill ex Maiden nas propriedades dos adesivos tânicos Effect of the acid hydrolyses of Eucalyptus grandis w. hill ex Maiden tannins in the properties of the tannic adhesives

Directory of Open Access Journals (Sweden)

Angélica de Cássia Oliveira Carneiro

2009-08-01

Full Text Available Este trabalho teve como objetivo avaliar o efeito da hidrólise ácida sobre as propriedades e resistência ao cisalhamento dos adesivos de taninos, extraídos a partir da casca de Eucalyptus grandis W. Hill ex Maiden. Os adesivos foram sintetizados com taninos hidrolisados, empregando-se quatro valores de pH, três tempos de reação e 10% de formaldeído em relação à massa seca de taninos. Foram produzidas 96 juntas coladas, constituídas de duas lâminas de madeira de Eucalyptus grandis. As resistências ao cisalhamento e falha na madeira foram determinadas de acordo com a norma ASTM D 2339-93. Concluiu-se que a hidrólise ácida dos taninos reduziu a viscosidade dos adesivos e aumentou a resistência ao cisalhamento na linha de cola. De modo geral, as juntas coladas apresentaram baixo percentual de falha na madeira.The objective of this research was to evaluate the effect of the acid hydrolysis of Eucalyptus grandis W. Hill ex Maiden bark tannins on the properties of tannic adhesives. Adhesives were synthesized with tannins hydrolyzed at four pH values, three reaction times and 10% of formaldehyde based on the tannin dry weight. Ninety-six glued joints were prepared with Eucalyptus grandis thin boards. Shear resistance and wood failure percentage were determined according to the ASTM D 2339-93 standards. It was concluded that tannin hydrolysis decreased adhesive viscosity and increased the glue line shear resistance. However, it was observed a low percentage of wood failure.

(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 ...

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

Although Citrus is the most globally significant tree fruit, its domestication history is poorly understood. Cultivated citrus types are believed to comprise selections from and/or hybrids of several wild progenitor species, but the identities of these progenitors, and their contribution to modern cultivars, remain controversial. Here we report the genomes of a collection of mandarins, pummelos, and oranges, including a high quality reference sequence from a haploid Clementine mandarin. By comparative genome analysis we show that these cultivated types can be derived from two progenitor species. Cultivated pummelos represent selections from a single progenitor species C. maxima. Unexpectedly, however, we find that cultivated mandarins are introgressions of C. maxima into a distinct second population that we identify with the ancestral wild mandarin species C. reticulata. Sweet and sour oranges are found to be interspecific hybrids. Sweet orange, the most widely cultivated citrus, arose as the offspring of previously admixed individuals. In contrast, sour (or Seville) orange is an F1 hybrid of pure C. maxima and C. reticulata parents, implying that wild mandarins were part of the early breeding germplasm. Surprisingly, we also find that a wild Chinese mandarin from Mangshan, China shows substantial sequence divergence from C. reticulata and appears to represent a distinct taxon. Understanding the relationships and phylogeny of cultivated citrus through genome analysis will clarify taxonomic relationships and enable previously inconceivable opportunities for sequence-directed genetic improvement. Citrus are widely consumed worldwide as juice or fresh fruit, providing important sources of vitamin C and other health-promoting compounds. Global production in 2012 exceeded 86 million metric tons, with an estimated value of US$9 billion (http://www.fas.usda.gov/psdonline/circulars/citrus.pdf). The very narrow genetic diversity of cultivated citrus makes it highly

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…

Lufenuron impact upon Anthonomus grandis Boheman (Coleoptera: Curculionidae) midgut and its reflection in gametogenesis.

Science.gov (United States)

Costa, Hilton Nobre; da Cunha, Franklin Magliano; Cruz, Glaucilane Santos; D'assunção, Carolline Guimarães; Rolim, Guilherme Gomes; Barros, Maria Edna Gomes; Breda, Mariana Oliveira; Teixeira, Alvaro Aguiar Coelho; Teixeira, Valéria Wanderley

2017-04-01

The insecticide Match® (lufenuron), one of the main insect growth regulators used in pest control, has been presented as a viable alternative against the boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), by inhibiting chitin synthesis. Thus, this study aimed to examine whether Match® interferes in the synthesis of the peritrophic matrix, leading to changes in the midgut epithelium, resulting in nutritional deficiency and reflecting, thereby, in the gametogenesis process of A. grandis. Floral cotton buds were immersed in the insecticide solution (800μL of Match®+200mL of distilled water) and offered to the adult insects. The midguts of the insects were evaluated after 24 and 120h after feeding. The gonads were evaluated after 120h. The results showed that Match®, in both evaluation periods, induced histopathological alterations such as disorganization, vacuolization and desquamation of the midgut epithelium; histochemical modifications in the distribution patterns of carbohydrates, although without quantitative changes; and a strong decrease in protein levels. No apoptosis were observed, however, there was an increase in the number of regenerative cell nests. In the testicles, a reduction in the amount of spermatozoids and reduced carbohydrate levels were observed, but no difference in protein levels. The ovarioles presented structural disorganization of follicular cells, yolk reduction and decrease in protein levels, however, no change in carbohydrates levels was noted. Therefore, it is concluded that Match® performs histopathologic and histochemical alterations in the midgut epithelium and the gonads of A. grandis adults, reflecting in the gametogenesis process, presenting itself as a promising tool in the management of this pest on cotton crops. Copyright © 2016 Elsevier Inc. All rights reserved.

Nucleases as a barrier to gene silencing in the cotton boll weevil, Anthonomus grandis.

Science.gov (United States)

Almeida Garcia, Rayssa; Lima Pepino Macedo, Leonardo; Cabral do Nascimento, Danila; Gillet, François-Xavier; Moreira-Pinto, Clidia Eduarda; Faheem, Muhammad; Moreschi Basso, Angelina Maria; Mattar Silva, Maria Cristina; Grossi-de-Sa, Maria Fatima

2017-01-01

RNA interference (RNAi) approaches have been applied as a biotechnological tool for controlling plant insect pests via selective gene down regulation. However, the inefficiency of RNAi mechanism in insects is associated with several barriers, including dsRNA delivery and uptake by the cell, dsRNA interaction with the cellular membrane receptor and dsRNA exposure to insect gut nucleases during feeding. The cotton boll weevil (Anthonomus grandis) is a coleopteran in which RNAi-mediated gene silencing does not function efficiently through dsRNA feeding, and the factors involved in the mechanism remain unknown. Herein, we identified three nucleases in the cotton boll weevil transcriptome denoted AgraNuc1, AgraNuc2, and AgraNuc3, and the influences of these nucleases on the gene silencing of A. grandis chitin synthase II (AgraChSII) were evaluated through oral dsRNA feeding trials. A phylogenetic analysis showed that all three nucleases share high similarity with the DNA/RNA non-specific endonuclease family of other insects. These nucleases were found to be mainly expressed in the posterior midgut region of the insect. Two days after nuclease RNAi-mediated gene silencing, dsRNA degradation by the gut juice was substantially reduced. Notably, after nucleases gene silencing, the orally delivered dsRNA against the AgraChSII gene resulted in improved gene silencing efficiency when compared to the control (non-silenced nucleases). The data presented here demonstrates that A. grandis midgut nucleases are effectively one of the main barriers to dsRNA delivery and emphasize the need to develop novel RNAi delivery strategies focusing on protecting the dsRNA from gut nucleases and enhancing its oral delivery and uptake to crop insect pests.

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...

Aplicação de uma técnica alternativa de manejo físico do solo no cultivo de Eucalyptus grandis W.Hill (Myrtaceae Application of an alternative technique for physical soil management in cultivation of Eucalyptus grandis W.Hill (Myrtaceae

Directory of Open Access Journals (Sweden)

João Paulo de Maçaneiro

2013-02-01

Full Text Available O objetivo deste estudo foi avaliar o processo de crescimento do Eucalyptus grandis quando submetido à irregularização do terreno. Baseando-se na "Ótica da Teoria do Caos" e partindo-se da hipótese de que as áreas reflorestadas por E. grandis são consideravelmente sensíveis às condições iniciais de preparação do solo, aplicou-se a técnica das rugosidades (variações do relevo alternando superfícies côncavas e convexas para desencadear ao longo do tempo propriedades emergentes que aceleram o processo de crescimento vegetal. A área de estudo localiza-se na Bacia Hidrográfica do Rio Itajaí, em Brusque, SC. Esta foi dividida em quatro parcelas menores: duas com tratamentos irregulares (IR-A e IR-B e outras duas com tratamentos regulares (R-A e R-B. Os tratamentos irregulares consistiram na abertura de cavas, utilizando-se uma retroescavadeira hidráulica, intercaladas com 1 m de largura, 4 a 5 m de comprimento e 0,5 m de profundidade. Nos tratamentos regulares foi adotado o cultivo mínimo do solo, onde o preparo do solo ficou restrito às linhas ou covas de plantio. Na análise do desenvolvimento de E. grandis (altura, diâmetro do colo e na altura do peito - DAP verificou-se diferenças estatísticas entre as técnicas de preparação do solo, sendo os maiores valores nos tratamentos irregulares. Nas parcelas irregulares (IR-A e IR-B foram encontrados os maiores valores médios de altura (5,29 m e 5,46 m, diâmetro do colo (45,65 mm e 45,4 mm e DAP (4,44 cm e 4,79 cm, respectivamente. Pressupõe-se que as rugosidades funcionaram efetivamente como componentes auxiliares na internalização da matéria, retendo água, sedimentos e nutrientes, fato que deve ter potencializado e acelerado o crescimento do E. grandis.The aim of this study was to evaluate the process of growth of Eucalyptus grandis non-regularization when subjected to the ground. Relying on "Optical Chaos Theory" and starting from the assumption that the reforested

Antioxidant, antiglycation and insulinotrophic properties of Coccinia grandis (L. in vitro: Possible role in prevention of diabetic complications

Directory of Open Access Journals (Sweden)

Packirisamy Meenatchi

2017-01-01

Full Text Available In an attempt to develop Complementary and Alternative Medicine (CAM for the treatment of diabetes and related complications, the antidiabetic potential of the mature unripe fruits of Coccinia grandis (CGF was evaluated. Oxidative stress and glycation plays an important role in manifesting of diabetes and vascular complications. Agents with antioxidant and antiglycation properties may retard these pathological alterations. In this study, the edible plant Coccinia grandis was assessed for in vitro estimation of antioxidant and antiglycation potential and its insulinotrophic properties in RINm5F cells. Antioxidant activity was evaluated as DPPH (1,1-diphenyl-2-picrylhydrazyl, hydrogen peroxide and superoxide anion scavenging activities, whereas the protein glycation inhibitory potential was evaluated using in vitro albumin-fructose glycation model. Glycation inhibition was estimated by different biochemical parameters viz. fructosamine, protein carbonyl group and protein aggregation using thioflavin T fluorescence. C. grandis extract exerted a dose dependent radical scavenging activity and exhibited a significant antiglycation potential. The extract also showed a significant insulinotrophic property with 1.28 and 1.71-fold increase in insulin release when compared to control at 0.25 and 0.50 mg/mL, respectively. These data suggest the possible antidiabetic role of CGF extract, presumably by its antioxidant, antiglycation and insulin secretory effects. Present findings provide experimental evidence that the fruits of C. grandis have potential antidiabetic activity which might be used as a functional food and safe remedy for the treatment of diabetes and associated complications. This study also revealed that the plant can be a promising source for development of natural antiglycating agents and novel insulin secretagogues.

Identification of PEG-induced water stress responsive transcripts using co-expression network in Eucalyptus grandis.

Science.gov (United States)

Ghosh Dasgupta, Modhumita; Dharanishanthi, Veeramuthu

2017-09-05

Ecophysiological studies in Eucalyptus have shown that water is the principal factor limiting stem growth. Effect of water deficit conditions on physiological and biochemical parameters has been extensively reported in Eucalyptus. The present study was conducted to identify major polyethylene glycol induced water stress responsive transcripts in Eucalyptus grandis using gene co-expression network. A customized array representing 3359 water stress responsive genes was designed to document their expression in leaves of E. grandis cuttings subjected to -0.225MPa of PEG treatment. The differentially expressed transcripts were documented and significantly co-expressed transcripts were used for construction of network. The co-expression network was constructed with 915 nodes and 3454 edges with degree ranging from 2 to 45. Ninety four GO categories and 117 functional pathways were identified in the network. MCODE analysis generated 27 modules and module 6 with 479 nodes and 1005 edges was identified as the biologically relevant network. The major water responsive transcripts represented in the module included dehydrin, osmotin, LEA protein, expansin, arabinogalactans, heat shock proteins, major facilitator proteins, ARM repeat proteins, raffinose synthase, tonoplast intrinsic protein and transcription factors like DREB2A, ARF9, AGL24, UNE12, WLIM1 and MYB66, MYB70, MYB 55, MYB 16 and MYB 103. The coordinated analysis of gene expression patterns and coexpression networks developed in this study identified an array of transcripts that may regulate PEG induced water stress responses in E. grandis. Copyright © 2017 Elsevier B.V. All rights reserved.

Green synthesis of silver nanoparticles mediated by Coccinia grandis and Phyllanthus emblica: a comparative comprehension

Science.gov (United States)

Nayagam, Vasanth; Gabriel, Melchias; Palanisamy, Kumaravel

2018-04-01

Fruit extracts also have the potentiality to synthesize silver nanoparticles, which serve as antimicrobial agent in the biological field. At present, the field of biomedical largely depends on the biosynthesized NPs to fight against the multi-drug-resistant pathogens. The fruit residue of Coccinia grandis and Phyllanthus emblica are employed for synthesizing AgNPs by green method. The NPs are further subjected to UV, FTIR, SEM, and XRD measurements. The ten different pathogens were tested against the AgNPs synthesized. The same were tested for early growth of some seed variety too, so as to check the advantages of AgNPs. The UV spectrum analysis showed 442 nm and 423 nm, respectively, and FTIR peaks for the functional group that is responsible for the conversion of NPs were observed at 1640.02 for N-H bond amines (Coccinia grandis) and at 1637.45 for N-H bond amines (Phyllanthus emblica). The SEM results also illustrated that AgNPs are spherical in shape. The XRD patterns indicate the crystalline nature of the AgNPs formed with both these plants. The antimicrobial assay of AgNPs from Coccinia grandis shows maximum zone of inhibition (14 mm) for Vibrio cholerae whereas the AgNPs from Phyllanthus emblica show maximum inhibition at distinct points, namely for Staphylococcus aureus, Vibrio cholerae, Salmonella typhi, and Proteus mirabilis (12 mm). Seed germination initiated by AgNPs is quiet effective and healthier compared to the water-induced seeds. Hence, biogenic AgNPs have various applications in favour of human society.

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.

Dinâmica populacional e parasitismo natural de Diaphorina citri Kuwayama (Hemiptera: Liviidae em pomares de citros em Sergipe

Directory of Open Access Journals (Sweden)

Adriano Farias

2018-04-01

Abstract. The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae, which is the vector of the Hunglongbing (HLB bacterium, has become a key citrus pest in Brazil. In addition to citrus, the ornamental plant known as Orange Jasmine, Murraya paniculata (L. Jack, also hosts the psyllid. The present work aimed at studying the population dynamics of the psyllid in citrus orchards and its parasitism in citrus and M. paniculata in the state of Sergipe, the fourth largest citrus-producing state in Brazil. The evaluations were performed fortnightly for eleven months in seven Pera Citrus sinensis (L. Osbeck orange orchards located in two municipalities of Sergipe state (Boquim, and Umbauba. The populations of eggs, nymphs and adults of D. citri were compared among all orchards and all developmental stages were related to the abiotic factors temperature, relative humidity and precipitation, in each locality. The psyllid was classified as an accessory species (not very abundant in the orchards of Sergipe, showing a higher population density in November, December and March. Precipitation was the only abiotic factor that contributed to the population increase of adults of the psyllid. High rates of parasitism (55% of psyllid nymphs by the exotic parasitoid Tamarixia radiata Waterston (Hymenoptera: Eulophidae were detected in M. paniculata plants. Based on the results, if the HLB bacterium is detected in Sergipe, shorter samplings should be performed in the spring and summer months aiming at vector management. In addition, T. radiata could be released inundatively in integrated vector management programs.

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

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...

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...

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.

Spatial-temporal distribution of sharpshooters (Hemyptera: Cicadellidae insect vectors of Xylella fastidiosa in citrus orchards = Distribuição espaço-temporal de cigarrinhas (Hemiptera: Cicadellidae vetores da Xylella fastidiosa em pomares cítricos

Directory of Open Access Journals (Sweden)

Rúbia de Oliveira Molina

2016-07-01

Full Text Available Variegated chlorosis (CVC is a citrus disease, reported initially in the northwest of São Paulo state and in the Triângulo Mineiro region of Minas Gerais state in 1987. The CVC is caused by the xylematic bacteria Xylella fastidiosa. The bacteria is spread through contaminated bubbles or by insect vectors belonging to the Hemyptera order and Cicadellidae family. The aimed of this study was to identify the species of Xylella fastidiosa insect vector and to determine its spatial and temporal distribution in commercial orchards of sweet orange [Citrus sinensis (L. Osbeck]. The experiment was conducted in a commercial area of sweet orange, Pêra variety, grafted on Rangpur lime, located in northwest Paraná. For sampling, yellow sticky traps were used, distributed in the peripheral and central area of the orchard with four replicates per street sampled (5, 30, 55 and 80th plant, each plant was considered a sample unit. Were evaluated ten plots per street, totaling 40 traps for sampling. Every thirty days during the evaluation period, the traps were renewed in the orchard. The main species caught were Acrogonia citrine and Dilobopterus costalimai. The highest incidences occurred from winter to spring, and summer to autumn of the next year. According to the geostatistical analysis, the spatial distribution of these species concentrated in the peripheral zone of the portion where a higher incidence of these species was captured. The results show that it is necessary to adopt pest management practices for the Cicadellidae vector of X. fastidiosa differentiated in space and time. = A clorose variegada dos citros (CVC é uma doença de plantas cítricas, constatada, em 1987, inicialmente nos municípios do noroeste paulista e da região do triângulo mineiro. Ela é causada por uma bactéria de xilema, denominada Xylella fastidiosa. Sua disseminação ocorre através de borbulhas contaminadas ou por meio de insetos vetores da ordem Hemiptera e fam

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...

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)

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

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.

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.

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

Determination of chemical elements in Eucalyptus grandis, manured with Ballad's, by neutrons activation analysis

International Nuclear Information System (INIS)

Mateus, Natalina de Fatima; Madi Filho, Tufic

2007-01-01

The biosolid is a mud resulting from the biological treatment of wasted liquids. It is considered as a profitable alternative and important to minimize the environmental impact generated by the sewage thrown in to sanitary lands, in forest cultures like the Eucalyptus grandis. The objective of this work was to detect which chemical elements are present in Eucalyptus grandis samples, fertilized with different quantities of biosolid. The eucalyptuses of Estacao Experimental de Ciencias Florestais of Itatinga were planted in March of 1998 and collected with five years old. The used biosolid was produced by Station of Treatment of Sewer of Barueri - SP, classified as kind B. For the determination of the presence and quantity of chemical elements in the eucalyptus samples, an analysis technique by neutronic activation (NAA) was used followed by gamma rays spectroscopy. The samples were irradiated in the Nuclear Reactor IEA-R1 of IPEN-SP, followed by the measure of induced gamma rays activity, using a Detector HPGe. The presence, mainly of Br, Mn, Na and K, was detected in all analyzed samples. (author)

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

Effects of soybean Kunitz trypsin inhibitor on the cotton boll weevil (Anthonomus grandis).

Science.gov (United States)

Franco, Octávio L; Dias, Simoni C; Magalhães, Claudio P; Monteiro, Ana C S; Bloch, Carlos; Melo, Francislete R; Oliveira-Neto, Osmundo B; Monnerat, Rose G; Grossi-de-Sá, Maria Fátima

2004-01-01

The cotton boll weevil, Anthonomus grandis, is an economically important pest of cotton in tropical and subtropical areas of several countries in the Americas, causing severe losses due to their damage in cotton floral buds. Enzymatic assays using gut extracts from larval and adult boll weevil have demonstrated the presence of digestive serine proteinase-like activities. Furthermore, in vitro assays showed that soybean Kunitz trypsin inhibitor (SKTI) was able to inhibit these enzymes. Previously, in vivo effects of black-eyed pea trypsin chymotrypsin inhibitor (BTCI) have been demonstrated towards the boll weevil pest. Here, when neonate larvae were reared on an artificial diet containing SKTI at three different concentrations, a reduction of larval weight of up to 64% was observed for highest SKTI concentration 500 microM. The presence of SKTI caused an increase in mortality and severe deformities of larvae, pupae and adult insects. This work therefore represents the first observation of a Kunitz trypsin inhibitor active in vivo and in vitro against A. grandis. Bioassays suggested that SKTI could be used as a tool in engineering crop plants, which might exhibit increased resistance against cotton boll weevil.

Magnesium alleviates adverse effects of lead on growth, photosynthesis and ultrastructural alterations of Torreya grandis seedlings

Directory of Open Access Journals (Sweden)

Jie Shen

2016-11-01

Full Text Available Magnesium (Mg2+ has been shown to reduce the physiological and biochemical stress in plants caused by heavy metals. To date our understanding of how Mg2+ ameliorates the adverse effects of heavy metals in plants is scarce. The potential effect of Mg2+ on lead (Pb2+ toxicity in plants has not yet been studied. This study was designed to clarify the mechanism of Mg2+-induced alleviation of lead (Pb2+ toxicity. Torreya grandis (T. grandis seedlings were grown in substrate contaminated with 0, 700 and 1400 mg Pb2+ per kg-1 and with or without the addition of 1040 mg kg-1 Mg2+. Growth parameters, concentrations of Pb2+ and Mg2+ in the plants’ shoots and roots, photosynthetic pigment, gas exchange parameters, the maximum quantum efficiency (Fv/Fm, root oxidative activity, ultrastructure of chloroplasts and root growth were determined to analyze the effect of different Pb2+ concentrations in the seedlings as well as the potential ameliorating effect of Mg2+ on the Pb2+ induced toxicity. The growth of T. grandis seedlings cultivated in soils treated with 1400 mg kg-1 Pb2+ was significantly reduced compared with that of plants cultivated in soils treated with 0 or 700 mg kg-1 Pb2+. The addition of 1040 mg kg-1 Mg2+ improved the growth of the Pb2+-stressed seedlings, which was accompanied by increased chlorophyll content, the net photosynthetic rate and Fv/Fm, and enhanced chloroplasts development. In addition, the application of Mg2+ induced plants to accumulate five times higher concentrations of Pb2+ in the roots and to absorb and translocate four times higher concentrations of Mg2+ to the shoots than those without Mg2+ application. Furthermore, Mg2+ addition increased root growth and oxidative activity, and protected the root ultrastructure. To the best of our knowledge, our study is the first report on the mechanism of Mg2+-induced alleviation of Pb2+ toxicity. The gener¬ated results may have important implications for understanding the

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...

Inhibiting ethylene perception with 1-methylcyclopropene triggers molecular responses aimed to cope with cell toxicity and increased respiration in citrus fruits.

Science.gov (United States)

Establés-Ortiz, Beatriz; Romero, Paco; Ballester, Ana-Rosa; González-Candelas, Luis; Lafuente, María T

2016-06-01

The ethylene perception inhibitor 1-methylcyclopropene (1-MCP) has been critical in understanding the hormone's mode of action. However, 1-MCP may trigger other processes that could vary the interpretation of results related until now to ethylene, which we aim to understand by using transcriptomic analysis. Transcriptomic changes in ethylene and 1-MCP-treated 'Navelate' (Citrus sinensis L. Osbeck) oranges were studied in parallel with changes in ethylene production, respiration and peel damage. The effects of compounds modifying the levels of the ethylene co-product cyanide and nitric oxide (NO) on fruit physiology were also studied. Results suggested that: 1) The ethylene treatment caused sub-lethal stress since it induced stress-related responses and reduced peel damage; 2) 1-MCP induced ethylene-dependent and ethylene-independent responsive networks; 3) 1-MCP triggered ethylene overproduction, stress-related responses and metabolic shifts aimed to cope with cell toxicity, which mostly affected to the inner part of the peel (albedo); 4) 1-MCP increased respiration and drove metabolism reconfiguration for favoring energy conservation but up-regulated genes related to lipid and protein degradation and triggered the over-expression of genes associated with the plasma membrane cellular component; 5) Xenobiotics and/or reactive oxygen species (ROS) might act as signals for defense responses in the ethylene-treated fruit, while their uncontrolled generation would induce processes mimicking cell death and damage in 1-MCP-treated fruit; 6) ROS, the ethylene co-product cyanide and NO may converge in the toxic effects of 1-MCP. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Melhoramento do limoeiro-taiti por seleção de clones Tahiti lime breeding through clonal selection

Directory of Open Access Journals (Sweden)

J. O. Figueiredo

1976-01-01

Full Text Available Neste trabalho são relatados os resultados de produção e vigor das plantas em um experimento de competição de seis clones de limoeiro-taiti (Citrus latifolia Tanaka enxertados no porta-enxerto limoeiro-cravo (Citrus limonia Osbeck. Os resultados de seis anos consecutivos mostraram que o clone IAC 5 foi o mais produtivo superando, em média, todos os outros nas colheitas de janeiro, julho e outubro. Em segundo lugar colocou-se o IAC 2, cuja produção máxima se localizou, porém, no mês de abril, quando os preços do mercado são os mais baixos. O IAC 6 foi inferior a todos. Os clones IAC 1, IAC 3 e IAC 4, comportaram-se de maneira intermediária e a distribuição da produção do IAC 1 foi a mais favorável. O clone IAC 5 foi também o mais vigoroso e não apresentou fissuras na casca do tronco e dos ramos. IAC 2 foi o clone de menor vigor e juntamente com IAC 1 e IAC 6, o mais suscetível à incidência de fissuras.Six selected clones of Tahiti lime (Citrus latifolia Tanaka were evaluated in a field trial at the Estação Experimental de Limeira for fruit production and plant vigor, during six consecutive years. All six clones had the Rangpur lime (Citrus limonia Osbeck as rootstock. The relationship between monthly fruit price and seasonal yield data was also investigated. The clone IAC 5 showed the highest yield in January, July, and October when Tahiti lime price is maximum. This selection had the most vigorous plants with absence of cracks in the bark of the trunk and branches. The least vigorous material was the IAC 2 selection with a top yield in April, when fruit price is minimum. The clones IAC 1, IAC 3, and IAC 4 showed intermediate production while IAC 6 revealed the lowest yield.

Digestion kinetics of carbohydrate fractions of citrus by-products

DEFF Research Database (Denmark)

Lashkari, Saman; Taghizadeh, Akbar

2015-01-01

The present experiment was carried out to determine the digestion kinetics of carbohydrate fractions of citrus by-products. Grapefruit pulp (GP), lemon pulp (LE), lime pulp (LI) and orange pulp (OP) were the test feed. Digestion kinetic of whole citrus by-products and neutral detergent fiber (NDF......) fraction and acid detergent fiber (ADF) fractions of citrus by-products were measured using the in vitro gas production technique. Fermentation kinetics of the neutral detergent soluble carbohydrates (NDSC) fraction and hemicelluloses were calculated using a curve subtraction. The fermentation rate...... of whole was the highest for the LE (p by-products lag time was longer for hemicellulose than other carbohydrate fractions. There was no significant difference among potential gas production (A) volumes of whole test feeds (p

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)

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.

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...

Chemical Composition of Different Botanical Origin Honeys Produced by Sicilian Black Honeybees (Apis mellifera ssp. sicula).

Science.gov (United States)

Mannina, Luisa; Sobolev, Anatoly P; Di Lorenzo, Arianna; Vista, Silvia; Tenore, Gian Carlo; Daglia, Maria

2015-07-01

In 2008 a Slow Food Presidium was launched in Sicily (Italy) for an early warning of the risk of extinction of the Sicilian native breed of black honeybee (Apis mellifera L. ssp sicula). Today, the honey produced by these honeybees is the only Sicilian honey produced entirely by the black honeybees. In view of few available data regarding the chemical composition of A. mellifera ssp. sicula honeys, in the present investigation the chemical compositions of sulla honey (Hedysarum coronarium L.) and dill honey (Anethum graveolens L.) were studied with a multimethodological approach, which consists of HPLC-PDA-ESI-MSn and NMR spectroscopy. Moreover, three unifloral honeys (lemon honey (obtained from Citrus limon (L.) Osbeck), orange honey (Citrus arantium L.), and medlar honey (Eriobotrya japonica (Thunb.) Lindl)), with known phenol and polyphenol compositions, were studied with NMR spectroscopy to deepen the knowledge about sugar and amino acid compositions.

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...

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

African Journals Online (AJOL)

oma

models of citrus, production of bottled citrus juice, jams and marmalades. Although a lot of work has been done in development of improved technologies for ..... Acta. Horticulturae 123:23-27. Owoeye, T (2010) Nigeria: Training farmers will boost agricultural production. www.freshplaza.com/news_detail. Umeh, V.C, Garcia ...

Distribuição de raízes da laranja 'Valência' irrigada por autopropelido Root distribution of 'Valência' orange under traveler gun irrigation

Directory of Open Access Journals (Sweden)

Roberto Testezlaf

2007-06-01

Full Text Available O objetivo deste trabalho foi avaliar a distribuição do sistema radicular de laranjas 'Valência' com porta-enxerto limão 'Cravo' (Citrus limonia Osbeck, com 36 anos de idade, irrigadas por autopropelido, em Latossolo Vermelho-Amarelo. Foram retiradas amostras de solo em dois raios ortogonais de cinco árvores, um na direção da linha da cultura e outro na entrelinha, até 60 cm de profundidade. A distribuição do sistema radicular foi determinada pela massa de matéria seca das raízes com diâmetro igual ou menor que 1,5 mm. A camada de 0-40 cm apresentou o maior porcentual de raízes, para ambos os raios de amostragem, com redução na concentração a partir do final da copa das árvores para as entrelinhas da cultura.The objective of this work was to evaluate root distribution of 36 years old 'Valência' oranges with Citrus limonia Osbeck rootstock, under traveler gun irrigation, in Typic Hapludox. Soil samples were taken from five trees in two orthogonal radii, one in the direction of the crop rows and the other in between rows, at 60 cm depth. The root system distribution was determined by dry weight of the roots with diameters equal or less than 1.5 mm. The 0-40 cm soil layer showed the larger percentage of root, with reduction of root concentration from the end of the tree canopy to between rows.

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...

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

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.

Large-scale transcriptional profiling of lignified tissues in Tectona grandis.

Science.gov (United States)

Galeano, Esteban; Vasconcelos, Tarcísio Sales; Vidal, Mabel; Mejia-Guerra, Maria Katherine; Carrer, Helaine

2015-09-15

Currently, Tectona grandis is one of the most valuable trees in the world and no transcript dataset related to secondary xylem is available. Considering how important the secondary xylem and sapwood transition from young to mature trees is, little is known about the expression differences between those successional processes and which transcription factors could regulate lignin biosynthesis in this tropical tree. Although MYB transcription factors are one of the largest superfamilies in plants related to secondary metabolism, it has not yet been characterized in teak. These results will open new perspectives for studies of diversity, ecology, breeding and genomic programs aiming to understand deeply the biology of this species. We present a widely expressed gene catalog for T. grandis using Illumina technology and the de novo assembly. A total of 462,260 transcripts were obtained, with 1,502 and 931 genes differentially expressed for stem and branch secondary xylem, respectively, during age transition. Analysis of stem and branch secondary xylem indicates substantial similarity in gene ontologies including carbohydrate enzymes, response to stress, protein binding, and allowed us to find transcription factors and heat-shock proteins differentially expressed. TgMYB1 displays a MYB domain and a predicted coiled-coil (CC) domain, while TgMYB2, TgMYB3 and TgMYB4 showed R2R3-MYB domain and grouped with MYBs from several gymnosperms and flowering plants. TgMYB1, TgMYB4 and TgCES presented higher expression in mature secondary xylem, in contrast with TgMYB2, TgHsp1, TgHsp2, TgHsp3, and TgBi whose expression is higher in young lignified tissues. TgMYB3 is expressed at lower level in secondary xylem. Expression patterns of MYB transcription factors and heat-shock proteins in lignified tissues are dissimilar when tree development was evaluated, obtaining more expression of TgMYB1 and TgMYB4 in lignified tissues of 60-year-old trees, and more expression in TgHsp1, TgHsp2, Tg

Migration and dispersal of Anthonomus grandis (Coleoptera: Curculionidae in South America

Directory of Open Access Journals (Sweden)

Teodoro STADLER

2007-01-01

Full Text Available El presente estudio sobre la dispersión de Anthonomus grandis Boheman, el picudo del algodonero, en Argentina, Brasil, Paraguay y Bolivia, explora las características ecológicas y fisiológicas que han permitido a este insecto dispersarse y establecerse exitosamente en América del Sur. La plasticidad fenotípica de A. grandis se caracteriza por un tiempo de desarrollo flexible, ciclo de vida multivoltino con generaciones superpuestas, la capacidad de alimentarse con polen de diversas familias botánicas así como de otras fuentes de alimento y por su habilidad para migrar y dispersarse con la ayuda del viento. Todo esto hace de esta especie una plaga clave para el cultivo del algodón. Los cultivos de cítricos en Misiones, Argentina, son posibles sitios para la hibernación de esta especie. En esta región fueron capturadas grandes cantidades de individuos prediapausantes, provenientes de algodonales en post-cosecha en Paraguay, atraídos probablemente por compuestos volátiles de cítricos cultivados en la zona. La quiescencia facultativa que atraviesan los adultos ante condiciones adversas, conlleva a un retraso en el desarrollo que se relaciona con las condiciones desfavorables. Esto sugiere que la hibernación en A. grandis puede ser definida como «oligopausa», una forma intermedia de diapausa. Desde su introducción en Brasil en 1983 y hasta el 2006, el picudo se ha dispersado en dirección sudoeste hacia Argentina, a una velocidad promedio de 61 km año-1. Sin embargo, le ha insumido aproximadamente diez años cruzar 250 km, desde Paraguay hacia el centro de la zona algodonera de Argentina. Este progreso más lento se debe probablemente a las acciones llevadas a cabo en el marco del programa de erradicación del picudo del algodonero, por parte del gobierno de Argentina. La llegada del picudo al área central de cultivo de algodón en la Argentina, así como a otras áreas de cultivo en Paraguay y Argentina, confirma el hecho de que

Propriedades de chapas de flocos fabricadas com adesivo de uréia-formaldeído e de taninos da casca de Eucalyptus grandis W. Hill ex Maiden ou de Eucalyptus pellita F. Muell. Properties of flakeboards made from urea-formaldehyde and bark tannins adhesives of Eucalyptus grandis or Eucalyptus pellita

Directory of Open Access Journals (Sweden)

Angélica de Cássia Oliveira Carneiro

2004-10-01

Full Text Available Os taninos foram extraídos da casca de Eucalyptus grandis e Eucalyptus pellita, com água quente, à qual se adicionaram 4,5% de sulfito de sódio, durante três horas. As temperaturas da solução foram iguais a 70 e 100 ºC para Eucalyptus grandis e Eucalyptus pellita, respectivamente. Para a produção dos adesivos e com o intuito de reduzir a sua viscosidade, os taninos foram sulfitados com sulfito de sódio e ácido acético. Formulações adesivas foram preparadas adicionando-se 0, 25, 50, 75 ou 100% de adesivos tânicos ao adesivo comercial de uréia-formaldeído. Foram fabricadas chapas de flocos de Pinus elliottii Engelm. e Eucalyptus grandis, utilizando-se 8% da formulação adesiva. As propriedades das chapas foram determinadas segundo a norma ASTM D-1037, de 1993. Observou-se que as propriedades das chapas foram superiores ao mínimo estabelecido pela norma ANSI/A 280.1-93, exceto no caso da resistência à umidade. Verificou-se, ainda, que o emprego de uma formulação adesiva contendo resina à base de uréia-formaldeído e tanino-formaldeído pode melhorar algumas propriedades.Bark tannins of Eucalyptus grandis and Eucalyptus pellita were extracted with 4,5% sodium sulfite in hot water solution for a period of three hours. Solution temperatures were 70 and 100ºC, for Eucalyptus grandis and Eucalyptus pellita bark respectively. Tannins were reacted with acetic acid and sodium sulfite to reduce adhesive viscosity. Adhesive formulations were prepared adding 0, 25, 50, 75 or 100% of tannin adhesives to the commercial urea-formaldehyde adhesive. Flakeboards were fabricated with 8% resin content. Board properties were determined according to ASTM D-1037 standards. Except for humidity, all board properties were superior to the values established by ANSI.A 208.1-93 commercial standard. Addition of tannins to the urea-formaldehyde adhesive improved some properties.

Projeção do Custo do Suco de Laranja Pela Aplicação da Simulação Bootstrap

OpenAIRE

Joaquim Eduardo de Moura Nicacio

2014-01-01

Essa pesquisa teve por objetivo a utilização da técnica Bootstrap na determinação do volume médio populacional de suco de laranja, obtida entre quatro amostras provenientes de produtores dessa fruta denominada Citrus sinensis (L) Osbeck, do município de Primavera do Leste.  A cadeia de produção agroindustrial da laranja, ainda incipiente nesse município, deve ser monitorada em suas operações principalmente a industrialização e, a qualidade da matéria prima deve ser rigorosamente controlada. A...

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...

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.

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.

RESISTÊNCIA BIOLÓGICA DA MADEIRA TRATADA DE Eucalyptus grandis E Eucalyptus cloeziana A FUNGOS APODRECEDORES EM ENSAIOS DE LABORATÓRIO

Directory of Open Access Journals (Sweden)

Magnos Alan Vivian

2015-01-01

Full Text Available The present study aimed to evaluate the biological resistance of treated wood from Eucalyptus grandis and Eucalyptus cloeziana under the action of biodeteriorative organisms in laboratory testing. Thus, we used trees of Eucalyptus grandis and Eucalyptus cloeziana, both 16 years old, which was converted into planks and subjected to preservative treatment in an autoclave with chromate copper arsenate (CCA. Then, it was made the specimens for the conduct of accelerated decay test, as recommended by ASTM. From the results, it was observed for the fungus Trametes versicolor that the preservative treatment was effective in reducing the biological degradation of the wood of the two species, with reduced mass loss in 35.17 and 82.31% for wood Eucalyptus grandis and Eucalyptus cloeziana, respectively, as for the fungus Gloeophyllum trabeum mass loss was reduced by 6.79 and 96.65%, compared to the control. Based on the conditions of realization of the present study, it was observed that preservative treatment with CCA is effective in the increasing the biological resistance of the wood under the action of fungi Trametes versicolor and Gloeophyllum trabeum.

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...

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.

Red de coexpresión de 320 genes de Tectona grandis Relacionados con procesos de estrés abiótico y xilogénesis

Directory of Open Access Journals (Sweden)

Vladimir Camel

2017-01-01

Full Text Available Tectona grandis es un árbol maderable de importancia económica en bosques tropicales y subtropicales. Mediante este estudio, se identificaron familias de factores de transcripción (FTs y genes codificantes para enzima, diferencialmente expresados en el xilema del tallo, implicados en la regulación de la respuesta a estrés abiótico y xilogénesis en T. grandis . Así, fue analizada la distribución evolutiva de 19 genes codificantes para FTs de T. grandis mediante análisis filogenéticos. También, fue utilizada la minería de bases de datos y publicaciones para identificar 320 genes de Arabidopsis thaliana (ortólogos a T. grandis como soporte experimental y predictivo. Como resultados, se encontraron FTs de las familias bZIP, MYB, NAC, ER, b HLH , NuY y genes que codifican enzimas. Así mismo, se logró analizar el interactoma de T. grandis encontrando correlaciones de Pearson significativas para genes que regulan vías metabólicas de fenilpropanoides y estrés abiótico. Además, la red de coexpresión reveló nodos y aristas entre los genes TgRAP1, TgMyB1, TgHSF1, TgMyB3, TgNAC1, TgTsiid1, TgLieTFs1, TgNuy3, TgRAP2 y TgNuy4 . En particular, los análisis de ontología génica mostraron 31 genes de respuesta a estrés abiótico, principalmente TgHShT1, TgHSF1 y TgHSF2 como correguladores. Además, se encontró que el regulador maestro TgNAC1 , está involucrado en la corregulación de otros factores de transcripción.

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.

Host status of grapefruit and Valencia oranges for Anastrepha serpentina and Anastrepha ludens (Diptera: Tephritidae).

Science.gov (United States)

Mangan, Robert L; Thomas, Donald B; Moreno, Aleena M Tarshis

2011-04-01

Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) is sporadically captured in the Rio Grande Valley of Texas. Although its preferred hosts are in the Sapotaceae family, several varieties of Citrus, including grapefruit and oranges are listed as alternate hosts. Although Mexican fruit fly, Anastrepha ludens (Loew), is known to be a major pest of Citrus, doubt exists as to the status of Citrus as a breeding host for A. serpentina. To evaluate the host status of commercial Citrus for A. serpentina we compared oviposition and development with that of A. ludens under laboratory conditions with 'Rio Red' grapefruit (Citrus paradisi MacFayden) and 'Valencia' oranges [Citrus sinensis (L.) Osbeck] in different stages of maturity. Both fly species oviposited in early season fruit in which the eggs and larvae died in the fruit albedo. Survival of either species to the adult stage occurred in later season grapefruit. In oranges, no A. serpentina larvae survived compared with 150 A. ludens surviving to adults. Survival on both Citrus species was much lower for A. serpentina, only approximately 5% of eggs eclosed into larvae in grapefruit compared with approximatley 50% for A. ludens. In oranges approximately 16% of A. serpentina eggs eclosed compared with approximately 76% for A. ludens. In grapefruit, only one fourth as many A. serpentina larvae survived to the adult stage compared with A. ludens. Additional experiments were performed in a greenhouse on small, caged trees of la coma (Sideroxylon celastrinum H.B.K.), a Texas species of Sapotaceae. The A. serpentina females readily oviposited into these berries and normal adults emerged. The present low incidence of the adults, coupled with the high mortality during development of the larvae, suggests that Texas citrus is unlikely to support a breeding population of A. serpentina.

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.

Investigation of ESEM/EDX to measure liquor penetration and diffusion in Eucalyptus grandis wood chips during kraft pulping

CSIR Research Space (South Africa)

Grzeskowiak, V

2011-01-01

Full Text Available Environmental scanning electron microscopy coupled with energy dispersive x-ray (ESEM/EDX) was optimised to measure the penetration and diffusion of cooking liquor into Eucalyptus grandis wood chips during kraft pulping. The moisture content...

Use of glass transition temperature for stabilization of board's cracks of Eucalyptus grandis

Directory of Open Access Journals (Sweden)

Fred W. Calonego

2010-09-01

Full Text Available The Eucalyptus grandis logs temperatures were determined and correlated with the board's cracks during steaming. Thermocouples were inserted in the logs center, registering their temperatures during steaming at 90"C. The logs were sawed and the board's cracks measured. It was concluded that: (1 the logistic S-shaped curve explains the logs temperature variation; (2 the logs with diameter of 20 to As temperaturas em toras de Eucalyptus grandis, durante a vaporização, foram determinadas e correlacionadas com as rachaduras das tábuas. Nos centros das toras foram inseridos termopares e registradas suas temperaturas durante a vaporização à 90"C. As toras foram desdobradas e as rachaduras das tábuas mensuradas. Concluiu-se que: (1 o modelo estatístico sigmoidal logístico explica a variação da temperatura nas toras; (2 as toras com 20 a <25, 25 a <30 e 30 a <35 cm de diâmetro apresentaram, respectivamente, 84,2"C, 73,1"C e 45,8"C ao final da vaporização; e (3 as rachaduras foramsignificativamente menores nas toras que atingiram a temperatura de transição vítrea.

MARCADORES RAPD PARA MAPEAMENTO GENÉTICO E SELEÇÃO DE HÍBRIDOS DE CITROS RAPD MARKERS TO GENETIC MAPPING AND SELECTION OF CITRUS HYBRIDS

Directory of Open Access Journals (Sweden)

ROBERTO PEDROSO DE OLIVEIRA

2001-12-01

Full Text Available Os marcadores moleculares apresentam várias aplicações no melhoramento de plantas, permitindo uma série de análises genéticas. Este trabalho foi realizado com o objetivo de estabelecer marcadores RAPD para serem utilizados em estudos de mapeamento genético e na seleção de híbridos entre tangerina-'Cravo' (Citrus reticulata Blanco e laranja-'Pêra' (C. sinensis (L. Osbeck. Extraiu-se DNA de folhas dos parentais e de seis híbridos F1. As reações de amplificação foram preparadas em 13 uL de solução, constituída por tampão 1x GIBCO BRL; soluções 1,54 mM de MgCl2 e 0,2 mM de cada dNTP; 15 ng de cada 'primer'; 1,5 unidade de 'Taq DNA Polymerase' e 15 ng de DNA genômico. As reações foram realizadas em termocicladores programados para 36 ciclos de 1 min a 92ºC, 1 min a 36ºC, 2 min a 72ºC e 10 min de extensão a 72ºC. Foram testados 'primers' decâmeros arbitrários dos 'kits' A, AB, AT, AV, B, C, D, E, G, H, M, N, P, Q, R e U da Operon, sendo selecionados 113 por apresentarem polimorfismo, com número de marcadores variando de 1 a 6 por 'primer'. Esses 'primers' amplificaram 201 (23,13% bandas polimórficas, aplicáveis no mapeamento genético e seleção de híbridos. A freqüência de 'primers' com 1; 2; 3; 4; 5 e 6 bandas polimórficas foi de 49,5%, 33,6%, 9,7%, 4,4%, 1,8% e 1,0%, respectivamente.Molecular markers have many applications in plant breeding, enabling some types of genetic analyses. The aim of this work was to establish RAPD markers to be used to genetic mapping studies and selection of hybrids between 'Cravo' tangerine (Citrus reticulata Blanco and 'Pêra' orange (C. sinensis (L. Osbeck. DNA of the parents and six hybrids F1 was isolated from the leaves. The amplification reactions were performed in volumes of 13 µL, composed by GIBCO BRL 1x buffer, 1,54 mM MgCl2, 0,2 mM of each dNTP, 15 ng of each primer, 1,5 unit of Taq DNA Polymerase and 15 ng of genomic DNA. These reactions were carried out in

Previsão do número de frutos a partir da quantidade de estruturas reprodutivas em laranjeiras

Directory of Open Access Journals (Sweden)

Glauco de Souza Rolim

2008-03-01

Full Text Available O trabalho buscou testar a hipótese de que o número final de frutos (nº/m³ depende da quantidade de botões florais, flores e/ou chumbinhos que ocorreram previamente. Esta hipótese baseia-se na premissa de que a planta integraliza as condições edafoclimáticas disponíveis para seu crescimento e desenvolvimento. A hipótese foi testada em laranjeira "Valência" (Citrus sinensis (L. Osbeck. enxertada em: tangerineira "Cleópatra" (VCL (Citrus reshni Hort. ex Tan. e limoeiro "Cravo" (VCR (Citrus limonia Osbeck. Foram avaliadas as seguintes relações entre as estruturas reprodutivas: Frutos= f(Chumbinhos; Frutos= f(Flores; Frutos= f(Botões; como também Flores= f(Botões, e Chumbinhos= f(Flores; além de Frutos= f(flores do lado noroeste para a VCL, e Frutos= f(botões do lado noroeste para VCR sugeridos por análise de cluster. As avaliações do número de estruturas reprodutivas foram realizadas nos quatro pontos cardeais da copa (1m³/setor. Devido aos elevados valores de R², índice de concordância (d e relativos baixos erros absolutos percentuais médios (EAPM, resultantes de regressão exponencial, em relação a: Flores = f(botões (R²=0,85 e R²=0,82; d= 0,95 e d= 0,95; EAPM= 15,2% e EAPM= 19,1%, para VCL e VCR, respectivamente e principalmente ao número de frutos (por exemplo: Frutos = f(botões; (R²=0,62 e R²=0,71; d= 0,89 e d= 0,88; EAPM= 5,0% e EAPM= 2,1%, para VCL e VCR, respectivamente, verificou-se que a hipótese proposta é verdadeira, ou seja, é possível a estimativa do número futuro de frutos, a partir do número atual de estruturas reprodutivas (botões florais e flores.

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...

Effects of an inducible aiiA gene on disease resistance in Eucalyptus urophylla × Eucalyptus grandis.

Science.gov (United States)

Ouyang, L J; Li, L M

2016-08-01

N-acyl-homoserine lactones (AHLs) are metabolites of mostly gram-negative bacteria and are critical signaling molecules in bacterial quorum-sensing systems. At threshold concentrations, AHLs can activate the expression of pathogenic genes and induce diseases. Therefore, reducing AHL concentrations is a key point of disease control in plants. AHL-lactonase, which is expressed by aiiA, is widespread in Bacillus sp and can hydrolyze AHLs. In the present study, we cloned aiiA from Bacillus subtilis by PCR. A plant expression vector of aiiA was constructed and name Pcam-PPP3-aiiA, in which expression of aiiA was controlled by the pathogen-inducible plant promoter PPP3. The recombinant plasmid was transferred into Eucalyptus × urophylla × E. grandis by an Agrobacterium-mediated transformation. PCR and Southern blotting showed that aiiA was successfully integrated into the E. urophylla × E. grandis genome and its expression was induced by Ralstonia solanacearum 12 h after inoculation, as shown by reverse transcription-PCR. The transcription efficacy of aiiA increased 43.88-, 30.65-, and 18.95-fold after inoculation with R. solanacearum, Erwinia carotovora ssp. zeae (Sabet) and Cylindrocladium quinqueseptatum, respectively as shown by RT-real-time PCR. Transgenic E.urophylla × E.grandis expressing the AIIA protein exhibited significantly enhanced disease resistance compared to non-transgenic plants by delaying the onset of wilting and reducing the disease index.

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.

Análise espaço-temporal da clorose variegada dos citros no Noroeste do Paraná, com uso de PCR para detecção de Xylella fastidiosa = Spatio-temporal analysis of the citrus variegated chlorosis (CVC in the Northwest of Paraná, using PCR for detection of Xylella fastidiosa

Directory of Open Access Journals (Sweden)

William Mário de Carvalho Nunes

2006-07-01

Full Text Available A citricultura é afetada por inúmeras doenças, como a clorose variegada do citros (CVC, causada pela bactéria Xylella fastidiosa. O objetivo deste trabalho foi determinar a distribuição espacial da doença dentro de pomares comerciais do Noroeste do Paraná com o uso de métodos moleculares. Foram selecionados pomares sintomáticos para CVC com as variedades ‘Pêra’, ‘Valência’ e ‘Folha Murcha’ (Citrus sinensis Osbeck. Foram marcadas para cada variedade, 4 plantas-referência positivas para CVC (por sintomas e análise molecular e 8 plantas ao redor de cada uma das plantas-referência foram amostradas, num total de 36 plantas por variedade. Realizou-se o teste da Reação da Polimerase em Cadeia (PCR para detecção da bactéria e na mesma época foram conduzidas avaliações visuais de sintomas de CVC. Os resultados da análise temporal, utilizando-se os modelos Monomolecular, Logístico e Gompertz, apontaram o modelo Logístico como o que melhor se ajustou para descrever o comportamento da doença no tempo, para todas as variedades estudadas. Observou-se que o comportamento espacial da doença diferiu quando a mesma área foiavaliada pelos métodos visual e molecular, resultando em uma diferença no padrão espacial das áreas avaliadas. Portanto, ambos os métodos empregados, sintomas e PCR, foram capazes de constatar asmudanças no padrão espacial apresentado, sendo que a análise molecular (PCR foi mais sensível para detectar as mudanças ocorridas.Countless diseases affect the citriculture, as the citrus variegated chlorosis (CVC which is caused by the bacteria Xylella fastidiosa.The aim of this work was to determine the space distribution of the disease inside commercial orchards in the Northwest of Paraná, using molecular methods. Symptomatic orchards were selected for CVC with the varieties 'Pêra', 'Valência' and 'Folha Murcha' (Citrus sinensis Osbeck. For each variety, 4 positive reference-plant for CVC

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.

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.

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.

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

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.

Activity of a Brazilian strain of Bacillus thuringiensis israelensis against the cotton Boll Weevil Anthonomus grandis Boheman (Coleoptera: Tenebrionidae).

Science.gov (United States)

Monnerat, R; Martins, E; Praça, L; Dumas, V; Berry, C

2012-02-01

A Brazilian Bacillus thuringiensis subspecies israelensis, toxic to Diptera, including mosquitoes, was found also to show toxicity to the coleopteran boll weevil Anthonomus grandis Boheman at an equivalent level to that of the standard coleopteran-active B. thuringiensis subspecies tenebrionis T08017. Recombinant B. thuringiensis strains expressing the individual Cyt1Aa, Cry4Aa, Cry4Ba and Cry11Aa toxins from this strain were assessed to evaluate their potential contribution to the activity against A. grandis, either alone or in combination. Whilst individual toxins produced mortality, none was sufficiently potent to allow calculation of LC50 values. Combinations of toxins were unable to attain the same potency as the parental B. thuringiensis subsp. israelensis, suggesting a major role for other factors produced by this strain.

Nutrient digestibility and evaluation of protein and carbohydrate fractionation of citrus by-products

DEFF Research Database (Denmark)

Lashkari, Saman; Taghizadeh, Akbar

2013-01-01

The protein and carbohydrate fractionation and nutrient digestibility of citrus by‐products were determined. Ruminal, intestinal and total tract CP disappearance values were measured by a modified three‐step (MTSP) method and in vitro CP disappearance method (IVCP). Test feeds were orange pulp (OP...... to the results, it could be concluded that citrus by‐products have high nutritive value and also, the in vitro techniques can be easily used to determine of the nutritive value of citrus by‐products....

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

Systematics and evolution of the Meriones shawii/grandis complex (Rodentia, Gerbillinae) during the Late Quaternary in northwestern Africa: Exploring the role of environmental and anthropogenic changes

Science.gov (United States)

Stoetzel, Emmanuelle; Cornette, Raphaël; Lalis, Aude; Nicolas, Violaine; Cucchi, Thomas; Denys, Christiane

2017-05-01

Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern (M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis, seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture

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)

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.

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...

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

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.

PHLOEM PROMOTERS IN TRANSGENIC SWEET ORANGE ARE DIFFERENTIALLY TRIGGERED BY Candidatus Liberibacter asiaticus

Directory of Open Access Journals (Sweden)

LUZIA YURIKO MIYATA

Full Text Available ABSTRACT The use of promoters preferentially expressed in specific plant tissues is a desirable strategy to search for resistance for pathogens that colonize these tissues. The bacterium Candidatus Liberibacter asiaticus (Las, associated with huanglongbing disease (HLB of citrus, colonizes phloem vessels. Some promoters, besides conferring tissue-specific expression, can also respond to the presence of the pathogen. The objective of the present study was to verify if the presence of Las could modulate the activation of the phloem-specific promoters AtPP2 (Arabidopsis thaliana phloem protein 2, AtSUC2 (A. thaliana sucrose transporter 2 and CsPP2 ( pCitrus phloemrotein 2, known to be expressed in Citrus sinensis phloem. ‘Hamlin’ sweet orange plants (Citrus sinensis L. Osbeck transformed with the uidA (GUS reporter gene under the control of AtPP2, AtSUC2 and CsPP2 promoters were infected to evaluate the interdependence between transgene expression and the concentration of Las. Plants were inoculated with Las by Diaphorina citri and eighteen months later, bacterial concentration and uidA expression were determined by qPCR and RT-qPCR, respectively. Reporter gene expression driven by AtSUC2 promoter was strongly and positively correlated with Las concentration. Therefore, this promoter combines desirable features of both tissue-specificity and pathogen-inducibility for the production of transgenic plants tolerant to Las.

Above-ground dry matter accumulation by Eucalyptus grandis and its relation to standard meteorological data

International Nuclear Information System (INIS)

Byrne, G.F.

1989-01-01

The relationship between the rate of increase of biomass in some stands of Eucalyptus grandis, growing near Coffs Harbour, N.S.W., Australia, is explored in terms of estimated evapotranspiration and radiation interception, and related to a similar previous study of Pinus radiata. A possible role of method of planting, site slope and site aspect in biomass increase is also discussed

Intercropping Acacia mangium stimulates AMF colonization and soil phosphatase activity in Eucalyptus grandis

OpenAIRE

Bini, Daniel; Santos, Cristiane Alcantara dos; Silva, Mylenne Calcciolari Pinheiro da; Bonfim, Joice Andrade; Cardoso, Elke Jurandy Bran Nogueira

2018-01-01

ABSTRACT: Arbuscular mycorrhizal fungi (AMF) are very important to plant nutrition, mostly in terms of acquisition of P and micronutrients. While Acacia mangium is closely associated with AMF throughout the whole cycle, Eucalyptus grandis presents this symbiosis primarily at the seedling stage. The aim of this study was to evaluate the dynamics of AMF in these two tree species in both pure and mixed plantations during the first 20 months after planting. We evaluated the abundance, richness an...

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.

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...

Traits and trade-offs in whole-tree hydraulic architecture along the vertical axis of Eucalyptus grandis.

Science.gov (United States)

Pfautsch, Sebastian; Aspinwall, Michael J; Drake, John E; Chacon-Doria, Larissa; Langelaan, Rob J A; Tissue, David T; Tjoelker, Mark G; Lens, Frederic

2018-01-25

Sapwood traits like vessel diameter and intervessel pit characteristics play key roles in maintaining hydraulic integrity of trees. Surprisingly little is known about how sapwood traits covary with tree height and how such trait-based variation could affect the efficiency of water transport in tall trees. This study presents a detailed analysis of structural and functional traits along the vertical axes of tall Eucalyptus grandis trees. To assess a wide range of anatomical and physiological traits, light and electron microscopy was used, as well as field measurements of tree architecture, water use, stem water potential and leaf area distribution. Strong apical dominance of water transport resulted in increased volumetric water supply per unit leaf area with tree height. This was realized by continued narrowing (from 250 to 20 µm) and an exponential increase in frequency (from 600 to 13 000 cm-2) of vessels towards the apex. The widest vessels were detected at least 4 m above the stem base, where they were associated with the thickest intervessel pit membranes. In addition, this study established the lower limit of pit membrane thickness in tall E. grandis at ~375 nm. This minimum thickness was maintained over a large distance in the upper stem, where vessel diameters continued to narrow. The analyses of xylem ultrastructure revealed complex, synchronized trait covariation and trade-offs with increasing height in E. grandis. Anatomical traits related to xylem vessels and those related to architecture of pit membranes were found to increase efficiency and apical dominance of water transport. This study underlines the importance of studying tree hydraulic functioning at organismal scale. Results presented here will improve understanding height-dependent structure-function patterns in tall trees. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

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.

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.