999 resultados para C. sinensis


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Orange seeds are a promising agroindustry-waste which can be implemented in the extraction and production of vegetable oil. The relationship between moisture content and water activity provides useful information for the processing and storage of this waste item. The aim of this study was to determine the mechanism of water sorption enthalpy-entropy of orange seeds (C. sinensis cv. Brazilians) according to the moisture content. Therefore, desorption isotherms were determined at five different temperature (30, 40, 50, 60, and 70 ºC) under a wide range of moisture content (0.005-0.057 kg kg-1 d.b.) and water activity (0.02-0.756). Theoretical and empirical models were used for modeling the desorption isotherms. An analytical solution of the Clausius-Clapeyron equation was proposed to compute the isosteric heat of sorption, the differential entropy, and Gibbs free energy using the Oswin model when the effect of temperature on the hygroscopic equilibrium was considered.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Transgenic Citrus sinensis (L.) Osb. cv. Hamlin plants expressing the hrpN gene were obtained by Agrobacterium tumefaciens (Smith and Towns) Conn-mediated transformation. hrpN encodes a harpin protein, which elicits the hypersensitive response and systemic acquired resistance in plants. The gene construct consisted of gst1, a pathogen-inducible promoter, a signal peptide for protein secretion to the apoplast, the selection genes nptI1 or aacC1 and the Nos terminator. The function of gst1 in citrus was evaluated in transgenic C. sinensis cv. Valencia harboring the reporter gene uidA (gus) driven by this promoter. Histochemical analysis for gus revealed that gst1 is activated in citrus leaves by both wounding and inoculation with Xanthomonas axonopodis Starr and Garces pv. citri (Hasse) Vauterin et al. Genetic transformation was confirmed by Southern blot hybridization in eight cv. Hamlin acclimatized plants. RT-PCR confirmed hrpN gene expression in seven cv. Hamlin transgenic lines before pathogen inoculation. Some hrpN transgenic lines showed severe leaf curling and abnormal growth. Six hrpN transgenic lines were propagated and evaluated for susceptibility to X axonopodis pv. citri. RT-PCR confirmed gene expression in all six hrpN transgenic lines after pathogen inoculation. Several of the hrpN transgenic lines showed reduction in susceptibility to citrus canker as compared with non-transgenic plants. One hrpN transgenic line exhibited normal vegetative development and displayed very high resistance to the pathogen, estimated as up to 79% reduction in disease severity. This is the first report of genetic transformation of citrus using a pathogen-inducible promoter and the hrpN gene. Further evaluations of the transgenic plants under field conditions are planned. Nevertheless, the evidence to date suggests that the hrpN gene reduces the susceptibility of citrus plants to the canker disease. (C) 2009 Elsevier B.V. All rights reserved.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

A study was made to observe the association between the resistance to reinfection induced by irradiated metacercariae (MC) of Clonorchis sinensis and antigen specific Th1- and Th2-type cytokine productions in rats. Rats were infected with 20 MC of C. sinensis, previously exposed to a single dose of gamma irradiation, which varied from 0 to 100 Gy. All of them, single dose of 12 Gy showed higher IgG antibody titer with lowest worm recovery. Thus, 50 MC were used to challenge infection in rats previously infected with 20 MC irradiated at 12 Gy and the highest resistance to challenge infection was observed. The results of lymphocyte proliferation with specific antigen, ES Ag were shown no difference of proliferative responses as compared with primary and challenge infection at 12 Gy irradiation dose. In the case of cytokines production were observed that interferon (IFN-gamma) and interlukin (IL-2) were significantly enhanced, while IL-4 and IL-10 was almost unchanged to make comparison between primary and secondary infection at 12 Gy irradiation dose. In conclusion, the single dose of 12 Gy could be adopted for induction of the highest resistance to challenge infection. Up-regulation of Th1 type cytokines, IFN-gamma and IL-2 may be affected to develop vaccine by irradiated MC.

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Pós-graduação em Ciências Fisiológicas - FOA

Relevância:

70.00% 70.00%

Publicador:

Resumo:

Celtis sinensis is an introduced plant species to the southeastern region of Queensland that has had a destructive affect on indigenous plant Communities and its pollen has been identified as an allergen Source. Pollen belonging to C. sinensis was sampled during a 5-year (June 1994-May 1999) atmospheric pollen-monitoring programme in Brisbane, Australia, using a Burkard 7-day spore trap. The seasonal incidence of airborne C. sinensis pollen (CsP) in Brisbane occurred over a brief period each year during spring (August-September), while peak concentrations were restricted to the beginning of September. individual CsP seasons were heterogeneous with daily counts within the range 1-10 grains m(-3) on no more than 60 sampling days; however, smaller airborne concentrations of CsP were recorded out of each season. Correlation co-efficients were significant each year for temperature (p0.05) and relative humidity (p>0.05). A significant relationship (r(2)=0.81, p=0.036) was established between the total CsP count and pre-seasonal average maximum temperature; however, periods of precipitation (>2mm) were demonstrated to significantly lower the daily concentrations of CsP from the atmosphere. Given the environmental and clinical significance of CsP and its prevalence in the atmosphere of Brisbane, a Clinical population-based Study is required to further understand the pollen's importance as a seasonal sensitizing source in this region.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Despite its outstanding position, the Brazilian citriculture is established on a very limited pool of varieties that limits its expansion and restricts the fruit availability throughout the year. This situation determines the urgent necessity of developing alternative scion and rootstock cultivars, with good performance under local conditions. `Folha Murcha` sweet orange (Citrus sinensis (L.) Osbeck) is a late-harvest cultivar, suitable both for the juice processing industry and the fresh fruit market, being described as tolerant to citrus canker (Xanthomonas citri subsp. citri Schaad et al.), and less affected by citrus variegated chlorosis (Xylella fastidiosa Wells et al.). A study was conducted in Bebedouro, Sao Paulo State, Brazil, to evaluate the horticultural performance of `Folha Murcha` sweet orange budded onto 12 rootstocks: the citrandarin `Changsha` mandarin (Citrus reticulata Blanco) x Poncirus trifoliata `English Small`: the hybrid `Rangpur` lime (Citrus limonia Osbeck) x `Swingle` citrumelo (P. trifoliata (L.) Raf x Citrus paradisi Macfad.); the trifoliates (P. trifoliata (L.) Raf.)`Rubidoux`, `FCAV`, and `Flying Dragon` (P. trifoliata var. monstrosa); the `Sun Chu Sha Kat` mandarin (C. reticulata Blanco); the `Sunki` mandarin (Citrus sunki (Hayata) Hart. ex. Tanaka); the `Rangpur` limes (C. limonia Osbeck) `Cravo Limeira` and `Cravo FCAV`; `Carrizo` citrange (C. sinensis x P. trifoliata), `Swingle` citrumelo (P. trifoliata x C. paradisi), and `Orlando` tangelo (C. paradisi x Citrus tangerina cv. `Dancy`). The experimental grove was planted in 2001, using a 7 m x 4 m spacing, in a randomized block design, with five replications and two plants per plot. No supplementary irrigation was applied. Fruit yield, canopy volume, tree tolerance to drought and to citrus variegated chlorosis, and fruit quality were assessed for each rootstock. Trees grafted onto the `Flying Dragon` trifoliate were smaller in size, but had largest yield efficiency when compared to those grafted onto other rootstocks. Lower alternate bearing index was observed on trees budded onto `Cravo FCAV` `Rangpur` lime. Both `Rangpur` lime rootstocks and the `Sunki` mandarin induced higher tree tolerance to drought. The `Flying Dragon` trifoliate induced better fruit quality and higher tolerance to citrus variegated chlorosis (CVC) to `Folha Murcha` trees. A cluster multivariate analysis identified three groups of rootstocks with similar effects on `Folha Murcha` tree performance. Among the 12 evaluated rootstocks, the `Flying Dragon` trifoliate has a unique effect on plant growth, tolerance to drought and CVC, fruit yield and fruit quality of `Folha Murcha` trees, and may be better suited for high-density plantings. (C) 2011 Elsevier B.V. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Somatic hybridization is a biotechnology tool that can be used in citrus breeding programs to produce somatic hybrids with the complete genetic combination of both parents. The goal of this work was to test the reaction of citrus somatic hybrids that may be useful as rootstocks to trunk and root infections caused by Phytophthora nicotianae van Breda de Haan (P parasitica Dastur) and to citrus tristeza virus (CTV). The somatic hybrids evaluated were `Caipira` sweet orange (Citrus sinensis L. Osbeck) + `Rangpur` lime (C. limonia Osbeck), `Caipira` sweet orange + `Cleopatra` mandarin (C. reshni hort. ex Tanaka), `Caipira` sweet orange + `Volkamer` lemon (C. volkameriana V Ten. & Pasq.), `Caipira` sweet orange + rough lemon (C. jambhiri Lush.), `Cleopatra` mandarin + `Volkamer` lemon, `Cleopatra` mandarin + sour orange (C. aurantium L.), `Rangpur` lime + `Sunki` mandarin (C. sunki (Hayata) hort. ex Tanaka), `Ruby Blood` sweet orange (C. sinensis L. Osbeck) + `Volkamer` lemon, `Rohde Red` sweet orange (C. sinensis L. Osbeck) + `Volkamer` lemon, and `Valencia` sweet orange + Fortunella obovata hort. ex Tanaka. For P. nicotianae trunk and root infection assays, plants of the somatic hybrids, obtained from 9-month semi-hardwood cuttings, were evaluated and compared with diploid citrus rootstock cultivars after mycelia inoculation in the trunk or spore infestation in the substrate, respectively. `Cleopatra` mandarin + sour orange, `Rangpur` lime + `Sunki` mandarin, `Cleopatra` mandarin + `Volkamer` lemon, `Ruby Blood` sweet orange + `Volkamer` lemon, `Rohde Red` sweet orange + `Volkamer` lemon, and `Caipira` sweet orange + `Volkamer` lemon had less trunk rot occurrence, whereas the somatic hybrids `Cleopatra` mandarin + `Volkamer` lemon, `Cleopatra` mandarin + sour orange, `Caipira` sweet orange + `Volkamer` lemon, and `Caipira` sweet orange + `Rangpur` lime were tolerant to root rot. For CTV assays, plants of the somatic hybrids along with tolerant and intolerant rootstocks were budded with a mild strain CTV-infected or healthy `Valencia` sweet orange budwood. Differences in average scion shoot length indicated that the hybrids `Cleopatra` mandarin + sour orange and `Valencia` sweet orange + Fortunella obovata were intolerant to CTV (c) 2007 Elsevier B.V. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Harmless bacteria inhabiting inner plant tissues are termed endophytes. Population fluctuations in the endophytic bacterium Pantoea agglomerans associated with two species of field cultured citrus plants were monitored over a two-year period. The results demonstrated that populations of P. agglomerans fluctuated in Citrus reticulata but not C. sinensis. A cryptic plasmid pPA3.0 (2.9 kb) was identified in 35 out of 44 endophytic isolates of P. agglomerans and was subsequently sequenced. The origins of replication were identified and nine out of 18 open reading frames (ORFs) revealed homology with described proteins. Notably, two ORFs were related to cellular transport systems and plasmid maintenance. Plasmid pPA3.0 was cloned and the gfp gene inserted to generate the pPAGFP vector. The vector was introduced into P. agglomerans isolates and revealed stability was dependent on the isolate genotype, ninety-percent stability values were reached after 60 hours of bacterial cultivation in most evaluated isolates. In order to definitively establish P. agglomerans as an endophyte, the non-transformed bacterium was reintroduced into in vitro cultivated seedlings and the density of inner tissue colonization in inoculated plants was estimated by bacterium re-isolation, while the tissue niches preferred by the bacterium were investigated by scanning electronic microscopy (SEM). Cells from P. agglomerans (strain ARB18) at similar densities were re-isolated from roots, stems and leaves and colonization of parenchyma and xylem tissues were observed. Data suggested that P. agglomerans is a ubiquitous citrus endophyte harboring cryptic plasmids. These characteristics suggest the potential to use the bacterium as a vehicle to introduce new genes in host plants via endophytic bacterial transformation.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

As moscas-das-frutas são as principais pragas da fruticultura mundial. Consideradas chaves para a produção de citros, torna-se necessário o seu monitoramento, visando a evitar os danos diretos. O experimento teve como objetivos conhecer a variação populacional de Anastrepha fraterculus e a relação de sua população com danos em pomares orgânicos de Citrus sinensis, cultivar ©u e de C. sinensis x Citrus reticulata tangor 'Murcott'. Os dados foram coletados em 2003 e 2004 durante o período de maturação dos frutos, na região do vale do Caí, RS, Brasil. O número de moscas-das-frutas foi registrado, semanalmente, por meio de armadilhas McPhail, contendo suco de uva, a 25%. Danos aos frutos foram determinados pela razão entre frutos sadios e frutos danificados pela mosca. Registros meteorológicos de temperatura, umidade relativa e precipitação pluviométrica foram obtidos, em estação meteorológica distante 30 km das áreas experimentais. Verificou-se que, em condições ideais de precipitação pluvial, maiores foram as populações de A. fraterculus, espécie predominante na região. A população estimada capaz de causar danos aos frutos variou de acordo com o cultivar, sendo a laranjeira '©u' a mais susceptível. Os maiores picos populacionais ocorrem na fase de mudança de coloração dos frutos. Porém, na fase de maturação, as moscas causaram os maiores danos, dada a intolerância dos frutos ao ataque. Conclui-se que a infestação dos frutos de citros por A. fraterculus está relacionada com espécie e cultivar e com fatores climáticos, principalmente com a precipitação pluvial. O monitoramento constante da população de mosca-das-frutas é importante na determinação da infestação na colheita.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Excavations at two sites dating from 2000 BC-1900 AD in southeastern areas of the Republic of Korea, revealed the remains of several structures. Examination of the contents suspected privies revealed the presence of eggs from 5 kinds of parasite: Ascaris, Trichuris, Clonorchis, and two species of unknown trematodes. Clonorchis sinensis eggs were found in a soil dating from around AD 668-935. This is the first record of C. sinensis eggs in archaeological materials in the Republic of Korea.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Marcadores moleculares RAPD foram utilizados para avaliar a diversidade genética em uma população de 94 híbridos de tangerina 'Cravo' (Citrus reticulata Blanco) com laranja 'Pêra' (C. sinensis (L.) Osbeck), obtidos por polinização controlada. Nas reações de amplificação foram usados 102 "primers" de¢meros de seqüência arbitrária, que amplificaram 640 fragmentos, sendo 77,2% monomórficos entre os parentais. Utilizou-se o coeficiente de Jaccard para estimar a similaridade genética entre os híbridos, o método UPGMA para gerar o fenograma (NTSYS 1,7) e o software BOOD para determinar a consistência de cada agrupamento. Verificou-se que a laranja 'Pêra' apresenta maior heterozigosidade que a tangerina 'Cravo', sendo, respectivamente, 180 e 126 os números observados de loci em heterozigose. Houve alta similaridade genética entre os parentais, caracterizada pelo baixo polimorfismo de marcadores RAPD. Não houve a formação de agrupamentos estatisticamente significativos dos híbridos entre si e com os parentais, demonstrando que a constituição genética dos híbridos foi originada pela segregação independente das marcas RAPD, sendo quebrado o efeito de ligação em função do tamanho amostral em estudo. Híbridos com maior similaridade genética em relação à tangerina 'Cravo' e laranja 'Pêra' podem ser facilmente selecionados a partir de marcadores RAPD.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

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.