220 resultados para Pineapple comosus
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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A transformation technique for the introduction of transgenes to control blackheart by particle bombardment has been developed for pineapple cv. Smooth Cayenne. Leaf callus cultures capable of high frequency organogenesis with a short regeneration time were used as explant material. Gus and gfp reporter genes were used to observe and determine transient and stable expression. The ppo gene, isolated from pineapple, was introduced to control blackheart. Co-transformation occurred with constructs containing the nptII gene conferring geneticin resistance. We have recovered 15 independent transgenic gus and gfp lines each from 8 separate experiments and 22 ppo lines from 11 experiments. Gus, gfp, ppo and nptII positive plants have been regenerated, which have been shown by Southern blot analysis to be stable transgenics containing multiple copies of the introduced genes. These results show that biolistic gene delivery in pineapple can be successfully achieved at an acceptable efficiency of 0.21-1.5% for genetic improvement of 'Smooth Cayenne', the industry standard throughout the world.
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A previously published partial sequence of pineapple bacilliform virus was shown to be from a retrotransposon (family Metaviridae) and not from a badnavirus as previously thought. Two newly discovered sequence groups isolated from pineapple were associated with bacilliform virions and were transmitted by mealybugs. Phylogenetic analyses indicated that they were members of new badnavirus species. A third caulimovirid sequence was also amplified from pineapple, but available evidence suggests that this DNA is not encapsidated, but more likely derived from an endogenous virus.
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A comparative analysis of transgenic pineapple lines transformed with a polyphenol oxidase (PPO) gene (ppo) and the untransformed cultivar ‘Smooth Cayenne’ was made from plants grown in a series of field trials under cool subtropical conditions in southeast Queensland. In the four field trials where blackheart was recorded, all of the control lines expressed blackheart on each occasion and exhibited the greatest incidence (50%) and severity (34%) of symptoms. Irrespective of the gene transfer method or the gene construct used, 38% of the lines produced were regarded as blackheart resistant, having no blackheart symptoms in two or more trials. Five blackheart resistant transgenic lines consistently performed as well as or better than control plants in terms of fruit characteristics and quality.
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Measures to control the cattle tick, Rhipicephalus (Boophilus) microplus, based only on chemical products are becoming unsustainable, mainly because of the development of resistance. The objective of this study was to test the effect of the aqueous extract of pineapple skin (AEPS) and bromelain extracted from the stem (Sigma-Aldrich®, B4882) on engorged females and larvae of R. (B.) microplus in vitro. These substances were diluted in water and evaluated at eight concentrations. Engorged females were collected and distributed in groups of 10, with three repetitions for each treatment. After immersion in the solutions, the females were placed in an incubator for observation of survival, oviposition and larval hatching. The larval packet method was used, also with three repetitions with about 100 larvae each. The packets were incubated and the readings were performed after 24h. The estimated reproduction and efficacy of the solutions were calculated. The LC50 and LC90 were estimated using the Probit procedure of the SAS program. The eight concentrations were compared within each treatment by the Tukey test. For the experiment with engorged females, the most effective concentrations were 125, 250 and 500mg/mL: 33%, 48% and 59% for the AEPS and 27%, 51% and 55% for the bromelain. The LC50 and LC90 values were, respectively, 276 and 8691mg/mL for AEPS and 373 and 5172mg/mL for bromelain. None of the dilutions tested was effective against the larvae of R. (B.) microplus. This is the first report of the action of pineapple extracts or their constituents on cattle ticks. The results demonstrate that further studies regarding composition of tick cuticle, with evaluation of other solvents and formulations, should be conducted seeking to enhance the effect of pineapple extracts and compounds against this ectoparasite. © 2013 Elsevier Inc.
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The development of resistance to anthelmintics has prompted research into alternative methods of controlling intestinal nematodes in ruminants. This study aimed to assess the activity of Ananas comosus on Haemonchus contortus in Santa Inês sheep. The aqueous extract of pineapple skin (AEPS), bromelain from pineapple stems (B4882) and residue from pineapple processing was evaluated in in vitro and in vivo tests. The enzymatic activity of substances was analyzed by the azocasein method. The egg hatch test (EHT) and larval development test (LDT) were performed using the Embrapa2010 isolate of H. contortus. In the in vivo test, 36 sheep artificially infected with H. contortus were divided into six groups: G1: 2g/kg BW of the aqueous extract administered for three days; G2: 2g/kg BW of the industrial pineapple residue for 60 days; G3: 180mg/animal of bromelain in a single dose; G4: negative control I; G5: positive control (levamisole phosphate); and G6: negative control II. The eggs per gram (EPG) in the feces were counted till 28 days after treatment. LC50 and LC90 were obtained by the probit procedure, while the in vivo test results were analyzed by GLM. The aqueous extract in the in vitro and in vivo test, the bromelain and industrial residue presented 0.102, 0.157, 1.864 and 0.048 enzyme units/mL, respectively. In the egg hatch test, the LC50 and LC90 were respectively 31 and 81mg/mL for the aqueous extract and 0.50 and 2mg/mL for bromelain. In the larval development test, the LC50 and LC90 were respectively 1.7 and 7.3mg/mL for the aqueous extract and 0.019 and 0.086mg/mL for bromelain. In the in vivo test, the general efficacies of the treatments in relation to the negative control were 22.6%, 42.2%, 3.65% and 89% for the aqueous extract, industrial pineapple residue, bromelain and positive control respectively. The transformed EPG values were 3.19±0.59, 3.32±0.25, 2.85±0.66, 3.44±0.50, 2.28±0.93 and 2.75±0.94 for the aqueous extract, industrial residue, bromelain, negative control I, positive control and negative control II respectively. The results for all the treated groups differed significantly (p<0.05) from the positive control, and although the residue presented efficacy of 42.2%, there was no statistical difference (p>0.05) in relation to the negative control. Therefore, both the aqueous extract and bromelain were effective in vitro, but showed reduced anthelmintic efficacy in vivo. For the pineapple residue, the 42.2% in vivo efficacy in reducing the EPG and the possibility of reducing environmental contamination through reuse of industrial residue indicate it can also be useful for control of this parasite. © 2013 Elsevier B.V.
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Flowering is a crucial developmental stage in the plant life cycle. A number of different factors, from environmental to chemical, can trigger flowering. In pineapple, and other bromeliads, it has been proposed that flowering is triggered by a small burst of ethylene production in the meristem in response to environmental cues. A 1-amino-cyclopropane-1-carboxylate synthase (ACC synthase) gene has been cloned from pineapple (ACACS2), which is induced in the meristem under the same environmental conditions that induce flowering. Two transgenic pineapple lines have been produced containing co-suppression constructs designed to down-regulate the expression of the ACACS2 gene. Northern analysis revealed that the ACACS2 gene was silenced in a number of transgenic plants in both lines. Southern hybridization revealed clear differences in the methylation status of silenced versus non-silenced plants by the inability of a methylation-sensitive enzyme to digest within the ACACS2 DNA extracted from silenced plants, indicating that methylation is the cause of the observed co-suppression of the ACACS2 gene. Flowering characteristics of the transgenic plants were studied under field conditions in South East Queensland, Australia. Flowering dynamics studies revealed significant differences in flowering behaviour, with transgenic plants exhibiting silencing showing a marked delay in flowering when compared with non-silenced transgenic plants and control non-transformed plants. It is argued that the ACACS2 gene is one of the key contributors towards triggering 'natural flowering' in mature pineapples under commercial field conditions.
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The potential of near infra-red (NIR) spectroscopy for non-invasive measurement of fruit quality of pineapple (Ananas comosus var. Smooth Cayenne) and mango (Magnifera indica var. Kensington) fruit was assessed. A remote reflectance fibre optic probe, placed in contact with the fruit skin surface in a light-proof box, was used to deliver monochromatic light to the fruit, and to collect NIR reflectance spectra (760–2500 nm). The probe illuminated and collected reflected radiation from an area of about 16 cm2. The NIR spectral attributes were correlated with pineapple juice Brix and with mango flesh dry matter (DM) measured from fruit flesh directly underlying the scanned area. The highest correlations for both fruit were found using the second derivative of the spectra (d2 log 1/R) and an additive calibration equation. Multiple linear regression (MLR) on pineapple fruit spectra (n = 85) gave a calibration equation using d2 log 1/R at wavelengths of 866, 760, 1232 and 832 nm with a multiple coefficient of determination (R2) of 0.75, and a standard error of calibration (SEC) of 1.21 °Brix. Modified partial least squares (MPLS) regression analysis yielded a calibration equation with R2 = 0.91, SEC = 0.69, and a standard error of cross validation (SECV) of 1.09 oBrix. For mango, MLR gave a calibration equation using d2 log 1/R at 904, 872, 1660 and 1516 nm with R2 = 0.90, and SEC = 0.85% DM and a bias of 0.39. Using MPLS analysis, a calibration equation with R2 = 0.98, SEC = 0.54 and SECV = 1.19 was obtained. We conclude that NIR technology offers the potential to assess fruit sweetness in intact whole pineapple and DM in mango fruit, respectively, to within 1° Brix and 1% DM, and could be used for the grading of fruit in fruit packing sheds.
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Two genes encoding polyphenol oxidase (PPO) were isolated from pineapple (Ananas comosus[L.] Merr. cv. Smooth Cayenne). Sequence analyses showed that both contained a single intron and encoded typical chloroplast-localized PPO proteins, the sequences of which corresponded to two pineapple PPO cDNAs, PINPPO1 and PINPPO2, recently described by Stewart et al. (2001). Southern blot analyses suggested that pineapple contained only two PPO genes. Analysis of expression of PINPPO1 promoter GUS fusion constructs showed this promoter had a low basal activity and was cold- and wound-inducible, consistent with known mRNA expression profiles. Striking homologies to gibberellin response complexes (GARC) were observed in sequences of both the PINPPO1 and PINPPO2 promoters. Transient assays in mature pineapple fruit and stable expression in transgenic tobacco showed that PINPPO1 promoter-GUS fusions were indeed gibberellin (GA) responsive. A role for the element within the putative GARCs in mediating GA-responsiveness of the PINPPO1 promoter was confirmed by mutational analysis. PINPPO2 was also shown to be GA-responsive by RT-PCR analysis. Mutant PINPPO1 promoter-GUS fusion constructs, which were no longer GA-inducible, showed a delayed response to cold induction in pineapple fruit in transient assays, suggesting a role for GA in blackheart development. This was supported by observations that exogenous GA3 treatment induced blackheart in the absence of chilling. Sequences showing homology to GARCs are also present in some PPO promoters in tomato, suggesting that GA regulates PPO expression in diverse species.
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In order to develop an efficient and reliable biolistics transformation system for pineapples parameters need to be optimised for growth, survival and development of explants pre- and post transformation. We have optimised in vitro conditions for culture media for the various stages of plant and callus initiation and development, and for effective selection of putative transgenic material. Shoot multiplication and proliferation is best on medium containing MS basic nutrients and vitamins with the addition of 0.1 mg/L myo-inositol, 20 g/L sucrose, 2.5 mg/L BAP and 3 g/L Phytagel, followed by transfer to basic MS medium for further development. Callus production on leaf base explants is best on MS nutrients and vitamins, to which 10 mg/L of BAP and NAA each was added. Optimum explant age for bombardment is 17-35 week old callus, while a pre-bombardment osmoticum treatment in the medium is not required. By comparing several antibiotics as selective agent, it has been established that a two-step selection of 2 fortnightly sub-cultures on 50 μg/mL of geneticin in the culture medium, followed by monthly sub-cultures on 100 μg/mL geneticin is optimal for survival of transgenic callus. Shoot regeneration from callus cultures is optimal on medium containing MS nutrients and vitamins, 5% coconut water and 400 mg/L casein hydrolysate. Plants can be readily regenerated and multiplied from transgenic callus through organogenesis. Rooting of shoots does not require any additional plant hormones to the medium. A transformation efficiency of 1 – 3.5% can be achieved, depending on the gene construct applied.
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Poucos são os estudos desenvolvidos com a aplicação via foliar de micronutrientes, na cultura do abacaxi. Este trabalho teve como objetivo avaliar os efeitos de B e Zn, em forma de quelato, ácido ou sal, via foliar, buscando-se obter respostas sobre os efeitos na produtividade e qualidade dos frutos. O experimento foi realizado em Guaraçaí (SP), em solo com textura média. Foram utilizadas mudas tipo filhote, da cultivar Smooth Cayenne (Havaiano). O delineamento experimental adotado foi o de blocos ao acaso, com quatro repetições, utilizando-se fontes para fornecer, em cada aplicação, 110 g ha-1de B e 250 g ha-1de Zn. Foram realizadas duas pulverizações foliares, aos 7 e 9 meses após o plantio. As fontes de B e Zn não exerceram efeito nos teores de sólidos solúveis totais, acidez titulável, diâmetro médio do fruto, comprimento do fruto sem coroa e índice de maturação. Apenas os teores de B, Zn e K, na folha, foram influenciados pelos tratamentos utilizados.
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O objetivo deste trabalho foi avaliar o efeito de um inibidor da diferenciação floral nas características físico-químicas dos frutos do abacaxizeiro, bem como, no período de colheita. Utilizou-se paclobutrazol a 100, 150 e 200 mg L-1 aplicados 2, 3 ou 4 vezes, em plantas de abacaxi cv. Smooth Cayenne. Os tratamentos não influenciaram nas características químicas dos frutos, e mesmo alterando algumas características físicas, os frutos permaneceram dentro dos padrões de qualidade para comercialização. O período de colheita foi ampliado em todos os tratamentos comparando-se com o controle, porém, 150 mg L-1 aplicados 2 vezes promoveu melhor resultado analisando-se em conjunto a época de colheita com a massa fresca do fruto.
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The objectives of this work were to characterize pineapple plants (Ananas comosus L. Merril) cv. Smooth Cayenne, cultured in vitro, in saline medium, in relation to bromelian activity, identifying the parts of the plant with the highest bromelian activity. Also under aim was the study of the influence of saline stress on the enzyme activity. Axillary buds of pineapple were cultivated in vitro in MS medium, supplemented with 2 mg.L-1 BAP and 1 mg.L-1 NAA. The levels of salinity tested were: 0.57 g.L-1 NaCl, 1.15 g.L-1 NaCl, and 2.30 g.L-1 NaCl. Bromelian activity was evaluated in the development of buds, shoots, and roots. The results showed that bromelian activity was higher in buds at the highest salt concentration at 15 days. Cultured shoots showed bromelian activity decreasing in the saline treatments in all the collection, up to 60 days in culture. The roots showed higher bromelian activity in the roots in saline medium.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Medicina Veterinária - FCAV