Monitoramento da fusariose em plantios de abacaxi 'Pérola' conduzidos em sistema de produção integrada no Estado do Tocantins.

O abacaxizeiro, Ananas comosus, é atacada por diversas doenças nas regiões produtoras no mundo tanto em condições de campo quanto em pós-colheita, com reflexos negativos na produtividade e qualidade dos frutos. Entre as doenças, aquelas causadas por fungos ocorrem em maior intensidade, enquanto causado por bactérias e por vírus ocorrem em menor escala. Além disto a ocorrência de anomalias de causa abiótica também é responsável por perdas significativas na produção e qualidades dos frutos. De todas as doenças que atacam o abacaxizeiro no Brasil a fusariose, causada pelo fungo Fusarium subglutinans (Wr. Rg.) Nelson, Tousson & Marasas, f. sp. ananas, Ventura, Zambolim & Gilbertson, é a mais destrutiva, incitando perdas significativas à produção de frutos. Considerando que as cultivares Gold, Red Spanish e Smooth Cayenne entre outras, amplamente cultivadas no mundo, são suscetíveis ao agente causal da fusariose, esta doença pode constituir uma séria ameaça à abacaxicultura mundial.

Monitoramento da murcha do abacaxizeiro associada à cochonilha Dysmicoccus brevipes em áreas de sistema de produção integrada no Estado do Tocantins - ciclo 2010.

No Brasil, cultiva-se o abacaxizeiro, Ananas comosus (L) na maioria das regiões ,sendo a 'Pérola' a cultivar mais plantada. Apesar de seu aspecto rústico, essa bromeliácea, em uma produção comercial, exige tratos culturais e fitossanitários rigorosos, para evitar problemas como a murcha que está associada à cochonilha Dysmicoccus brevipes Cockerell (1893) (Hemiptera: Pseudococcidae), cujas perdas na produção, em cultivares suscetíveis, podem ultrapassar os 80% (SANCHES, 2005). O mercado interno é ainda o mais visado pelos produtores de abacaxi, sendo a aquisição ou venda de mudas entre produtores uma prática muito comum que, propicia a dispersão desse inseto de uma propriedade para outra ou de uma região para outra. O Sistema de Produção Integrada de Abacaxi é uma prática de apoio aos produtores para atender as exigências crescentes do mercado consumidor quanto à produção de alimentos seguros. Esse sistema é baseado nas boas práticas agrícolas traduzindo em valorização do ser humano, conservação do meio ambiente (solo e água), melhoria da qualidade de vida dos produtores rurais, respeito à legislação trabalhista e segurança do trabalhador.

O cultivo do abacaxi para o Amazonas.

Informacoes sobre a situacao do cultivo do abacaxi no Amazonas, os aspectos agroclimaticos e variedades, mudas, plantio, pragas e doencas, colheita e rendimento, coeficientes tecnicos para a implantacao e manutencao de 1ha, e o cultivo em sistemas agroflorestais.

A cultura do abacaxizeiro no Amazonas.

Características da planta. Exigências edafoclimáticas. Ciclos da planta. Principais variedades. Tipos de mudas. Preparo de área. Adubação de plantio. Cura. Plantio. Adubação de cobertura. Controle de plantas invasoras, pragas e doenças. Indução floral. Colheita e pós-colheita. Rendimento. Coeficientes técnicos para o plantio e a manutenção de 1 hectare de abacaxi (51 mil mudas).

Etablierung von Mikrosatellitenmarkern für die Pitcairnioideae (Bromeliaceae) und ihre Anwendung für populationsgenetische Fragestellungen

Die neotropisch verbreitete Unterfamilie der Pitcairnioideae (Bromeliaceae) besteht aus den Gattungen Dyckia, Deuterocohnia, Encholirium, Fosterella und Pitcairnia. Viele der mehr als 630 Arten dieser Unterfamilie weisen eine beträchtliche morphologische Plastizität auf, was oftmals eine sichere Artbestimmung erschwert. Um den Genfluss zwischen benachbarten Populationen bzw. nah verwandten Arten ermitteln zu können und somit mögliche Hinweise auf Artbildungsprozesse und Artabgrenzung zu erhalten, sind hochsensitive molekulare Marker erforderlich. Die vorliegende Dissertation beschäftigt sich schwerpunktmäßig mit der Entwicklung von Mikrosatellitenmarkern sowie ihre beispielhafte Anwendung für populationsgenetische Fragestellungen innerhalb der Pitcairnioideae. Als Quelle für diese Marker diente zum einen eine öffentliche ’expressed sequence tag’ (EST)-Datenbank von Ananas comosus, zum anderen wurden die drei Bromelienarten Fosterella rusbyi, Dyckia marnier-lapostollei und Deuterocohnia longipetala mittels der 454-Technik partiell sequenziert. Beide Ansätze lieferten insgesamt 164.137 Rohsequenzen, auf deren Basis einige tausend perfekte Mikrosatelliten identifiziert und zahlreiche flankierende PCR-Primerpaare sowohl für das Kern- als auch das Chloroplastengenom abgeleitet wurden. Nach umfangreichen Funktionalitätstests mit Fokus auf interspezifischer Übertragbarkeit sowie intraspezifischer Variabilität der Mikrosatellitenloci in der jeweiligen Zielart wurden schließlich 48 nukleäre und sieben plastidäre Mikrosatellitenmarker etabliert. Das Potenzial der nukleären Mikrosatellitenmarker zur Abgrenzung nah verwandter und morphologisch sehr ähnlicher Arten innerhalb der Pitcairnioideae wurde zum einen in den im Nordosten Brasiliens verbreiteten Arten Dyckia pernambucana, Dy. limae, Dy. dissitiflora und Dy. macedoi durch die Genotypisierung von insgesamt 89 Individuen von neun natürlichen Standorten überprüft. Hierbei konnte basierend auf den Alleldaten an 15 nukleären 454-Mikrosatellitenloci eindeutig zwischen dem Artenkomplex ’Dy. limae/Dy. pernambucana’ auf der einen Seite und Dy. dissitiflora bzw. Dy. macedoi auf der anderen Seite unterschieden werden, eine Abtrennung der Arten Dy. limae und Dy. pernambucana war hingegen mit keiner der verwendeten Auswertemethoden möglich, was darauf hindeutet, dass es sich hierbei nicht um getrennte Arten handelt. Zum anderen wurden 190 Individuen von 28 natürlichen Standorten der in Bolivien bzw. Zentralamerika heimischen und morphologisch sehr ähnlichen Arten Fosterella christophii, F. villosula und F. micrantha untersucht. Unter Verwendung von je vier nukleären EST- und 454-Mikrosatellitenmarkern und verschiedenen Clusteranalysen konnten zwei genetisch voneinander getrennte und geographisch determinierte Gruppen definiert werden. Dabei umfasste die größere der beiden Gruppen alle drei Arten, deren Siedlungsbereich neben einem Areal in den bolivianischen Departamentos Beni, La Paz und Cochabamba auch das gesamte Verbreitungsgebiet von F. micrantha in Zentralamerika beinhaltete. Die zweite, kleinere Gruppe enthielt nur Populationen von F. christophii und F. villosula und war auf eine relativ kleine Region im bolivianischen Departamento Santa Cruz beschränkt. Innerhalb von Bolivien liegt dieser Verteilung möglicherweise eine genetische Barriere im Bereich des Andenknicks zugrunde, infolge welcher alle Populationen südlich und nördlich dieser Region weitgehend unabhängig von ihrer Artzugehörigkeit gruppieren. Eine klare Trennung der drei Arten war nicht möglich, sodass davon ausgegangen werden kann, dass der Artbildungsprozess innerhalb der sog. ’micrantha-Gruppe’ noch keineswegs abgeschlossen ist. In einem dritten Ansatz wurden 15 nukleäre und sieben plastidäre Mikrosatellitenmarker zur Genotypisierung von 253 Individuen aus 30 natürlichen Populationen von Fosterella rusbyi eingesetzt. Damit sollte die Verteilung der genetischen Diversität und der Genfluss zwischen den Populationen dieser in den bolivianischen Anden inselartig verbreiteten Art untersucht werden. Die einzelnen Populationen erwiesen sich als genetisch deutlich voneinander differenziert, wobei nahezu jede Population durch eine individuelle Kombination von Genotypen charakterisiert war. Auf Ebene der Populationen wurde weiterhin ein deutliches Heterozygoten-Defizit über nahezu alle Loci ermittelt, was am ehesten durch Faktoren wie Inzucht und Selbstbestäubung in Kombination mit einer Tendenz zu klonalem Wachstum erklärt werden kann. Mögliche Gründe für den eingeschränkten Genfluss zwischen den Populationen werden diskutiert.

Spider-fed bromeliads: seasonal and interspecific variation in plant performance

Background and Aims Several animals that live on bromeliads can contribute to plant nutrition through nitrogen provisioning (digestive mutualism). The bromeliad-living spider Psecas chapoda (Salticidae) inhabits and breeds on Bromelia balansae in regions of South America, but in specific regions can also appear on Ananas comosus (pineapple) plantations and Aechmea distichantha. Methods Using isotopic and physiological methods in greenhouse experiments, the role of labelled ((15)N) spider faeces and Drosophila melanogaster flies in the nutrition and growth of each host plant was evaluated, as well as seasonal variation in the importance of this digestive mutualism. Key Results Spiders contributed 0.6 +/- 0.2% (mean +/- s.e.; dry season) to 2.7 +/- 1% (wet season) to the total nitrogen in B. balansae, 2.4 +/- 0.4% (dry) to 4.1 +/- 0.3% (wet) in An. comosus and 3.8 +/- 0.4% (dry) to 5 +/- 1% (wet) in Ae. distichantha. In contrast, flies did not contribute to the nutrition of these bromeliads. Chlorophylls and carotenoid concentrations did not differ among treatments. Plants that received faeces had higher soluble protein concentrations and leaf growth (RGR) only during the wet season. Conclusions These results indicate that the mutualism between spiders and bromeliads is seasonally restricted, generating a conditional outcome. There was interspecific variation in nutrient uptake, probably related to each species` performance and photosynthetic pathways. Whereas B. balansae seems to use nitrogen for growth, Ae. distichantha apparently stores nitrogen for stressful nutritional conditions. Bromeliads absorbed more nitrogen coming from spider faeces than from flies, reinforcing the beneficial role played by predators in these digestive mutualisms.

Correlation between citric acid and nitrate metabolisms during CAM cycle in the atmospheric bromeliad Tillandsia pohliana

Crassulacean acid metabolism (CAM) confers crucial adaptations for plants living under frequent environmental stresses. A wide metabolic plasticity can be found among CAM species regarding the type of storage carbohydrate, organic acid accumulated at night and decarboxylating system. Consequently, many aspects of the CAM pathway control are still elusive while the impact of this photosynthetic adaptation on nitrogen metabolism has remained largely unexplored. In this study, we investigated a possible link between the CAM cycle and the nitrogen assimilation in the atmospheric bromeliad Tillandsia pohliana by simultaneously characterizing the diel changes in key enzyme activities and metabolite levels of both organic acid and nitrate metabolisms. The results revealed that T. pohliana performed a typical CAM cycle in which phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxykinase phosphorylation seemed to play a crucial role to avoid futile cycles of carboxylation and decarboxylation. Unlike all other bromeliads previously investigated, almost equimolar concentrations of malate and citrate were accumulated at night. Moreover, a marked nocturnal depletion in the starch reservoirs and an atypical pattern of nitrate reduction restricted to the nighttime were also observed. Since reduction and assimilation of nitrate requires a massive supply of reducing power and energy and considering that T. pohliana lives overexposed to the sunlight, we hypothesize that citrate decarboxylation might be an accessory mechanism to increase internal CO(2) concentration during the day while its biosynthesis could provide NADH and ATP for nocturnal assimilation of nitrate. Therefore, besides delivering photoprotection during the day, citrate might represent a key component connecting both CAM pathway and nitrogen metabolism in T. pohliana: a scenario that certainly deserves further study not only in this species but also in other CAM plants that nocturnally accumulate citrate. (C) 2010 Elsevier GmbH. All rights reserved.

Detection of urease in the cell wall and membranes from leaf tissues of bromeliad species

Urea is an important nitrogen source for some bromeliad species, and in nature it is derived from the excretion of amphibians, which visit or live inside the tank water. Its assimilation is dependent on the hydrolysis by urease (EC: 3.5.1.5), and although this enzyme has been extensively studied to date, little information is available about its cellular location. In higher plants, this enzyme is considered to be present in the cytoplasm. However, there is evidence that urease is secreted by the bromeliad Vriesea gigantea, implying that this enzyme is at least temporarily located in the plasmatic membrane and cell wall. In this article, urease activity was measured in different cell fractions using leaf tissues of two bromeliad species: the tank bromeliad V. gigantea and the terrestrial bromeliad Ananas comosus (L.) Merr. In both species, urease was present in the cell wall and membrane fractions, besides the cytoplasm. Moreover, a considerable difference was observed between the species: while V. gigantea had 40% of the urease activity detected in the membranes and cell wall fractions, less than 20% were found in the same fractions in A. comosus. The high proportion of urease found in cell wall and membranes in V. gigantea was also investigated by cytochemical detection and immunoreaction assay. Both approaches confirmed the enzymatic assay. We suggest this physiological characteristic allows tank bromeliads to survive in a nitrogen-limited environment, utilizing urea rapidly and efficiently and competing successfully for this nitrogen source against microorganisms that live in the tank water.

Specific leaf areas of the tank bromeliad Guzmania monostachia perform distinct functions in response to water shortage

Leaves comprise most of the vegetative body of tank bromeliads and are usually subjected to strong longitudinal gradients. For instance, while the leaf base is in contact with the water accumulated in the tank, the more light-exposed middle and upper leaf sections have no direct access to this water reservoir. Therefore, the present study attempted to investigate whether different leaf portions of Guzmania monostachia, a tank-forming C(3)-CAM bromeliad, play distinct physiological roles in response to water shortage, which is a major abiotic constraint in the epiphytic habitat. Internal and external morphological features, relative water content, pigment composition and the degree of CAM expression were evaluated in basal, middle and apical leaf portions in order to allow the establishment of correlations between the structure and the functional importance of each leaf region. Results indicated that besides marked structural differences, a high level of functional specialization is also present along the leaves of this bromeliad. When the tank water was depleted, the abundant hydrenchyma of basal leaf portions was the main reservoir for maintaining a stable water status in the photosynthetic tissues of the apical region. In contrast, the CAM pathway was intensified specifically in the upper leaf section, which is in agreement with the presence of features more suitable for the occurrence of photosynthesis at this portion. Gas exchange data indicated that internal recycling of respiratory CO(2) accounted for virtually all nighttime acid accumulation, characterizing a typical CAM-idling pathway in the drought-exposed plants. Altogether, these data reveal a remarkable physiological complexity along the leaves of G. monostachia, which might be a key adaptation to the intermittent water supply of the epiphytic niche. (C) 2009 Elsevier GmbH. All rights reserved.

Agro-Based Biocomposites for Industrial Applications

Leaf fibers are fibers that run lengthwise through the leaves of most monocotyledonous plants such as pineapple, banana, etc. Pineapple (Ananas comosus) and Banana (Musa indica) are emerging fiber having a very large potential to be used for composite materials. Over 150,000 ha of pineapple and over 100,000 ha of banana plantations are available in Brazil for the fruit production and enormous amount of agricultural waste is produced. This residual waste represents one of the single largest sources of cellulose fibers available at almost no cost. The potential consumers for this fiber are pulp and paper, chemical feedstock, textiles and composites for the automotive, furniture and civil construction industry.

Susceptibility of citrus species to Alternaria alternata, the causal agent of the Alternaria brown spot

Alternaria alternata, the causal agent of Alternaria brown spot (ABS), causes necrosis on leaves, twigs, and fruit, reducing the productivity and quality of fruits. Tangerines and their hybrids are highly susceptible to the disease. Species, hybrids, and cultivars of Citrus from the germplasm bank of the Estacao Experimental de Citricultura de Bebedouro, São Paulo, Brazil, were evaluated in 2004 and 2005 with respect to their resistance to A. alternata, both through natural infection and by inoculation. Detached leaves were also used to demonstrate susceptibility or resistance to the disease. Ten cultivars of Satsumas (Citrus unshiu), and 14 cultivars of Clementine mandarin (C. clementina) did not show any symptoms of the disease in their leaves, either through natural infection or when inoculated in the field. The Burguess SRA-412, Wallent SRA-438, Carvalhais, Ampefy SRA-459, Ananas SRA, and Macaque SRA-426 mandarin hybrids (C. reticulata) did not show symptoms of the disease under natural or artificial infection in the field. Some cultivars of C. deliciosa, C. tangerina, C. erythrosa, and C. temple showed symptoms of the disease, even though no previous record of their susceptibility to Alternaria brown spot had been previously reported. The hybrids Fairchild, Nova, Page, Fortune, and Sunburst were susceptible to the disease. However, Fremont mandarin (a crossing between C. clementina and C. reticulata), Encore (C. nobilis x C. deliciosa), and Fallglo (C. reticulata x C. paradisi) did not show symptoms in field, and few symptoms were verified in detached leaves. These materials are promising for the cultivation of tangerines, and will enable genetic improvement for the development of cultivars resistant to Alternaria brown spot. (c) 2007 Elsevier B.V. All rights reserved.

Temperatura e tipo de preparo na conservação de produto minimamente processado de abacaxi-'Pérola'

O presente trabalho teve como objetivo avaliar o efeito do tipo de preparo (rodelas e metades) e da temperatura de armazenamento (3ºC, 6ºC e 9ºC) na conservação de produto minimamente processado de abacaxi-'Pérola'. Os frutos, depois de selecionados, lavados e desinfectados com cloro, foram armazenados por 12 horas a 10ºC, antes de serem processados sob condições higiênicas, embalados em contentores de polietileno tereftalatado (rodelas) ou bandeja de isopor recoberta com filme de cloreto de polivinila esticável (metades) e armazenados por até 12 dias. Os produtos foram avaliados quanto à evolução da atmosfera interna na embalagem, respiração, quantidade de suco drenado e evolução da massa fresca e da aparência. Foram testadas, durante o período de armazenamento, a aceitabilidade pelos consumidores, no início do experimento e enquanto a aparência e a análise microbiológica permitiram. A presença de bactérias mesofílicas e coliformes totais e fecais foi avaliada a cada três dias. Durante o armazenamento, a porcentagem de O2 nas embalagens apresentou decréscimo, enquanto a de CO2 aumentou até 20% para as metades e até 1,86% para as rodelas. A intensidade dos cortes no preparo teve influência direta na respiração, assim como nas perdas de suco e de massa fresca. A temperatura influenciou na respiração e foi fator limitante à vida de prateleira do produto, pois os produtos armazenados a 9ºC, conservaram-se por 6 dias, enquanto os mantidos a 3ºC e 6ºC, por até 9 dias.

AVALIAÇÃO DE PLANTAS MATRIZES DE ABACAXIZEIRO CULTIVAR SMOOTH CAYENNE UTILIZANDO MARCADORES RAPD E PADRÕES ISOENZIMÁTICOS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação por RAPD de plantas de abacaxizeiro cultivar Smooth Cayenne derivadas do seccionamento do talo e cultura de tecidos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação física e química de produtos minimamente processados de abacaxi-'Pérola'

O objetivo deste trabalho foi avaliar, física e quimicamente, produtos minimamente processados de abacaxi-'Pérola', rodelas e metades, armazenados sob diferentes temperaturas (3ºC, 6ºC e 9ºC). Frutos selecionados, quanto ao grau de maturação e ausência de danos, foram lavados, desinfeccionados com cloro (200 mg.L-1) e armazenados a 10ºC, por 12 horas, antes do processamento. O produto minimamente processado foi embalado em bandejas de isopor recobertas com filme de PVC esticável (metades) ou bandejas de tereftalato de polietileno (rodelas) e armazenado sob refrigeraç ;ão, com avaliação a cada 3 dias, quanto à textura, coloração, pH, e conteúdos de sólidos solúveis totais, acidez total titulável, ácido ascórbico e de açúcares, solúveis e redutores. Durante o armazenamento, o produto tornou-se menos firme, e sua polpa apresentou escurecimento. Os conteúdos de açúcares solúveis e redutores e de sólidos solúveis totais não foram afetados pelo tipo de preparo, temperatura ou embalagem. Os teores de acidez total titulável aumentaram e foram influenciados pela temperatura, sendo que os mantidos a 9ºC apresentaram os maiores teores, havendo, como conseqüência, decréscimo no pH. Os produtos armazenados a 9ºC também apresentaram evolução mais rápida no escurecimento, na redução do teor de ácido ascórbico e menor vida útil (6 dias), enquanto, para os armazenados a 3ºC e 6ºC, este período foi de 9 dias. Os resultados obtidos permitiram concluir que a temperatura de armazenamento foi o fator limitante para a vida útil destes produtos.