ABSTRACT. In soybeans, the integument or seed coat is an important modulator between the external and internal environment. It plays a fundamental role in seed vitality, and its lignin content may influence the seed quality. The objective of this experiment was to evaluate the quality of soybean seeds from a partial diallel and their reciprocals and its relationship with lignin content, seed coat thickness, and deposition location. The seeds were also evaluated for physiological quality through germination and accelerated aging tests. The lignin content was quantified by absorbance, and the integument thickness was analyzed and measured using scanning electron microscopy. The most contrasting cultivars for lignin content were analyzed using fluorescence microscopy and histochemical techniques. Cultivars and their reciprocals differed in seed physiological quality. We found differences in the genotypes for integument thickness. Using histochemical techniques, autofluorescence was observed in the same regions identified as lignified. Positive staining for lignin was observed in the hilum region. Among the genotypes, we found variations in the physiological quality of seeds (germination and accelerated aging test), lignin content, and integument thickness. ABSTRACT soybeans environment vitality location tests absorbance techniques lignified region test, test , test)

ABSTRACT Preliminary results of in vitro experiments with multicontaminated soils and solid media indicated that nodulating diazotrophic bacteria of the genus Cupriavidus are promising for the remediation of contaminated environments due to their symbiosis with legumes and metal tolerance. Thus, strains of Cupriavidus spp. (LMG 19424T, UFLA 01-659, UFLA 01-663, and UFLA 02-71) were tested for their ability to tolerate and bioaccumulate cadmium (Cd), copper (Cu), and zinc (Zn) in Luria-Bertani broth. Changes in the growth pattern of Cupriavidus strains in the presence or absence of heavy metals were analyzed by scanning electron microscopy and metal allocation by transmission electron microscopy, to clarify the mechanisms of bioremediation. Highest tolerance was detected for strain UFLA 01-659 (minimum inhibitory concentration of 5, 4.95, and 14.66 mmol L−1 of Cd, Cu, and Zn, respectively). Among the removal rates of the metals tested (9.0, 4.6, and 3.2 mg L−1 of Cd, Cu, and Zn, respectively), the bacterial activity was clearly highest for Cd. The efficiency of strain UFLA 01-659 in removing the heavy metals is associated with its high biomass production and/or higher contents of heavy metals adsorbed and absorbed in the biomass. In response to the presence of heavy metals in the liquid culture medium, the bacteria produced exopolysaccharides and small and aggregated cells. However, these responses varied according to the strains and heavy metals. Regarding allocation, all heavy metals were adsorbed on the cell wall and membrane, whereas complexation was observed intracellularly and only for Cu and Zn. These results indicate the possibility of using C. necator UFLA 01-659 for remediation in areas with very high Cd, Cu, and Zn contents.

Objetivou-se induzir a formação de calos em Jatropha curcas L., avaliar a ultraestrutura e o comportamento citoquímico dos calos. Os calos foram induzidos com 2,4-D, picloran, cinetina e BAP: (1) testemunha; (2) 4,52 µM 2,4-D; (3) 9,04 µM 2,4-D; (4) 4,14 µM PIC; (5) 8,28 µM PIC; (6) 4,52 µM 2,4-D + 2,32 µM KIN; (7) 9,04 µM 2,4-D + 4,64 µM KIN; (8) 4,14 µM PIC + 2,32 µM KIN; (9) 8,28 µM PIC + 4,64 µM KIN; (10) 4,52 µM 2,4-D + 2,22 µM BAP; (11) 9,04 µM 2,4-D + 4,44 µM BAP; (12) 4,14 µM PIC + 2,22 µM BAP and (13) 8,28 µM PIC + 4,44 µM BAP. Foi avaliado a porcentagem de cobertura dos explantes por calos (%CEC), microscopia eletrônica de varredura (MEV) e dupla coloração com carmim acético/azul de evans. A calogênese é otimizada em meio MS acrescido de 4,52 µM de 2,4-D, condição em que pela análise de microscopia eletrônica de varredura e dupla coloração carmim acético/azul de evans há expressão de potencial embriogênico nos calos de J. curcas.

This study aimed to induce callus formation in Jatropha curcas L. and to evaluate the ultrastructure and cytochemical behavior of the calli. Calluses were induced with 2,4-D, picloram-PIC, kinetin (Kin) and BAP: (1) control; (2) 4.52 µM 2,4-D; (3) 9.04 µM 2,4-D; (4) 4.14 µM PIC; (5) 8.28 µM PIC; (6) 4.52 µM 2,4-D + 2.32 µM KIN; (7) 9.04 µM 2,4-D + 4.64 µM KIN; (8) 4.14 µM PIC + 2.32 µM KIN; (9) 8.28 µM PIC + 4.64 µM KIN; (10) 4.52 µM 2,4-D + 2.22 µM BAP; (11) 9.04 µM 2,4-D + 4.44 µM BAP; (12) 4.14 µM PIC + 2.22 µM BAP and (13) 8.28 µM PIC + 4.44 µM BAP. It was evaluated the percent coverage of the explants by callus (% CEC) and performed scanning electron microscopy (SEM) and acetocarmine/Evans blue double staining to analyze the embryogenic potential of the calli. As shown by scanning electron microscopy and acetocarmine/Evans blue staining, we found that J. curcas callus formation was optimal with 4.52 µM of 2,4-D.

Determinou-se o tempo de subcultivo de calos de Jatropha curcas. Uma curva de crescimento dos calos foi estruturada por 16 períodos de cultivo e para cada período foi feita análise ultraestrutural em microscopia eletrônica de transmissão e varredura. O padrão de desenvolvimento dos calos de J. curcas é uma sigmóide com cinco fases e é ao final da desaceleração que deve ser realizada a repicagem, em média aos 28 dias de cultivo. No início do cultivo dos calos, na fase exponencial, as células estão desorganizadas subcelularmente; na fase linear é retomado o metabolismo respiratório por reestruturação das primeiras mitocôndrias, e em meados da fase de desaceleração as células estão completamente ativas, podendo se detectar várias organelas. Este nível organizacional se mantém por toda a fase estacionária, durante a qual pré-embriões somáticos foram identificados. Ao final da fase estacionária começa a desestruturação subcelular, as células entram em processo de senescência, caracterizando a fase de declínio da curva de crescimento de calo de J. curcas.

The aimed was characterization and determining the time for Jatropha curcas callus subculture. The pattern of J. curcas callus development is sigmoidal with 5 distinct phases, and transplantation should be performed at the end of the deceleration phase (approximately day 28). During callus development, it was observed that at the onset of growth in the exponential phase the cells were internally disorganized; in the linear phase, respiratory metabolism was resumed through reorganization of the first mitochondria; and by the mid-deceleration phase, the cells were entirely active, and several organelles were detected. This organizational status was maintained throughout the stationary phase during which somatic pre-embryos were identified. At the end of the stationary phase, intracellular disruption began, and the cells entered senescence, which characterized the decline phase for the J. curcas calli growth curve.

O objetivo deste trabalho foi selecionar e avaliar o potencial de óleos essenciais (OEs) e leite de vaca integral (LVI) no controle do oídio da soja e determinar as concentrações mais efetivas destes produtos na redução da severidade dessa doença. Foram realizados três experimentos: um experimento em casa de vegetação para avaliação e seleção dos produtos mais efetivos na redução da severidade do oídio da soja; um experimento para a verificação do efeito do LVI e OEs de citronela, capim-limão, eucalipto, canela e árvore-de-chá sobre o patógeno, por meio da análise ultraestrutural de folíolos infectados por Erysiphe diffusa em microscópio eletrônico de varredura (MEV) e de luz (ML); e finalmente um experimento em casa de vegetação, utilizando os produtos mais ativos, em diferentes concentrações, com o propósito de determinar as concentrações efetivas na redução da severidade da doença. Os tratamentos LVI (100mL L-1) e OEs de citronela, capim-limão e eucalipto a 1.0mL L-1, apresentaram controle de 67 a 74% da doença. Por meio da análise ultraestrutural em MEV e ML, foi evidenciado um efeito direto sobre as estruturas de E. diffusa, por parte de todos os produtos naturais testados. Concentrações de 1.5mL L-1, para os OEs de citronela, capim-limão e eucalipto e de 180mL L-¹ para o LVI foram mais efetivas contra E. difusa em soja.

This research aimed to evaluate the potential of essential oils (EOs) and cow's whole milk (CWM) in order to control soybean powdery mildew and to estimate the most effective concentrations of these natural products in reducing the disease severity on soybean plants. Three experiments were carried out: The first experiment evaluated and selected the most effective treatments to reduce the severity of soybean powdery mildew under greenhouse conditions; the second experiment evaluated the effect of CWM and EOs of citronella, lemongrass, eucalyptus, cinnamon and tea tree on the pathogen through the ultrastructure analysis of soybean leaflets infected by Erysiphe diffusa using the scanning electron microscope (SEM) and light microscope (LM) technology. In the third experiment, the most effective products were tested at several concentrations in order to define the most effective concentrations to reduce disease severity under greenhouse conditions. The treatments CWM (100mL L-1) and EOs of citronella, lemongrass and eucalyptus (1.0mL L-1), reduced the disease severity from 67 to 74%. Direct effects from all natural products tested on the structures of E. diffusa were demonstrated through the SEM and LM analysis. Concentrations at 1.5mL L-1 for EOs of citronella, lemongrass and eucalyptus and also at 180mL L-1 for the treatment CWM were the most effective against E. diffusa on soybean.

Com o objetivo de se estudar o comportamento nuclear durante o ciclo sexual do cogumelo Agaricus blazei , técnicas de coloração e a utilização de fluorocromos foram testadas, visando a uma padronização metodológica para estudos citogenéticos futuros. Das técnicas avaliadas neste trabalho (método de Feulgen, coloração com Giemsa e fluorescência-DAPI), a coloração com Giemsa e o fluorocromo DAPI apresentaram os melhores resultados para evidenciar núcleos. O corante Giemsa permitiu a visualização de compartimentos multinucleados. Com o DAPI, não foi possível a visualização dos septos, sendo necessária a utilização adicional de calcofluor, que tem a propriedade de corar a quitina que delimita os compartimentos das hifas.

In order to study the nuclear behavior during the sexual cycle of Agaricus blazei , some coloration and fluorescent stain techniques were tested for a method standardization for fut ure cytogenetical works. Among the studied techniques (Schiff reactive, Giemsa, and fluorescent stain - DAPI), the Giemsa and fluorescent DAPI technique provided the best results. With Giemsa stain, it was possible to visualize multinucleate cell compartments. It was not possible to stain compartmental delimitation with DAPI stain, which was possible only with an additional fluorescent stain - calcofluor, which is specific for chitin.

Este trabalho teve como objetivo verificar a relação entre o teor de 2-tridecanona (2-TD) em materiais selecionados e o nível de resistência à traça-do-tomateiro (Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae)) em gerações avançadas de Lycopersicon spp. derivado de cruzamentos interespecíficos. Foi usada uma população de tomateiros segregantes (geração F4RC2) para 2-TD, uma metilcetona que confere resistência à traça-do-tomateiro. Genótipos foram selecionados e avaliados quanto à resistência do tipo não-preferência: três materiais com alto teor do aleloquímico 2-TD (HI1, HI2, HI3) e dois materiais com baixo teor (LO1, LO2), além das testemunhas. Após infestação controlada, foram avaliados: contagem do número de ovos postos, evolução da lesão nos folíolos, porcentagem de folíolos atacados, e índice geral de lesão causada pela traça. Plantas com alto teor de 2-TD (HI1 e HI3) tiveram uma baixa progressão das lesões ocasionadas pelo ataque de T. absoluta. A planta LO1 foi muito atacada pela praga, o mesmo não ocorrendo com a planta LO2, que foi infestada acidentalmente por ácaros do gênero Tetranychus, acarretando, provavelmente, uma disputa de nicho ecológico entre os dois artrópodes. Concluiu-se que altos teores de 2-TD estão ligados a mecanismos de resistência à traça-do-tomateiro do tipo não-preferência por oviposição e alimentação.

This work had the objective to verify the relation between 2-tridecanone (2-TD) in selected plants and resistance level to tomato pinworm (Tutaabsoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae)) in advanced generations of Lycopersicon spp. interspecific crosses. It was used a tomato population (F4RC2 generation) segregant for 2-TD, a methyl ketone that controls the resistance of the tomato pinworm. Materials were selected and evaluated for a non-preference mechanism of resistance. Three genotypes with high level of the allelochemic 2-TD (HI1, HI2, HI3), two with low level (LO1, LO2) and two check genotypes were used. After a controlled infestation, oviposition preference, type and percent of leaflet damage, and damage index caused by the tomato pinworm were evaluated. Plants with high level of 2-TD (HI1, HI3) had a low progression of leaflet damage by Tuta absoluta. The LO1 genotype was much attacked by the tomato pinworm, while the LO2 genotype was accidentally attacked by acari of the Tetranychus genus, probably causing a dispute between the two arthropods. It was concluded that 2-TD high levels are associated to non-preference ovipositions and feeding resistance mechanisms to tomato pinworm.