Filling the Gap in the Classification of Phlogopite-Bearing Ultramafic Rocks

In recent years, the many new occurrences reported in the literature of ultramafic rocks that have phlogopite as a major constituent and do not fall into the categories of kimberlites, lamproites, and lamprophyres have highlighted the need for a classification that includes this abundant mineral phase. Currently, a broadly accepted classification with phlogopite does not exist, and the only term used by scientists is “phlogopite-bearing” when this phase is above 5 vol% and up to 90 vol%. For this reason, we propose a new classification that integrates phlogopite into the current classification of ultramafic rocks without modifying the already accepted terminology or the classificative criteria (i.e., the mineral modal abundances). Phlogopite is added as an end member in the ultramafic-rocks classification diagrams, changing their shapes from triangular to tetrahedral. An Excel spreadsheet containing the new diagrams and a macro that automatically classifies the rocks is provided

Chitosan in the induction of resistance to the damping off tomato seedlings caused by Rhizoctonia solani Kuhn

The objective of this study was to evaluate the potential of chitosan in the damping off tomato resistance induction caused by Rhizoctonia solani. The tomato seeds were submerged in solution with chitosan for twenty minutes in concentrations of 0.25; 0.5; 1 and 2% and in the control (distilled water only). The seeds were sown in polystyrene trays containing substrate inoculated with R. solani and kept in a growth chamber with 12 hours photoperiod and temperature of 25 ºC ± 2 °C for 14 days. After this period we evaluated the survival of seedlings, length and fresh weight and activity of the enzyme phenylalanine ammonia lyase (PAL), chitinase and β-1,3-glucanase. The results showed that chitosan when applied to the treatment of tomato seeds at a concentration of 0.30%, favoring the survival of seedlings inoculated with the pathogen substrate. This result is mainly related to the activation of resistance mechanisms in the plant, evidenced by activation of FAL enzymes, chitinase and β-1,3-glucanases.The objective of this study was to evaluate the potential of chitosan in inducing resistance against damping off in tomato caused by Rhizoctonia solani. The tomato seeds were submerged in solution with chitosan for 20 minutes in concentrations of 0.25%; 0.5%; 1% and 2% and in the control (distilled water only). The seeds were sown in polystyrene trays containing substrate inoculated with R. solani and kept in a growth chamber with 12 hours photoperiod and temperature of 25 ± 2 ºC for 14 days. After this period we evaluated the survival of seedlings, length and fresh weight and activity of the enzyme phenylalanine ammonia lyase (PAL), chitinase and β-1.3-glucanase. The results showed that chitosan when applied on tomato seeds at concentration of 0.30% incresead the survival of seedlings growing in substrate inoculated with the pathogen. This result is mainly related to the activation of resistance mechanisms in the plant, evidenced by activation of PAL, chitinases and β-1.3-glucanases enzymes

Óleo essencial de Aloysia citriodora no controle de Sclerotinia sclerotiorum em pepino e atividade antifúngica in vitro

O presente trabalho teve como objetivo principal avaliar o potencial do óleo essencial de erva-luísa (Aloysia citriodora) no tratamento de sementes de pepino, para controle de tombamentos de plântulas causados por Sclerotinia sclerotiorum e atividade antifúngica in vitro. Foram realizados dois experimentos in vitro e um teste in vivo com o tratamento das sementes com o óleo essencial. No primeiro experimento, avaliou-se atividade antifúngica in vitro de concentrações do óleo essencial em meio BDA, no crescimento micelial de S. sclerotiorum, em placas de Petri. No segundo experimento in vitro, avaliou-se o efeito do óleo essencial em concentrações em meio de cultura BDA, na germinação miceliogênica de escleródios. No terceiro experimento, testou-se o tratamento das sementes em óleo essencial de A. citriodora diluído em água destilada mais espalhante adesivo Tween 80. As sementes foram semeadas em substrato inoculado com S. sclerotiorum. Avaliou-se neste experimento: porcentagem de emergência; tombamento de plântulas de pós-emergência; massa verde média por plântula; altura média de plântulas; e análises bioquímicas (teor de proteínas; atividade enzimática de peroxidases; fenilalanina amônia-liase (FAL); ?-1.3-glucanases e quitinases). Os resultados obtidos demonstraram que o óleo tem potencial fungistático e fungicida in vitro sendo a maior redução observada nas maiores doses testadas e também no controle do tombamento de plântulas, onde observou-se melhor resultado na concentração de 0,06%. Além disso, o óleo essencial de A. citriodora aplicado às sementes, induziu mecanismos bioquímicos de resistência, evidenciados pelo aumento da atividade bioquímica das peroxidases até a concentração de 0,24% e da FAL e ?-1.3-glucanases em todas as concentrações testadas

Redução no tombamento de Fusarium sp. em plântulas de beterraba, pelo tratamento das sementes com óleo essencial de Aloysia citriodora Palau

This study aimed to evaluate the potential of essential oil of Aloysia citriodora in the induction of resistance in beet seedlings against damping off caused by Fusarium sp. The work was carried out by treating the seeds with concentrations (0.0625%; 0.125% and 0.25%) of essential oil of A. citriodora in distilled water plus surfactant Tween 80® (0.5%) and control treatment (distilled water plus surfactant Tween 80® 0.5%). The seeds after treated with essential oil were sown in substrate inoculated with Fusarium sp. It was evaluated after 14 days of sowning: the percentage of emergency at 4 and 14 days; the incidence of post-emergence damping off; green mass; the length of seedlings and biochemistry of plant tissues (total protein content, enzymatic activity of peroxidases, phenylalanine ammonia lyase, β-1.3-glucanases and chitinases). The results showed that the essential oil of this plant applied on seeds reduced the damping off caused by Fusarium sp. and induced biochemical plant defense mechanisms, by increasing the activity of peroxidases.O presente trabalho teve como objetivo principal, avaliar o potencial do uso do óleo essencial de Aloysia citriodora na indução de resistência em plântulas de beterraba ao tombamento causado por Fusarium sp. O trabalho foi realizado por meio do tratamento das sementes com concentrações (0,0625%; 0,125% e 0,25%) do óleo essencial de A. citriodora em água destilada mais espalhante adesivo Tween 80® (0,5%) e o tratamento testemunha (água destilada mais espalhante adesivo Tween 80® a 0,5%). As sementes, após tratadas com o óleo essencial, foram semeadas em substrato inoculado com Fusarium sp. Avaliou-se após 14 dias de implantação do experimento: a porcentagem de emergência aos 4 e 14 dias; a incidência de tombamentos de plântulas de pós-emergência; a massa verde; o comprimento de plântulas e análises bioquímicas dos tecidos vegetais (teor de proteínas totais, atividade enzimática de peroxidases, fenilalanina amônia-liase, β-1,3-glucanases e quitinases). Os resultados obtidos permitiram concluir que o óleo essencial desta planta aplicado nas sementes, diminuiu o tombamento causado por Fusarium sp. e induziu mecanismos bioquímicos de resistência, pelo aumento da atividade enzimática de peroxidases