Potencial fisiológico de sementes de soja enriquecidas com molibdênio no armazenamento e sua influência na atividade de enzimas do metabolismo do nitrogênio

Molybdenum is one of the essential micronutrients for soybeans, acting directly on nitrogen metabolism as enzyme cofactor of nitrogenase. Usually, this nutrient is supplied to the plants through seed treatment or foliar application. The aim of this study was to evaluate the molybdenum effects by foliar in the physiological potential of soybean seeds and verify its interference in the enzyme activities involved in nitrogen metabolism. Soybean seeds of BMX Turbo cultivar were used, produced in Erechim, RS, harvest 2013, from plants treated with the following Mo concentrations: 0; 25; 50 and 75 g ha-1, supplied through two commercial products (Biomol and Molybdate) and stored during 0 and 6 months in uncontrolled conditions. The first experiment was conducted in Seedtes Seed Analysis Laboratory in Pato Branco, PR. The used design was completely randomized in a factorial analysis 4 x 2 x 2 with four replications each. The physiological potential of the seeds was evaluated by the germination test, seedling growth, accelerated aging and emergence on the soil. The second experiment was conducted in a greenhouse, where the seeds derived from treatments with different concentrations of Mo: 0; 25; 50 and 75 g ha-1 supplied through two commercial products (Biomol and Molybdate) were grown in vases. The used design was completely randomized in a factorial analysis 4 x 2 with four replications. Evaluations were performed when the plants reached the R1 phenological stage concerning the nodulation, dry matter of root and shoot of the plants and the determination of the activity of the enzymes glutamine synthetase and glutamate synthetase and the content of total soluble proteins. The data were submitted to variance analysis and when significant they were assessed by Tukey’s test for comparison of products and seed storage and with regression study to the concentrations at 5% probability. Analyses were performed using SISVAR statistical software. The soybean seed storage under uncontrolled conditions affected the seed vigour produced with Mo, regardless of the commercial product used during production. The application of Mo through foliar positively influences the production of soya beans which presented increasing responses in the germination and vigour with the application of Mo above 25 g ha-1 . The enrichment of Mo through foliar did not affect the nodulation of plants of the next generation, however, the use of Mo above 25 g ha-1 provided an increase in the activity of enzymes involved in nitrogen metabolism as well as on the total protein content.

Quitosana na indução de resistência ao tombamento de plântulas de espécies olerícolas e no controle de fitopatógenos in vitro

Induction of resistance is defined as the activation of a state of resistance against diseases which is induced systemically in plants by the use of biotic or abiotic agents without any modification of the plant genome, occurring non-specific way, by activating genes coding for various plant defense responses. Chitosan is a polymer derived from the deacetylation of chitin, which is found in large quantities in crustacean shell, and studied with the potential to control plant pathogens, both by its direct fungistatic action, as the ability to induce protection of plants, indicating the presence of molecules of elicitoras characteristics. Three experiments with objective of evaluating the potential of chitosan in the seedling resistance induction were developed, beet (Beta vulgaris) seeds, cucumber (Cucumis sativus) seeds and tomato (Solanum lycopersicum) seeds, and the control of Fusarium sp., Rhizoctonia solani K¨uhn e Pythium sp. in vitro conditions. The experimental design was completely randomized, with four replications. Beet seeds, tomato and cucumber were submerged in chitosan solution for 20 minutes, in concentrations of 0.25, 0.5, 1 and 2% in the control and distilled water. Seeds were sown in trays containing Plantmax Florestalr substrate sterilized and inoculated with Fusarium sp., Rhizoctonia solani K¨unh and Pythium sp., respectively for the three cultures. The experiment was conducted for 14 days in growth chamber with controlled temperature (25 C 2 C), light (12 hour photoperiod) and humidity (70% 10%). The evaluations were seed emergency, seedling damping-off, seedling length, fresh weight and activity of the enzymes phenylalanine amˆonia-liase (PAL), chitinase and b-1,3-glucanase. It was also rated the mycelial growth of Fusarium sp., Pythium sp. and R. solani on P.D.A. (Potato-Dextrose and Agar) culture medium containing chitosan at the same concentrations evaluated in seeds. For beet growing, seed treatment with chitosan presented higher emergence and the length of the seedlings, and reduced the percentage of tipping. Treatment with chitosan activated the systemic acquired resistance with expression of chitinase and b-1,3-glucanase enzymes. For the tomato crop in chitosan concentration of 0.25% favored the emergency of seedlings, reduced the incidence of tipping and activated the PAL enzymes, chitinase and b-1,3-glucanase. In cucumber on the concentration of up 0.5% favored seedlings emergence and reduces the incidence of tipping. Chitosan activated the PAL enzymes and b-1,3-glucanase. Chitosan also presented fungistatic action on the initial growth of Pythium sp. and R. solani in vitro conditions, however, such action did not prevail until the end of the experiment. To Fusarium sp. the concentration of chitosan resulted in the reduction of mycelial growth in vitro.

Desempenho de fosfitos de potássio no manejo de mofo branco em soja

Soybean plays an important role in the Brazilian agriculture being one of the products most exported by the country. Its yield may be affected by diseases such as white mold, caused by the fungus Sclerotinia sclerotiorum Lib. de Bary, which, under favorable field conditions prevents the crop of expressing all its productive potential. The fungus is cosmopolitan and infects more than 400 species of plants. This disease is difficult to control, and the use of chemicals has not been sufficient to avoid significant losses, thus, this products are expensive and may cause environmental damage. Alternative methods, such as foliar fertilizers based on potassium phosphite, can also be used in the management of this disease. In this context, this work aimed to study different sources of potassium phosphite and its effects in the control of white mold in soybeans, as well as the time of application in culture, its action in inducing plants defense responses and/or its influence over the seeds quality. The effect of phosphites, over the pathogen, was evaluated in vitro, on mycelial inhibition, the mass of dry mycelium and germination of sclerotia. In all tests, the following phosphites were utilized: Phosphite A (P2O5-40%; K2O-20% - 1 L/ha); Phosphite B (P2O5-40%; K2O-28% - 1 L/ha); Phosphite C (P2O5-40%; K2O-20% - 1 L/ha) e Phosphite D (P2O5-30%; K2O-20% - 2,4 L/ha). At the induction of resistance tests were evaluated the synthesis of phytoalexin in soybean cotyledons and the enzymes FAL and POX evaluated in seedlings in growing chamber, sprayed with phosphites and the fungicide fluazinam. Field experiment was carried out at Coronel Domingos Soares-PR, in the 2012/2013 season, in an area with natural infestation of the pathogen. Soybean cultivar BMX Active was no-till seeded with 0,5m between rows. The experimental was laid out as a factorial 5 x 4 scheme (treatment x application time). Phosphites sources were used, as described above, and water was sprayed in the control treatment. Treatments were applied at four different growth stages: V4, V4 + R1, R1 and R2 at the rates recommended by the manufacturer. Soybean yield components and seeds and health and physiological quality were evaluated after harvesting. None of the tested phosphites affected mycelial growth and sclerotia germination or influenced phytoalexin synthesis. Phosphites C and D stood out due to an increasing in the phenylalanine ammonia-lyase activity 48 hours after its inoculation. These same products also induced the synthesis and peroxidases and phosphite C kept the levels of this enzyme elevated up to 72 hours after inoculation. At the field trials, phosphites C and D stood out in the control of white mold. There was no significant interaction of potassium phosphite on physiological and sanitary quality of the seeds.

Indução de resistência e tratamento de sementes de soja com fosfitos de potássio

The use of inputs containing phosphites have been presenting results in many studies, taking on importance to the control of diseases in some cultures and demonstrating the resistance induction in seedlings, with ability to activate defense mechanisms, conferring protection to plants against microorganisms. The soybean crop is recognized for its importance in providing grains and derivatives for human consumption, animal, production of biofuels, pharmaceuticals, among others. Positive results obtained through studies based on resistance inducers in some cultures arouse the interest for further study. The objective of this study was to evaluate the effect of potassium phosphites on the resistance induction and treatment of soybean seeds. Therefore were conducted four laboratory studies at the Federal Technological University of Paraná, Campus of Dois Vizinhos. In the first study it was evaluated the quality attributes of the seeds and the resistance induction as seed treatment. Then it was verified that phosphites have action upon the seedlings metabolism in due to seed treatment, having the phosphite Reforce® contributed to seed quality attributes and phosphites FitofosK® and Fitofos K Plus® induced the resistance increasing the activity of β-1,3-glucanase. In the second study it was evaluated the the resistance induction in soybean cotyledons, in which the phosphites demonstrated induction potential of phytoalexin gliceolin. In the third study It was evaluated the soybean seed health treated with potassium phosphites.. it was observed that the phosphites reduced the incidence of many fungi on seeds, especially of storage fungi like Aspergillus sp. and Fusarium semitectum. In the fourth study it was evaluated the in vitro effect of potassium phosphites on pathogenic fungi of the culture. And it was found direct action of phosphites on the mycelial growth of Fusarium semitectum, Pythium sp. and Sclerotinia sclerotiorum. Based on these results, we concluded that potassium phosphites have potential in seeds treatment, as resistance inducer and on in vitro control of phytopathogens.

Desempenho de soja associado à posição do fertilizante e tamanho de sementes

The seed size used for seeding has caused doubts among soybean producers. The study aimed to determine whether there may be differences between seed size with respect to depth of fertilizer deposition. The field experiment was conducted at the Experimental Area UTFPR Campus Pato Branco, using a precision seeder for direct seeding. The design was a randomized blocks, with five repetitions. The treatments were composed by the combination of two seed sizes (large seed with 6,5 mm and 5,5 mm with small seed) and two fertilizer deposition depths in relation to the seed (fertilizer near the seed with about 3 cm away and fertilizer distant from the seeds with about 10 cm). Data were subjected to analysis of variance. When the test value F was significant at 5% probability was applied to the Duncan test for comparison of means. The shallower depth of fertilizer deposition provided larger number of pods per plant and increased number of grains per plant. Already the largest depth of fertilizer deposition provided greater plant height at 30 days after sowing and R2 stage, greater ground area mobilized, higher plant population in all periods, greater depth of deposition of seeds and a higher rate of emergency speed.

Validação de metodologia analítica por CLAE-DAD para determinação de compostos fenólicos e atividade biológica em coprodutos agroindustriais

The southern region of Brazil, especially the states of Parana and Santa Catarina stand out for growing grapes and apples for fresh consumption and in order to add value to these products, process the material for the production of wine, juices and jellies . As a result large quantities of by-products, such as peels, seeds and pulp are produced becoming environmental problems. Studies reuse of these by-products have attracted interest because they have shown a high biological potential, due to the presence of high levels of phenolic compounds, which are associated with a lower incidence of disease caused by oxidative stress, due to its antioxidant, antiinflammatory and antibacterial properties. Currently, few studies are presented on the phenolic composition and biological potential of waste grape variety Bordô (Vitis labrusca) and apple (Malus domestica) Gala variety, cultivated in southern Brazil. Within this context, the objectives of this study were: compare the efficiency of solidliquid and liquid-liquid extraction, perform the optimization and validation of analytical methodology by HPLC-DAD for the separation, identification and quantification of multiclass phenolic compounds, evaluate the activity antioxidant by sequestering methods of free radical 2,2-diphenyl-1 picrilhidrazina (DPPH) and 2,2-azino-bis (3- ethyl-benzthiazoline-6-sulphonic acid) (ABTS) solution, reduction of Fe3+ in Fe2+ method (FRAP), ORAC, RP-HPLC-ABTS online, Rancimat and determination of total phenolics three agro-industrial byproducts, pomace and stems grape Bordô produced in Paraná Southwest region and Gala apple pomace coming from the Santa Catarina West. Optimization and validation of chromatographic method showed satisfactory quality parameters for the compounds of interest and the solidliquid extraction was more efficient in extracting phenolic evaluated. The three byproducts evaluated showed significant levels of phenolic compounds when analyzed by HPLC, especially flavonoids, catechin and epicatechin besides that showed significant antioxidant capacity. The grape stems extract had the highest sequestration capacity of DPPH and ABTS radical and reduced iron, and high content of phenolic compounds. The apple pomace extract showed the best response to the Rancimat method, which indicates a high potential to protect the oil from lipid oxidation, was no significant difference when compared to synthetic antioxidant TBHQ. The results of this study showed that the agro-industrial coproducts analyzed are rich in phenolic compounds of high antioxidant capacity and therefore must be better explored by the food and pharmaceutical industries.