Avaliação da sensibilidade in vitro de isolados de Colletotrichum lindemuthianum a fungicidas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do tratamento químico na qualidade sanitária e fisiológica de sementes de soja infectadas por Sclerotinia sclerotiorum

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Acidovorax citruli: genetic analyses and protocol for its detection in seeds

Bacterial fruit blotch of cucurbits (BFB), caused by the seed borne Gramnegative bacterium Acidovorax citrulli is a serious threat to cucurbit industry worldwide. Since late 1980`s after devastating outbreaks in watermelon fields in southern United States, BFB has spread worldwide and has been reported in other cucurbit crops such as melon, pumpkin, cucumber and squash. To date, there is evidence for the existence of at least two genetically and pathogenically distinct populations of A. citrulli. In Brazil, the first report of BFB was in 1991, in a watermelon field in São Paulo. Although widespread in the country, BFB has been a major problem to melon production. More precisely, BFB has caused significant yield losses to melon production in northeastern Brazil, which concentrates > 90% of the country`s melon production. Despite the management efforts and the recent advances in A. citrulli research, BFB is still a continuous threat to the cucurbit industry, including seed producers, growers and transplant nurseries. To better understand the population structure of A. citrulli strains in Brazil, and to provide a basis for the integrated management of BFB, we used pulsed-field gel electrophoresis (PFGE), multilocus sequence analysis (MLSA) of housekeeping and virulence-associated genes and pathogenicity tests on different cucurbit seedlings to characterize a Brazilian population of A. citrulli strains from different hosts and regions. Additionally, we conducted for the first time a comparative analysis of the A. citrulli group I and II population at genomic level and showed that these two groups differ on their genome sizes due to the presence of eight DNA segments, which are present in group II and absent in group I genomes. We also provide the first evidence to suggest that temperature might be a driver in the ecological adaptation of A. citrulli populations under nutrient-rich or -depleted conditions. Finally, in order to improve the routine detection of A. citrulli on melon seedlots, we designed a new primer set that is able to detect the different Brazilian haplotypes, thus minimizing the risk of false-negatives on PCR-based seed health testing.

Germinação de sementes, adubação e níveis de sombreamento no desenvolvimento de mudas de jatobá (Hymeneae courbaril L. var. Stilbocarpa)

Pós-graduação em Agronomia - FEIS

Uso do efeito xênia em híbridos comerciais de milho (Zea mays L.)

Pós-graduação em Agronomia - FEIS

Influência dos dopantes potássio e lítio na cerâmica relaxora niobato de chumbo e magnésio (PMN)

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

Avaliação do potencial alelopático de substâncias isoladas em sementes de araticum (Annona crassiflora)

Este estudo visou identificar substâncias biologicamente ativas e o potencial alelopático de esteroides glicosilados, provenientes das sementes de Annona crassiflora. O isolamento dos esteroides glicosilados foi realizado com a separação dos constituintes químicos do extrato bruto de acetato de etila em coluna cromatográfica, sendo a completa elucidação estrutural por meio de espectroscopia de RMN 1H. Testes de germinação com as espécies Euphorbia heterophylla e Ipomoea grandifolia foram conduzidos em câmaras tipo BOD a 25ºC e fotoperíodo de 12 horas, monitorados durante 10 dias com avaliação diária, nas concentrações de 0, 20, 40, 80 e 100 mg L^-1 dos materiais isolados. Utilizando as mesmas concentrações, os experimentos de desenvolvimento de radícula e hipocótilo foram mantidos em câmara de germinação a 25ºC e fotoperíodo de 24 horas, com avaliação no décimo dia. Após o extrato de acetato de etila ser submetido ao fracionamento, verificou-se a presença de sinais característicos de fitoesteróis no espectro do RMN ¹H, resultando em uma mistura de estigmasterol glicosilado e sitosterol glicosilado. Os resultados indicam que as substâncias estigmasterol e sitosterol não proporcionaram inibição na germinação e no índice de velocidade de germinação (IVG) de E. heterophylla e I. grandifolia. Por outro lado, estigmasterol e sitosterol interferiram no desenvolvimento de radícula e hipocótilo de E. heterophylla.

Resistência de progênies de Stylosanthes capitata e S. macrocephala à antracnose causada por Colletotrichum gloeosporioides

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Influence of spray mixture volume and flight height on herbicide deposition in aerial applications on pastures

The objective of the present study was to analyze the influence of spray mixture volume and flight height on herbicide deposition in aerial applications on pastures. The experimental plots were arranged in a pasture area in the district of Porto Esperidião (Mato Grosso, Brazil). In all of the treatments, the applications contained the herbicides aminopyralid and fluroxypyr (Dominum) at the dose of 2.5 L c.p. ha-1, including the adjuvant mineral oil (Joint Oil) at the dose of 1.0 L and a tracer to determine the deposition by high-performance liquid chromatography (HPLC) (rhodamine at a concentration of 0.6%). The experiment consisted of nine treatments that comprised the combinations of three spray volumes (20, 30 and 50 L ha-1) and three flight heights (10, 30 and 40 m). The results showed that, on average, there was a tendency for larger deposits for the smallest flight heights, with a significant difference between the heights of 10 and 40 m. There was no significant difference among the deposits obtained with the different spray mixture volumes.

Alternative methods for detecting soybean seeds genetically modified for resistance to herbicide glyphosate

The objective of this study was to verify application of two methodologies: substrate moistened with herbicide solution (SM) and immersion of seeds in herbicide solution (IH) for detecting soybean seeds genetically modified. For this, non-transgenic and transgenic soybean seeds, harvested in the 2008/2009 crop seasons were used. The treatments with substrate moistened were: SM1) 0.03% herbicide solution, at 25 ºC, with evaluation in the sixth day (hs -0.03% -25 ºC, 6th d); SM2) HS -0.03% -35 ºC, 5th d; SM3) HS -0.03% - 40 ºC, 5th d; and SM4) hs -0.06% -5 ºC, 5th d. In the methodology of immersion of seeds the following treatments were performed: IH1) seed immersion in a 0.6% herbicide solution, at 25 ºC, for 1 h, (si -0.06% -25 ºC, 1 h; IH2) si -0.06% - 35 ºC, 30 min.; IH3) si -0.06% -40 ºC, 30 min.; IH4) si -0.12% -35 ºC, 30 min.; and IH5) si -0.12% -40 ºC, 30 min. Bioassays allow detecting soybean seeds tolerant to glyphosate herbicide within five days. The seeds of non-genetically modified and genetically modified soybean cultivars may be easily distinguished through the treatments SM2 and SM4 of the moistened substrate methodology; and treatments IH3, IH4, and IH5 of seed immersion methodology. Both methodologies are easily feasible, practical, and applicable in seed analysis laboratories, once do not require special equipments.

Soluble sugars and germination of Annona emarginata (Schltdl.) H. Rainer seeds submitted to immersion in GA3 up to different water contents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Water uptake by Annona diversifolia Saff. and A. purpurea Moc. & sessé ex dunal seeds (Annonaceae)

Annonaceae seeds are known by presenting dormancy mechanisms, whose reports ranging from coating impermeable to the physiological dormancy. By this way, the present study aimed to evaluate water uptake in Annona diversifolia Saff and Annona purpurea Moc & Sessé ex Dunal seeds. For this study, seeds were placed under immersion in distilled water, and used four replicates of 25 seeds of each species, which were weighed during the 480 hours that were immersed. To determine the place of purchase of water, Annona diversifolia seeds were sealed with paraffin at different locations. Based on the results, seeds from both species reached the phases I and II of water uptake, which indicates they are not hard; however, germination (Phase III) was not reached. Annona diversifolia seeds completed Phase I with, 50h and Annona purpurea with 70h from imbibitions begin, which shows that even slowly, water is acquire.

Assessment of the physiological potential of spinach seeds (Tetragonia tetragonoides (Pall.) Kuntze)

The efficiency of vigor tests in assessing the physiological potential of seeds depends on their standardization for different species. In this context, the research aimed to study specific methodologies to evaluate the vigor of spinach seeds (Tetragonia tetragonoides). For this purpose, five lots of spinach seed cv. New Zealand were submitted to germination, first count of germination, seedling emergence in the field, accelerated aging (with and without use of saturated solution of NaCl at 41and 45 ºC for 24,48 and 72 hours), controlled deterioration (18,21 and 24% seed water content adjustments for 24 hours at 45 ºC) and electrical conductivity tests with variations inwater volume (25, 50 and 75 mL), seed quantity (25 and 50) and soaking period (1, 2, 4, 8,12, 16 and 24 hours) at 25 ºC. The first count test allowed obtaining preliminary information about seed vigor, and other tests in general showed similarity with seedling emergence in the field. Thus, it was concluded that traditional accelerated aging test 24 h /41 ºC and accelerated aging test with saturated salt solution for 24 h at 41 ºC and 45 ºC, and controlled deterioration test with 21% seed water content / 24 h / 45 ºC were all efficient for evaluating the physiological potential of spinach seeds.

Carcass and meat traits of lambs fed by-products from the processing of oil seeds

We evaluated the effect of adding by-products from the processing of oil seeds in the diet of lambs on the carcass and meat traits. Twenty-four non-castrated weaned male Santa Inês lambs with approximately 70 days of age and initial average weight of 19.11 ± 2.12 kg were distributed into a completely randomized design. Treatments consisted of diets containing by-products with 70% of concentrate and 30% of tifton hay (Cynodon spp.) and were termed SM: control with soybean meal; SC: formulated with soybean cake; SUC: formulated with sunflower cake and PC: formulated with peanut cake. Diets had no effects on the carcass traits evaluated. There was no significant effect on the mean values of perirenal, omental and mesenteric fats (0.267, 0.552 and 0.470 kg, respectively) and there was no influence on the percentages of moisture, ether extract, crude protein or ash in the loin between experimental diets. Diets containing by-products from the processing of oil seeds did not change fatty acids found in lamb meat. The use of by-products from oil seeds provided similar carcass and meat traits, thus their use can be recommended as eventual protein and energy sources for feedlot lambs.

Fungicidas e reguladores vegetais nas características fisiológicas e produtivas de alface ‘Vera’

Pós-graduação em Agronomia (Horticultura) - FCA