Tais Leite Ferreira Pinto

Avaliação da viabilidade de sementes de pinhão manso pelos testes de tetrazólio e de raios X

The Jatropha curcas L. presents a great potential for fuel, but there are few studies to assess seed quality of this species. Therefore, this research aimed to study the performance of the tetrazolium salt test procedures and to verify the efficiency of the X-ray test to evaluate the seed viability of this species. Seeds were hydrated between paper towel and immersed in water to reach 30 and 40% m.c.. Following, seed coat was removed manually and seeds were immersed in 0,075 and 0,5% tetrazolium solutions for 120 min., respectively, at 40oC. Best results of tetrazolium test comprised the hydration between paper, until the seeds reach 30% m.c. and coloration in contact with a solution of 0,5%. The Jatropha curcas L. seeds were also submitted to X-ray test, in intensity of the 25Kv for 60s. Results of tetrazolium and X-ray tests were compared to germination and it was shown that both are efficient to assess Jatropha curcas L. seeds viability.

Avaliação de danos por umidade, em sementes de soja, utilizando a técnica da análise de imagens

RESUMO - Entre os problemas envolvidos na producao de sementes de soja destacam-se os danos por umidade, queresultam em perdas de germinacao e de vigor. A tecnica de analise de imagens, por meio do teste de raios X, e ummetodo de precisao que possibilita examinar , com detalhes, a regiao danificada ou alterada, sua localizacao e extensao.Por ser um metodo nao destrutivo, as sementes em analise podem ser submetidas a testes fisiologicos e, desta forma,e possivel estabelecer as relacoes de causa e efeito. O presente trabalho teve como objetivo avaliar a eficiencia datecnica de analise de imagens, por meio do teste de raios X, na identificacao dos danos por umidade em sementes desoja, comparativamente ao teste de tetrazolio. Sementes de diferentes lotes de um mesmo cultivar (BRS 184) foramsubmetidas ao teste de raios X e, posteriormente, destinadas ao teste de primeira contagem de germinacao, de forma arelacionar os danos com os possiveis prejuizos proporcionados as sementes. Paralelamente, foi realizado o teste detetrazolio visando comparacao com o teste de raios X. Para a analise interpretativa do teste de raios X, foram consideradasa severidade e a localizacao dos danos, juntamente com as fotografias digitais das plântulas ou sementes mortasresultantes do teste de primeira contagem de germinacao. Com os resultados obtidos, pode-se afirmar que a analise deimagens mostrou-se eficiente na deteccao dos danos por umidade em sementes de soja.Termos para indexacao : Teste de raios X, qualidade de sementes, Glycine max ( L.) Merrill.IMAGE ANAL YSIS TECHNIQUE T O EVALUA TE WEA THERING DAMAGE IN SOYBEAN SEEDSABSTRACT - Image analysis is a very promising technique to determine damage in seeds, which can result in germinationand vigor losses. This precise method examines seeds individually using enlarged images in which damaged areas, aswell their exact location and extension, can be found and examined in detail. Since this is a non-destructive method,analyzed seeds can be submitted to physiological tests to establish the relationship between damage and quality loss.The goal of this research was to study the efficiency of the image analysis technique, by the X-ray test, to identifyweathering damage in soybean seeds, compared with the tetrazolium test. Seeds of different lots of soybean, cultivarBRS 184, were submitted to the X-ray test and, consecutively , used for the first count of the germination test, in orderto determine the possible relationship between cause and ef fect. Simultaneously , the X-ray test was compared with thetetrazolium test. For the interpretation of X-ray test, the severity and location of weathering damage was considered.The results showed that image analysis, by the X-ray test, was efficient in detecting weathering damage in soybeanseeds.Index terms: X ray , seed quality , Glycine max ( L.) Merrill

Spatial variability of soil fertility and its relationship with seed physiological potential in a soybean production area

The correlation of soil fertility x seed physiological potential is very important in the area of seed technology but results published with that theme are contradictory. For this reason, this study to evaluate the correlations between soil chemical properties and physiological potential of soybean seeds. On georeferenced points, both soil and seeds were sampled for analysis of soil fertility and seed physiological potential. Data were assessed by the following analyses: descriptive statistics; Pearsons linear correlation; and geostatistics. The adjusted parameters of the semivariograms were used to produce maps of spatial distribution for each variable. Organic matter content, Mn and Cu showed significant effects on seed germination. Most variables studied presented moderate to high spatial dependence. Germination and accelerated aging of seeds, and P, Ca, Mg, Mn, Cu and Zn showed a better fit to spherical semivariogram: organic matter, pH and K had a better fit to Gaussian model; and V% and Fe showed a better fit to the linear model. The values for range of spatial dependence varied from 89.9 m for P until 651.4 m for Fe. These values should be considered when new samples are collected for assessing soil fertility in this production area.

Avaliação da viabilidade de sementes de coração-de-negro (Poecilanthe parviflora Benth. - Fabaceae-faboideae) pelo teste de tetrazólio

The increasing demand for Brazilian tree species seeds has been followed by the raise of the necessity to develop methods to evaluate seeds viability, mainly due to fast tests, as such as the tetrazolium. Poecilanthe parviflora (coracao-de-negro) is a Brazilian tree species used in forest restoration. However, there is no established test to determine its seeds viability. So, the goal of this research was adequate the tetrazolium test to determine the seeds viability of this species. After preliminary studies, the seeds were pre-conditioned by their immersion in water, until they reach the moisture contents 30% and 40%, and hydrated between papers previously soaked with water, until they reach the moisture content 40%. After the pre-conditioning, seeds coats were removed manually and the embryos were immersed in 0,075% tetrazolium solution for 90 minutes, at 40°C. Tetrazolium test results were compared with the ones obtained in the germination test. The results indicated that the tetrazolium test can be used to evaluate P. parviflora seeds viability, mainly by the seeds immersion in water until they reach the moisture content 40% remove the seed coat and stain the embryo in 0,075% tetrazolium solution for 90 minutes at 40°C.

Avaliação da viabilidade e do vigor de sementes de pepino pelo teste de tetrazólio

We assessed the usefulness of the tetrazolium test for determining the quality of cucumber seeds (Cucumis sativus). The base of cucumber seeds were scarified opposite the embryonic axis and the seeds hydrated between moist paper at 25 oC and by immersion in water at 40 oC for 30 minutes or 60 minutes. After hydration, the tegument was removed and the seeds re-soaked in water at 40 oC for 30 minutes or 60 minutes to remove the membrane covering the embryo. The embryos were immersed, in the dark, for 60 minutes at 40 °C in either 0.075% (w/v) or 1% (w/v) tetrazolium solution and the seeds classified as vigorous, viable but non-vigorous, or unviable. Twelve lots of cucumber seeds were subsequently evaluated by the tetrazolium test and compared to tests based on germination, seedling emergence and accelerated aging. Our results show that the tetrazolium test can be used to evaluate the viability and vigor of cucumber seeds by scarifying the seeds, soaking them in water at 40 oC for 60 minutes to remove the tegument, removing the embryo membrane by soaking in water for a further 60 minutes at 40 oC and staining the embryos at 40 oC by immersing them for 60 minutes, in the dark, in 0.075% tetrazolium solution.

Efeitos de potenciais hídricos do substrato e teores de água das sementes na germinação de feijão

Many environments factor can affect the germination, among them, the water availability and the seeds moisture content are important. The objective of the present investigation was to verify the influence of water availability of the substratum and moisture content of several cultivars of beans seeds in their germination and to verify the possible effects of imbibitions damage. The treatments were constituted with bean seeds of seven cultivars: IAC-Tuna, IAC-Ybate, IAC-Apua, IAC-Tybata, IAC-Votuporanga, IAC-Carioca and Carioca with moisture content of 9, 11 and 13% and submitted the water availability of the substratum of -0,04, -0,1, -0,2 and -0,4 MPa. The germinations percentage of each cultivar was evaluated for each condition. Therefore, the conclusion was that when the water availability decrease, with the increase of the hydro deficiency, the germination is reduced to any moisture content condition in the seeds for the seven cultivars. As for the seeds moisture content, it was not checked the influence in the germination. The imbibitions damage was not observed in the conditions which the seeds had been submitted.