Eletrical conductivity and deterioration of soybean seeds exposed to different storage conditions

Abstract

-Research with soybean seeds has revealed that the results of the electrical conductivity test may be influenced by storage temperature, particularly low temperature, such as 10ºC, suggesting that seed deterioration at low storage temperatures does not seem to be directly related to the loss of the cell membrane integrity. This study was conducted with seeds of two soybean cultivars with the objective of: a) studying the effect of different storage temperatures (10ºC; 20ºC; 25ºC; 20/10ºC and 25/10ºC) on the results of the electrical conductivity test; b) observing the behavior of fatty acids and carbohydrates during storage and studying its relation with the electrical conductivity results. Every three months, from a total of 18 months of storage, the physiological quality of seeds was evaluated using the germination, accelerated aging and electrical conductivity tests. Based on the obtained results, it can be concluded that the electrical conductivity test was not shown to be a good indicative of the deterioration process of seeds stored at low temperatures, and no direct relationship between changes in the fatty acids and carbohydrates and the behavior of the mentioned test for seeds stored at 10ºC was found.Index terms: Glycine max, vigor, physiological quality. CONDUTIVIDADE ELÉTRICA E DETERIORAÇÀO DE SEMENTES DE SOJA SUBMETIDAS A DIFERENTES CONDIÇÕES DE ARMAZENAMENTORESUMO -Pesquisas com sementes de soja têm revelado que os resultados do teste de condutividade elétrica podem ser influenciados pela temperatura de armazenamento, especialmente as mais baixas, como 10 o C, sugerindo que a deterioração da semente a baixas temperaturas de armazenamento parece não estar relacionada diretamente com a perda da integridade das membranas celulares. Este trabalho foi conduzido com sementes de dois cultivares de soja objetivando: a) estudar o efeito de diferentes temperaturas de armazenamento (10ºC; 20ºC; 25ºC; 20/10ºC e 25/10ºC) sobre os resultados do teste de condutividade elétrica; b) observar o comportamento dos ácidos graxos e carboidratos durante o armazenamento e estudar sua relação com os resultados do teste de condutividade elétrica. A cada três meses, num total de 18 meses de armazenamento, a qualidade fisiológica das sementes foi avaliada pelos testes de germinação, envelhecimento acelerado e condutividade elétrica. O teste de condutividade elétrica não mostrou ser um indicador eficiente do processo de deterioração de sementes armazenadas a baixas temperaturas, também não foi observada nenhuma relação direta entre as mudanças nos ácidos graxos, nos carboidratos e no comportamento do referido teste, para sementes armazenadas a 10 o C.Termos para indexação: Glycine max, vigor, qualidade fisiológica.

Seedling image analysis and traditional tests to evaluate onion seed vigor

“…In this first evaluation period, electrical conductivity allowed the lots to be stratified in more vigor levels than the other tests conducted. This may be explained by the evaluated characteristic, in this case, the integrity of the membrane system, which is one of the first changes that occurs in seeds during the deterioration process (Panobianco and Vieira, 2007).…”

“…The accelerated aging test was conducted by uniformly distributing 3.0 g of seeds on an aluminum screen within Gerbox ® type boxes containing 40 mL of saturated NaCl solution (40 g of NaCl in 100 mL of water) (Jianhua and McDonald, 1996), which were kept in a B.O.D. chamber at 41 ± 0.3 °C for 72 hours (Rodo and Marcos-Filho, 2003). At the end of this period, the germination test was conducted, as previously described, with evaluation at six days.…”

“…After that, Sako et al (2001) developed an automated system for evaluating the vigor of lettuce seeds through computerized seedling analysis, the Seed Vigor Imaging System (SVIS ® ), which supplies information such as seedling length and indexes of vigor, growth, and uniformity of growth. This software has already been successfully tested on other species, such as melon (Marcos-Filho et al, 2006), soybean (MarcosFilho et al, 2009), maize (Mondo et al, 2011), sweet corn (Alvarenga et al, 2012), cucumber (Chiquito et al, 2012), rattlepod (Silva et al, 2012), okra (Kikuti and Marcos-Filho, 2013), lettuce (Kikuti and Marcos-Filho, 2012), dry edible bean (Gomes Junior et al, 2014), eggplant (Silva and Cícero, 2014a), and tomato (Silva and Cícero, 2014b).…”

Computerized image analysis of seedlings to evaluate broccoli seed vigor

“…The accelerated aging, for example, expresses seed performance after a period of high temperature and relative air humidity, thus interfering with the storage potential of the lots (Torres and Marcos-Filho, 2003). The electrical conductivity test evaluates the reorganization capacity of cell membranes so that the more advanced it is the deterioration, slower it is the restructuring during imbibition, thus the greater is the electrical conductivity of the solution the lower is the seed quality (Panobianco and Vieira, 2007). Therefore, lots of different vigor levels may be classified differently by these tests (Marcos-Filho, 2015).…”

Assessment of Storage Dependent Physiological Parameters of Sesamum indicum seeds

“…Thus, reviewing the deterioration process of seeds. On the other hand, Panobianco et al(2007) found that alterations in carbohydrates during storage could affect the cell membrane permeability, thus contributing to the reduction in the physiological quality and germination of seeds. This could be the reason of our finding that short term.…”