Physiological quality and protein patterns of corn seeds produced under water and salt stresses

This study evaluated the effect of water and salt stresses on the physiological quality and on the electrophoresis patterns of heat resistant proteins in corn seeds. The experiments were carried out in the laboratories of seed analysis and biotechnology at the Universidade Federal de Lavras. Corn seeds of the hybrid GNZ 2004 and the inbred line LE 57 were used. The seeds were produced in soils with an electric conductivity of 3 dS m-1 (under stress) and 0.4 dS m-1 (without stress) and in pots containing substrate with a water holding capacity of 40% (with stress) and 70% (without stress). The randomized complete block design with treatments arranged in a split-plot scheme was used with four replications . Seeds were harvested at different stages of development. Seed physiological quality was evaluated using the tests of germination, artificial aging and cold test. The patterns of heat resistant proteins were evaluated by electrophoresis. The results showed that depending on seed developmental stage there was an effect of water and salt stresses on the seed vigor. The electrophoretical patterns of heat resistant proteins were stable in seeds produced under different stress conditions.   Key words: Zea mays, developmental stages, late embryogenesis abundant proteins (LEA proteins).