Enzymatic and physiological alterations of lines maize seeds submitted to different Temperatures

During seeds germination period, the temperature is an important factor, which influences the seedling establishment in the field. Thus, tolerant cultivars at both low and / or high temperatures in these phases are fundamental in plant breeding programs. The objective in this work was to verify the enzymatic and physiological alterations of lines maize seeds submitted to different temperatures. We used maize lines (L30, L64, L63, L91) from the maize breeding programs of the company Geneseeds Genetic Resources Ltda. Seeds from this lines were submitted to germination test, first count of germination, root protrusion and emergence test at different temperatures of 15, 20, 25, 30 and 35°C. We also calculated the emergence speed index (ESI) and the expression of catalase, esterase, malate dehydrogenase, alcohol dehydrogenase and α-amylase enzymes, for all treatments. The experimental design was completely randomized, in factorial scheme of 4x5, with four lines and five temperatures. The maize lines 30 and 64 are susceptible to high temperatures of germination. The temperature variations compromised the physiological quality of lines maize seeds. There is variation in the expression of ADH, MDH, catalase, esterase and alpha amylase enzymes in maize lines of the evaluated lines.