Respiratory activity of rice seeds stored for 10 years at different temperatures

The use of seeds of great physiological potential, which is influenced by several factors from field to storage, is necessary to achieve high yields. Storage, when irregularly performed, may lead the seeds to deterioration, promoting changes on the cell membrane system and respiratory activity that may cause problems to general activities of protein synthesis, thus, to seed germination and vigor. Our objective was to evaluate the physiological potential and respiratory activity of rice seeds stored for 10 years at different temperatures. Rice seeds of the cultivars BRS Pelota, BRS Atalanta, and BRS Firmeza were used, which were placed in impermeable packaging, and stored for 10 years at -15; 1; and 18°C. The physiological potential was evaluated by germination, seedling emergence under greenhouse conditions, germination rate, length and dry matter of aerial part and roots, and respiratory activity. Rice seeds of BRS Pelota cultivar stored at -15°C presented better physiological potential. For BRS Atalanta and BRS Firmeza cultivars, the storage temperature of 1°C maintained the seed physiological potential, confirming the results observed for respiratory activity. We concluded that it is possible to maintain the physiological potential of BRS Pelota, BRS Atalanta, and BRS Firmeza rice seeds after 10 years of storage at -15 and 1°C. The evaluation of seed respiratory activity indicated that it presents relationship with vigor of seeds stored at different temperatures.