Evaluation of naturally and artificially aged seeds of Phaseolus vulgaris L.

Seed ageing is natural phenomenon that occurs in all seeds, including those stored in dry and low temperature rooms. Phaseolus vulgaris L. cv. 'Carioc a' seeds harvested in five different years were stored in at 15 degreesC. S eed samples were germinated and evaluated according to The Brazilian Rules for Testing Seeds. The newest seed sample was submitted to artificial agein g. Small (similar to 1g) samples of all materials (naturally and artificial ly aged) were ground and proteins extracted. Equal quantities of protein we re loaded onto the gels and electrophoresis carried out Although seeds subm itted to 24, 48, 72 and 96 hours of artificial ageing did not show any stat istical difference (5%) in relation to unaged seeds in physiological parame ters related to emergence, some statistically different parameters related to dry matter and length of shoots and roots occurred. A 24 h of artificial ageing at 41 degreesC improved these factors. Protein patterns were change d after 72 h of artificial ageing and naturally aged seeds showed alteratio ns after two years storage at 15 degreesC. Aged seeds, naturally and artifi cially, had decreasing germination, vigour, and changes in the characterist ic banding pattern of proteins. Physiological parameters and electrophoresi s examination showed that for naturally aged seeds physiological parameters were more sensitive while artificially aged seeds, (41 degreesC/100% RH), had electrophoretic profiles that were more efficient for seed lot discrimi nation.