The Effects of Priming and Ageing on Resistance to Deterioration of Tomato Seeds

Abstract

The influence of seed priming and ageing treatments on viability and rate of germination of tomato (Lycopersicon esculentum Mill.) seeds was examined under both long-term and controlled-deterioration storage conditions. Seeds of a single lot of tomato were either primed or aged to increase or decrease the rate of germination (Argerich and Bradford, 1989). They were then stored at 6% moisture content (dry weight basis) at either 4 °C or 30 °C for 1 year. Both viability and germination rate were unaffected by either storage temperature in control seeds, or by 4 °C storage in primed or aged seeds. At 30 °C, however, viability and germination rate of primed and aged seeds was markedly reduced after 6 months of storage. The temperature dependence of the germination rate and the spread of germination times within the population was also adversely affected by high temperature storage, particularly for primed seeds. Under controlled deterioration conditions (13.5% moisture content and 50 °C), the rate of loss of viability was greater for primed seed than for control or aged seeds. The relationship between seed viability and the mean germination rate, however, was not influenced by the seed treatments. These data are analysed in relation to current models of seed deterioration during storage and seed repair during priming. The results indicate that enhancement of seed germination rates by priming treatments simultaneously lowers the resistance of seeds to deterioration. Primed tomato seeds must, therefore, be considered to be vigorous seeds with a reduced storage life.