The Effect of Low Temperature Pre-Sowing Treatment on the Germination Performance and Membrane Integrity of Artificially Aged Tomato Seeds

Loss of seed viability and decrease in germination rate appear to be due to two independent sets of events occurring during artificial ageing in tomato (Lycopersicon esculentum Mill) seeds. Only the second category of physiological damage is reversible: a low temperature pre-sowing treatment being capable of greatly reducing the time to fifty percent germination of both unaged and aged seeds, but having no effect on germination capacity. Leakage of ionic solutes from the seeds did not increase following ageing, but there were considerable increases in losses of small organic molecules. Low temperature pretreatments did not reduce the rate of loss of either amino acids or reducing sugars from aged seeds. The implications of the use of artificial ageing in combination with low temperature pre-sowing treatments in the study of small seed physiology is discussed, as is the value of solute leakage studies in this kind of seed.