The Influence of Pre and Post-storage Hydration Treatments on Chromosomal Aberrations, Seedling Abnormalities, and Viability of Lettuce Seeds

Abstract

A 2 h soaking treatment in distilled water, or in aqueous solutions of cysteine, potassium iodide, or sodium thiosulphate, had no significant effect (P > 0.25) on the subsequent longevity of lettuce seeds (Lactuca sativa L.) in two different storage environments. Neither did these treatments influence relations between loss in germination and the frequency of chromosomal aberrations observed during first mitoses after storage. In contrast partial hydration of lettuce seeds after storage by exposure to moist air (humidification) or to an osmoticum (priming) reversed some of the damage which resulted from ageing. Most of the benefits occurred during the first 3 d of humidification during which seed moisture content rose to 34 per cent, or during the first 7 d of priming when seed moisture content increased to 44 per cent. Both post-storage hydration treatments reduced the frequency of chromosomal aberrations, increased the rate of root growth, and decreased the frequency of morphologically abnormal seedlings. Either treatment could be of practical use, but it is suggested that humidification is more convenient. Consideration should be given to adopting a humidification treatment as standard practice following long-term seed storage for genetic conservation