Changes in Sucrose, Cyclitols and their Galactosyl Derivatives with Seed Ageing

Abstract

Soluble carbohydrates were studied in relation to seed desiccation tolerance and storability. The changes in sucrose, cyclitols and their galactosyl derivatives were related to seed aging of maize, rice, soyabeans, cotton and lettuce. Seeds were aged at 75% relative humidity and 45°C. Aging reduced percentage germination and the coefficient of the rate of germination for all crop species studied. A decline in raffinose in maize axes and rice embryo tissues was correlated with the decrease in percentage germination. A similar correlation between the raffinose series of oligosaccharides and aging was not found in seeds of soyabean, cotton and lettuce, possibly due to changes in the carbohydrate pools during aging. Sorbitol, an acyclic polyol, increased significantly from undetectable or trace amounts to high levels as a function of seed aging for all five species.