Soluble sugars in maturing pea seeds of different lines in relation to desiccation tolerance.

The relationship between the accumulation of soluble non-reducing sugars and the acquisition of desiccation tolerance during maturation of four pea lines differing in the content and composition of soluble carbohydrates was analysed. Maturing seeds were harvested at 4-day intervals, tested for desiccation tolerance (measured as the ability to germinate after slow and fast drying) and the soluble carbohydrates in axis and cotyledons were assayed. Immature seeds of RR RbRb and SD9 lines containing the lowest levels of raffinose were more sensitive to rapid drying as compared with seeds of other lines, but finally reached maximum desiccation tolerance at full maturity. Acquisition of desiccation tolerance was preceded by accumulation of sucrose and its development was accompanied by the accumulation of raffinose family oligosaccharides. Seeds of SD1 and SD6 lines did not accumulate verbascose, but this had no effect on their desiccation tolerance.