Accumulation of soluble sugars related to desiccation tolerance during rice (Oryza sativa L) seed development and maturation

A comparative analysis of soluble sugar contents of rice varieties zhongzu1 and chunjiang15, were used to establish the relationship of soluble carbohydrates levels and the occurrence of desiccation tolerance during maturation of the seeds of these rice types. Our data showed that the desiccation tolerance of chunjiang15 seeds between 23 and 40 day after pollination (DAP) and zhongzu1 seeds between 15 and 25 DAP were both increased. There was a decline in reducing sugars such as monosaccharide and maltose but an increase in sucrose content. Seeds subjected to slow drying treatments at different developmental stages could induce sucrose accumulation. When the moisture content was reduced to 10%, the desiccation tolerance between the two kinds of rice (Oryza sativa L) was not significantly different, but after ultra-drying the desiccation tolerance of zhongzu1 was obviously higher than chunjiang 15. With moisture content reductions (10-20%), there was further accumulation of raffinose and sucrose in the embryo of zhongzu1, whereas the content of the two sugars were reduced especially the raffinose in the chunjiang15 variety. Desiccation tolerance in rice was tightly associated with raffionse accumulation in the embryos.