Among other mechanisms, the presence of certain soluble sugars in seed seems to be involved in the acquisition and maintenance of desiccation tolerance. In this study, the composition of. soluble sugars in hybrid corn seeds with different levels of tolerance to high drying temperature as well as the relationship between the content of those sugars and desiccation tolerance was researched. Seeds of ten hybrid corn cultivars presenting reciprocal effect to the tolerance to high drying temperature were employed. The seeds were harvested with a water content of about 35% and dried at 45ºC. The physiological quality of the seeds was evaluated by means of the germination test, cold test without soil and accelerated aging test. The sugars glucose, fructose, sucrose, raffinose and stachiose were extracted from the embryos in the presence of methanol and separated by means of the High Performance Liquid Chromatography (HPLC) technique. Variation in the presence of sugars among the hybrid seeds and those of their reciprocals was detected. A higher concentration of sucrose was verified in hybrid seeds tolerant to high drying temperature. It was not possible to establish a ratio between sucrose and raffinose which could serve as a parameter of the tolerance to high drying temperature in corn seeds. Increased tolerance of the seeds was associated with a greater ratio of sucrose, raffinose and stachiose/glucose and fructose.
Zea mays; desiccation tolerance; soluble sugars; physiological quality
