Changes in Nutrient-Homeostasis and Reserves Metabolism During Rice Seed Priming: Consequences for Seedling Emergence and Growth

In this study influence of different seed priming treatments on the nutrient-homeostasis and reserve metabolism during seedling emergence and growth of rice were determined. Seed priming treatments included pre-germination, hydropriming for 48 h, osmohardening with KCl and CaCl₂, ascorbate priming and hardening. All treatments shortened the emergence time and enhanced the energy and index of seedling emergence. Seedlings from primed seeds had greater length, number of roots and fresh and dry mass than control. Among the treatments, CaCl₂, ascorbate and KCl proved better in enhancing emergence and seedling growth. Seed priming changed the pattern of N and Ca²⁺ homeostasis both of the seeds and seedlings, which were associated to enhancing α-amylase activity and reducing sugars content. Positive correlations of seedling attributes with nutrient content suggested that as a result of seed priming, most of N and Ca²⁺ were partitioned to embryo, which enhanced seedling emergence and subsequent growth of rice seedlings.