Priming effect on the physiological potential of maize seeds under abiotic stress1
ABSTRACT Abiotic stress directly influences seed performance, so poor-vigor seeds under adverse conditions tend to show lower germination speed and rate. By controlling the hydration level of seeds (i.e., priming) with the addition of chemical agents, it is possible to elicit the maximum physiological potential of seeds, even under stress conditions. This study aimed to evaluate the priming effect of different chemical agents on the physiological potential of maize seeds under abiotic stress (polyethylene glycol induced water stress, hypoxia, low temperature and salt stress after controlled deterioration). The experimental design was completely randomized, in a 5 x 2 factorial scheme, consisting of different chemical agents used to hydrate the seeds [control without priming; control primed with water; calcium nitrate (0.2 %); amino acid L-phenylalanine (0.05 %); amino acid L-phenylalanine (0.5 %) + calcium nitrate (0.2 %)] and 2 seed lots, with four replicates. Priming with calcium nitrate lead to a greater germination and higher emergence rate of the seedlings under suboptimal temperature conditions, and seeds that underwent controlled deterioration showed greater germination levels with the use of calcium nitrate + phenylalanine in the priming process, regardless of the lot used. In general, seed priming allowed a greater expression of seed vigor, even though an interaction with lots was observed in some variables.