Abstract:

[Objective] The aim of the present study was to explore the effects of exogenous brassinosteroids （BR） priming on aged oat （Avena sativa） seed vigor. [Method] Artificially aged oat seeds were used as experimental materials and were primed with different concentrations （0, 0.01, 0.10, 0.50, 1.00, and 10.00 μmol/L） of BR solution for 0 （CK）, 1, 6, 12, 18, and 24 h, respectively. The changes in the germination percentage, germination index, mean germination time, and seedling vigor index were characterized. [Result] Different concentrations of exogenous BR, priming time and their interaction had extremely significant （P<0.01） effects on germination percentage, germination index, mean germination time, and seedling vigor index of the aged oat seeds. The aged oat seeds exhibited the highest germination rate, germination index, seedling vigor index as well as the lowest mean germination time when they were primed with BR at the concentration of 0.01 μmol/L for 24 h. After BR priming for 1-24 h at the concentration of 10.00 μmol/L, the germination rate, germination index, and seedling vigor index of the aged oat seeds were all lower than the other concentrations, while the mean germination time was significantly （P<0.05） higher than the other concentrations. [Conclusion] Low concentration of exogenous BR priming could increase the aged oat seed vigor, while high concentration exhibited the opposite effect. Under the experimental conditions in this study, the optimal treatment to alleviate the oat seed aging was priming with BR for 24 h at a concentration of 0.01 μmol/L.

Key words: brassinosteroids, seed aging, oat, seed vigor, seed germination