The levels of GA3 and GA20 may be associated with dormancy release in Onopordum nervosum seeds

Endogenous levels of two gibberellins, GA(3) and GA(20), were quantified in unimbibed Onopordum nervosum seeds collected from two different populations, which showed differences in their germination capacity. After purifying the seed extracts, gibberellin levels were evaluated by gas chromatography mass spectrometry by using selected ion monitoring (GC-MS-SIM) adding deuterated gibberellins as internal standards. The intraspecific differences in germination capacity were associated with differences in the endogenous levels of both gibberellins. The contents of GA(3) and GA(20) in seeds with high germination rate were twice and five times higher, respectively, than those from seeds with a low germination rate, indicating a possible role of gibberellins in dormancy release in this plant species.