Identification of abscisic acid, indole-3-acetic acid, jasmonic acid, indole-3-acetonitrile, methyl jasmonate and gibberellins in developing, dormant and stratified seeds of ash (Fraxinus excelsior)

Abscisic acid (ABA), indole-3-acetic acid (IAA), indole-3-acetonitrile (IAN), jasmonic acid (JA), methyl jasmonate (MeJA) and gibberellins (GAs); GA(1),GA(3),GA(8),GA(9),GA(12),GA(15),GA(17),GA(19),GA(20),GA(24),GA(29), GA(44),GA(51) and GA(53), were identified in seeds of ash (Fraxinus excelsior L.) by combined gas chromatography-mass spectrometry. The presence of ABA, IAA, IAN, JA and MeJA was confirmed in developing, dormant and stratified seeds by comparison of Kovat's retention indices (KRI) and spectral data with those obtained for standard compounds. Also, the presence of GA(1),GA(3),GA(9),GA(19),GA(20) and GA(44) was confirmed by comparison of KRI and spectral data with those of standards, while the presence of the remaining GAs was confirmed by comparison of KRI and spectral data with literature values. All of the GAs identified were detected in extracts of developing seeds, while only GA(17) and GA(19) were detected in dormant seeds and GA(1),GA(8),GA(19),GA(20) and GA(29) were detected in stratified seed. The results suggest it is likely that the GAs are important in development and in breaking dormancy of ash seed. While ABA, JA and MeJA may be important in control (i.e. onset and maintenance) of dormancy. The roles of IAA and IAN are unclear, but it is possible that they are important in the development of ash seed, and as part of the dormancy controlling mechanism.