The Role of Hormones in Controlling the Mechanically Induced Dormancy of Suaeda spp.

Seeds of several taxa in the genus Suaeda with a mechanically resistant testa were stimulated to germinate with applications: of 1 × 10−4M gibberellic acid (GAg). The barley endosperm bioassay indicated that the non‐dormant taxa, S. macrocarpa, had high initial gibberellin‐like activity while the dormant varieties, S. flexilis and S. vulgaris, had not. Soaking for 2 days increased the gibberellin‐like activity of the dormant taxa. At 20 days hormonal activity was repressed, and few seeds germinated. The barley endosperm bioassay also revealed an inhibitor activity in the dormant varieties. The wheat coleoptile bioassay and UV irradiation of thin layer chromatograms indicated that an inhibitor occurred at the Rf of cochromatographed ABA and that it had similar inhibitory characteristics.