“…Although a few studies have investigated the endogenous GA content of vernalized compared to nonvernalized plants using either bioassays or GC-MS, results have been variable (Suge, 1970;Michniewicz et al, 1981;Joseph et al, 1983;Lin and Stafford, 1987). Bioassay results with Brassica napus (Margara, 1963), Brassica rapa (Suge and Takahashi, 19821, chicory (Joseph et al, 19831, radish (Suge, 1970;Michniewicz et al, 1981), and winter wheat (Chailakhyan and Lozhnikova, 1962;Reda et al, 1978) have indicated the presence of additional GA-like substances or increases of certain GA-like substances in vernalized tissues. In contrast, in another member of the Brassicaceae, Thlaspi arvense, increases in endogenous GA-like substances did not appear to be directly induced by low temperature, but rather thermoinduction may have resulted in altered GA sensitivity or GA metabolism (Metzger, 1985).…”