Endogenous gibberellins in the shoots of normal- and bush-typeCucumis sativus L.

Endogenous gibberellins (GAs) in the shoots of normal- (cv. Yomaki, YO) and bush-type (cv. Spacemaster, SP) cultivars of cucumber (Cucumis sativus L.) grown under natural conditions were analyzed. From both YO and SP grown for 40 days, after sowing, a series of C-13-H GAs including GA₄, GA₉, GA₁₅, GA₂₄, GA₂₅, GA₃₄, and GA₅₁ were identified by gas chromatography-mass spectrometry (GC-MS; full scan). In addition to the above GAs, GA₁₂ and GA₇₀ were similarly identified from both YO and SP grown for 61 days after sowing. The endogenous levels of GA₄ and GA₉, which are highly active in promoting cucumber hypocotyl elongation, were quantified by GC-selected ion monitoring (GC-SIM) using [²H₂]GA₄ and [²H₄]GA₉ as internal standards. No remarkable difference in terms of endogenous levels of GA_4/9 was observed between YO and SP in both growth stages (40 and 61 days after sowing).