Growth and gibberellin relations of the extreme dwarf <i>d</i>^x tomato mutant

The extreme dwarf d x tomato ( Lycopersicon esculentum Mill.) mutant has very short internodes which were found to contain shorter and fewer epidermal cells. The leaves are highly abnormal. The mutant showed a substantial stem growth response to GA 3 , without approaching normal stature or morphology. The active gibberellin GA 1 and its precursors GA 19 and GA 20 were identified by coupled gas chromatography‐mass spectrometry (GC/MS) in d x shoots. Quantitative GC/MS revealed that GA 20 accumulated to far higher levels than normal in stems and leaves of the mutant.