Identification and characterisation of a gibberellin-related dwarf mutant in pumpkin (Cucurbita moschata)

'Non-vine I' is a dwarf variety of pumpkin (Cucurbita moschata) with short vines, while 'Yellow wolf' is a normal variety with long vines. The phenotypes of 'Non-vine I' and 'Yellow wolf' pumpkin were compared, and changes in the length of the vine in'Non-vine F were observed after treatment with gibberellin A(3) (GA(3)), naphthylacetic acid (NAA) or brassinolide (BL). Cell sizes in the internode in'Non-vine F were then observed and compared after application of 0.6 mM GA(3) or water (control). The results obtained showed that: (1) the morphological characteristics of 'Non-vine F plants were similar to normal pumpkins except for the vine trait; (2) 'Non-vine F plants were sensitive to exogenous GA(3) which significantly promoted the elongation of vines and petioles, but did not respond to exogenous auxin (NAA) or brassinolide (BL); (3) internode cells of 'Non-vine I' plants were shorter than those of normal pumpkins, and GA(3) promoted internode cell elongation in 'Non-vine I' plants. We propose that 'Non-vine I' is a GA-related mutant, and the dwarf trait results from the failure of normal internode cell elongation.