CHANGE IN EPILOBIUM PHYLLOTAXY DURING REPRODUCTIVE TRANSITION

摘要: The ontogeny of Epilobium hirsutum grown under natural summer photoperiod in a glasshouse was divided into vegetative, early transitional, and floral stages. Bijugate phyllotaxy, common to both the vegetative transitional stages, is transformed spiral phyllotaxy during stage by an initial change divergence angle single primordium inserted at unique level on shoot. Leaf primordia subsequently are arrangement indeterminate shoot apex. apical meristem about 1.5 times volume but expands two-thirds relative plastochron rate increment meristem. There progressive decreases rates radial vertical growth through ontogeny. Relative chronological growth, however, not altered Spiral transformation results from changes points insertion leaf These accompanied increased initiation more circular similar that which artificially induced chemical modification auxin concentration gradients apex, with additional feature there increase prior transformation. Size meristem, appears have little influence phyllotaxy; geometric shape well correlated bijugate transformations. This suggests parameters should be considered theoretical models