COMPARISON OF EARLY LATERAL VEIN FORMATION IN LINUM USITATISSIMUM LEAVES WITH THEORETICAL NETWORK MODELS

The plastochron age of the Linum leaf that first exhibited lateral leaf vein divergences, the divergent leaf, increased through shoot ontogeny, but the size of the divergent leaf remained constant. There were progressive decreases in the plastochron and relative plastochron rate of leaf elongation, but no significant change in relative chronological rate of leaf elongation, through ontogeny. Thus, divergent leaves of similar sizes occupied different relative positions in the array of leaves on stems of different plastochron ages. These observations are partially consistent with theoretical network model predictions on early leaf vein development. The empirical data of this study suggest additional features of leaf development that should be incorporated into future simulation models for leaf vein development.