The effect of leaf primordia and auxin on leaf initiation rate in strawberry.

Removal of the leaf primordia hastens the rate of leaf initiation at the apex, and a paste containing 0.2% IAA in lanoline will substitute for the effect of the leaf primordia. Physical factors involved in the alteration in bud structure resulting from defoliation, such as gaseous diffusion and shading from light, have only negligible effect on the rate of leaf initiation, and the compsition of the internal atmosphere of the intact buds is not very different from the external atmosphere.The evidence suggests that developing leaf primordia inhibit cell division of the apical meristem through their production of auxin which is discharged into the stem at points which are morphologically basal to the apical cells; this, therefore, could be another case of correlative inhibition by auxin, comparable with the inhibition of lateral buds by the terminal apex.