Diurnal dynamics of natural growth substances in peach leaves and shoots

A study has been made of the level of naturally-occurring growth substances and inhibitors in acid-soluble fraction of peach leaves and shoots using paper chromatography and bioassay methods. The content of substances which stimulate growth ofAvena coleoptile sections calculated on a fresh weight basis can be expressed by a one-peak curve with a maximum at 10 a.m. The shoots were higher in growth substances than leaves in all periods of time examined. The extract contained two substances which significantly stimulated the growth of coleoptile (accelerator-2 and-3). High inhibition was found in the area of inhibitor-β and to a lesser extent in the area of inhibitor-α. The changes in the concentration of inhibitors were different in leaves and shoots.