Interactions between myo‐inositol and cytokinins: Their basipetal transport and effect on peach roots

Root growth of partly defoliated young peach seedlings [Prunus persica (L.) Batsch. cv. Lovell] was significantly promoted by application of myo‐inositol to the cut surface of the stem. Addition of benzylaminopurine (BA) combined with sucrose enhanced the promotive effect of myo‐inositol on root growth, but addition of sucrose alone, suppressed it. Spraying rooted peach cuttings (nectarine cv. Sunred) with myo‐inositol and defoliating them after 5 days increased the incorporation of amino acids into proteins in excised roots, obtained from the sprayed plants, as compared with roots from plants sprayed with water, or sucrose, or sucrose + myo‐inositol. Myo‐inositol applied in combination with kinetin or BA to stems of young peach seedlings (cv. Lovell) or rooted peach cuttings (cv. Almog) promoted the basipctal translocation of the two cytokinins in the stem and acropetally into the small lateral roots. Addition of sucrose voided this effect on the cytokinins. BA, when applied together with myo‐inositol, was partly converted into an additional cytokinin‐active compound in the roots. Application of BA to either roots or tops of rooted peach cuttings (cv. Almog) resulted in the accumulation of myo‐inositol (supplied through the cut surface of the stem) in the plant part to which BA had been applied.