INFLUENCE OF DIFFERENT AUXINS ON IN-VITRO ROOTING OF SWEET CHERRY CULTIVARS (PRUNUS-AVIUM L)

Three auxins were tested for their rooting effect in the sweet cherry cultivars 'Regina', 'Burlat', 'Buttners', and 'Stella'. Irrespective of the concentration used, IAA and IBA induced low rooting percentages (< 50 %). NAA proved to be the best auxin for in vitro rooting of sweet cherry cultivars. At a concentration of 0.5 mg/l NAA in one half strength MS, roots were induced in more than 90 % of the shoots of all cultivars tested. All roots were long, white, and vigorous. The shoots resumed growth immediately after root formation. Under high concentrations, especially 2.0 mg/l, short and weak roots were induced. Shoots became necrotic and turned yellowish. The basis of the shoots was callused. Such plants produced high losses after transfer to soil.