INFLUENCE OF GROWTH REGULATORS ON IN VITRO PROPAGATION OF PYRUS COMMUNIS CV. KOPORECKA

Abstract

The effect of different concentration of the plant growth regulators BAP (6-benzylaminopurine), IBA (indolebutyric acid) and TDZ (thidiazuron) on in vitro performance of pear (Pyres communis) 'Koporecka' was tested. Micropropagation was improved by culturing on MS medium. The highest proliferation rate 5.6 was obtained on medium containing 2 mg l -1 BAP, but this BAP concentration caused shorter shoots (0-0.5 cm) with growth abnormalities including 86.7% of these shoots that had narrow and non-expanded leaves. The shoots failed to proliferate and died after rooting phase and subsequent transfer to non-sterile conditions. The combination of 1 mg l -1 BAP with 0.1 mg l -1 IBA for multiplication produced 2.5 new shoots with larger and well-expanded leaves, which were ideal for acclimatization. A concentration of 1 mg l -1 TDZ caused abundant callus at the explant base and high level of hyperhydricity in growing shoots. Microcuttings, coming from each proliferation medium, were rooted in MS medium with 1 mg l -1 IBA. The micropropagated plants with good foliage showed 79.2% survival after rooting and transfer to soil.