EVALUATION AND PROPAGATION Of SOME WOODY TREE HYBRIDS BY USING TISSUE CULTURE TECHNIQUE FOR CONTROLLING SOME ENVIRONMENTAL STRESSES

Abstract

The main objective of this investigation was to propagate some superior lines of three Eucalyptus species by using tissue culture techniques and to evaluate transpiration of their in vitro formed plantlets. The species used are Eucalyptus camaldulensis, E. botryoides and E. rudis. The results showed that liquid modified MS medium supplemented with 0.5 mg/L BA and 0.1 mg/L NAA was the best medium for the establishment of shoot tip and stem segment explants. Autumn was the most suitable time for collection of shoot tip and stem segment explants of E. camaldulensis and E. rudis. Stem segment during this season gave the highest survival percentage (88.9%) and (88%) for shoot tips and (62.1% and 60%) for stem segment, respectiv ly. However, Summer was the best season for shoot tip and stem segments of E. botryoides giving 46.7% and 70.97% survival percentage. Autumn and Summer may be optimum time for explants collection since they represent the active growing season when low levels of endogenus phenolic compounds are found in the explants.