MICROPROPAGATION OF THE PINE HYBRID PINUS-BRUTIA (TEN) X PINUS-HALEPENSIS (MILL) BY CULTURING FASCICLE SHOOTS

Fascicle shoots proved to be an ideal plant material for micropropagat ion of the pine hybrid P brutia (Ten) x P halepensis (Mill). This coul d be possibly attributed to their morphological and physiological stat e. Induced fascicle shoots of 4-yr-old seedlings were used as explants . Their induction was achieved by spraying once with the new herbicide Arsenal (1 000 mg l-1). First, explants were elongated in vitro on LP medium and then transferred to the multiplication stage. Multiplicati on was accomplished by decapitating, quick-dipping in 0.22 mM BA and i noculating the explants on BIMI medium. On the induced first-generatio n shoots the same procedure was applied, in order to obtain second-gen eration shoots and then these were proceeded to the rooting and acclim atization stages. In particular, when microcuttings were pretreated wi th 2.46 muM IBA + 2.7 muM NAA + 0.65% agar w/v + 1.5% sucrose w/v for 7 d and then transferred to greenhouse conditions, a good root system was developed within an 8-12-week period. A large variation in rootabi lity was noted between clones. The above method may be proved to be ef ficient for clones that exhibit high rooting ability.