بررسي تاثير جيبرليك اسيد بر كشت مريستم سيب پاكوتاه گمي آلماسي

INVESTIGATION ON THE EFFECT OF GA3 ON DWARF APPLE `GAMI ALMASIʹ MERISTEM CULTURE

This research was carried out for in vitro propagation of dwarf apple rootstock cv. `Gami Almassiʹ (native clone of Azarbaijan) using meristem with 2 leaf primordia. Plant regeneration was induced on half-strengh MS medium supplenented with (mg 1^-1 ) BAP 0.2, 1BA 0.1, GA3 0.4, 0.6 and 0.8 and 20 g 1^-1 sorbitol. Results of first stage showed non significant effect between callus and leaf formation, but 0.4 mg 1^-1 of GA3 with other growth regulators increased meristem growth. Shoot multiplication was achieved on media with (mg 1^-1 ) BAP 0.5, IBA 0.1 and GA3 0 and 0.1. In this phase, the effect of different GA3 concentrations on the number of new formed shoots and shoot length were tested and best result was obtained with 0.1 mg^-1 GA3. Rooting was induced by subculturing plantlets on a one-third strength MS medium containing 7 g 1^-1 agar and liquid medium supplemented with either 0, 1, 2 or 3 mg 1^-1 IBA. In this stage, shoots of 2-cm length and 1-mm diameter were used. Results of rooting stage showed that considering measured traits (including rooting ability, root number, root length and callus induction) there was a significant difference between medium type and IBA concentration. However, mean comparisons indicated that using 3 mg 1^-1 IBA had the best effect on them, but with decreased callus formation. Using the solid medium had the similar effect. Treatment combinations used in solid medium with 0.0 and 3.0 mg 1^-1 IBA and in liquid medium with 1.0 mg l^-1 IBA gave the most satisfying effects on rooting of micro-cuttings and in the latter one, the number of roots was the highest. The lowest rate of callus formation and the highest rate of root length were achieved from solid medium with 3.0 mg 1^-1 IBA.