In Vitro Direct Shoot Regeneration of Kaman 1 Walnut Variety and Kaman 5 Walnut Genotype (Juglans regia L.)

In this study, a simple and effective clonal micropropagation protocol was developed from axillary buds of Kaman 1 walnut variety and Kaman 5 walnut genotype. For surface sterilization of explants, they were first treated in 70% ethanol for 1 minute and then treated with 0.2% HgCl2 containing two drops of Tween 20 for 5 minutes. To prevent browning of the explants, 100 mg/l Ascorbic Acid, 100 mg/l Citric Acid and 100 mg/l Ascorbic Acid+100 mg/l Citric Acid were added to the MS nutrient medium. In addition, explants were subcultured at 3, 24 and 48 hour intervals. It was observed that the most effective treatment in both Kaman 1 walnut variety and Kaman 5 walnut genotype was 100 mg/l AA + 100 mg/l SA + 48 hours subculture. Within the scope of the shoot regeneration study, six different combinations of 0.5, 1.0 and 1.5 mg/l doses of BAP and 0.5 and 1.0 mg/l doses of IBA were tried. The highest average number of shoots per explant 2.67 was obtained from the Kaman 1 variety on MS medium supplemented with 0.5 mg/l BAP and 1.0 mg/l IBA. On the other hand, in the medium containing 0.5 mg/l BAP and 0.5 mg/l IBA, the average number of shoots was 2.00 for the Kaman 1 cultivar and 0.67 for the Kaman 5 genotype. After the shoots were kept in a solution containing 4 mg/l IBA for 10 minutes, they were planted in pots containing a peat: perlite (1:1) mixture, but rooting couldn’t be achieved from the shoots.