In vitro propagation of a new clonal apple rootstock candidate Hatay

Some clonal apple rootstocks are traditionally propagated using the layering technique. However, traditional propagation methods are seasonal and require a lot of space and labor. In addition, the multiplication rate is low with these methods, resulting in low-profit sapling production for growers. In vitro propagation techniques provide an efficient and effective method of obtaining species-appropriate, quality saplings in less time and space. The study aims to determine the in vitro propagation protocol of the Hatay genotype and to establish an appropriate method. In the study, the highest number of shoots was observed in media containing BA and mT at concentrations of 2 mg/L. The lowest shoot lengths were also detected in these media. At 2 mg/L concentrations of BA-and mT-containing media, 5.75 and 5.80 shoots per explant were obtained, respectively, and shoot lengths were measured as 0.98 cm and 1.47 cm. Rooting was achieved between 86.67% and 100% in all treatments except the control. The highest number of roots was detected in ½MS (9.93 roots per explant) and MS (6.80 roots per explant) media containing 1.0 mg/L IBA, respectively. A generally higher number of roots was obtained in ½MS medium compared to MS medium; however, plant height and development were determined to be higher in MS medium. The highest root lengths were also detected in ½MS (2.47 cm) and MS (2.19 cm) media containing 1.0 mg/L IBA. 100% callus formation occurred in all media except the control. Although the addition of IBA to the medium triggered root formation, it also caused undesirable callus formation. Undesirable callus formation reduced the acclimatization rate of in vitro propagated plantlets. It was determined that a concentration of 1 mg/L IBA created a thinner callus layer.