Investigation of In Vitro Propagation Potentials of Prunus Rootstocks Developed by Selection and Hybridization

Abstract

This study investigated in vitro regeneration and rooting performance in 41 rootstock candidates obtained through selection and hybridization breeding methods. The highest shoot formation (13.66 shoots/explant) was observed in the control rootstock Myrobolan 29C, followed by GN-22 (12.66), KL-30 (12.66), and KL-6 (12.00). Among the 46 genotypes, 26 (56.5%) achieved a success rate of ≥3.3 shoots/explant. Shoot lengths varied between 2.29–30.36 mm, with 71.7% of shoots reaching ≥14.6 mm. Callus formation (33.3–55.0%) and vitrification (11.7–33.3%) were observed in only three genotypes. Regeneration failure was detected in six rootstock candidates (13%). KL-59 exhibited the highest rooting performance (7.66 roots/explant), while KL-2 showed the lowest (1.33 roots). Among the genotypes, 87.5% achieved ≥2.33 roots/explant. Root lengths ranged from 4.9–25.75 mm, with 92.5% exceeding 10 mm. The results were consistent with previously reported genotype-dependent variations in Prunus species (Koaym, 2025). Notably, the rootstock coded KL-59 demonstrated superior performance. The low vitrification rates observed at the end of the study reflected the success of protocol optimization. Furthermore, this study revealed that in vitro micropropagation success in Prunus rootstocks varies significantly depending on genotype and highlighted the importance of identifying high-performance clones like KL-59 for commercial production. The findings are expected to contribute significantly to stone fruit rootstock breeding programs.