Tarbiat Modares University Journal of Agricultural Science and Technology 1680-7073 15 6 2013 11 01 In Vitro Establishment and Clonal Propagation of Sebri Pear Cultivar 1209 1217 14793 EN S. Karimpour Department of Horticulture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran. G. H. Davarynejadur Department of Horticulture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran. A. Bagheri Department of Biotechnology and Plant Breeding, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran. A. Bagheri Department of Biotechnology and Plant Breeding, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran. A. Tehranifar Department of Horticulture, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Islamic Republic of Iran. Journal Article Two experiments were performed for <em>in vitro</em> establishment, proliferation and shoot growth in axillary bud explants of Sebri pear cultivar. In the first experiment, the effect of different concentrations of IBA(Indole-3-butyric acid) on explants’ establishment was evaluated. In a second experiment, the influence of several combinations of PGRs (Plant growth regulators)on shoot proliferation and shoot growth was investigated. IBA at 0 and 0.1 mg L^-1 concentration led to successful bud establishment. At higher IBA concentrations, callus was induced, but fewer explants were successfully initiated. BAP increased shoot proliferation, while TDZ(Phenyl-N'-(1, 2, 3-thiadiazol-5-yl) urea) did not show any effect on shoot proliferation. BAP, at 3 mg L^-1 was more effective than 2 mg L^-1 on the number of proliferated shoots. Maximum shoot length was obtained for the medium containing BAP(6-benzylaminopurine) (2.0 and 3.0 mg L^-1)+IBA (0.1 mg L^-1) and BAP (2.0 and 3.0 mg L^-1)+IBA (0.1 mg L^-1)+GA₃(0.5 mg L^-1). IBA in BAP combinations induced lateral bud swelling, while GA₃(Gibberelic acid) inhibited it. Maximum leaf number was obtained for MS medium with 2.0 mg L^-1 TDZ and 0.5 mg L^-1 GA₃. Moreover, medium supplemented with 2.0 mg L^-1 BAP+IBA (0.1 mg L^-1)+GA₃(0.5 mg L^-1) and 2.0 mg L^-1 TDZ+GA₃(0.5 mg L^-1)produced maximum shoot length. Vegetative growth habit varied with different combinations and BAP concentrations, being the highest in BAP (2.0 mg L^-1)+IBA (0.1 mg L^-1) treatment. The combination of BAP at 2 mg L^-1 and 0.5 mg L^-1 of GA₃ is finally recommended for a proliferation of Sebri pear cultivar. https://jast.modares.ac.ir/article_14793_6c2665d7c3ed1e5bfd8ba600f026eb55.pdf