In Vitro Establishment and Clonal Propagation of Sebri Pear Cultivar

Abstract

Two experiments were performed for in vitro establishment, proliferation and shoot growth in axillary bud explants of Sebri pear culti var. In the first experiment, the effect of different concentrations of IBA(Indole-3-butyric ac id) 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 expla nts 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 m g 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 )+GA 3 (0.5 mg L -1 ). IBA in BAP combinations induced lateral bud swelling, while GA 3 (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 GA 3 . Moreover, medium supplemented with 2.0 mg L -1 BAP+IBA (0.1 mg L -1 )+GA 3 (0.5 mg L - 1 ) and 2.0 mg L -1 TDZ+GA 3 (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 GA 3 is finally recommended for a proliferation of Sebr i pear cultivar. Keywords : Establishment, In vitro, Pyrus communis , Pyrus pyrifolia , Shoot proliferation.