The effects of BAP, IBA and genotypes on in vitro germination of immature walnut embryos

A prerequisite for most plant transformation systems is an efficient and reliable method to regenerate phenotypically normal plants. The present studies were undertaken with a view to the effects of Benzyl amino purine (BAP) and Indol butyric acid (IBA) hormones and genotypes on in vitro germination of immature embryos in walnut (Juglans regia L.). The immature embryos of walnut were excised from different cultivars and cultured on DKW basal medium supplemented with different plant growth regulators. Significant differences were observed among different cultivars and different concentration of BAP and IBA. The BAP and IBA induced the shoot, root and callus proliferation and embryo germination, but it was dependent on genotypes and hormones concentrations. The best performing medium for immature embryos germination was DKW basal medium supplemented with 1 mg L-1 alone and 1.5 mg L-1 BAP in conjunction with 0.01, 0.05 and 0.1 mg L-1 IBA (germination ratio vary between 49.32% and 67.76%). Percent germination of immature embryos was more when BAP and IBA were simultaneously applied as compared to those when applied separately. Keywords: Casein hydrolysate; DKW basal medium; Immature embryo; In vitro development; Juglans regia L.; Root, Shoot