Effect of desiccation, cold storage, and gibberellic acid on germination of somatic embryos in walnut (Juglans regia)

The effect of desiccation, cold storage, gibberellic acid (GA(3)), and various combinations of desiccation with GA(3) and cold storage treatments on root formation and germination of walnut (Juglans regia) somatic embryos originating from immature cotyledons of open-pollinated and non-pollinated seeds was investigated. Desiccation was effective on germination and cold storage (4 weeks at 4 degrees C or GA(3) (2.9, 8.6, 14.3, 20.0, and 25.7 mu m) treatment together with desiccation improved the germination rate of walnut somatic embryos. The highest percentage of germination (69.1 %) was determined with desiccated embryos originating from open-pollinated seeds of 'Bilecik' genotype on 'Driver' and 'Kuniyuki' walnut (DKW) basal medium containing 8.6 mu m GA(3). The germination levels of embryos originating from both open-pollinated and non-pollinated seeds were found to be similar.