Adventitious Root Generating Process and Hormone and Enzyme Changes in Vitro Paeonia suffruticosa Histolog ical and Hormonal Characters during the Rhizogenesis of in Vitro Walnut Shoots Adventitious Root Generating Process and Hormone and Enzyme Changes in Vitro Paeonia suffruticosa Polyploid Induction in Pear in vitro Treatment With Gamma-rays Histolog ical and Hormonal Characters during the Rhizogenesis of in Vitro Walnut Shoots Cryopreservation of In Vitro Shoot Tips of Potato by Droplet Vitrification and Genetic Stability of Regenerated Plantlets Cryopreservation of In Vitro Shoot Tips of Potato by Droplet Vitrification and Genetic Stability of Regenerated Plantlets Conservation of in Vitro Shoots of Persimmon and Date Plum by SlowGrowth and Genetic Stability of Recovered Plantlets Polyploid Induction in Pear in vitro Treatment With Gamma-rays