Ex Vitro Rooting and Simultaneous Micrografting of the Walnut Hybrid Rootstock ‘Paradox’ (Juglans hindsi × Juglans regia) cl. ‘Vlach’

In vitro micropropagation is already a current multiplication tool for walnut self-rooted cultivars and rootstocks, but grafting still performed in the field or greenhouses, mainly using seedlings as rootstocks. The present work describes new approach to obtain clonal walnut-grafted plants, involving shoot production of ‘Paradox’ (Juglans hindsi × Juglans regia) cl. ’Vlach’, be used rootstock, J. regia cv. ‘Chandler’, scion. After completing phase seven-day root induction treatment, ‘Vlach’ explants are transferred ex conditions expression while being simultaneously grafted produced ‘Chandler’ scions. importance presence leaves on both scion rootstock success rate technique was evaluated. Under optimal conditions, average rates 82% rooting, 72% micrografting survival, 84% plant acclimatization were achieved. This rooting/grafting combination seems able compete with traditional techniques nursery grafting, allowing obtaining high-quality plants independently external weather significantly shorter time.