Improving the Ex Vitro Acclimation Efficiency of Hybrid Hazelnuts (Corylus avellana L. X C. americana Marshall)
Micropropagation of hybrid hazelnuts (Corylus avellana L. X C. americana Marshall) commercially has been limited due to their poor rooting ability plus low survival and slow growth within the greenhouse. The objective of this study was to develop an efficient and cost-effective commercial in vitro rooting and acclimation protocol. Rooting hazelnuts in vitro within a Temporary Immersion System (TIS) induced a higher rooting (91.7%) than semi-solid rooting (27.2%) after 3 weeks. The TIS rooting technique was found to support a high in vitro density of 36 explants/vessel and plantlets exhibited a >90% survival in the greenhouse. Plantlets transplanted into a high organic matter growth medium, grown under low light (100 µmol/m2/s) and repotted after 9 weeks allowed a greater shoot growth (145.4 mm) after 12 weeks than plantlets repotted and grown under 250 µmol/m2/s (80.5 mm). This study allows for the rapid production of high quality hazelnut trees year round.