LAUSR

In this elaboration, effective methods of in vitro propagation of a Paulownia tomentosa × Paulownia fortunei hybrid are presented, and the variable costs of commercial production evaluated. Plant regeneration of the P. tomentosa × P. fortunei hybrid was achieved through organogenesis in nodal explants. Different concentrations of BAP (6-benzylaminopurine), 0.2, 0.5, 1 mg/L, and light conditions were investigated. The best results were obtained using a half-strength MS medium containing 0.5 mg/L BAP. In standard light conditions, 2 shoots were grown with 3.5 culturable nodes on each, and in 70% reduced light, 2 new shoots were grown with 6 culturable nodes on each. Rooting was successfully achieved when using a hormone-free half-strength MS medium containing vitamin, and 2% sucrose with 95% efficiency. Acclimatization and survival were shown to be 90% in regenerated plants. The cost of production of a single plant of P. tomentosa × P.fortunei hybrid grown in standard light conditions was $0.084 and $0.082 when grown in 70% reduced light where only variable costs were considered. Two major factors affecting P. tomentosa × P fortunei hybrid micropropagation is labor, materials and chemicals. Focusing on reducing this cost can highly lower plantlet price.