In vitro and ex vitro rooting of Spiraea betulifolia subsp. aemiliana (Rosaceae), an ornamental shrub

Abstract

Two methods of rhizogenesis – in vitro and ex vitro of Spiraea betulifolia subsp. aemiliana (C.K. Schneid.) H. Hara microshoots have been compared. Pulse treatment of microshoots with aqueous solutions of 4% “Heteroauxin” or 2% succinic acid (ex vitro rooting) did not effective -rooting frequency ranged from 3 to 19%. It was established that the in vitro rooting on nutrient media supplemented with auxins was a more effective technique, providing a high percentage of rooted microshoots. The use of half- strength MS medium supplemented with 0.1 μM indolyl-3-butyric acid (rooting frequency 8 8%, root number 3.5 ± 0.3 per plantlet) was found to be the most efective for in vitro rooting. The in vitro rooted regenerated plantlets were successfully acclimatized with 55% of survival rate.