Requirements for in vitro rooting of Paeonia suffruticosa Andr. cv. ‘Mme de Vatry’

Abstract

The effect of different auxin treatments on in vitro rooting of tree peony ( Paeonia suffruticosa Andr.) was studied. Of the three methods tried, a protocol involving a root induction phase followed by a root development phase was the most effective. Root induction required darkness and high indole-3-butyric acid levels (75 μM) for 10 days, while the best root quality and quantity was obtained when the root development medium contained 0.3% activated charcoal but no auxin. Preliminary elongation of shoots of tree peony in a medium containing GA 3 and 6-benzyl-aminopurine reduced rooting capacity as compared with non-elongated microcuttings. Rooting percentage and mean number of roots of elongated microcuttings increased if axillary buds were removed from their bases before transfer to the root induction medium. In contrast, rooting of non-elongated microcuttings was favoured if basal axillary buds were maintained. Overall, non-elongated shoots gave better rooting response than the elongated shoots.