Protocols for Micropropagation of Woody Trees and Fruits

CHAPTER 44
IN VITRO CULTURE OF TREE PEONY THROUGH
AXILLARY BUDDING
M. BERUTO 1 AND P. CURIR 2
1 Istituto Regionale per la Floricultura, Via Carducci, 12-18038
Sanremo (IM)-Italy; E-mail: beruto@regflor.it
2 C.R.A.- Istituto Sperimentale per la Floricultura, Corso Inglesi, 508-18038
Sanremo (IM)-Italy
1. INTRODUCTION
Peonies are long living perennials belonging to the family Paeoniaceae, which
is one of the world’s most ancient flowering plant group once included in the
Ranunculaceae. These plants have proved to be useful for medicinal use and they
have also been attractive ornamental flowers for over 3.000 years in China and at
least for years 500 in Europe. The genus Paeonia is native to Morocco and Spain
across the mountainous regions of Europe and the Mediterranean, through the
Caucasus to central Asia, and into China and Japan and even the western United
States. It consists of a relatively small number of species (about 33 species, according
to Rogers, 1995) and it is taxonomically very complex. There are two basic
types of peonies: herbaceous and tree. The former ones are the most common and, as
their name implies, these plants present an annual thermoperiodic life cycle where a
perennial crown serves for the accumulation of the storage products and plant
renewal (Barzilay et al., 2002). Tree peonies are flowering shrubs which grow from
1 to 6 feet tall and are divided into two main groups: the hybrid and the non hybrid
group. The latter ones are varieties of P. suffruticosa, comprising more than 500
cultivars.
P. suffruticosa cultivars are used as outside ornamentals and as pot plants. Their
cultivation under warmer climates, where the flowering process is accelerated,
provides an excellent early market niche as cut flowers. The reproduction, under a
commercial point of view, is mainly done by two primary methods of vegetative
propagation: tuft division and grafting. In division methods, a large plant is simply
divided into small plants, each bearing its own roots. In grafting methods, an
herbaceous rootstock is used to nourish a tree peony scion until the tree peony
477
S.M. Jain and H. Häggman (eds.), Protocols for Micropropagation of Woody Trees and Fruits, 477–497.
© 2007 Springer.