Protocols for Micropropagation of Woody Trees and Fruits

IN VITRO CULTURE OF TREE PEONY 479
Figure 1. Tree peony cultivars tested to develop the micropropagation protocol in our laboratory.
a) Bai Yu; b) Feng Dan Bai; c) Shi Yuan Bai; d) White Pearl; e) Xue Lian; f) Yao
Huang; g) Huang Hu; h) Orange Yellow; i) Golden Palace; j) Hu Hong; k) Da Jin Fen;
l) Fish Scale Pink; m) Zhuang Yuan Hong; n) Zi Zy Qiao; o) First Red; p) Red Diamont;
q) Zhu Sha Lei; r) Orange; s) Red; t) Old Pink .
However, a part from the genotype, many other factors have been shown to be of
considerable importance for successful micropropagation of tree peony. Among
others, the physiological status of the shoots, the medium formulation and the type
and concentrations of cytokinins. BA has been found to be a cytokinin effective in
inducing organogenesis from shoots of P. suffuticosa which can be used alone (Bouza
et al., 1994a) or in combination with kinetin (Yulong et al., 1984), 2iP (Harris &
Mantell, 1991) and NAA (Černá et al., 2001). Generally, hormone concentration
must be carefully tested in order to avoid shoot hyperhydricity and a different performance
can be scored according to the genotype. The number of subcultures can
influence the multiplication efficiency and the quality of the shoots (Bouza et al.,
1994a) and, once again, this could support the reaction of tree peony shoots to the
hormonal supply. Tree peony shoots have been cultured on both MS (Murashige &
Skoog, 1962) and WPM (Woody Plant Medium of Lloyd & McCown, 1980) with Ca 2+
in double strength (Bouza et al., 1994a; Černá et al., 2001; Beruto et al., 2004). Apical
and leaf necroses leading also to the shoot death can occur if calcium concentration