Protocols for Micropropagation of Woody Trees and Fruits

CHAPTER 27
MICROGRAFTING OF PISTACHIO
(PISTACIA VERA L. CV. SIIRT)
A. ONAY*, E. TILKAT, C. ISIKALAN AND S. NAMLI
Department of Biology, Faculty of Science and Literature The University of Dicle,
21280 Diyarbakır/TURKEY. *E-mail: ahmeto@dicle.edu.tr
1. INTRODUCTION
Pistacia vera L. is a dioecious tree species cultivated widely in the Mediterranean
regions of Europe and North Africa, the Middle East, China and California, USA.
Development of pistachio plantations is limited by the absence of adequate nursery
stock due to the difficulty of propagating Pistacia plants by conventional methods,
such as cutting and grafting. Consequently, many efforts have focused on establishing
in vitro propagation procedures for Pistacia vera and several other Pistacia
species (Hansman & Owens, 1986; Barghchi & Alderson, 1989; Onay & Jeffree,
2000; Onay, 2003; Onay et al., 2004a,b,c; Onay, 2005).
The initiation of cultures from mature material usually involves pruning, grafting
as well as BA and GA3 spray treatments that stimulate new growth of shoots
(Barghchi, 1986; Gonzales & Frutos, 1990). There has been some success in establishment
of mature pistachios by direct organogenesis (Yang & Lüdders, 1993; Dolcet-
Sanjuan & Claveria, 1995; Onay, 2000) and somatic embryogenesis (Onay et al.,
1995, 1996, 1997, 2000; Onay et al., 2004a). Onay (2000) harvested 3–4 cm long
terminal lignified stem sections from 30-year-old pistachio trees and immersed the
cut ends in plant growth regulator solutions, before placing them in a greenhouse
medium. New, softwood shoots were forced in the greenhouse under a 24 h photo-
period until they were sufficiently large to excise, surface disinfest and place
in vitro. However, despite this progress, establishment and multiplication of field-
grown mature P. vera clones remain problematic. In vitro micrografting can
overcome these limitations. The first attempts to rejuvenate mature materials by micrografting
in vitro mature scion shoot tips onto juvenile P. vera rootstocks were
reported by Barghchi (1986). However, the growth of scion was very slow and
elongation did not occur. Micrografting was investigated in vitro as well as in vivo
by Abousalim & Mantell (1992), but rejuvenation was not reported when mature
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S.M. Jain and H. Häggman (eds.), Protocols for Micropropagation of Woody Trees and Fruits, 289–298.
© 2007 Springer.