Liquid Culture Systems for in vitro Plant Propagation

Chapter 27
Induction and growth of tulip ‘Apeldoorn’ bulblets from
embryo cultures in liquid media
Anna Bach & Agata Ptak
Department of Ornamentals, Agricultural University, al. 29 Listopada 54, Kraków, Poland.
E-mail: robach@cyf-kr.edu.pl
Abstract: Bulbing has been induced in somatic embryos formed in ovary tissue cultures of
Tulipa gesneriana ‘Apeldoorn’. A high frequency of adventitious bulb formation took place
on the stolons developing from embryos converted into plantlets in the liquid medium lacking
growth regulators and containing 6% of sucrose. Number of bulblets per explant and
individual fresh weight significantly increased in liquid medium (160 mg per bulblet) as
compared to control (49 mg per bulblet). Plantlets must be chilled at 5�C in dark during 12
weeks period before formation and growth of adventitious bulbs. Plantlets, which were
exposed to white light and cultured at temperature of 25�C (before chilling period), resulted in
a higher crop of bigger bulblets (149 mg per bulblet, an average fresh weight) as opposed to
embryos cultivated in darkness or irradiated by red light (59 mg per bulblet, an average fresh
weight). After chilling period bulbs grew well in darkness and a temperature of 25�C. The
temperature of 20�C of the liquid medium was less suitable for bulblet formation and growth,
resulting in a lower percentage of large 200 mg bulblet (2.2%) in comparison to a medium
temperature of 25�C (25.4%). Small bulbs, weighing less then 200 mg per bulblet, did not
survive during the acclimatisation. Analysis of the level of ploidy of regenerated tulip plants
did not reveal any changes.
Key words: bulb formation, in vitro, liquid media, somatic embryo, tulip
Abbreviations: BA-6-benzylaminopurine; MS-Murashige & Skoog's (1962) medium;
NAA-naphthalene acetic acid
1. Introduction
In vitro propagation of tulip includes a 2-steps- process: the induction of
adventitious shoots or somatic embryos and the induction of bulbing. As
initial explants, flower stems (Wright at al., 1982; Gude and Dijkema, 1997),
bulb scales (Nishiuchi, 1986; Baker at al., 1990; Koster, 1993), and ovary
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A.K. Hvoslef-Eide and W. Preil (eds.), Liquid Culture Systems for in vitro Plant Propagation, 359–364.
© 2005 Springer. Printed in the Netherlands.