African Journal of Agricultural Research Vol. 6(15), pp. 3583-3587, 4 August, 2011
Available online at http://www.academicjournals.org/AJAR
ISSN 1991-637X ©2011 Academic Journals
Full Length Research Paper
Ex vitro shoot regeneration and lateral buds of freshly
harvested saffron corms
Amirreza Sadeghi Bakhtavari, Khalid Mahmood Khawar* and Neset Arslan
Department of Field Crops, Faculty of Agriculture, Ankara University, 06110, Diskapi, Ankara, Turkey.
Accepted 28 June, 2011
After formation of the replacement corms, the saffron leaves wither and the apical buds enter
dormancy, which is released after-ripening at 23 to 30°C. This study aimed to break this dormancy and
reports successful ex vitro shoot regeneration from saffron corms, just after harvesting by pulse
treating for 30, 60, 90, 120 and 150 min with 50 mg/L Indole acetic acid (IAA) or 50 mg/L IAA + 10 mg/L
Thidiazuron (TDZ). All corms were cultured in organic matter rich soil contained in plastic sieve trays in
greenhouse with day time temperature in range of 9 to 15°C and night temperature in range of 5 to 8°C
during experimentation with relative humidity of 50 to 60%. After 2 to 3 weeks, the pulse treated corms
regenerated multiple number of shoots, which increased to 5-6 shoots per corm after 10 weeks of
culture; showing statistically different and superior regeneration on 50 mg/L IAA + 10 mg/L TDZ pulse
treated corms compared to IAA pulse treated corms. This protocol will help to increase and improve
flowering for an extended period of time.
Key words: Ex vitro, shoot regeneration, lateral buds, saffron, multiplication.
INTRODUCTION
The domesticated saffron (Crocus sativus L.), belonging
to the Iridaceae family; is a perennial sterile auto-
triploid mutant; which is cultivated for its stigmas since
time immemorial (Karaoglu et al., 2007). The saffron
plant is a geophyte and is propagated by vegetative
reproduction through the formation of daughter corms
from the mother corm. The stigmas of saffron are used
as important high valued spice and are characterized as
the most expensive spice by weight unit. They are also
used for various therapeutic purposes in medicine, food
seasoning and coloring (Sampathu et al., 1984; Karaoglu
et al., 2007). Saffron contains more than 150 volatile and
aroma-yielding compounds. It also has many nonvolatile
active components, many of which are carotenoids,
including zeaxanthin, lycopene, and various α- and β-
carotenes. However, saffron's golden yellow-orange
colour is primarily the result of α-crocin (Abdullaev, 2002).
Saffron is produced in a very few countries of the world
and invariably involves traditional labour intensive
methods, which contribute to its very high price.
*Corresponding author. E-mail: kmkhawar@gmail.com. Tel:
0090 312 596 15 40. Fax: 0090 312 318 26 66.
Autotriploid nature of the species renders improvement
by breeding very difficult (Basker and Negbi, 1989).
Saffron has been produced and exported from Turkey
until the 19
th
century.
However, due to a number of socio-economic and
technical problems, now the cultivation of saffron has
been limited to a few villages in the Safranbolu District of
Karabuk province of Turkey (Karaoglu et al., 2007).
Saffron is propagated by corms as the flowers are sterile
and fail to produce viable seeds. A corm survives for only
one season, producing up to ten "cormlets" that
eventually give rise to new plants (Deo, 2003). It is
common observance that after the formation of the
replacement corms, the saffron leaves wither and the
apical buds enter dormancy (Saiedian et al., 2007). This
dormancy is released by high summer temperature and
sprouting occurs only after a period of after-ripening
obtained by curing bulbs at 23 to 30°C. Therefore,
reproduction is human dependent; the corms must be
manually dug up, broken apart and replanted. The natural
propagation rate of most geophytes (Sevimay et al.,
2005; Parmaksiz and Khawar, 2006; Ozel and Khawar,
2007; Aasim et al., 2008; Ozel et al., 2008), including
saffron is relatively low (Karaoglu et al., 2007).
The aim of the study was to develop a successful ex