Saffron from Wild to the Field
M.H. Rashed-Mohassel
Faculty of Agriculture
FerdowsiUniversity of Mashhad
P. O. Box 91775-1163
Mashhad
Iran
Keywords:Crocus, DNAband,saffron dendrogram,saffron phylogeny
Abstract
Crocus, a genus of Iridaceae including of85 species mostly grown in areas with cold winter and low rainy hot summer. Crocus consist of some house plants with beautiful flowers, as ornamentals in home gardens, rock gardens, parks, and in wild naturewherethey usually dispersed in vast groups and produce interesting sceneries of different color of flowers. Solid corms of saffron which are covered within sheath of different orientations terminate to adventitious basal roots keep saffron actively growing from fall to late spring. Cultivated saffron (Crocus sativus) is triploid (2n=3X=24), but related wild species are diploids with 2n=12, 2n=16, 2n=20, and 2n=24 chromosomes. There are nine species of wild saffron existed in Iran or vicinities.Three of them are endemic (C. almehensis, C. gilanicus, and C. michelsonii)to Iran. The most similar species to cultivated saffron is C. cartwrightianus in Greece. C.pallasii subsp. haussknectii has also similarities to cultivated saffron.The latter two species are fall flowering and 2n=16, so their closer relationship to cultivated saffron is more likely. In this presentation attempts will be focused on wild species of saffron, and explaining the possible ways that this valuable industrial/medicinal product of great significance in agricultural economy has beenintroduced from wild to the field.
INTRODUCTION
Saffron (Crocus sativus L) a crop of high economical and medicinal value (Duke, 1987; Mansoori, 2003), belong to Iridaceae (Iris family) with 1750 species and 4 tribes with the following characteristics (Dahlgreen et al., 1985; Judd et al., 1990).
1-Isophysioideae with superior ovary e. g. Isophys.
2-Nivenioideae with separate blue flowers and some woody species e. g. Aristen.
3-Iridioideae with nectar gland and long style divided below the anthers which extended under 3 outward folded petaloid stigmas e. g. Sisyrhinchum, Iris.
4-Ixioideae with united perianth, having corms, closed sheaths, flowers with no petiols, exine with porous sculptures and ancestor of this tribe have nectars on their sepals, e. g. Crocus,Gladiolus, Romulea, Geissorhiza.
Similarities exist between Romulea, Syringodea, and Crocus, However, the relationship between cultivated Crocus (grows mostly in Iran), Romulea, and Siryngodea is obscure (Dahlgreen et al, 1985).
Geographically, saffron is distributed in Mediterranean climate, west Asia (latitude 30° N and longitudes of 10° E – 80° W), mainly in Iranotouranian regions with low annual precipitation, cold winters and hot summers (Mathew, 1999). Saffron is well adapted to such conditions. Some Crocus species grows wild, and some are used for ornamental purposes. It grows actively from fall to late spring and survives in soils due to its fresh hard corm which is covered with coriaceous, membranous, or reticulate sheath (Ghahraman, 1995; Wendelbo, 1977).
Saffron included of 85 species, some with beautiful flowers are grown as ornamental house plants, home gardens, rock gardens, and parks (8). Crocus species start their growth early in rainy season of the fall by producing flowers/leaves, but in some species flowering delays until winter or spring. Based on flowering period, species of crocus are subdivided into 3 categories (7; Rechinger, 1975).
1-Spring flowering species e. g. C.biflorus, Crocus almehensis.
2-Fall flowering species e. g. C. caspius. C. gilanicus, C. cancellatus, C. pallasii subsp. Hausknechtii, C.speciosus, C. cartwrightianus.
3-Winter flowering e.g. C. michelsonii, C. korolkowii.
The chromosome number of different species in Iran have been reported 2n = 12, 14, 16, and 20. However, cultivated saffron is triploid (2n =3x = 24) (Judd et al, 1990; Mathew and Brighton, 1998; Wendelbo, 1977).
The Crocus is native to Europe and western Asia (2006). The main center of Crocus distributions is Turkey, Greece, and Iran (2; Mathew, 1999; Rashed Mohassel, 1989; Rashed Mohassel, 2006). Since, I plan to discuss wild species of saffron in Iran and adjacent boundaries, cultivated saffron, and its probable ancestor, concentration is focused to the species belong to these categories. Nine species of saffron have been reported from Iran including C.sativus, C. pallasii, C. pallasii, C. cancellatus, C. caspius, C. speciosus, C. almehensis,C. gilanicus, C. michelsonii, and C. biflorus. C. korolkowii have been reported from western Afghanistan and it is possible to be found in the border of Afghanistan and Iran. Finally, C. cartwrightianus, a wild species in Greece, is the most similar species to cultivated saffron (Mathew, 1982; Mathew, 1989). Some researchers believe that C. Sativus derived from C.cartwrightianus , and it is possibly a mutant of it (Douglas and Perry, 2003; Mathew, 1999).
Idetification keys to Iran saffron species
The following keys adapted from other keys and tested, can help us to identify the above mentioned species.
Key for CrocusSpecies Based on Vegetative Growth and Post Floral Structure
(Ahuja et al 1994; Lewis, 1954; Rashed Mohassel, 1993; Rashed Mohassel, 2006; Rechinger, 1975; Wendelbo, 1977).
1- Corm tunics membranous or leathery, without conspicuous fibers...………2
1- Corm tunics rough or fine, with reticulate or parallel fiber... ……………...5
2- The width of mature leaves 4 to 5mm…...... 3
2- The width of mature leaves 1 to 3 mm …………………………………….4
3- Leaves navicular with few distinct grooves either side of the keel
C. Almehensis
3- Leaves ± wide with grooves neither side of the keel...... ……C. speciosus
4- Capsule ± spherical, corm sheath is not quite annular at the base
C. caspius
4- Capsule cylindrical or elliptical, corm sheath is quite annular at the base
C. biflorus
5- Corm with 9-10 leaves…………………………………………………….6
5- Corms with 3-7 leaves……………………………………………………..7
6- Leaves grayish, no distinct vein either side of the leaves, corm with a mat
of reticulate fibrous sheath..…………………………………………….....9
6- Leaves green, with one or more distinct veins either side of leaves, corm
with parallel or ± reticulate fibrous sheath…………………..C. korolkowii
7- Corm sheath reticulate and rough..……….………………....C. cancellatus
7- Corm sheath fine ± reticulate or parallel..……...…………………………8
8- Corm sheath a thick mat ± reticulate fibers..…………..…...C. michelsonii
8- Corm sheath with very fine and ± loose parallel fibers………C. gilanicus
9- Corm 5cm. diameter, capsule 1.5 -3cm. seed 3 -4mm. diploid...………10
9- Corm 4cm. or less, capsule small and elongated, seedless or rarely with
seeds, triploid………………………….………………………..C. sativus
10- Corm 1 – 2cm. in diameter………………….……….C. cartwrightianus
10- Corm 3cm. in diameter………………..…………… C. Hausskenechtii
Key for CrocusSpecies Based on Floral Structure
(Ahuja et al 1994; Lewis, 1954; Rashed Mohassel, 1993; Rashed Mohassel, 2006; Rechinger, 1975; Wendelbo, 1977).
1- Flowers yellow, sometimes outer portion bronze…………………………..2
1- Flowers other colors, sometimes yellow at throat…………………………..3
2- Leaves (-7cm.) and 10 – 20, 1.5 – 3mm. width, corm tunics fibrous
C. korolkowii
2- Leaves3-4, 4-5mm. width, corm tunics membranous………...C. almehensis
3- Flowers and leaves produce simultaneously in spring...…………………... 4
3- Flowering fall or early winter, corm tunics at leaf stage fibrous or
membranous without ring at the base...…………………………………….5
4- Corm tunics with a mat of fine fibers, style whitish……. …...C. michelsonii
4- Corm tunics membranous or coriaceous with distinct rings at the base,
style usually yellow or orange red……..…….………………...... C. biflorus
5- Style 3 lobate or somehow lobate…...... 6
5- Style with 3 arms……………………………………………………………8
6- Flowering after leafing, flower throat dark yellow.……..…...... C. caspius
6- Flowering before leafing, flower throat not yellow……..…………………7
7- Style barely or with indistinctive lobes, creamy or yellow,corm with fine
Tunics, ± fibrous……………………...………………………C. gilanicus
7- Style with 3 distinctive lobes, yellow or orange red, corm with thick tunics
and fibrous………………………………………………………………..9
8- Corm tunics with thick reticulate fibers, leaves grayish...……C.cancellatus
8- Corm tunics membranous or coriaceous, annular at base, leaves dark
Green………………………………………………………….C. speciosus
9- Flowers white or bluish, inner and outer perianth unequal,style red to
Orange, style arms 3 to 15mm…………………………..….C. hausknechtii 9- Flowers lilac, purple or bluish white, inner and outer perianth equal, style
10 to 35mm………………….…………………….………………………10
10- Flowers blue violet or pink, stigma arms broad, 25to35mm. triploid (2n =3x = 24)...... ………………………………….……………. C. sativus
10- Flowers pale, lilac to whitish color, stigma arms27mm,diploid (2n = 16) C. cartwrightianus
PHYLOGENY OF CULTIVATED SAFFRON
Saffron researchers indicate that the probable ancestor of C. sativus should be fall flowering. The chromosome number of this species and chromosome segregation may explain how C.sativus derived from possible crosses sometimes.
Taking a brief look at these eleven saffron species, we see that C. sativus, C.cartwrightianus, C. pallasii subsp. Hausknechtii, C. cancellatus, C. speciosus, C. caspius, and C. gilanicus are fall flowering among which, C. sativus is triploid(2n = 3x= 24), others are diploid but inC.cartwrightianus, C. pallasii subsp. Hausknechtii 2n =16. It is likely that sometimes abnormal chromosome segregation have resulted that all 16 chromosome migrate to one pole and combined with 8 chromosom of one of the above fall flowering, possibly C. cartwrightianus or C. Pallasii subsp.Hausknechtii(9; Mathew, 1999). Another less possibility is that mutation either in C. cartwrightianus or in C. pallasii subsp.Hausknechtii resulted in formation atetraploid plant and diploid gamete which in turn by fusion of this gamete with a gamete of a diploid plant (2x = 16) resulted in a triploid saffron. Tarazi et al. by using tissue culture technique could observe diploid and tetraploid cells in saffron callus (Tarazi et al). Recently, Trazi and Rashed (2006) tried to form a live collection of Iran saffron. Unfortunately, C. biflorus and C. gilanicus were not available in areas that they were found by other researchers. Probably because of constructions and other human disturbances these two species were extinct or are in the process of extinction and hard to find. C. almehensis is endemic to protected area of almeh and could not be collected due to Environmental Protection Organization restrictions. So, they could collect six species including C. pallasii subsp. Hausknechtii, C. cancellatus, C. speciosus, C. caspius, C. michelsonii, and C. sativus. The preliminary phytochemical study of stigmatic arms of saffron species indicated that flavenoids and glycosides are present in all species but alkaloids tannins, and saponins were absent (see table 1). Other researchers also did some studies in the same line. Rajabian(Rajabian, 1992; Rajabian, 2000) worked on saffron pigments and concluded that type and quantity of cerocins differs based on saffron species. Saboora(1994) pointed out that saffron leaves include flavenoids, specially isofellavenons, substances of medicinal interest
Tarazi and Rashed (2006) did DNA molecular comparison using RAPDs markers on six above mentioned species in Iran. The results of DNA bands are shown in figure 1. The correlation coefficient and genetic distances of these species are shown in table 2. Table 2 shows that the highest genetic distance was between cultivated saffron and C.michelsonii(.8948), and the least distance was between cultivated saffron and C.pallasii subsp. Hausknechtii(.6178). The highest genetic correlation coefficient belonged to latter species as well. The dendrogram showing the relationship of these species (Figure 2) shows that these species are divided in two groups. Group 1 included of C. sativus, C. pallasii subsp. Hausknechtii, and C. cancellatus, while group 2 including C. speciosus, C. caspius and C. Michelsonii. Considering The genetic characteristics of these 2 groups and Knowing That genetical characteristics are the basis of plant responses against the environment we may expect that on one hand this is true between C. caspius and C. speciosus across Caspian areas. Historical books about cultivated saffron indicates that saffron were cultivated in most parts of Iran including west. If this is so, we may conclude that the origin of cultivated saffron in Iran is western Iran possibly Zagros area possily from C. pallasii subsp. Hausknechtii. The presence of genetic distance is a factor for a better reply to genetic interferences between these groups. Another word, the possibility of genetic fertility between members within each group is more than between groups. Considering that ovule in cultivated saffron is somehow fertile we should also expect that by using pollen of C. pallasii subsp. Hausknechtii, we fertilize C. sativus ovule in order to produce seeds and plants for further genetic improvement.
So far, no data were available concerning Iran saffron comparisons. However, Saboora (1994) used Isozyme protein marker and concluded that C. pallasii subsp. Hausknechtii and C. cancellatus are closest to C. sativus among Iran saffrons. Similarly, Rajabian by using stigma pigment of Iran crocus concluded that C. pallasii subsp. Hausknechtii is the closest species while C. michelsonii is furthest species to cultivated saffron. Experimental evidence due to morphological similarities also suggests that C. pallasii subsp. Hausknechtii and C. sativus are close relatives. The present project also confirms former reports on the basis of genetic nature.
The similar results obtained by using RAPDs markers with other results confirm that RAPDs markers are a useful tool for determination of saffrons relationship. However, RAPDs marker does not have capability to differentiate between cultivated saffron of different areas in Iran probably due to small genetic differences because of vegetative reproduction.
SUGGESTIONS
The lack of enough investigation related to different aspects of saffron species in Iran implies the suggestion of following challenges.
1-Conducting a detail botanical study of saffron.
2-Formation of a live collection of Iran saffron’s to prevent extinction of endangered species.
3-Conducting a detail botanical study of saffrons.
4-Transgenic studies and transformation of useful traits from wild species to cultivated saffron.
5-Formation of seeds in cultivated saffron with the aids of other pollen species by suing tissue cultures.
6-Using wild saffron species as ornamentals by conducting different breeding programs
7- Detail phytochemical studies of saffron.
8-Conducting researches on medicinal and anti carcinogenic substances of saffron (Douglas and perry, 2003; Mansoori, 2003).
9-Other usage of different part of saffron e.g. forage values, cosmetics, dye, etc.
10-The allelopathic effect of saffron against saffron and other plants.
Literature Cited
Ahuja, A., Skoul, S., and Ram, G. 1994. Somatic embryogenesis and regeneration ofplantlets in saffron (Crocus sativus L.) Indian J. Exp. Biology,52:135-140.
Autumn flowering saffron Crocus. 2006. Copy right © by Paghat the Ratgirl. file://D:\Backup\saffron\saffran\Paghat′s GardenCrocus sativus htm
Dahlgreen, R.M.T., Clifford, H.T., and P.F. Yeo. 1985. The families of the monocotyledons. Springer-Verlag, Berlin.
Duke, J.A. 1987. Hand book of medicinal herbs. CRC Press Inc. Pp. 148-149.
Douglas, M.H., and Perry, N. 2003. Growing saffron- the word's most expensivespice. Newzeland Institute for Crop and Food Research Ltd.
Ghahraman, A. 1995. Plant systematic, cormophytes of Iran. Volume 4: second printing, Iran University Press.
obduedu/webroot/instr/sci/plant. nsf/payes/saffron.
Judd, W.S., Campell, C.S., Kellogg, E.A., and Stevens P.F. 1990. Plant systematics. Aphylogenic approach. Sinauer Associates Inc. Pp. 191-192.
Lewis, F.U. 1954. Some aspects of the morphology, phylogeny, and taxonomy of the South African Iridaceae. Annuals of the SouthAfricanMuseum. 40:15-113.
Mansoori, M. Cancer chemopreventive and antitumoral characteristics of saffron (Crocus sativus). 3rd National Symposium on Saffron, Mashhad, Iran, 2-3 Dec. 2003.
Mathew, B. 1982. The Crocus- a revision of genous Crocus (Iridaceae). Batsford, PP. 11- 12. London.
Mathew, B. 1999. Botany, taxonomy and cytology of Crocus sativus L. and its allies. In saffron (Crocus sativus) (ed.) Harwood Academic Publisher, Pp. 19-30.
Mathew, B., and Brighton C.A. 1998. Four central Asian Crocus species. IranianJournal of Botany, 1: 20.
Rajabian, T. 1992. The study of saffron pigments in intact plant and tissue culture, M. Sc. Thesis, College of Science, University of Tehran.
Rajabian, T. 2000. The study of Iran saffron secondary metabolite (Crocine and picrocrocine) in Intact plant and tissue culture. Ph. Thesis., college of Agriculture, University of Tehran.
Rashed- Mohassel, M.H. 1989. The identification and distribution of saffron genus in Iran. Proceedings of First Saffron Conference, Eslam Abad, Ghaen.
Rashed- Mohassel, M.H. 1993. Khorasan vegetations. Volume 1. FerdowsiUniversity of Mashhad Publication, Mashhad, Iran.
Rashed- Mohassel, M.H. 1994. Khorasan vegetations. Volume 2. FerdowsiUniversity of Mashhad Publication, Mashhad, Iran.
Rashed-Mohassel, M. H. 2006. Saffron botany. In Saffron (Crocus sativus) production and processing 2006, pp. 13-38. ( eds. Kafi, M., Koocheki, A., Rashed, M. H., and Nassiri, M.,) Science Publishers, Enfield, Jersey, Plymouth.
Rechinger, K. Flora Iranica. 1975. Iridaceae. Volume 112. Academische Druck. U. Verganstalt, Granz, Austria.
Rudall, P. 1994. Anatomy and systematic if Iridaceae. Botanical Journal of
Linnean Society.114-121.
Saboora, O. 1994. The preliminary ontogeny and pyllogeny study of some saffron species in Iran. M. Sc. Thesis, college of Science, University of Tehran.
Tarazi, M., Deljoo, A., Ebrahimzadeh, A., and Karamian, R. 2003. The study ofg Changing ploidy level in the cells of saffron via tissue culture. 3rd National Symposium on Saffron, Mashhad, Iran, 2-3 Dec. 2003.
Tarazi, M., and Rashed-Mohassel, M.H. 2006. Phytochemical study and Live collection preparation of Iran saffrons. Khorasan Science and technology park, Mashhad, Iran.
Wendelbo, P. 1977. Tulips and Irises of Iran and their relatives. Botanical Inistitute of Iran, Botanical Garden, Tehran, Iran.
Table 1. Phytochemical results from Iran saffron species.
speciesC. sativus / C. cancellatus / C. caspius / C. speciosus / C. michelsonii / C. pallasii
Subsp. Hauskhechtii / compound
- / - / - / - / - / - / Alkaloids
- / - / - / - / - / - / Tannins
- / - / - / - / - / - / Sapponins
+ / + / + / + / + / + / Flavenoids
+ / + / + / + / + / + / Glycosides
Table 2. Correlation coefficient (upper asterisk) and genetic distance (lower asterisk) of six Iran saffron species.
Saffron species / SpeciesC. michelsonii / C. speciosus / C. pallasii / C. caspius / C. cancellatus / C. sativus
0.4087 / 0.4348 / 0.5391 / 0.4522 / 0.4783 / **** / C. sativus
0.5304 / 0.4522 / 0.5391 / 0.4174 / *** / 0.7379 / C. cancellatus
0.4870 / 0.4783 / 0.4435 / *** / 0.8737 / 0.7937 / C. caspius
0.4696 / 0.4087 / *** / 0.8131 / 0.6178 / 0.6178 / C. pallasii
0.5391 / **** / 0.8948 / 0.7376 / 0.7937 / 0.8329 / C. speciosus
*** / 0.6178 / 0.7559 / 0.7196 / 0.6341 / 0.8948 / C. michelsonii
Fig. 1. DNA bands pattern from six different saffron species in Iran (each species with two replications) using RAPDs technique and a starter. From left to right wells 1&2 from C. sativus, wells 3&12 from C. michelsonii, wells 4&11 from C. cancellatus,wells 5&6 from C. caspius,wells 7&8 from C. pallasii Subsp. Hauskhechtii,wells 9&10 from C. speciosus andwells 13 related to weight marker.
Fig. 2. Dendrogram showing the relationship of six different saffron species
in Iran.