Crocus sativus

{{Speciesbox

|name = Saffron crocus

|image = Crocus sativus2.jpg

|image_alt = A single shell-shaped flower is in sharp centre focus amidst a blurred daytime and overcast garden backdrop of soil, leaves, and leaf litter. Four narrow spine-like green leaves flank the stem of the blossom before curving outward. From the base of the flower emerge two crooked and brilliant crimson rod-like projections pointing down sideways. They are very thin and half the length of the blossom.

|image_caption = Flowers showing crimson stigmas

|genus = Crocus

|species = sativus

|authority = L.

|synonyms =

{{Plainlist | style = margin-left: 1em; text-indent: -1em; |

Crocus autumnalis Sm. nom. illeg.
Crocus officinalis (L.) Honck.
Crocus orsinii Parl.
Crocus pendulus Stokes
Crocus setifolius Stokes
Geanthus autumnalis Raf.
Safran officinarum Medik.

}}

|synonyms_ref ={{cite web

|url=http://www.theplantlist.org/tpl1.1/record/kew-327454

|title=The Plant List: A Working List of All Plant Species

|access-date=23 April 2015}}

}}

Crocus sativus, commonly known as saffron crocus or autumn crocus, is a species of flowering plant in the iris family Iridaceae. A cormous autumn-flowering cultivated perennial, unknown in the wild,{{GRIN | access-date=23 April 2015}} it is best known for the culinary use of its floral stigmas as the spice saffron. Human cultivation of saffron crocus and the trade and use of saffron have endured for more than 3,500 years and span different cultures, continents, and civilizations.

Common names

The plant is most commonly known as the saffron crocus. The alternative name autumn crocus is also used for species in the Colchicum genus, which are not closely related but strongly resemble the true crocuses; in particular, the superficially similar species Colchicum autumnale is sometimes even referred to as meadow saffron. However, the true crocuses have three stamens and one style supporting three long stigmas, while colchicums have six stamens and three styles; and belong to a different family, Colchicaceae. Colchicums are also toxic, making it particularly crucial to distinguish them from the saffron crocus.{{cite book |title=A Handbook of Crocus and Colchicum for Gardeners |last=Bowles |first=E. A. |publisher=D. Van Nostrand Company, Inc. |date=1952 |page=154}}{{Cite web | url=https://www.rhs.org.uk/Plants/4190/Colchicum-autumnale/Details |title = Colchicum autumnale | meadow saffron/RHS Gardening}}

Description

Crocus sativus is a perennial herb{{Cite book |last1=Vakhlu |first1=Jyoti |url=https://books.google.com/books?id=UvGcEAAAQBAJ&q=saffron+crocus |title=The Saffron Genome |last2=Ambardar |first2=Sheetal |last3=Salami |first3=Seyed Alireza |last4=Kole |first4=Chittaranjan |publisher=Springer Nature |year=2022 |pages=5 |isbn=9783031100000 |language=en}} that grows about 10 to 30 cm high.Mollazadeh, Hamid "Razi's Al-Hawi and saffron (Crocus sativus): a review". Iranian Journal of Basic Medical Sciences, Dec 2015. It develops as an underground corm, which produces leaves, bracts, bracteole, and the flowering stalk.{{cite book|editor1-last=Kafi|editor1-first=M.|editor2-last=Koocheki|editor2-first=A. |editor3-last=Rashed|editor3-first=M. H. |editor4-last=Nassiri|editor4-first=M.|year=2006|title=Saffron (Crocus sativus) Production and Processing|edition=1st|publisher=Science Publishers|isbn=978-1-57808-427-2|url=https://books.google.com/books?id=kO8prjfiiCEC|ref={{Sfnref|Kafi et al.|2006}}}} It generally blooms with purple flowers in the autumn. Flowers are sterile, have six petals and three red to orange colored stigmas. Leaves are simple, rosulate in arrangement with entire margins.{{Cite web |title=Crocus sativus (Autumn Crocus, Saffron, Saffron Crocus) {{!}} North Carolina Extension Gardener Plant Toolbox |url=https://plants.ces.ncsu.edu/plants/crocus-sativus/ |access-date=2023-07-15 |website=plants.ces.ncsu.edu}}File:Crocus sativus plant with corm.png

Genetics

Saffron crocus is a triploid with 24 chromosomes (2n = 3x = 24), making the plant sexually sterile due to its inability to pair chromosomes during meiosis.{{citation |last=Saxena |first=R. |title=Botany, taxonomy and cytology of Crocus sativus series |journal=AYU |volume=31 |issue=3 |pages=374–81 |year=2010 |doi=10.4103/0974-8520.77153 |pmc=3221075 |pmid=22131743 |doi-access=free }} Its most probable ancestor is the wild species Crocus cartwrightianus.{{cite journal|last1=Rubio-Moraga|first1=A|last2=Castillo-Lopez|first2=R|last3=Gomez-Gomez|first3=L|last4=Ahrazem|first4=O|title=Saffron is a Monomorphic Species as Revealed by RAPD, ISSR and Microsatellite Analyses|journal=BMC Research Notes|date=23 September 2009|volume=2|issue=189|pages=189|doi=10.1186/1756-0500-2-189|pmid=19772674|pmc=2758891|doi-access=free}}{{cite journal|last1=Harpke|first1=Dörte|last2=Meng|first2=Shuchun|last3=Rutten|first3=Twan|last4=Kerndorff|first4=Helmut|last5=Blattner|first5=Frank R.|title=Phylogeny of Crocus (Iridaceae) based on one chloroplast and two nuclear loci: Ancient hybridization and chromosome number evolution|journal=Molecular Phylogenetics and Evolution|year=2013|volume=66|issue=3|pages=617–627|doi=10.1016/j.ympev.2012.10.007|pmid=23123733|url=https://www.researchgate.net/publication/232812358}}{{Cite journal|last1=Schmidt|first1=Thomas|last2=Heitkam|first2=Tony|last3=Liedtke|first3=Susan|last4=Schubert|first4=Veit|last5=Menzel|first5=Gerhard|title=Adding color to a century-old enigma: multi-color chromosome identification unravels the autotriploid nature of saffron (Crocus sativus) as a hybrid of wild Crocus cartwrightianus cytotypes|journal=New Phytologist|language=en|volume= 222|issue= 4|pages=1965–1980|doi=10.1111/nph.15715|pmid=30690735|issn=1469-8137|year=2019|doi-access=free}}{{Cite journal|last1=Nemati|first1=Zahra|last2=Blattner |first2=Frank R. |last3=Kerndorff |first3=Helmut |last4=Erol |first4=Osman |last5=Harpke |first5=Dörte |date=2018-10-01 |title=Phylogeny of the saffron-crocus species group, Crocus series Crocus (Iridaceae)|journal=Molecular Phylogenetics and Evolution|volume=127|pages=891–897|doi=10.1016/j.ympev.2018.06.036|pmid=29936028| s2cid=49409790 |issn=1055-7903}} Although C. thomasii and C. pallasii were still being considered as potential predecessors or genetic contributors,{{cite journal|last=Grilli Caiola|first=M.|s2cid=89990377|year=2003|title=Saffron Reproductive Biology|periodical=Acta Horticulturae|publisher=ISHS|volume=650|issue=650|pages=25–37|doi=10.17660/ActaHortic.2004.650.1}} these hypotheses have not been successfully verified by chromosome and genome comparisons.

Domestication

It is thought that the domesticated saffron crocus most likely arose as a result of selective breeding from the wild C. cartwrightianus in the southern portion of mainland Greece.{{Cite journal|last1=Blattner|first1=Frank R.|last2=Kerndorff|first2=Helmut|last3=Gemicioglu|first3=Almila|last4=Harpke|first4=Doerte|last5=Nemati|first5=Zahra|date=2019-02-01|title=Saffron (Crocus sativus) is an autotriploid that evolved in Attica (Greece) from wild Crocus cartwrightianus|url=https://www.biorxiv.org/content/10.1101/537688v1|journal=bioRxiv|language=en|pages=537688|doi=10.1101/537688|doi-access=free}} An origin in Western or Central Asia, although often suspected, is not supported by botanical research.{{cite journal |last=Mathew |first=B. |title=Crocus sativus and its allies (Iridaceae) |journal=Plant Systematics and Evolution |volume=128 |issue=1–2 |pages=89–103 |year=1977 |doi=10.1007/BF00985174 |jstor=23642209|s2cid=7577712 }}

Uses

The stigmas of the flower are used as the culinary spice saffron. It is also used for health purposes, especially in traditional Asian medicine - owing to biologically active chemical compounds (mainly alkaloids, anthocyanins, carotenoids, flavonoid, phenolic, saponins, and terpenoids) saffron causes among others mood-enhancing effect (including persons with major depressive disorder).{{cite journal|last1=Matraszek-Gawron|first1=R|last2=Chwil|first2=M|last3=Terlecki|first3=K|last4=Skoczylas|first4=MM.|title=Current Knowledge of the Antidepressant Activity of Chemical Compounds from Crocus sativus L.|journal=Pharmaceuticals|year=2022|volume=16|issue=1|pages=58|doi=10.3390/ph16010058|pmid=36678554|pmc=9860663|doi-access=free}} Depending on the size of harvested stigmas, the flowers of between 50,000 and 75,000 individual plants are required to produce about 1 pound of saffron;{{cite book|last1=Hill|first1=T|title=The Contemporary Encyclopedia of Herbs and Spices: Seasonings for the Global Kitchen|year=2004|publisher=Wiley|isbn=978-0-471-21423-6|page=[https://archive.org/details/contemporaryency0000hill/page/273 273]|edition=1st|url=https://archive.org/details/contemporaryency0000hill/page/273}} each corm produces only one or two flowers, and each flower produces only three stigmas. Stigmas should be harvested mid-morning when the flowers are fully opened. Saffron crocus can be used as an ornamental.{{Cite web |title=Crocus sativus - Plant Finder |url=https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=281106 |access-date=2023-07-15 |website=www.missouribotanicalgarden.org}}

Cultivation

As a sterile triploid, C. sativus is unknown in the wild and relies upon manual vegetative multiplication for its continued propagation. Because all cultured individuals of this plant are clonal, there is minimal genetic diversity from the single domestication event, making it quite hard to find cultivars with new, potentially beneficial properties, let alone combine them by breeding.{{cite journal |last1=Alsayied |first1=NF |last2=Fernández |first2=JA |last3=Schwarzacher |first3=T |last4=Heslop-Harrison |first4=JS |title=Diversity and relationships of Crocus sativus and its relatives analysed by inter-retroelement amplified polymorphism (IRAP). |journal=Annals of Botany |date=September 2015 |volume=116 |issue=3 |pages=359–68 |doi=10.1093/aob/mcv103 |pmid=26138822 |pmc=4549961}} Cultivars of saffron are nevertheless produced by a number of means:{{cite book |last1=Shokrpour |first1=Majid |chapter=Saffron (Crocus sativus L.) Breeding: Opportunities and Challenges |title=Advances in Plant Breeding Strategies: Industrial and Food Crops |date=2019 |pages=675–706 |doi=10.1007/978-3-030-23265-8_17|isbn=978-3-030-23264-1 |s2cid=208574298 }}

Clonal selection. Any plant with a desirable mutation is kept and further grown. This is the traditional approach.
Mutation breeding. Mutagenesis can be used to cause a wide range of mutations to select from. The traditional clonal process follows.
Sexual reproduction. Breeding for desirable features is much easier in fertile plants.
Although the plant is not self-fertile, some wild relatives can be successfully cross-pollinated with saffron pollen in vitro and form seeds. This creates fertile diploid plants containing genomic material from C. sativus, allowing new traits to be explored via further cross-pollination.
Chromosome doubling could in principle also create a fertile hexaploid plant. Such a change may be possible via colchicine.{{cite report |last1=Aqayef |first1=Yusof |last2=Fathi |first2=Mohammad |last3=Shakib |first3=Ali Mohammad |title=Investigation of possibility of obtaining hexaploid saffron forms through treatment of plants by colchicine. |date=2007 |url=https://agris.fao.org/agris-search/search.do?recordID=IR2008000154 |publisher=Agricultural Biotechnology Research Institute of Iran |language=fa}}

Corms of saffron crocus should be planted {{convert|4|in|cm|order=flip|abbr=on|0}} apart and in a trough {{convert|4|in|cm|order=flip|abbr=on|0}} deep. The flower grows best in areas of full sun in well-drained soil with moderate levels of organic content.{{cite web|title=Growing and Harvesting Saffron Crocus|url=https://www.whiteflowerfarm.com/how-to-harvest-saffron-crocus|website=White Flower Farm}} The corms will multiply after each year, and each corm will last 3–5 years.{{cite web|title=Saffron Farming Information Guide|url=http://www.agrifarming.in/saffron-farming/|website=AgriFarming|date=8 August 2015}}