Secale cereale (Rye)

Life > eukaryotes > Archaeoplastida > Chloroplastida > Charophyta > Streptophytina > Plantae (land plants) > Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants) > Angiospermae (flowering plants) > Monocotyledons > Order: Poales > Family: Poaceae

Rye is thought to have originated in eastern Turkey and Armenia and initially became domesticated as a weed in wheat and barley crops. It became a favoured crop in north temperate regions of Europe because it is more cold tolerant than wheat. Rye has a low gluten content, has high water retention properties and is used for making bread, crisp bread and in the manufacture of some alcoholic spirits.

The evidence suggests that Rye was domesticated in what is now eastern Turkey and adjacent Armenia from the subspecies Secale cereale vavilovii sometime during the Neolithic (5000 -10000 years ago). It is thought that initially it was a weed of cultivated wheat and barley and was exposed to the same selection pressures as the latter two crops where those plants that retained their seeds (non-shattering) were selected over those that lost them prior to the harvest. Hence, non-shattering Rye 'weeds' were being harvested with the wheat and barley. Eventually, rye was being grown as a dedicated crop but the first good evidence for this comes only from the Bronze Age. It is interesting that today, wheat farmers in Turkey and Armenia tolerate contamination of their wheat crop by rye weeds because when the wheat crop fails because of cold weather, they usually get a harvest of some rye (nicknamed the 'wheat of Allah'). 

Rye is able to grow under colder conditions than wheat and hence is often the crop of choice in north temperate regions although some barley varieties are even more cold-resistant.

Uses

• Rye flour is used in producing rye bread and crisp bread. Dark rye is derived from rye grains that have not been heavily milled and hence retain most of the bran and germ. Hence dark rye is healthier than light rye. It is a source of magnesium, trace minerals, folic acid, thiamin and niacin. The German bread called pumpernickel is the most well-known example of a dark rye bread. As rye is poor in gluten, the bread does not rise well and hence has a heavy consistency. In its favour, rye flour has a very high water-binding capacity due to it containing high amounts of long chains of 5-carbon sugars called pentosans. Hence rye bread tends to be moister than wheat bread. It also means that when you eat rye crisp bread, it tends to absorb a lot of water in your stomach and make you feel full.
•  Rye is used in producing some alcoholic spirits (e.g. gin, some American whiskeys and some types of vodka).

Relationship with the ergot fungus

The ergot fungus is able to grow on rye under suitable conditions and is apparent as thin fruiting bodies that grow out of the flowering stalk. From the 11th to 16th centuries in Europe this fungus caused a sickness called Holy Fire or Saint Anthony's Fire, the symptoms of which included (1) gangrene in which extremities hurt, went numb, turned black, shrank and then dropped off; and (2) mental disturbances characterised by twitching and fits. From the beginning of the middle ages, it was found that this fungus could be used as a drug. For instance, it was used to speed up labour during childbirth. Later studies of this fungus revealed that it i has a complex of alkaloids each of which cause different physiological effects including (1) stimulating the uterine muscles (hence its use in child birth; (2) causing hallucinations; and (3) constricting the blood vessels (hence the gangrene associated with ergot poisoning. These substances have been used for treating hypertension, migraine headaches and postoperative shock. These alkaloids evidently all have a common component called lysergic acid and it is interesting that this is the active component in the hallucinogenic drug LSD (lysergic acid diethylamide), which was discovered by the Swiss scientist Albert Hofmann in the course of his studies on ergot-related alkaloids.

Nowadays, the milling process for rye ensures that the fungus is removed from seeds.

Publications

• McGee, H. 1991 (first published 1984). On Food and Cooking. The Science and Lore of the Kitchen. Harper Collins, London. 

• Sauer, J.D. 1993. Historical geography of crop plants - a select roster. CRC Press, Boca Raton, Florida.

• Zohary, D. & Hopf, M. 1993. Domestication of plants in the old World - The origin and spread of cultivated plants in West Asia, Europe, and the Nile Valley. Clarendon Press, Oxford.