Cultivated rye (Secale cereale cereale) probably descended directly from the wild rye (Secale cereal vavilovii) and is the same species. If another species (Secale strictum, formerly Secale montanum), which is multiannual and forms stolons also played a role is not clear. Wild rye grows only to 0.5-0.8metres height and grows in Turkey, Armenia, Azerbajian and also Central Asia. The ear of wild rye at maturity fragments into many parts. The corns are small and completely covered in spelts.
The Anatolian plateau is considered to be the origin of cultivated rye. Rye is not self fertilizing and in places where wild rye occurs never could display all of its crop traits since wild rye or intermediary forms were always backcrossed. Nevertheless the farmers of the highlands of Anatolia and Armenia valued the rye especially together with wheat. It was typical to plant both at once in fields. In bad, very cold and dry years wheat fails and then rye secures the survival of farmers as it still produces a yield. In the Alps it was also common to seed combined rye-wheat. In good years wheat dominates, in bad years rye.
Our rye came to Central Europe in two ways. The first led over Ukraine and the second over the Mediterranean coast through Italy and France and then up the Rhone valley. The rye took a long time to be accepted as a crop. For millennia it was tolerated as an accompanier of other cereals. It still did not have any importance to the Bronze and Iron Age. Only in the Roman times did this change when it became an oft-cultivated crop in some regions. Rye together with barley is the most important crops of the High Alps valleys. Rye is cultivated as both winter and summer rye. It starts growing at lower temperatures than other crops and is thus suited for marginal regions with short vegetation times. Furthermore it is the only cereal that when seeded in late summer can easily survive the long and snowy winters of the mountains. Winter rye has the advantage over summer rye that it immediately continues to grow after the snow thaws and flowers more quickly. Rye is not demanding, deep rooted and produces good yields even on poor sandy soils. Rye is conspicuous by its long leaves which contribute to filling its corns. Rye straw was used to cover roofs, for bedding material, kummet filling and is still used for braiding.
Rye is a freely threshed cereals, often the mature corns aren’t completely covered in spelts. During wet weather the humidity can thus be more easily taken up by the corn and facilitate germination. This causes precocious germination. Precociously germinated cereals cannot be used to make bread and are only suited as animal food. Rye bread has little glue proteins. It’s principally the slimes in the dough which hold the gas formed during fermentation and thus let the dough expand. Rye is poorly digestible, a sourdough preparation makes the bread more aromatic and easier to digest. Another possibility to aid digestion is the production of pumpernickel. Pumpernickel is a grist rye bread, which is baked at low temperatures for 15-16 hours. The starch caramelizes and thus the sweet-is taste of pumpernickel is born.

Literature
Miedaner, Thomas (2014): Kulturpflanzen: Botanik — Geschichte — Perspektiven. Berlin Heidelberg: Springer-Verlag. ISBN: 364255292-2
Schilperoord, Peer und Heistinger, Andrea 2011. Literaturstudie alpine Kulturpflanzen Vs. 5.0 130320. 277 S. www.berggetreide.ch/Archiv.html
Zohary, Daniel; Hopf, Maria; Weiss, Ehud (2012): Domestication of plants in the Old World. The origin and spread of domesticated plants in Southwest Asia, Europe, and the Mediterranean Basin. 4. Aufl. Oxford: Oxford University Press. ISBN: 978-0199549061