Triticeae is a botanical tribe within the subfamily Pooideae of grasses that includes genera with many domesticated species. Major crop genera found in this tribe include wheat (see wheat taxonomy), barley, and rye; crops in other genera include some for human consumption, and others used for animal feed or rangeland protection. Among the world's cultivated species, this tribe has some of the most complex genetic histories. An example is bread wheat, which contains the genomes of three species with only one being a wheat Triticum species. Seed storage proteins in the Triticeae are implicated in various food allergies and intolerances.
Genera of Triticeae
Genera recognized in Triticeae according to Robert Soreng et al.:
Aegilops
Agropyron
Amblyopyrum
Anthosachne
Australopyrum
Connorochloa
Crithopsis
Dasypyrum
Douglasdeweya
Elymus (syn. Campeiostachys, Elytrigia, Hystrix, Roegneria, Sitanion) Eremopyrum Festucopsis Henrardia Heteranthelium Hordelymus Hordeum (syn. Critesion) Kengyilia Leymus (syn. Aneurolepidium, Eremium, Macrohystrix, Microhystrix) Pascopyrum Peridictyon Psathyrostachys Pseudoroegneria Secale Stenostachys Taeniatherum Thinopyrum Triticum
Cultivated or edible species
Aegilops
Various species (rarely identifiable to species in archaeological material) occur in pre-agrarian archaeobotanical remains from Near Eastern sites. Their edible grains were doubtless harvested as wild food resources. speltoides - ancient food grain, putative source of B genome in bread wheat and G genome in T. timopheevii tauschii - Source of D genome in wheat
Amblyopyrum
muticum - Source of T genome.
Elymus
Various species are cultivated for pastoral purposes or to protect fallow
land from opportunistic or invasive species
canadensis - edible, bread-flour capable, fiddly seeds
trachycaulus - pastoral cultivar
Hordeum
Many barley cultivars
vulgare - common barley (6 subspecies, ~100 cultivars) bulbosum - edible seeds murinum (mouse barley) - cooked as piñole, bread-flour capable, medicinal: diuretic.
Leymus
arenarius (Lyme grass) - bread-flour capable, possible food additive
racemosus (Volga Wild Rye) - drought tolerant cereal, used in Russia
condensatus (Giant Wild Rye) - Edible seeds, harvesting problematic small seeds
triticoides (Squaw grass) - used in North America, seed hairs must be singed
Secale
Ryes
cereale (Cereal Rye) - Livestock feed and sour dough bread - 6 subspecies. cornutum (spurred rye) - herbal medicine: ergot (ergot of spurred rye) at very low doses; dangerously toxic as food. strictum - actively cultivated sylvestre - (Tibetan Rye) - actively cultivated in Tibet and China highlands. vavilovii (Armenian Wild Rye) - edible seeds, thickener.
Triticum
(Wheat) aestivum (bread wheat) - (AABBDD Genome) compactum (club wheat) macha (hulled) spelta (hulled, spelt) sphaerococcum (shot wheat) monococcum (Einkorn wheat) (A Genome) timopheevii (Sanduri wheat) turgidum (poulard wheat) (AABB Genome) carthlicum (Persian black wheat) dicoccoides (wild emmer wheat) dicoccum (cultivated emmer wheat) - used to make Farro durum (durum wheat) paleocolchicum polonicum (Polish wheat) turanicum
Genetics
Triticeae and its sister tribe Bromeae (bromes or cheat grasses) when joined form a sister clade with Poeae and Aveneae (Oats). Inter-generic gene flow characterized these taxa from the early stages. For example, Poeae and Aveneae share a mtDNA genetic marker with barley and 10 other members of Triticeae, whereas all 19 genera of Triticeae bear a wheat marker along with Bromeae.
Genera within Triticeae contain diploid, allotetraploid and/or allohexaploid genomes, the capacity to form allopolyploid genomes varies within the tribe. In this tribe, the majority of diploid species tested are closely related to Aegilops, the more distal members (earliest branch points) include Hordeum (Barley), Eremian, Psathyrostachys. The broad distribution of cultivars within the Tribe and the properties of the proteins have implication in the treatment of certain digestive diseases and autoimmune disorders.
Evolution of the tribe
One of the earliest branches in Triticeae, to Pseudoroegeneria, produces the genome StSt and another Hordeum then genome = HH. Allotetraploid combinations of Pseudoroegeneria and Hordeum and are seen in Elmyus (HHStSt), but also shows introgression from Australian and Agropyron wheatgrasses. Elymus contains mostly Pseudoroegeneria mtDNA.