Agropyron cristatum

Agropyron cristatum is one of several closely related grass species referred to as crested wheatgrass. It is unable to hybridize with its similar relatives, as it is a diploid species, whereas its closest relative, Agropyron desertorum, is a tetraploid species. It was introduced from Russia and Siberia to North America in the first half of the twentieth century, and widely used to reseed abandoned marginal cropland undergoing varying degrees of soil erosion and secondary succession. A. cristatum is very long lived, with stands often remaining productive for 30 years or more. ==Description==

Agropyron cristatum is a densely tufted grass, with culms ranging from 30 to 50 cm high at maturity. Its sheaths are scabrous or the lowest ones pubescent. Its blades are up to 8 mm wide and scabrous to pubescent above. Its spikes are flat and range from 2–7 cm long, with spikelets ranging from 8–15 mm long, being 3–5-flowered, densely crowded, and spreading to ascending. Its glumes are 4–6 mm long, awn-tipped, and its lemmas are 6–8 mm long and either awnless or awn-tipped. Agropyron cristatum is known among other grasses and wheats for its relatively high granivory. Granivory, or granivores, describe the interaction between animals and seeds. Agropyron cristatums high granivory indicates that animals feed on the seeds of the plant as their primary, or even exclusive, food source. Although this raises concerns about the plant's continued ability to reproduce if its seeds are all being consumed, the high granivory of this species does indicate that Agropyron cristatum is an important food source. ==Habitat==

Agropyron cristatum is best adapted to dry rangeland conditions and is most frequently found in such circumstances. It prefers from 23 to 38 cm of precipitation per year, but can tolerate more moisture on favourable sites, extending its range into tundra and taiga conditions and elevations up to 2000 m above sea level in the southern portions of its adapted area. It prefers well drained, deep, loamy soils of medium and moderately coarse texture, including Chernozemic, Solonetzic, Regosolic, Brunisolic and Luvisolic soils. A. cristatum can tolerate salinity in the range of 5 to 15 mS/cm and prefers moderately alkaline conditions. It will not tolerate prolonged flooding. It achieves this drought tolerance by starting growth very early in the season, then going dormant from seed set until fall when it will exhibit vegetative regrowth if moisture is sufficient. ==Uses==

Agropyron cristatum has been bred into many cultivars selected for attributes ranging from forage yield to drought tolerance to turf types that will exhibit more pronounced degrees of rhizomatous growth habit. Plants with a translocation on chromosome 6P yield wheat of greater weight and longer spike length than those without the mutation. These regulators were specifically found to be on the 6PS and 6PL chromosome arms. Agropyron cristatum’s genes can be used to instill leaf resistance in other species of wheat. It also establishes rapidly relative to many other grasses. It also has a resistance to barley yellow dwarf, wheat streak mosaic viruses, and leaf rust disease as well as containing high protein content. One such fear is that its seedlings' emergence does not decrease under herbicide treatment. ==Tenacity==

The importance of Agropyron cristatum is often undermined, as the plant has not been domesticated for modern agricultural use. Agropyron cristatum’s ability to withstand various environmental and biological blighting makes it a truly unique and valuable organism. Recent studies highlight the importance of A. cristatum in future agricultural development because it exhibits several desirable traits for the improvement of domesticated wheat. While some of these traits may be related to yield production of the wheat, other significant traits include biotic and abiotic stress resistance genes that enable A. cristatum to grow proficiently. The importance of this knowledge is that researchers can use this genetic information regarding stress resistance genes to introduce new desirable traits in other domesticated wheat species that aid their growth in harsh environments. Ultimately, this leads to better yields for more human consumption. The phenotypic success that Agropyron cristatum experiences is primarily due to the success of its root system. Recent studies show how root development contributes to the competitiveness of A. cristatum by testing its ability to flourish over other forms of vegetation in grassland environments. These studies provide data on how long the roots grow and how concentrated soil volume becomes with roots of A. cristatum. The results shows that A. cristatum typically allocates more of its biomass in its roots than its shoots when compared to other grassland species. Interpretation of this data suggests that because A. cristatum has a better foundation, it can outcompete other species for resources. Using the method of intergenic translocations, the research shows that successful integrations have been completed and that those plants do in fact grow normally as well. To sum up, the numerous biotic and abiotic resistance genes that A. cristatum presents leads to the success of the species which could and can be applied to modern day food production of the wheat domesticated species. ==Notes==