Cultivated wheats (Triticum spp.) are characterized by purple-, red/brown- and white-colored pericarp in their kernels (Belay et al., 1995). The taxonomic status of purple-grained tetraploid wheat remains unclear (Zeven, 1991). Only one accession of common wheat (T. aestivum L.), native to China, is known to have purple pericarp. The rest of the reported purple-grained tetraploid wheats are found in Ethiopian collections of the tetraploid (2n = 4x = 28) wheat taxa (included by some taxonomists within the broad species T. turgidum L. sensu lato) (Belay et al., 1995). References have also been made to T. dicoccum, T. durum, T. polonicum, and "T. aethiopicum Jakubz" (syn. "T. abyssinicum"), which is T. durum from Ethiopia (Zeven, 1991). All tetraploid wheat taxa that are found in Ethiopia, with the possible exception of T. dicoccon Shrank (locally known as Adja), may possess the purple pericarp color, although in varying frequencies — very low in T. polonicum L., and high in T. carthlicum Nevski and T. durum Desf (Belay et al., 1995). Sometimes the color might be deep purple or brownish-purple, and the latter may be almost black or violet, as in Chinese black-grained wheat (Li et al., 2005). When the purple-grain character is transferred to hexaploid wheat, derivatives may show colors different from the tetraploid parent. Altitude, light intensity, and temperature may also influence the production of anthocyanins (Belay et al., 1995).
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