Different wheat relatives have contributed greatly towards economic improve
ment of hexaploid bread wheats. Since its discovery by Aaronsohn in 1906, w
ild emmer has been widely described and phenotyped for many useful traits s
uch as stripe-rust resistance and high protein. A cultivated emmer landrace
, Yaroslav emmer, has contributed durable stem-rust resistance to variety '
Hope', which has become a paramount germplasm for improving resistance to s
tem rust in bread wheats. Other lines of cultivated emmer, Triticum dicoccu
m, are being used for improved protein percentage. Recently, following the
examples of Yaroslav emmer, the International Maize and Wheat Improvement C
enter, CIMMYT (Centro Internacional De Mejoramiento De Maiz Y Trigo) has em
barked on utilization of Aegilops tauschii (DD genome) for resistance to Se
ptoria tritici leaf blotch and Fusarium head scab, drought tolerance, and g
ood bread-making quality traits. Some wild perennial members of the Tritice
ae genera Leymus and Thinopyrum are additional promising sources for genes
conferring head-scab resistance. Important sources tested in breeding for h
igh protein content and end-use quality traits in bread wheat are wild and
cultivated diploid wheats that carry the AA genomes.