Abstract
Thirteen strains of Triticum macha, 105 cultivars of T. spelta and a single strain of T. vavilovii, all having the same genome constitution (AABBDD) as bread wheat, were studied to determine their necrosis and chlorosis genotypes by crossing them to appropriate testers.
Results of this and previous investigations indicate that common wheat has differentiated into two geographical populations, i.e. Asian and Western, irrespective of species. The Asian population was characterized by a high frequency of Ne1-carriers and the Western population by Ne2-carriers. A strong isolation barrier between T. macha and the rest of common wheat species due to the complementary chlorosis genes, Ch1 and Ch2 was found.
Based on necrosis data, European T. spelta is assumed to have originated from Ne2-carrying T. aestivum and q-carrying T. dicoccum, while the origin of T. macha is ascribed to hybridization between T. aestivum and Ch1-carrying T. dicoccum. At least, two independent introgressions of genes from emmer wheat seem to have played important roles in species differentiation in common wheat.
