Division of Genetics, Indian Agricultural Research Institute, New Delhi, India
Nine tetraploid Triticum species, each represented by a variety typical for the respective diagnostic features, were assessed for the genetic divergence by using the Mahalanobis D2 statistic. Nine characters, some of diagnostic value and others of fitness, were considered. Judging on the basis of D2 values, the relative divergence between group formed by T. timopheevi and T. araraticum and the groups formed by the rest of the species was far more than the inter se divergence among the latter, viz., T. turgidum, T. durum, T. pyramidale, T. polonicum, T. turanicum and T. carthlicum. This supports the revised classification of these species into two main species, T. timopheevi with araraticum as its sub-species and T. turgidum with the rest as its sub-species. Importance of tetraploid Triticums in wheat improvement is discussed.
