The Molecular Basis of Genetic Diversity among Cytoplasms of TRITICUM and AEGILOPS Species. II. on the Origin of Polyploid Wheat Cytoplasms as Suggested by Chloroplast DNA Restriction Fragment Patterns

Abstract

In attempts to identify the phylogenetic donors of cytoplasm to Emmer-Dinkel and Timopheevi groups of wheat (Triticum), and the Aegilops kotschyi-Ae. variabilis complex, the restriction fragment patterns of chloroplast DNAs of representative species were compared with those of their putative diploid ancestors. The following seven restriction enzymes were used; BamHI, EcoRI, HindIII, KpnI, PstI, SmaI and XhoI. The restriction fragment patterns of an Emmer and a Dinkel (common) wheat were identical with those of Ae. longissima , and different from those of Ae. aucheri, Ae. bicornis, Ae. searsii, Ae. sharonensis, Ae. speltoides, and T. urartu by 4 to 12 fragments. The restriction fragment patterns of a Timopheevi wheat were identical with those of Ae. aucheri, and different from those of all other diploids by four to nine fragments. The restriction fragment patterns of Ae. variabilis were identical to those of Ae. bicornis and Ae. searsii , and different from those of all other species. Thus, we have concluded that Ae. longissima, Ae. aucheri and Ae. bicornis (or Ae. searsii) were the cytoplasm donors to the Emmer-Dinkel and the Timopheevi groups, and the Ae. kotschyi-Ae. variabilis complex, respectively. A diphyletic origin of Emmer and Timopheevi groups is supported by the present results.