GENETIC-STUDIES OF ALPHA-AMYLASE ISOZYMES IN WHEAT .7. VARIATION IN DIPLOID ANCESTRAL SPECIES AND PHYLOGENY OF TETRAPLOID WHEAT

In order to investigate the phylogeny of polyploid wheat, the genetic variation of alpha-amylase isozymes in 127 strains of two diploid wheat species and five Aegilops species belonging to section Sitopsis was analyzed. Three types of zymogram were detected in 39 strains of Triticum monococcum and three other different types were detected in another diploid wheat, T. urartu. Two varieties of Ae. speltoides, var. ligustica and var. aucheri (subsection Truncata), were similar to each other and showed wide variation of zymograms. Sixteen strains of Ae. longissima and 13 strains of Ae. sharonensis were each grouped into four types. Ten strains of Ae. bicornis were grouped into three types, each including three or four strains. On the other hand, zymograms from five strains of Ae. searsii, which was formerly treated as a variety of Ae. longissima, were very different from those of Ae. longissima. In contrast to subsection Truncata, the zymogram types were rather simple and similar among species in subsection Emarginata (Ae. longissima, Ae. sharonensis, and Ae.bicornis) except for Ae. searsii. Finally, the phylogeny of tetraploid wheat was discussed on the basis of the results presented here along with those of the previous authors.