Nuclear DNA content in diploid wheat and its relatives in relation to the phylogeny of tetraploid wheat

Abstract

In order to elucidate the origin of tetraploid wheat, nuclear DNA content (1C or 4C) in eight accessions of Triticum urartu, 21 of four Sitopsis species of genus Aegilops and three artificial tetraploids obtained from the F1 hybrid between Ae. longissima, Ae. sharonensis or Ae. bicomis and T. monococcum was measured by means of Feulgen-cytophotometry. T. urartu showed uniform DNA content among the accessions, and was the same DNA as T. monococcum in its DNA content. Some intraspecific variation was noticed in three species, Ae. longissima, Ae. sharonensis and Ae. searsii. Whereas two other species, Ae. speltoides and Ae. bicornis did not show any significant intraspecific variation. 4C DNA content in three synthesized tetraploids was the same as the sum of the contents of their parents' and was nearly equal to that of Emmer wheat, indicating that all Ae. longissima, Ae. sharonensis and Ae. bicomis can be a candidate of the B genome donor to polyploid wheat. On the other hand, T. urartu and Ae. speltoides have less DNA content than the B genome of polyploid wheat. © 1986, The Genetics Society of Japan. All rights reserved.