Studies on maternal inheritance in polyploid wheats with cytoplasmic DNAs as genetic markers.

Restriction fragment patterns of DNA fragments obtained after EcoRI cleavage of chloroplastic (cp) and mitochondrial (mt) DNAs isolated from different wheat species were compared. T. aestivum, T. timopheevi, Ae. speltoides, Ae. sharonensis and T. urartu gave species specific mt DNA patterns. Consequently, the cytoplasmic genomes of wheat cannot have originated from contemporary Ae. speltoides, Ae. sharonensis and T. urartu species. It is shown that cp and mt DNAs of Ae. ventricosa, a tetraploid used to transfer eyespot resistance into T. aestivum, contains cp and mt DNAs differing from DNAs isolated from T. aestivum and other wheats. In contrast, the cytoplasmic DNAs of Ae. ventricosa and Ae. squarrosa reveal an important homology, suggesting that Ae. squarrosa was the female parent of Ae. ventricosa. Disomic addition lines (T. aestivum - Ae. ventricosa) in both Ae. ventricosa cytoplasm and T. aestivum cytoplasm contained cytoplasmic DNAs identical to those of the maternal parent. Restriction patterns of the cp and mt DNAs isolated from eight lines of Triticale differing in their cytoplasm have been compared to those of the maternal parent. A strict maternal inheritance has been observed in each case.