Interactive Genotypic Influence of Durum Wheat and Aegilops tauschii on their Crossability and Fertility of Synthetic Amphiploids

Bread wheat (Triticum aestivum L., AABBDD) is an allohexaploid (AABBDD, 2n=6x=42) originated from hybridization which occurred about 8000 years BC between a cultivated tetraploid wheat (T. turgidum L.; AABB, 2n=4x=28) and the wild goat grass Aegilops tauschii (DD, 2n=2x=14). In order to synthesize bread wheat, crosses were carried out between seven genotypes of durum wheat and 13 ecotypes of A. tauschii of various origins. The production of synthetic hybrids was made with and without the implementation of embryo rescue technique. Four genotypes of durum wheat, carrying genes for the production of unreduced gametes, produced partially fertile hybrids after their cross with the ecotypes of A. tauschii. The percentage of grain germination harvested from these hybrids varied between 22.2 and 65.2%. Growth abnormalities were observed on hybrid plants. The barriers of incompatibility between the two species were manifested by leaf chlorosis and lethal necrosis on hybrid plants. (C) 2018 Friends Science Publishers