Genetic Heterogeneity of a Diploid Grass Aegilops tauschii Revealed by Chromosome Banding Methods and Electrophoretic Analysis of the Seed Storage Proteins (Gliadins)

Resumo

Genetic diversity of diploid grass Ae. tauschii Coss (2n = 2x = 14, DD), the D-genome progenitor of common wheat, was assessed using fluorescence in situ hybridization (FISH) with eleven DNA probes representing satellite and microsatellite DNA sequences as well as the 45S and 5S rRNA gene families and by electrophoretic (EF) analysis of seed storage proteins (gliadins). A clear genetic differentiation of accessions into groups strangulata (Str) and tauschii (Tau) was observed. The groups differed in the presence of microsatellite repeats GAA_n and ACT_n and in the distribution of satellite DNA families, especially pAs1. On the basis of similarities of labeling patterns of DNA probes used in the study, we concluded that the Str group was phylogenetically closest to the D genome of common wheat. A comparison of spectra of gliadins revealed the highest similarity of Armenian and Azerbaijani accessions of Ae. tauschii to common wheat, which may indicate a contribution of Transcaucasian members of the Str group in the formation of the genetic pool of common wheat.