P1. Syst. Evol. 209:123-137 (1998) Plant- Systematics and Evolution © Springer-Verlag 1998 Printed in Austria High molecular weight glutenin subunit variation in wild and cultivated einkorn wheats ( Triticum spp., Poaceae) M. CIAFH, L. DOMINICI, and D. LAFIANDRA Received June 5, 1996; in revised version June 22, 1996 Key words: Poaceae, Triticum urartu, T. boeoticum, T. monococcum.- A genome, storage proteins, HMW-glutenin subunits, electrophoresis, wheat phylogeny. Abstract: Variation in high molecular weight (HMW) glutenin subunit composition among wild and cultivated einkorn wheats (2n = 2x = 14, AA) was investigated using one- (SDS- PAGE and urea/SDS-PAGE) and two-dimensional (IEF x SDS-PAGE) electrophoretic analyses. The material comprised 150 accessions of Triticum urartu, 160 accessions of T. boeoticum, 24 accessions of T. boeoticum subsp, thaoudar and 74 accessions of primitive domesticated T. monococcum from many different germplasm collections. The biochemical characteristics of HMW-glutenin subunits of T. boeoticum and T. monococcum were highly similar to one another but distinctly different from those of T. urartu. All the species analysed were characterised by large intraspecific variation and only three HMW-glutenin subunit patterns were identical between T. boeoticum and T. monococcum. Consistent with the distinct nature of T. urartu, all its HMW-glutenin patterns were different from those found in T. boeoticum and T. monococcum. The differences detected between these species might reflect their reproductive isolation and are consistent with recent nomenclatural and biosystematic treatments that recognise T. urartu as separate species from T. boeoticum and T. monococ- cure. The presence of three distinct glutenin components in some accessions of the species studied seems to be evidence for the existence of at least three active genes controlling the synthesis of the HMW-glutenin subunits in the A genome of wild and primitive domesticated diploid wheats. Results indicate also that HMW-glutenin subunits could represent useful markers for the evaluation of genetic variability present in different wild diploid wheat collections and subsequently for their conservation and future utilisation. Wild species of Triticum L. and Aegilops L. provide a useful source of new genetic variation for wheat improvement. There are numerous examples of successful transfers of genes carrying resistance to various pathogens, environmental stresses or nutritionally and technologically useful characteristics from wild diploid relatives into the genome of polyploid wheats (see GALE &: MILLER 1987, AVVELS & LAGUDAH 1990, for reviews). The further evaluation of genetic variability needs to include a detailed study of the genetic structure and differentiation of wild populations