Diversity for HMW glutenin subunit composition and the origin of polyploid wheats

Abstract

The phylogenetic relationship between the diploid and polyploid species was investigated on the basis of variability for high molecular weight (HMW) glutenin subunit composition in wild diploid and tetraploid progenitor species of cultivated wheats. The analysis of diploid progenitor species showed that T. urartu(Au) possesses two type of accessions, one expressing only Ax subunit and other expressing both Ax and Ay subunits at Glu Al locus. All accessions of other diploid species, T. boeoticum (Ab), possesess both the Ax and Ay subunits. The presence of only Ax subunits or null allele at Glu A1 locus in cultivated polyploid species indicated that T.urartu possessing only Ax subunit is the plausible donor of the A genome to wheat. Observations on HMW glutenin profiles also suggested that Ae. speltiodes may have contributed the G genome to T. araraticum (AG) and some other S genome species might have contributed the B genome.