Studies of two groups of kernel proteins in polyploid wheats with G genome

High molecular weight glutenin subunits (HMW-GS) are part of the storage proteins encoded by two tightly linked x- and y-type genes at three complex loci (Glu-A1, Glu-B1, Glu-D1) on the homoeologous group-1 chromosomes while waxy proteins (Wx) are a group of kernel proteins related to the amylose synthesis, a component of starch with amylopectin, encoded by genes located on the short arm of the chromosomes 7A, 7D and on the long arm of chromosome 4A (Wx-A1 Wx-B1 Wx-D1 loci). The influence exerted by these two different type of proteins on technological properties of dough has been established and these knowledges are being used in wheat quality improvement. From this point of view an interesting source of novel genes is represented by Triticum timopheevii ssp. timopheevii (cultivated) and ssp. araraticum (wild) (2n=28, AtG) and related species Triticum militinae (2n=28, AtG), Triticum miguschovae, (2n=42, AtGD), T. timonovum (2n=56, AtAtGG) and Triticum zhukovskyi (2n=42 AmAtG). In order to detect novel variation at Glu-1 and Wx-1 loci, the characterization of the two groups of kernel proteins and corresponding genes have been carried out by one-dimensional electrophoretic separation (SDS-PAGE) and polymerase chain reaction (PCR) technique in polyploid wheats with G genome. Results have permitted to associate different x- and y-type glutenin subunits and waxy proteins to the A, G and D genomes and to reveal the presence or the absence of expressed proteins and of corresponding genes at the Glu-1 and Wx-1 loci. Different structural features existing between homoeologous B and G genomes, probably justify the absence of PCR products corresponding to x- and y-type genes at the Glu-G1 and Wx-G1 loci, in all species analysed, except in T. timonovum.