PCR ANALYSIS OF GENES ENCODING ALLELIC VARIANTS OF HIGH-MOLECULAR-WEIGHT GLUTENIN SUBUNITS AT THE GLU-D1 LOCUS

Genes encoding high-molecular-weight (HMW) glutenin subunits, present in bread-wheat lines and cultivars, were studied by RFLP (restriction fragment length polymorphism) and PCR (polymerase chain reaction) anal yses. In particular, allelic subunits of the x-or y-type, encoded at t he Glu-D1 locus present on the long arm of chromosome 1D, were investi gated. The variation in size, observed in different allelic subunits, is mainly due to variation in the length of the central repetitive dom ain, typical of these proteins. Deletions or duplications, probably ca used by unequal crossing-over, have given rise to the size heterogenei ty currently observed. The possibility of using the PCR technique for a detailed analysis of HMW glutenin genes in order to obtain a more ac curate estimation of the molecular weight of their encoded subunits, a nd the detection of unexpressed genes, is also described.