Transfer of the Glu-D1 locus encoding high molecular weight glutenin subunits 5+10 from breadwheat to diploid rye

A fragment of chromosome 1DL of breadwheat (Triticum aestivum L.) with the locus Glu-D1 encoding high molecular weight glutenin subunits 5+10 was tran slocated in hexaploid triticale (x Triticosecale Wittmack) to chromosome 1R L of rye ( Secale cereale L.) where it replaced a corresponding fragment co ntaining locus Sec-3 encoding rye secalins. The translocated chromosome 1R was transferred to diploid rye through backcrosses. During the transfer, at least two crossover events must have taken place that reduced the lengths of the 1DL inserts to about 5-8% of 1RL. These short inserts were selected on the basis of normal male transmission from heterozygotes and by low pair ing with chromosome 1D in the F-1 hybrids with wheat, and tested by the in situ hybridization with total genomic DNA. While the wheat introgression in rye did not affect plant morphology or fertility, preliminary observations of the first population of homozygotes suggested that grain yield was lowe r, probably as a result of about 15% reduction of the 1000 kernel weight. T he presence of a single wheat glutenin locus was insufficient to create rye with wheat-like breadmaking properties. However, relative to controls, the SDS-sedimentation value increased by about 75% and loaf volume was greater in test bakes using the procedure adapted for wheat-rye blends. Loaf volum e for bread baked using the procedure for rye flour was not affected. Ryes with various glutenin subunits could be used in wheat-rye blends.