Transfer of rye chromosome segments to wheat by a gametocidal system.

A gametocidal chromosome derived from Aegilops triuncialis (3C) induces chromosome mutations in gametes lacking the 3C chromosome in common wheat (Triticum aestivum L.). We combined 3C with chromosome 1R of rye (Secale cereale L.) in a common wheat line to know how efficiently 3C induces transfers of small 1R segments to wheat. In the 811 progeny of this wheat line, we found five wheat chromosomes (2A, 2D, 3D, 5D and 7D) carrying segments of the 1R satellite. Wheat plants carrying these translocations were tested for the presence of a storage protein locus Sec-1 and a cluster of resistance genes for wheat rust diseases, Sr31, Lr26 and Yr9. The 2A and 2D translocations had the Sec-1 and three rust resistance loci. The 3D and 5D translocations had Sr31, Lr26 and Yr9 but not Sec-1. The 7D translocation lacked Sec-1, Lr26 and Yr9, but the presence of Sr31 in this translocation was not determined. This showed that the translocation points fell into three regions of the 1R satellite, namely, proximal to Sec-1, between Sec-1 and the rust resistance loci, and distal to the rust resistance loci. Thus, the 3C gametocidal system was demonstrated to be effective in transferring small rye chromosome segments.