Deletion-based physical mapping of barley chromosome 7H

Chromosomal mutations in barley (Hordeum vulgare, 2n=2x=14, HH) chromosome 7H added to the common wheat (Triticum aestivum, 2n=6x=42, AABBDD) cultivar Chinese Spring were induced genetically by the gametocidal activity of cer tain alien chromosomes derived from wild species of the genus Aegilops. The rearranged barley chromosomes were characterized by C-banding, FISH and GI SH. Twenty two deletion or translocation chromosomes in a hemizygous condit ion were selected for deletion mapping of 17 AFLP and 28 STS markers that a re specific to 7H. Of the 22 breakpoints in chromosome 7H, seven involved t he short arm (7HS), 12 the long arm (7HL) and three were in the centromeric region, The seven 7HS breakpoints separated all four 7HS-specific AFLP mar kers and split the 21 STS markers into six groups. One breakpoint occurred between two STS markers formerly occupying the same position in the genetic map. All seven 7HS breakpoints were separated from each other by either th e AFLP or STS markers. The 12 breakpoints in 7HL divided the 13 7HL-specifi c AFLP markers into seven groups, and the seven STS markers into three grou ps. On the other hand, the 12 breakpoints in 7HL were divided into six grou ps by the AFLP markers and into two groups by the STS markers. This deletio n-based map was in accordance with previously published genetic and physica l maps using the same STS markers. The breakpoints, AFLP markers and STS ma rkers were arrayed in a consistent order.