In order to facilitate the map-based cloning of the barley stem rust resistance gene Rpg1, we have demonstrated a high degree of synteny at a micro level between the telomeric regions of barley chromosome 1P and rice chromosome 6. We have also developed and applied a simple and efficient method for selecting useful probes from large Insert genomic YAC and cosmld clones. The gene order within the most terminal 6.5 cM of barley chromosome 1P was compared wtth the most terminal 2.7 cM of rice chromosome 6. Nine rice probes, previously mapped In rice or Isolated from YAC or cosmld clones from this region, were mapped In barley. All, except one, were In synteny with the rice gene order. The exception, probe Y617R, was duplicated in barley. One copy was located on a different chromosome and the other in a non-syntenic position on barley chromosome 1 P. The barley probes from this region could not be mapped to rice, but two of them were inferred to be In a syntenlc location based on their position on a rice YAC. This work demonstrates the utility of applying the results of genetic and physical mapping of the small genome cereal rice to map-based cloning of interesting genes from large genome relatives.
Bibliographical noteFunding Information:
Scientific paper 9506-16, College of Agriculture and Home Economics Research Center, Washington State University, Pullman, WA, USA, Project 0951. This study was supported by USDA-CSRS Special Grant Agreement 90-34213-5190 to the North American Barley Genome Mapping Project (NABGMP), USDA-CSRS competitive grant 93-37300-8860 and the Society of Technoinnovation of Agriculture, Forestry and Fisheries (STAFF) in Japaa Special thanks to Dr Yuichi Katayose for the cosmid library, Mr Hiroshi Tanoue for handling the rice YAC clones and Miss Hiromi Kajiya for the rice mapping of pM13. Some of this research was performed while A. Kleinhofs was at the Rice Genome Program (RGP), Tsukuba, Japan. A.K. thanks the RGP and its members for the opportunity and the excellent interactions during his stay.