GENETIC-LINKAGE MAP OF ISSR AND RAPD MARKERS IN EINKORN WHEAT IN RELATION TO THAT OF RFLP MARKERS

The potential of PCR-based markers for construction of a genetic linka ge map in Einkorn wheat was investigated. From a comparison of polymor phisms between two Einkorn wheats, Triticum monococcum (Mn) and T. boe oticum (Bt), we obtained 49 polymorphic bands produced by 33 primers f or inter-simple sequence repeat (ISSR) and 36 polymorphic bands shown by 25 combinations of random amplified polymorphic DNA (RAPD) primers for mapping in 66 individuals in the F-2 population. Although 44 ISSR fragments and 29 RAPD fragments statistically showed a 3:1 segregation ratio in the F-2 population, only 9 markers each of the ISSR and RAPD bands were able to be mapped on the RFLP linkage map of Einkorn wheat . ISSR markers were distributed throughout the chromosomes. The mapped positions of the ISSR markers seemed to be similar to those obtained by the RFLP markers. On the other hand, 4 of the 9 RAPD markers could map the RFLP marker-poor region on the short arm of 3A(m), suggesting a potential to map novel regions containing repetitive sequences. Comp arisons of the genetic linkage map of Einkorn wheat to the linkage map and cytological map of common wheat revealed that the marker orders b etween the two maps of Einkorn wheat and common wheat coincided except for 4A, which harbors chromosome rearrangements specific for polyploi d wheats, indicating a conservatism between the two genomes. Recombina tions in Einkorn wheat chromosomes took place more frequently around t he centromere and less at the distal part of chromosomes in comparison to those in common wheat. Nevertheless, recombinations even in Einkor n wheat chromosomes were strongly suppressed around the centromere. In fact, the markers located within 1 cM of the centromere were located almost in the central part of the chromosome arm.