Abstract:

The wild species of common wheat were confirmed to have many agronomically useful characters such as tolerance to salt stress, resistance of diseases and high quality. Interest in Lophopyrum elongatum as a source of genes for wheat improvement has been enhanced by the development of its amphiploids and addition, subbstitution and translocation lines. In order to rapidily further exploit and utilize key genes in this wild species of wheat, in this paper, forty-two degenerate primers, which were designed from the conserved motifs of known plant resistance gene products, were used to amplify the resistance gene analog polymorphisms (RGAP) from the genomic DNAs of common wheat cultivar Chinese Spring (CS), Lophopyrum elongatum, CS-Lo. elongatum ampliploid, and their addition and substitute lines. The amplification products could be obtained from 38 primers combinations, among which 35 primers combinations could amplify the polymorphic fragments between CS and CS-Lo. elongatum ampliploid, with an average of 38.5 bands per primers combination. A total of 275 bands were detected on E^e genome of Lo. elongatum in Chinese Spring background, with a polymorphic frequency of 17.44%, indicating that Ee genome showed high genetic diversity in common wheat background. To establish a set of specific resistance gene analogues markers for E chromosomes, RGAP molecular marker technology was used with 26 primer combinations to reveal polymorphism between Chinese Spring and the amphiploid, and the polymorphic bands also appeared in their addition and substitute lines, respectively. This indicated that the polymorphic bands were the specific RGAP markers of E chromosomes. A total of 30 specific RGAP markers, which were distributed in the diferent E specific chromosomes, were detected. The development of chromosome-specific markers of Lo. elongatum could be useful for scanning the alien chromosomes or chromosome fragments of Lo. elongatum in common wheat backgrounds.

Key words: Wheat, Lophopyrum elongatum, RGAP marker, Addition line, Substitute line