Study of interspecific SSR polymorphism among 14 species from Triticum-Aegilops group

Abstract

In the present study, using in-gel hybridization and PCR based approaches, interspecific SSR polymorphism was studied among 14 species of Triticum-Aegilops group. The material represented seven different genomes and three ploidy levels (2x,4x,6x). In-gel hybridization involved 13 probe-enzyme combinations (four SSR oligonucleotide probes in combination with 2-4 enzymes) and resolved 5 to 20 bands (0.40kb to > 23kb) in each of the 14 individual species. This suggested ubiquitous distribution and interspecific polymorphism of SSRs among different species of Triticum-Aegilops group. The available polymorphism also proved helpful in discriminating not only the species with different ploidy levels and possessing different genomes, but also those possessing similar or very closely related genomes. The amplification of SSR loci using 15 primer pairs derived from hexaploid wheat was also carried out in all the 14 species. The primer pairs, each amplified SSR loci not only in species containing A, B and D genomes, but also in 2 to 10 of the remaining species that contained other genomes. This suggested that wheat SSRS might have been derived from the corresponding SSRs in an ancestral genome and are conserved across a number of species in the Triticum-Aegilops group. Also, two pairs of SSRs (one consisting of WMC243 and WMC415 and the other consisting of WMC35 and WMC404) each discriminated all the 14 species examined during the present study. Therefore, one can infer from the present study that SSR primers can be used in studies on DNA polymorphism, genetic diversity, gene mapping and synteny conservation across different species of Triticum-Aegilops group.