Submitted to: Grassland Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2006
Publication Date: 10/18/2006
Citation: Kindiger, B.K. 2006. Cross-species amplification of Lolium microsatellites in Poa ssp. markers. Grassland Science. 52(3):105-115. Interpretive Summary: Bluegrass is an extremely popular turf and forage grass grown throughout the world. The bluegrass genus comprises a complex array of species with high chromosome numbers, unknown taxonomic relationships and a diversity of reproductive forms. As a consequence, little research has been focused on generating molecular markers for these species that could be utilized for marker-assisted breeding or cultivar identification. Bluegrass may be distantly related to the complex of species represented by perennial ryegrass and tall fescue. Consequently, molecular markers developed for those species may have application in bluegrass genome studies. This research examines the value for breeding bluegrass in utilizing a particular type of molecular marker, microsatellites, that were developed for perennial ryegrass and are known to have cross-species application in tall and meadow fescue. If these molecular markers can identify genotypic differences between several bluegrass species, informative markers for bluegrass genome studies would be available. The research evaluated 47 perennial ryegrass-derived microsatellite markers across nine bluegrass species. Twenty-eight of these markers were found to be informative across most bluegrass species and several of their hybrids. This information, when combined with the perennial ryegrass markers found in public and proprietary databases, should result in the accelerated development of additional bluegrass-specific molecular markers.
Technical Abstract: The genus Poa has been suggested to be related to the same complex of species of which Lolium ssp. and Fescue ssp. are representive. Cross-species amplification of 47 Lolium perenne microsatellite primers were evaluated across nine Poa turf and forage species to determine the predisposition of Lolium microsatellite primers to provide informative molecular markers for an array of diverse Poa ssp. Among the Lolium SSR primers examined in this study, 28 generated one or more amplification products across the Poa species or sub-species. Comparative DNA sequence analysis of the Lolium and Poa amplification products suggest genome regions exhibiting both high and low sequence divergence. Among the Poa ssp., DNA sequence comparisons suggest levels of sequence similarity as well as divergence. Evaluation of sequence data from the amplified Poa PCR products suggest that few useful Poa ssp. microsatellite regions will be identified with Lolium SSR primers. Those primers generating informative Poa amplification products suggest most markers will be dominant in their inheritance and expression. The study also demonstrates the potential for utilizing the informative cross-species primers in a Poa ssp. interspecific hybrid breeding program. The application of this data to public and proprietary Lolium SSR primer databases indicates that additional markers can be generated for Poa ssp. improvement programs. This information will be valuable to geneticists and plant breeders developing bluegrass cultivars in both academic and commercial research institutions.