A Molecular Phylogenetic Framework for Timothy (Phleum pratense L.) Improvement

Abstract

The recent molecular phylogenetic analysis of Phleum germplasm has provided a clear evolutionary history of the genus from which modern hexaploid germplasm and their cultivars have evolved. This framework will allow us to effectively use the full set of germplasm from all ploidies (2x, 4x, 6x and 8x) for a more systematic improvement of Timothy. The many new molecular forms of Phleum now known offer a huge potential to expand the gene pool of commercial hexaploid Timothy. The opportunity exists to hybridize and incorporate many new forms of molecular diversity into Timothy. However, genebank samples of many of these new forms are absent and urgently require collection. In addition, many of the novel diploid, tetraploid, hexaploid and octoploid forms are under serious threat from habitat degradation and climate warming in situ. It is also critical that core collections are developed and maintained using molecular phylogenetic and genetic diversity information as a basic framework. In order to apply molecular resources in an effective and balanced manner, it is important to ensure pragmatic field breeding programmes are continued in all major regions. This is a concern for Timothy, as it is a species with limited international breeding investment.