Parental Intermated Recombinant Inbred (IRI) lines and meiotic pairing
in perennial ryegrass Lolium x Festuca hybrids

Olli Anhalt (PhD student) involving a collaboration between Dr Susanne Barth/Teagasc (The Irish Agriculture and
Food Development Authority) Oak Park Research Laboratories, Carlow (project page at Teagasc), and Pat Heslop-Harrison and Trude Schwarzacher/University of Leicester.


Plants from Lolium x Fescue hybridsIntermated recombinant inbred lines (IRIs) are valuable for fine mapping and cloning of genes and for the transfer of traits between genera and species in breeding programmes. Such population structures have allowed identification of functional genes and related phenotype to genotype in the model genetic plant species Arabidopsis. Once IRI lines are fully developed, multiple applications of these lines are possible, e.g. for the mapping of quantitative trait loci (QTL) of agronomic traits, or the identification and positional cloning of genes. In the Oak Park breeding programme, inbred perennial ryegrass lines have been developed during a cytoplasmic male sterile (cms) programme utilising crosses of Festuca pratensis and Lolium, with multigeneration backcrossing to the Lolium recurrent parent against the outbreeding nature of the species. These lines harbour Festuca characteristics and include Festuca chromosomal segments that provide an outstanding resource for physical mapping of the genome, gene identification and cloning, and the utilisation of this information in development of advanced lines for breeding and research. In this project, the parental lines and the initial IRI generations are being characterised using in situ hybridisation of characteristic repetitive and low-copy DNA sequences (molecular cytogenetics), molecular markers (both anonymous and of known genes) and by phenotypic and morphological analysis. Meiotic pairing in inter-species crosses is being measured as basis for the functionality of true-breeding hybrids and for physical analysis of chromosomal pairing. Both molecular and chromosomal diversity will be analysed to characterise the nature and amount of variation within the parents and the extent and locations of recombination within the IRI lines. Overall, the project will involve a combination of observational and hypothesis driven work, with both fundamental and applicable aspects using genomics.

Lolium - Fescue trial plots at Carlow


The project is supported by a Walsh Fellowship from Teagasc.

For details of the Walsh Fellowship scheme and current opportunities please see