Utilization of Flow Cytometry to Identify Chimeral Sectors in Leaf Tissue of Lolium multiflorum x L. arundinaceum Hybrids

We have identified a method whereby Lolium multiflorum (Lm) or L. arundinaceum (Fa) genomes are preferentially eliminated through a mitotic loss behavior in interspecific Lm x Fa F1 hybrids, generating either dihaploid Lm lines or Fa lines. Flow cytometry, a method of rapidly characterizing optical properties of cells and cell components within individuals, has been applied to identify the prevalence and timing of chimera formation in these Lm x Fa F1 hybrids through measurements of genome size estimation. Preliminary results indicate flow cytometry can clearly identify genomic sectors within nuclei extracted from leaf tissue, predict the size and frequency of the genomic sectors and can suggest the particular environmental parameters that enhance or reduce chimera formation. Due to the high-throughput capabilities of flow cytometry, the method has also been effectively applied toward the rapid identification of both Lm or Fa dihaploid individuals, greatly reducing the need for standard root-tip chromosome squash methods.