Use of Flow Cytometry for Screening Wide Hybrids in Festuca x Lolium Crosses.

The forage grass breeding project at the University of Kentucky has utilized wide hybridization as a means of improving tall fescue, development of festulolium germplasm, and studies of genomic relationships in the Festuca-Lolium complex.  Several species can be used, including meadow fescue, annual and perennial ryegrass, Festuca mairei, F. gigantea, and several subspecies of 'tall fescue' ranging in ploidy from 2n=28 to 2n=70.  Because these grasses are almost always highly self-incompatible, any seed produced has the potential to be a desired hybrid.  By using flow cytometry to screen germinating seedlings and comparing to parents of the cross, the presence of hybrids in seedlings can be detected.  This paper reports on the range of wide hybrids attempted and the confirmation of success by using DNA content differences as measured by flow cytometry.