The controlled introgression of Festuca arundinacea genes into Lolium multiflorum

Summary Using phosphoglucoisomerase (PGI/2) as a genetic marker, it has been shown to be possible to transfer genes from Festuca arundinacea into diploid Lolium multiflorum using the pentaploid hybrid L. multiflorum (4x) x F. arundinacea (6x). The pentaploid hybrid was sufficiently fertile to be used in reciprocal crosses with diploid. L. multiflorum. When used as the male parent, only two backcross generations were then required to reconstitute the diploid genotype. Intergeneric recombinants including a F. arundinacea PGI/2 allele were found among the diploid BC₂. Cytological data indicates that although the majority of chromosome associations involve only homologous Lolium chromosomes, associations involving Lolium and Festuca chromosomes also occur.Interpollinating the pentaploid hybrids prior to commencing a backcrossing programme increases the number of cycles of recombination and improves the chance of recovering intergeneric recombinants. The crossing programme described is proposed to be an effective method of introducing F. arundinacea genes into L. multiflorum.