Reproductive disturbances and phosphoglucoisomerase instability in festuca arundinacea (tall fescue) plants regenerated from callus and cell suspension cultures

Shoot tips of four Festuca arundinacea Schreb. genotypes (breeder's lines) were cultured in vitro in order to induce callus formation. In addition, cell suspension cultures were established from some of the calli. Plants were regenerated after at least 1 month under callus culture, and all of them remained hexaploid, except for one mixaploid. The flowering response was greatly altered, with some plants flowering without vernalization in the first year after culture, and one plant which did not flower even in the second year. Chromosome aberrations (reciprocal translocations, paracentric inversions, sticky chromosomes and deletions) were present in all genotypes, even after only 1 month in callus culture. There was probably an isochromosome in one plant regenerated from cell suspension culture. Abnormal microsporogenesis affecting pollen sterility was common and genotype dependent. Two genotypes showed instability at the phosphoglucoisomerase (PGI-2) isozyme locus.