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 li nes) were cultured in vitro in order to induce callus formation. In ad dition, cell suspension cultures were established from some of the cal li. Plants were regenerated after at least 1 month under callus cultur e, and all of them remained hexaploid, except for one mixaploid. The f lowering response was greatly altered, with some plants flowering with out vernalization in the first year after culture, and one plant which did not flower even in the second year. Chromosome aberrations (recip rocal translocations, paracentric inversions, sticky chromosomes and d eletions) were present in ah genotypes, even after only 1 month in cal lus culture. There was probably an isochromosome in one plant regenera ted from cell suspension culture. Abnormal microsporogenesis affecting pollen sterility was common and genotype dependent. Two genotypes sho wed instability at the phosphoglucoisomerase (PGI-2) isozyme locus.