GENOTYPE EFFECTS ON PLANT-REGENERATION IN CALLUS AND SUSPENSION-CULTURES OF AVENA

Regenerative potential of the calli of nineteen genotypes of Avena sat iva, Avena nuda, Avena byzantina and one interspecific hybrid were com pared over three successive cultures. Highly significant genotype and genotype x subculture interactions were observed. Among the highest pl ant regenerable genotypes were 'Corbit' (first subculture); 'GAF/Park' and '88Ab3073' (second subculture); and 'GAF/Park' and '87Ab5932' (th ird subculture). These genotypes regenerated on an average 10 to 17 pl ants each from a 200 mg callus mass after a 30 to 45 proliferation per iod. 'GAF/Park', a progeny of an interspecific cross, regenerated plan ts at a significantly higher level (11.85 plants/rep), followed by the similarly performing A. sativa (6.23 plants) and A. nuda (5.06 plants ) genotypes, which were significantly higher than the A. byzantina gen otypes (2.07 plants). Four genotypes were tested for their adaptabilit y to suspension culture and plant regeneration potential by separating their cells and cell clusters into two sizes: larger and smaller than 3 mm. Larger clusters yielded plants for three genotypes 'GAF/Park', '88Ab3073', and 'Tibor'. The smaller clusters only regenerated plants for 'GAF/Park' and '88Ab3073'. From one gram of callus used to initiat e suspensions of 'GAF/Park' and '88Ab3073', 119.9 and 18.8 plants, res pectively, were regenerated. The plants regenerated for various genoty pes from agar-solidified or suspension culture experiments had normal growth and seed set. This study confirms high and sustained regenerati ve capabilities of 'GAF/Park', a restricted genotype due to the weedy Avena fatua genetic background and identifies alternative genotypes, e specially 88Ab3073 for future tissue culture and transformation studie s.