THE EFFECTS OF GENOTYPE, PLOIDY LEVEL AND COLD PRETREATMENT IN BARLEYANTHER CULTURE RESPONSIVENESS

Five barley (Hordeum vulgare L.) genotypes were tested for their anthe r culture responses under two conditions with or without cold pretreat ment. Among these genotypes, four (Thibaut, Morex, Steptoe and Villa 2 X) were diploid. The last one (Villa 4X), was an autotetraploid genoty pe obtained by colchicine treatment of Villa 2X. The experimental desi gn was a randomized complete block with 4 replicates. Each replicate c onsisted of one pot with three plants per genotype and per cold pretre atment. Anther donor plants were grown in a controlled greenhouse. The study of about 1400 anthers per genotype and per cold pretreatment sh owed that the effect of genotype on androgenic ability was highly sign ificant. Thibaut was by far the most androgenic genotype while, at the other extreme, Villa 4X did not even produce a single green plantlet. The anther culture responses dropped significantly in Villa 4X compar ed with Villa 2X, probably because autotetraploids typically exhibit a great loss of pollen fertility. Finally, the cold pretreatment of exc ised spikes at 4 degrees C for 14 days significantly enhanced the perc entage of responding anthers and the number of embryoids produced as w ell as the frequency of green plantlet regeneration.