The effects of genotype, ploidy level and cold pretreatment in barley anther culture responsiveness

Five barley (Hordeum vulgare L.) genotypes were tested for their anther culture responses under two conditions with or without cold pretreatment. Among these genotypes, four (Thibaut, Morex, Steptoe and Villa 2X) were diploid. The last one (Villa 4X), was an autotetraploid genotype obtained by colchicine treatment of Villa 2X. The experimental design was a randomized complete block with 4 replicates. Each replicate consisted of one pot with three plants per genotype and per cold pretreatment. Anther donor plants were grown in a controlled greenhouse. The study of about 1400 anthers per genotype and per cold pretreatment showed that the effect of genotype on androgenic ability was highly significant. 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 compared with Villa 2X, probably because autotetraploids typically exhibit a great loss of pollen fertility. Finally, the cold pretreatment of excised spikes at 4 degrees C for 14 days significantly enhanced the percentage of responding anthers and the number of embryoids produced as well as the frequency of green plantlet regeneration.