Androgenic ability and chromosome doubling by different colchicine treatments in anther culture of hexaploid wheat genotypes (Triticum aestivum L.)

Five spring hexaploid wheat genotypes were evaluated for their androgenic ability, rate of spontaneous chromosome doubling and efficiency of different colchicine treatments on plantlets, and on embryoids obtained 45 days after anther culture. A concentration of 500 mg/1 of colchicine was used for 1 or 3 days for embryoid treatment. Results show significant genetic effects on androgenesis parameters; ‘Yecora Rojo’ and ‘Pavon’ being the best genotypes. Total, green and albino regeneration rates decreased when embryoids were colchicine treated. In most cases there were no significant differences between 1 or 3 days treatment, except for PI-49 and ‘Chenab’ genotypes which could not regenerate green plants with 3 days treatment. Chromosome doubling rates varied according to genotype. Spontaneous doubling ranged from 0% for PI-49 and ‘Chenab’ genotypes to 56% for ‘Yecora Rojo’. Chromosome doubling rate was at least 50% and raised to 100% in some cases when embryoids were colchicine treated, but because of a low regeneration frequency of these embryoids, treatment efficiency remained low. We propose that embryoid treatment with colchicine be recommended, for genotypes producing a high number of embryos or those which have a low rate of spontaneous chromosome doubling.