ADDITION OF COLCHICINE TO WHEAT ANTHER CULTURE MEDIA TO INCREASE DOUBLED HAPLOID PLANT-PRODUCTION

Chromosome doubling is critical for obtaining doubled-haploid plants f rom wheat (Triticum aestivum L.) anther culture. The most common doubl ing method applies colchicine to the plant. However, colchicine is phy totoxic and can induce a high frequency of plant death. In this experi ment, anthers from two wheat genotypes ('Pavon 76' and 'Centurk') were placed on nine embryoid initiation media having three sugar sources ( maltose, sucrose, and maltose + glucose) with three colchicine concent rations (0.0, 0.1, and 0.2 g . l-1). Wheat starch was used as a gellin g agent. After three days, the anthers were washed and moved to fresh media without colchicine. Increasing the colchicine concentration decr eased the number of embryoids produced from 77.4 embryoids/100 anthers to 29.9 embryoids/100 anthers, but did not significant affect the fre quency of plant regeneration (0.49 green plants/embryoid to 0.40 green plants/embryoid), and increased the frequency of doubled-haploid plan ts (19.0 doubled-haploid plants/100 green plants to 72.3 doubled-haplo id plants/100 green plants). Considering the total number of doubled-h aploid plants produced, low levels of colchicine added to the initiati on media were very effective.