Abstract The effect of two in planta factors (growth conditions, genotype) and two in vitro factors (time of embryo rescue, embryo rescue medium) on doubled haploid (DH) plant production in bread wheat via maize technique was investigated in nine F1 hybrids produced after crossing four bread wheat cultivars. During the first year one group of F1 plants was grown in a field and at the proper stage pollinated with maize pollen (sweet corn popu-lation). In parallel, a second group of F1 plants was grown in a growth chamber and pollinated as in the former group. In the second growing season the experiment was repeated but only field-grown plants were used. All the produced haploid embryos were cultured in three different media and the resulting 146 haploid plants were sub-sequently treated with aqueous solution of colchicine. Finally, 86 doubled haploid plants were obtained. We noted that the growing conditions of the parental plants and the intervening time between day of pollination and day of embryo rescue influenced the percentage of haploid embryo production. Culture medium also influenced haploid and doubled haploid plant production. The two media (MS/2, B5) were found equally effective. Most of the haploid embryos originated from the Penios × Acheloos cross, whereas most of the doubled haploid plants were produced from the KVZ × Penios cross. Doubled haploid plants were produced from all crosses.

Abstract The present study was conducted to determine the effect of the D genome on embryoid induction and green plant regeneration in wheat anther culture and how it is influenced by low temperature and mannitol treatment. For this reason, the anther culture response of two Canadian bread wheat cultivars and their extracted tetraploids (AABB) was studied. As controls two cultivars well responding to anther-culture (i.e. cvs. Kavkaz/Cgn and Acheron) and a no-responding cultivar (cv. Vergina) were used. Approximately 3000 anthers of these cultivars were cultured and three pre-treatments were applied: cold pre-treatment for 7 and 18 days at 4°C, and 0.3M mannitol for seven days at 4°C. W14 and 190-2 were used as induction and regeneration media, respectively, and the basic MS medium as the rooting medium. No green plants were produced from the tetraploids, which supports the view that the D-genome chromosomes are necessary for androgenic response in wheat. Furthermore, the Canadian cultivars performed better after 18-day pre-treatment at 4°C. The extracted tetraploids produced fewer embryoids and performed better after seven days of cold pre-treatment. The controls well responding to anther culture performed better than the Canadian cultivars, although their best response was recorded after seven-day cold pre-treatment. Cultivar Vergina produced no green plants. The presence of mannitol influenced negatively both embryoid and green plant production. It was concluded that the D genome plays a crucial role in anther culture response of wheat and that this response is influenced by both the genotype and the duration of cold pre-treatment.