Callus formation and plantlet regeneration from immature Triticum durum Desf. embryos

Experiments upon in vitro culture of immature durum wheat embryos, harvested at different growth stages, were made in two consecutive years. Callus formation and plantlet regeneration were obtained. The ability to form callus and the degree of morphogenetic processes varied with the different hormonal treatments used and with the age of the embryos. In the first year the best response for callus growth was observed with 2,4-D 2 mg l-1 plus adenine 50 mg l-1 or 2,4-D 5 mg l-1 alone in the more mature embryos (15 and 20 days after anthesis). On the contrary, NAA 5 mg l-1 had a greater shoot regeneration effect. In the next year, at all 2,4-D concentrations and for the two different ages of the embryos tested, all embryos formed callus. Regeneration of plantlets was obtained in higher percentage in calli originated from the more developed embryos. The effect of changed media upon plantlet regeneration was studied after callus transplant.