Effect of physical, physiological and genetic factors on callus induction, differentiation and regeneration of winter triticale (× TriticosecaleWittm.)

Callus was initiated from immature embryos of winter hexaploid triticale cultivars Bogo, Moniko, Moreno, Newcale, Salvo and Vero. Salvo was used in its original version (cytoplasm Triticum aestivum)and as alloplasmic (fertile) inbred line (B11) with Triticum timopheevicytoplasm (SalvoTt). The MS induction medium was supplemented with 4 mg/cm3of dicamba. Regeneration was performed on hormone free MS medium. In this study, the influence of genotype, embryo size and cold treatment during the induction phase on the culture efficiency were determined. Calli fresh weight, their differentiation pattern and plant regeneration rate were evaluated. On average from 3 to 14 plants per plated embryo were obtained. Genotype, embryo size and their interaction significantly influenced the culture parameters while the treatment of 5 °C (10 days) applied after 4 weeks of induction made no effect. Salvo and SalvoTt responded at the highest rate to the culture conditions, however T. timopheevi cytoplasm influenced negatively the regeneration rate. Embiyo at late globular or early scutellar stage produced calli with the highest regeneration potential.