The Effect of Trifluralin on Post-in vitro Morphogenesis of Five Genotypes of Head Cabbage (Brassica oleraceae var. capitata)

Six genotypes of head cabbage ('Flexima', 'Mutsuma', 'Septima', 'Zeus', DC6, 'Ancoma') have been studied to find an effective method of obtaining polyploids using trifluralin. The effect of various trifluralin concentrations (0.5, 1.0, 1.5, and 2.0 mg·L-1) and treatment conditions (24 °C/24 h, 24 °C/48 h, 30 °C/24 h, and 30 °C/48 h) on organogenesis of organogenic callus, hypocotyl, and seeds was tested. Ploidy level was detected using a flow cytometer. As a result, low survival of hypocotyls and calli was obtained. The shoots induced from calli and hypocotyls failed to develop quality plantlets and most calli and hypocotyls remained recalcitrant for further differentiation. Treated seeds seemed to be promising objects basing on a considerable percentage of plant regeneration. With the increased concentration of trifluralin and increasing press of treatment conditions, the seed germination rate was significantly reduced. Shoot induction from germinated seeds varied among genotypes and treatments. The root induction was independent of treatments but also reduced considerably compared to the control. Under tested conditions, none of the polyploids resulted. Further studies are required to be successful in protocol development.