Response of Mature Triticale Embryos to Aluminium-Toxic Callus Induction Media

Abstract

Callus induction of threefold cut mature embryos of one winter triticale (x Triticosecale Wittmack) variety (“Lasko”) and three spring triticale genotypes (PFT 8512, Ocepar 1 and PFT 8710) was determined in a recently developed aluminium (Al)-toxic medium. Callus weight and pH alteration of spent medium were assessed at the end of the callus induction phase of 7 weeks in media containing different levels of AlCl₃ (0.1 – 10mM) and being sterilised either by filter or by autoclaving.

In filter-sterilised media with concentrations higher than 2mM none of the four examined triticale genotypes developed calli and the pH-level of the spent medium remained nearly constant. Lower concentrations of 0.5mM and 1mM Al yielded callus weights significantly higher than the pH 3.6-control without AI, but less than the pH 4.6-control, and pH increased on the same level as in either control. In all concentrations below 2mM Al, somatic embryos could be observed. In contrast, the toxic effect of autoclaved Al-toxic media was expressed by inferior callus quality - even the controls were poor - and did not result in any somatic embryo.

Consequently, filter-sterilised Al-toxic media should be preferred and could serve to select Al-tolerant cell lines, e.g. in suspension cell cultures, or may be useful to investigate Al-tolerance mechanisms at the celluar level.