Increasing the androgen induction frequency of anther cultures is an important objective of plant biotechnology. Anther cultures provide breeders with double haploid lines showing high hereditary variance more quickly. The aim of our experiments conducted in maize anther culture was to reveal the effect of cold pre-treatment often performed to increase induction frequency, as well as the chemical pre-treatment with n-butanol on the cellular structure of the microspores in order to gain better understanding of the cytologic and structural background of androgenesis.

Both cold pre-treatment and n-butanol treatment increased the proportion of microspores providing androgenic response. However, the most significant microspore induction which was greatly increased in comparison with the control was induced by simultaneously performing both treatments (20.95 embryos per 100 anthers).

In order to perform an analysis of the effect of treatments on the cellular structure, the microtubules were marked with immunofluorescence and actin filaments were marked with rhodamine phalloidin. Changes in cell structure were tracked with histological methods.

Cold pre-treatment increased the amount of actin filaments in microspores, while there was no impact observed on the microtubule network. On the contrary, the use of n-butanol resulted in the reversible depolymerisation of microtubules, while the amount of actin filaments remained the same. The obtained results support the hypothesis that the transition between the generative development of microspores and the androgenic development path is assisted by the reorganisation of the cell structure, possibly by means of helping symmetrical divisions.

Keywords: maize, anther culture, cold pre-treatment, n-butanol, cell structure