Regeneration of doubled haploid plants from in vitro selected microspores to improve aluminium tolerance in wheat

The present study was designed to investigate the possibility of selection for aluminium tolerant doubled haploid lines from wheat anther culture. To carry out the experiment anthers from Mv16 were cultured on a solidified W14 induction media supplemented with 50 and 100 mu mol/L aluminium sulfate, at low pH (pH 4.5). After 5 weeks of induction period the obtained embryoids were regenerated on 190-2 regeneration medium supplemented with Al in the concentrations as mentioned above. The offspring generation was rested in hematoxilin staining test to define the Al tolerance of the obtained DH lines. According to the results obtained Al added to the induction media had no negative effect on the androgenic responses (anther response, induction frequency of embryo like structures and their regeneration ability) of the genotype examined. The application of in vitro Al selection significantly increased the probability of obtaining DH lines with significantly higher tolerance, compared to the original genotype. Seeds of 10 selected DH lines were multiplied under field conditions for physiological studies. Seeds of the R4 generation were germinated in 10, 50 and 100 mu mol/L Al containing media, and the root and shoot growth characteristics were measured after 10 days of germination. The chlorophyll and Al contents were also determined. In the physiological tests the shoot and root elongation of the Al tolerant lines was also inhibited but the degree of inhibition was significantly less pronounced up to 50 mu mol/L Al. Similar concentration dependent responses were obtained by comparing the fresh and dry weight of sensitive and tolerant lines. The toxic effect of Al was also reflected in chlorophyll content of the leaves. The increasing Al concentration decreased the chlorophyll content of the sensitive lines, but not in the Al tolerant ones.