Effects of plant hormones and genotypes on anther culture response of safflower (Carthamus tinctorius L.)

Safflower (Carthamus tinctorius L.) belongs to the composite family with various uses, from the stem to the seeds. In vitro flowering and embryo rescue are common techniques for improving safflower hybrid fertility by overcoming breeding constraints. However, anther culture expedites the production of superior types. The aim of the study was to evaluate the effect of plant hormones and genotypes on anther culture responses and to develop a suitable protocol. In both safflower genotypes, callus, shoot, and root formation were investigated using ten factorial hormone treatments. To promote callus induction and shoot regeneration, variable doses of Thidiazuron (TDZ) at 1 mg/l indole butyric acid (IBA) and variable benzylaminopurine (BAP) at 0.5 mg/l NAA were added to the MS medium, respectively. 1/2 MS media with varying IBA concentrations at a fixed 0.5 mg/l NAA were used for root regeneration. Results showed that Turkan was superior in all aspects of callus induction, and the highest degree of callus formation (46 %) was observed at 0.5 mg/l TDZ. On the other hand, the local safflower performed better for shoot and root regeneration. The highest shoot regeneration capacity (20 %) was shown at 2.0 mg/l BAP, while shoot rooting was reached (21 %) at 1.0 mg/l IBA of culture media. Despite successful in vitro regeneration, acclimated plantlets did not survive in the glasshouse. In this study, we demonstrated the higher capability for both shoot and root regeneration of calli produced from local safflower anthers. More effort is required to improve shoot and root development for both genotypes.