Abstract

Haploid breeding is an effective method of shortening the breeding period of plants. In this study, to develop a haploid breeding technique, optimum conditions of the culture medium were investigated for anther-derived callus induction in the strawberry cultivar Seolhyang. The effects of the culture medium type, myo-inositol, auxin and cytokinin combination treatment, silver nitrate (AgNO3), and ferric ethylenediaminetetraacetic acid (Fe-EDTA) on anther-derived callus induction were analyzed. Anthers were incubated in Murashige and Skoog (MS) medium, Gamborg B5 medium (B5), and Lichter medium (NLN) for 8 weeks. Each culture medium had 0.4 mg∙L–1 of 6-benzyladenine (BA), 0.1 mg∙L−1 of indole-3 acetic acid (IAA), and 2.0 mg∙L−1 of 2,4-dichlorophenoxyacetic acid (2,4-D) added to it. Results showed that MS medium was most effective in callus induction. When 100 mg∙L−1 of myo-inositol was added to each medium, the callus induction rate increased. Auxin and cytokinin combination treatment was more effective with the addition of 0.4 mg∙L−1 of BA, 0.1 mg∙L−1 of IAA, and 2.0 mg∙L−1 of 2,4-D to MS medium compared to the addition of 0.1 mg∙L−1 of BA, 2.0 mg∙L−1 of IAA, and 0.4 mg∙L−1 of 2,4-D. With AgNO3 treatment, the highest callus induction rate was found at a concentration of 25 mg∙L−1. The callus induction rate increased as the AgNO3 concentration increased; however, a significant decrease was seen at 30 mg∙L−1. In the case of Fe-EDTA, the most effective concentration for callus induction was 25 mg∙L−1. Therefore, supplementing myo-inositol, AgNO3 and Fe-EDTA can help in anther-derived callus induction in Seolhyang strawberries.

Key words: Anther culture, auxin, B5 medium, callus induction, cytokinin, haploid breeding, NLN medium.