In vitro tissue culture protocol of ancient einkorn (Triticum monococcum ssp. monococum) wheat via indirect shoot regeneration

Einkorn indirect shoot regeneration was obtained from leaf, coleoptile, and root explants cultured on full, ½, and ¼ strength Murashige and Skoog (MS) medium containing 0.5 to 10 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D). Calluses derived from coleoptile and root explants were cultured on full-strength MS medium supplemented with 0.5 to 5 mg L−1 thidiazuron (TDZ) for 6 wk to induce plant regeneration. Only callus cultures derived from coleoptile explants regenerated shoots. For root induction, 1.0 to 10 mg L−1 indole-3-acetic acid (IAA) was used for 4 wk. The highest rate of callus formation (93%) was from root explants cultured on full-strength MS medium with 4 mg L−1  2,4-D. Coleoptile explants had the highest callus formation (100%) after culture on full-strength MS medium with 3 to 6 mg L−1 of 2,4-D. The highest indirect shoot regeneration (7.0 ± 1.1 shoots produced per callus with a 67% shoot formation frequency) was from calluses derived from coleoptile explant cultured on full MS medium supplemented with 5 mg L−1 of TDZ. Of the different IAA concentrations investigated for rooting, the greatest number of roots per explant (7.7 ± 0.088 roots produced per regenerated shoot with a 100% root formation frequency) was observed on MS medium supplemented with 6 mg L−1 IAA. This indirect shoot regeneration protocol for coleoptile-derived einkorn wheat callus will be useful for future wheat genetic and improvement studies.