Anther Culture of Blast-resistant Indica-japonica Hybrid, Yunyin

  Objective   To improve callus induction and seedling formation rates of the anther culture for an expedited and stable breeding program utilizing blast-resistant Indica-japonica hybrid rice Yunyin as a parent, an optimized medium and conditions for the auxiliary breeding technology in creating new materials and varieties were investigated.

  Method   The young spikes of F₁ hybrid of Yunyin and a conventional Indica rice Yuejingsimiao were disinfected and inoculated. From 12 formulations of base media, carbon sources, and 2,4-D concentrations as well as culture conditions, an optimal anther cultivation according to the rates of callus induction, green seedling, seedling yield, and anther cultivation performance was selected.

  Result  The maximum anther cultivation performance using the NB medium was merely 0.52%, whereas, M8 significantly higher at 0.90%–1.92%. The M8 medium with sucrose for carbon source reached 11.32% on the performance at the early stage of callus induction. The use of 1.0 mg·L⁻¹ or 2 mg·L⁻¹ 2,4-D in the medium did not differ significantly on the performance, i.e., 1.89% vs 1.92%. A peaked green seedling rate up to 18.3% was achieved when 0.2 cm-sized calluses were used for the differentiation.

  Conclusion   The optimal culture conditions of Yunyin Indica-japonica hybrid anthers were to use calluses inducing on M8 medium with added 50 g·L⁻¹ sucrose and 1–2 mg·L⁻¹ ​​​​​​​2,4-D, then, when grew to 0.2 cm in size, transferring to a differentiation medium.