Construction of an Efficient Tissue Culture System for Sorghumusing Mature Embryos

Mature embryos as explants are more convenient to operate and not subjected to time constraints in tissue culture systems. In this research, 120 sorghum varieties were screened to select an appropriate material for establishing a high efficient tissue culture system using mature embryos as explants. Loose, soft, and yellowish primary calluses were induced from the mature embryos of only one variety (No. 32) out of the 120. Therefore, No. 32 was selected to establish a culture system. The highest callus induction frequency was 58.58% when mature embryos werecultured on induction medium supplemented with 2.375 mg/L CuSO4·5H2O and 5 mg/L 2,4-D. Higher frequency of embryogenic calluses induction was achieved on subculture medium with 2 mg/L 2,4-D. The best combination of 6-benzylaminopurine (BAP) and indole-3acetic acid (IAA) in regeneration medium was 1 mg/L of each. The results showed that the optimal subculture time for callus regeneration was no more than one week. Our research provides a solid basis for genetic transformation of sorghum using mature embryos as explants.