Different Amino Acids Inhibit or Promote Rhizome Proliferation and Differentiation in Cymbidium goeringii

Abstract

The proliferation and differentiation of rhizomes are crucial for the propagation of Cymbidium species. We systematically assessed the effects of different concentrations of 20 amino acids on the proliferation and differentiation of C. goeringii rhizomes. Rhizome proliferation rates were significantly higher in media with 2.0 mmol·L−1 cysteine, 0.5 mmol·L−1 arginine, 0.2 mmol·L−1 asparagine, 1.0 mmol·L−1 proline, and 0.5 mmol·L−1 lysine compared with those in the control. Additionally, 1.0 mmol·L−1 tyrosine, 0.5 mmol·L−1 asparagine, and 0.2 mmol·L−1 aspartate were beneficial for rhizome differentiation. Furthermore, two combinations of amino acids, 0.5 mmol·L−1 arginine + 1.0 mmol·L−1 proline and 0.5 mmol·L−1 arginine + 2.0 mmol·L−1 cysteine, resulted in proliferation rates of 3.05 and 3.01, respectively, after 60 days. The highest differentiation rate (5.39 after 60 days) was observed in media with 0.5 mmol·L−1 asparagine + 0.2 mmol·L−1 aspartate. This study demonstrated that certain combinations of amino acids can effectively promote the proliferation and differentiation of rhizomes during the rapid propagation of C. goeringii.