Dynamic Effects of NaOH and Chitosan on Nutrients of Teak Seeds during Germination

In order to understand the effects of NaOH concentration (%), chitosan concentration (%) and soaking time on the dynamic changes of soluble sugar and starch during seed germination of Tectona grandis factorial levels and their treatment combinations (TCs) of, the L₉(3⁴) orthogonal design was employed to implement the experiment. The above two parameters were measured before sowing （initial） and at 7, 14, 21, 28 days after sowing. The results were as follows: the initial soluble sugar content was 1.39 mg·g^-1, and other four stages of the TCs were 0.20-1.44, 0.11-0.70, 0.10-0.63 and 0.15-0.54 mg·g⁻¹, respectively. The soluble sugar content among the treatment combinations after sowing is extremely significant (P<0.01) and significant (P<0.05, 28 d). The initial seed starch content was 0.41 mg·g⁻¹, and the contents of four treatment combinations after sowing were 0.14-2.16, 0.35-0.90, 0.44-0.68 and 0.32-1.01 mg·g⁻¹, respectively. The starch content was significant (P<0.05) or extremely significant (P<0.01-7 d). The chitosan concentration was the dominant factor affecting the change of soluble sugar content, and the optimal TC facilitating physiological activity of soluble sugar of teak seeds was 0.2% chitosan solution presoaking seeds for 12 hours after 3% NaOH concentration solution soaking seed. NaOH concentration was the dominant factor affecting the changes of starch content, and the optimal TC to promote the increase of starch content was soaking in 5%NaOH concentration and then soaking in 0.2% chitosan for 18h.