Abstract
In the seedling production method using Solution Extracted from Homogenized Thalli (SEHT), we examined the light quantity and light source tissue culture conditions to increase branch formation from U. prolifera subfragments. For light quantity, the average of branch formation rate was 0％ at 0 μmol m-2 s-1, 0.4％ at 10 μmol m-2 s-1, increasing to 14.4％ at 25 μmol m-2 s-1 and reached 60.4％ at 50 μmol m-2 s-1. Subsequently, it increased gently to 70.0％ at 100 μmol m-2 s-1. For light sources, the average of branch formation was 30.4％ under fluorescent light, 21.6％ under white LEDs, 27.6％ under red LEDs, 10.0％ under green LEDs, 26.8％ under blue LEDs. As a result of Steel-Dwass multiple comparisons test, the average of branch formation rate was almost constant of the various the light sources. However, blue LEDs promoted branch growth of U. prolifera subfragments. In the seedling production method using SEHT, we recommend culture conditions for increased branch formation of U. prolifera subfragments as light quantity of over 50 μmol m-2 s-1 and a light source of blue LEDs.
https://ror.org/044vy1d05 
