Growth and development of Griffithsia heteroclada under varying light intensity and cell type conditions

To investigate the effects of internal and external factors on the growth and development of Griffithsia heteroclada, the optimal culture medium and conditions were first established. Subsequently, individual apical cell (Ca), rhizoid cell (Cr), shoot cell (Cs), and nodal cell (Cn) were cultured under varying light intensities. The findings indicated that the most suitable culture media for G. heteroclada are Provasoli-enriched seawater and Tropic Marin, with optimal culture conditions comprising an irradiance of 60 μmol photons · m^-2 · s^-1, a salinity of 25, a temperature of 25°C, and a pH of 8. Any single cell could regenerate into a new plant, but regeneration varied by cell type, with the promoting effect being most pronounced in the order of Cn = Cs > Cr ≥ Ca. High light intensity inhibited energy transfer from accessory pigments to reaction centers in Ca and Cr, thereby diminishing their light capture capacity and photosynthetic efficiency. Fresh weight is deemed an appropriate biomass indicator for G. heteroclada, and the cell enlargement rate is considered a suitable growth indicator. Developmental indicators include cell number, division rate, branch number, and branch initiation time, while cell length, branching rate, elongation rate, and area are not suitable.