Abstract: This study irradiated the marine alga Platymonas subcordiformis with a 1 341 nm Nd:YAP laser. After a period of cultivation, the absorption spectrum of the algal suspension was measured using a Lambda 950 UV-Vis-NIR spectrophotometer, and the ultrastructural changes of the algae were observed by transmission electron microscopy (TEM). The aim was to analyze the influence of laser irradiation on the absorbance of algal pigments and intracellular components, such as starch grains and lipid droplets. The experimental results indicated that while laser irradiation did not alter the maximum absorption wavelengths of the pigments, it significantly affected their absorbance. Concurrently, variations were observed in the number of starch grains and the quantity of lipid droplets within the cells. This provides a theoretical and practical basis for the subsequent selection of high-quality algal strains through laser breeding.
Keywords: Platymonas subcordiformis; absorption spectrum; absorbance; starch grains; lipid droplets
（Acta Laser Biology Sinica, 2026, 35(3): 270-274）