| Abstract:Objective: The study aims in determining appropriate cultivation and production measures via the effects of different light intensities on the growth, photosynthetic characteristics and bioactive content of Epimedium pubescens (“Cultivar Guitong Roumao No. 1”). Methods: Four light intensities were set, including L1（36.4±5 μmoL·m–2·s–1）、L2（91.0±5 μmoL·m–2·s–1）、L3（145.6±5 μmoL·m–2·s–1）and L4（200.2±5 μmoL·m–2·s–1）. Growth parameters (number of branches and leaves) were determined at 10, 20, 30, 40 days, respectively. In the 40th day, photosynthetic parameters (net photosynthetic rate（Pn）, transpiration rate（Tr）, stomatal conductance（Gs）, intercellular CO2 concentration（Ci） ) and the icariin flavonoid content (Epimedin A, Epimedin B, Epimedin C and Icariin) were determined as to the mature leaves after germinated. Results: With the increase of light intensity from L1 to L4, the total number of branches and leaves increased significantly, the rapid increase period occurred in 20~40 days, wherein the treatment of L1~L3 had the highest increase in 30 d, which increased by 48.52%, 70.00% and 83.53%, respectively. Notably, L4 treatment can reach the highest increase of 165.00% in 20d, which was twice that of L3 treatment. In terms of photosynthetic characteristics, chlorophyll content showed a slight downward trend from L1 to L4, while Pn、Tr and Gs showed an overall upward trend, and Ci showed a decreasing trend. The icariin flavonoid content increased gradually and then remained unchanged from L1 to L4. The total content can reach the highest level in L3 treatment （61.49±1.00） mg·g–1. Conclusion: Under high-light treatment, the number of branches and leaves, Pn and the flavonol glycosides revealed an increased trend, which were consistent with those of other Epimedium species. However, the adaptability and tolerance to higher light intensity for cultivar E. pubescens were significantly higher, which was significantly different from other Epimedium species. |
