The effect of decrease in salinity on the dynamics of abundance and the cell size of Corethron Hystrix (Bacillariophyta) in laboratory culture
Effect of salinity on abundance dynamics and cell size of microalga Corethron hystrix Hensen (Bacillariophyta) were studied. C. hystrix can normally grow within a rather narrow salinity range between 32 and 28‰. The viable cells of this microalga change their morphological characters at a salinity of 24‰. This salinity level probably marks the beginning of cell division restriction, because the general number of cells by the end of the experiment was lower than in the control. The decrease of salinity to 16‰ caused pronounced irreversible morphological changes: cell height increased, chloroplasts compressed, protoplasm became granular, cytoplasm retracted, and spines shortened.
Objective To control the quality of Herba Leonuri by studying the content of stachydrine hydrochloride in different parts of it. Method A HPLC method was developed for the content detetmination of stachydrine hydrochloride in flower, stem, leafage from Herba Leonuri. Spherisorb SCX colum was used with mobile phase of 20 mmol/L sodium dihydrogen phosphate (containing 0.04% triethylamine and 0.15% phosphoric acid). The colum temperature was 25 ℃, the detective wavelength was 192 nm. Results Stachydrine hydrochloride content was the highest in leafage and the lowest in stem. Conclusion To ensure the quality of Herba Leonuri, it is significant to choose medical material with more leafage.