Removing the endosperm of ginseng and American ginseng seeds results in embryos developing into normal seedlings

Both ginseng and American ginseng are world-famous traditional medicines with multiple bioactivities. The deep dormancy of their seeds causes serious problems in artificial cultivation. However, little is known about the physiological mechanism of seed dormancy and how to shorten the seed dormancy period for these two plant species. An experiment was conducted to determine whether endosperm removal would promote embryo development in ginseng and American ginseng and if in vitro embryos would suffer nutrient deficiency during seedling establishment. The results show that excised embryos developed radicles longer than 2 mm, using any culture method, whereas no germination was observed for intact seeds. Excised embryos, without the endosperm nutrient-supply have the ability of developing into a normal seedling, but in vitro embryos grown on MS medium have greater fresh weight, seedling height and radicle length than those grown on filter paper and pure agar medium. In summary, removing endosperm can overcome physiological dormancy of ginseng and American ginseng seeds, and nutrient level determines the development and growth rate of the embryo.