Effects of light intensity on the growth and diurnal variation of photosynthesis in Evod iarutaecarpa seedlings Influence of diethyl sulfate (DES) mutagenesis on growth properties and pigment secondary metabolites of Phellinus igniarius Effect of soil nitrogen levels on the growth, photosynthetic properties and artemisinin content of Artemisia annua seedling Effects of sand burial on growth, survival,photosynthetic and transpiration properties of Agriophyllum squarrosum seedlings