Effects of salt and water stresses on ion selective adsorption and activities of enzymes in leaf of Helianthus tuberosus seedlings Regulation of exogenous brassinosteroid on growth and photosynthesis of Helianthus tuberosus seedlings and cadmium biological enrichment under cadmium stress Effects of seawater irrigation on soil safety and crop yield in coastal semi-arid area Effects of nitrogen fertilization on biomass, caloric value and ash content of Helianthus tuberosus L. Effect of Nitrogen on the Plant Height and Dynamic Biomass Allocation of Helianthus tuberosus Effects of Root Cutting on the Tuber Biomass and Material Distribution of Helianthus tuberosus Effects of Alkaline Stress on Growth,Photosynthesis and Antioxidation of Helianthus tuberosus Seedlings