Studies on Dormancy and Germination of “Two-Year Seeds” Studies on the Treatment of Hard Seeds of Some Plants with Sulphuric Acid Effect of Calcium on the Functions of Antioxidant Systems and Mitochondria in Malus hupehensis var. pingyiensis Roots under Acid Treatment Effects of pretreatment and seed size on seed germination of guarana(Paullinia cupana var.sorbilis)