Change of diastase activity of Puccinellia tenuiflora cv.Qinghai seeds under sodium carbonate stress Preliminary Study ou Physiology and Biochemistry in Fritillaria thunbergii Miq. in the Alternate Process of New and Old Organs Study on the Diastase and Reducing Sugr in Fritillaria thunbergii Miq. During the Process of Relieving Dormancy with Low Temperature CHANGES OF ORGANIC MATTERS, RESPIRATION AND SEVERAL ENZYME ACTIVITIES OF PUCCINELLIA TENUIFLORA SEEDS UNDER ALKALINE SALT STRESS