Ca^2＋参与乙烯消减NaCl对苜蓿种子萌发的抑制

外源乙烯能消减ＮａＣｌ对苜蓿种子萌发的抑制，乙烯的这种作用对包被（种皮和胚乳）具有依赖性；胚与包被处于分离时，外源乙烯的消减作用消失；加回包被后，外源乙烯的作用恢复．分析表明，包被中存在某种易溶于水的、热稳定的小分子物质为乙烯作用所必需；当包被存在时，ＥＤＴＡ及ＥＧＴＡ都能减少乙烯的作用．分析显示：包被中Ｃａ２＋含量较大，且Ｃａ２＋能代替包被作用；无包被存在时，Ｃａ２＋对外源乙烯的有效性具决定作用，表明包被中的有效物质可能是Ｃａ２＋，乙烯的作用依赖于Ｃａ２＋．

Ca 2 INVOLVED IN ETHYLENE RELIEVING NaCl INHIBITION OF ALFALFA SEED GERMINATION

The germination of alfalfa seed was inhibited in 0.25 mol/L NaCl solution, but exogenous ethylene or ethephon could relieve the inhibition. When the embryo of alfalfa seed was separated from endosperm and testa, the effect of ethylene disappeared, and after the endosperm and testa were put back with the embryo, the effect of ethylene recovered. The effective factor in the endosperm and tasta which was indispensable for the effect of ethylene was proved to be a soluble in water,heat stable and small molecular substance. The addition of EDTA and EGTA could reduce the effect of ethylene in the presence of endosperm and tasta or in total seed. In the absence of endosperm and tasta, the addition of Ca 2 could relieve the inhibition of increase in fresh weight of separated embryo by NaCl as substitutor of endosperm and tasta in the presence of ethephon.The experimental results indicated that the effective factor in the endosperm and testa was supposed to be Ca 2 .