Efects of progressive drying and rewatering on ohysiological and biochemical indicators in maize seedlings

The pot experiments show that the relative water content of root，stern and leaf is reduced 10．41％ ．12．03％ and 10．82％ during the process of soil moisture declining from 70％ tO 30％ and it is increased after rewatering enough．The more the water deficit is．the more the relative water content is increased after rewatering．The order of relative water contents is always root> stem> lear at different extents of water deficit．The soluble sugar in stem and lear is increased at first．then declined．Its maximum value is arrived at 50％ water leve1．But its content shows trend of increase in root．The soluble protein．osmotic potential and water potential decline under the drying and increase after rewatering．They arerestored to the natural level at 50％ and 60％ after rewatering of 12 hours．The osmotic adjustment ability of root．stern and leaf is significantly affected because of severe water deficit at 30％ and 40％ leve1．and the osmotic adjustment ability of root is the minimum．