EFFECT OF WATER-STRESS ON FUNCTIONING AND STRUCTURE OF CICER-ARIETINUM L MODULES

Chickpea (Cicer arietinum L. cv. 235) plants were grown in sand cultur e at moisture equal to 45 - 50% of sand saturation capacity under gree nhouse conditions. 60 d after sowing, pots were divided into four lots , leaving one as control and sand moisture content of others was broug ht to 25 - 30% (S-1), 12 - 15% (S-2) and 5 - 6% (S-3) of sand saturati on capacity, by withholding the water supply and then maintaining the required levels gravimetrically till the harvest. Relative water conte nt of leaves and nodule water content were measured as indices of wate r stress. With increase in the severity and duration of water stress n itrogenase activity and nitrogen and leghemoglobin content of the nodu les decreased and the ratio of leghemoglobin components I and II were changed. Nodules developed under limited water availability showed dec reased branching, breakdown of the endodermis, greater compactness and decreased vacuolation of cells in the central symbiotic tissue as com pared to the control.