Partitioning and Utilization of Carbon and Nitrogen in Nodulated Roots and Nodules of Chickpea (Cicer arietinum) Grown at Two Moisture Levels

The partitioning and utilization of carbon (C) and nitrogen(N) in nodulated roots and nodules of chickpea (Cicer arietinumL.) was studied at two moisture levels at 10-d intervals 40–140d after sowing (DAS). More C was used in respiration and lessin growth of nodulated roots and nodules under water stresscompared to controls during all growth stages except at theearly vegetative stage. Similarly, less nitrogen was investedin dry matter of both nodules and nodulated roots under stress,except during the vegetative stage where more nitrogen was used.Calculated over the entire growth period, as much as 14 and20% of the total nitrogen and 3 and 4% of the total carbon fixedby the plant was lost to the rooting medium under controlledand stressed conditions, respectively. The efficiency of nitrogen fixation with respect to net C utilizationwas maximal during seed filling under both control and stressconditions However, the efficiency of nitrogen fixation wasalways greater under drier conditions. Carbon, chickpea (Cicer arietinum L.), nitrogen, nitrogen fixation, partitioning