Induced Nodule Senescence and Nitrogen Metabolism at Various Growth Stages in Chickpea (Cicer Arietinnum L.)

The present investigations were conducted on chickpea (Cicer arietinum L.) cv. H-82-91, with a view to study the nitrogen metabolism in nodules during their natural and induced senescence. In natural senescing nodules, maximum N₂ ase activity was observed at 80–95 DAS, linked with total soluble carbohydrates (TSC) and leghemoglobin (Lb) contents. NRA and NO₂ were found to be maximum at 100 DAS, whereas NO₃ and N remained up to 90 DAS. GS activity and nodule respiration were maximum at 60–65 DAS. During induced nodule senescence, N₂ ase activity, Lb, TSC and nodule respiration were significantly decreased up to 10 days after treatment (DAT) at all sampling stages. Maximum decrease was observed with 20 mM KNO₃ This decrease in N₂ ase activity was linked with the decrease in Lb, ISC and respiration of nodules.