This study compares the water-stress responses of two Moroccan chickpea varieties (Cicer arietinum L.), Rizki (tolerant) and Bouchra (sensitive), under two nitrogen sources: mineral and symbiotic (via the Rhizobium strain B95). The experiment was conducted under controlled conditions on an inert substrate, applying six levels of drought stress ranging from 100% to 50% of field capacity. The results showed that biological nitrogen fixation (BNF) was markedly inhibited at 60% of field capacity in both varieties, highlighting the sensitivity of rhizobial symbiosis to water deficit. Rizki maintained better growth, greater stability of photosynthetic pigments (chlorophylls and carotenoids), more resilient nodular activity, and higher accumulation of osmoprotectants (proline and soluble sugars). In contrast, Bouchra exhibited a pronounced reduction in biomass and a rapid degradation of pigments and nodulation. A specific accumulation of manganese (Mn²⁺) in the stems, observed only in Rizki under stress, suggests an ionic adaptation mechanism linked to drought tolerance. These findings highlight two promising markers for varietal selection: (i) carotenoid stability as an indicator of photosynthetic protection, and (ii) Mn²⁺ accumulation in stems as an ionic adaptation trait. Keywords: Cicer arietinum, water stress, biological nitrogen fixation, varietal tolerance, manganese, carotenoids.