Photosynthetic activity of Triticum dicoccum × Triticum aestivum alloplasmic lines during vegetation in connection with productivity traits under varying moister conditions

Drought is a key stressor under global climate change conditions around the world. Triticum dicoccum Shuebl is a species with high potential drought tolerance. Photosynthesis is the primary physiological process affected by water deficit. Rapid light curves (RLCs), recorded using PAM-fluorometers, appear suitable for drought tolerance determination in breeding material. Chlorophyll fluorescence parameters at different vegetation stages, morphophysiological traits, and their relationship with the productivity were analyzed in nine alloplasmic lines (allolines) of T. dicoccum Shuebl × T. aestivum L. partially exposed to drought conditions. Quantum yield parameters at the beginning of RLC at the early vegetation stages correlated with the productivity of investigated lines. Parameters related to photosynthetic capacity had a stronger correlation with the productivity at the stages of subflag and flag formation. For drought tolerance screening, quantum yield of nonorganized energy passive dissipation is particularly promising. Chlorophyll fluorescence and productivity data confirm the potential of the presented breeding strategy in allolines D-d-05 and D-d-05b.