Soil water leaf gas exchange and biomass production of Buffelgrass (Cenchrus ciliaris L.) with two ploidy levels under arid zone

Cenchrus ciliaris corresponds to a perennial grass that is widespread in arid environments. This study aimed to assess growth and leaf exchange under water deficit stress of tetraploid (P1) and hexaploid (P2) individuals of C. ciliaris. The experiment was conducted under four treatments (Tc, T1, T2, and T3). Growth phenology, photosynthesis (A), stomatal conductance (Gs), CO₂ concentration, and transpiration (Tr) were observed during the stress cycle. The obtained results revealed that the highest growth potentialities were recorded for P2 population in both treatments. Both populations responded differently to water deficit stress displaying various values for tiller and the number of spikes. A significant effect of soil moisture treatments on C. ciliaris plant biomass was recorded (P < 0.05). Moreover, there were different responses to drought stress between both contrasting populations. The results also demonstrated that polyploidy level affected only the phenological parameters. Photosynthetic parameters, such as (A) and (Gs) significantly decreased under severe stress between populations and treatments. It could be inferred that C. ciliaris accessions respond to drought through showing significant changes in their physiological and phenological behavior.