Genotype Variability in Photosynthetic Characteristics in Finger Millet

High variability in leaf gas exchange and related traits were found in 30 genotypes of field grown finger millet. The variability in carbon exchange rate per unit leaf area (P_N) can be partly attributed to the differences in the stomatal conductance (g_s) and area leaf mass (ALM). The P_N was positively correlated with total dry matter (TDM). However, no relationship between P_N and seed yield was found. The leaf area showed a positive and significant correlation with total biomass. None of the other gas-exchange traits had significant relationship either with TDM or with seed yield. The ALM showed a strong positive association with P_N. However, it was not correlated with either total biomass or seed yield. As a result, the use of ALM as surrogate for P_N for identifying high biomass producing genotypes only had a limited value. Hence selection for high P_N would result in higher biomass producing types.