Sorghum hybrids Jiza 305 and Jiza 127 were used as experimental materials to study the effects of drought and rewatering at seedling and filling stages on photosynthetic characteristics and dry matter production of sorghum.The results showed that the photosynthesis of two sorghum cultivars was inhibited under drought stress at the seedling and filling stages. The net photosynthetic rate(Pn), stomatal conductance(Gs), intercellular CO2 concentration(Ci), transpiration rate(Tr), maximum photochemistry(Fv/Fm),...