Effect of waterlogging on photosynthetic and biochemical parameters in pigeonpea

We studied the effect of waterlogging stress on photosynthetic and biochemical parameters in pigeonpea [Cajanus cajan (L.) Mill sp.] genotypes viz. ICPL-84023 (waterlogging resistant) and MAL-18 (waterlogging susceptible). Plants at early growth stage (20 days) were subjected to stress by keeping the pots in water filled containers. Stress was imposed for six days. Waterlogging reduced carbon exchange rate, stomatal conductance, intercellular CO2 concentration and transpiration rate. Photosynthesis was limited by stomatal as well as nonstomatal components under waterlogging. Reduction in chlorophyll, starch and increase in alcohol dehydrogenase activity along with the membrane injury were observed under waterlogging. High carboxylation efficiency, more chlorophyll content, starch availability, alcohol dehydrogenase activity, and membrane stability were associated with better survival of ICPL-84023 under waterlogging.