Effect of waterlogging on physiological traits and yield in black gram (Vigna mungo L.) in field condition

Waterlogging is an important abiotic factor affecting crop productivity worldwide. Black gram (Vigna mungo L.) is very sensitive to waterlogged conditions. A field experiment was conducted in randomized complete block design to evaluate three black gram genotypes for waterlogging tolerance. Stress was imposed by maintaining the water level above the soil surface for 10 days after 30 days of sowing. Different physiological parameters including chlorophyll (Chl), chlorophyll fluorescence, normalized difference vegetation index (NDVI), sugars, along with the yield per plant and thousand grain weight (TW) were recorded in control and stressed plants. Results showed that NDVI, Chl, chlorophyll fluorescence, sugars, seed yield and TW reduced significantly during stress. Stress susceptibility index (SSI) for grain yield varied from 0.32 to 2.38. Linear correlation study showed that SSI was negatively correlated with NDVI (0.43),Chl (0.68) and TW (0.42) and grain yield (0.96). NDVI and sugars were correlated to TW under stress. IC530491 and IC559933 (SSI < 0.5) were waterlogging tolerant under field conditions. The study concluded that identified black gram lines may be utilized as trait donors in breeding program.

Waterlogging tolerance in black gram [Vigna mungo (L.) Hepper] is associated with chlorophyll content and membrane integrity

Black gram (Vigna mungo L.) is waterlogging sensitive legume crop. We studied the effect of waterlogging stress on membrane stability index (MSI), lipid peroxidation, superoxide dismutase (SOD) activity, chlorophyll content and chlorophyll fluorescence in four Vigna genotypes namely (Uttara, T-44, IC530491, IC519330). Stress was imposed for 10 days at vegetative stage (30 days after sowing). Thereafter, excess water was drained to allow recovery in stressed plants. Waterlogging treatment significantly increased lipid peroxidation and SOD activity in all the genotypes, which showed the oxidative injury posed by stress conditions. Chlorophyll content and fluorescence reduced under stress conditions. SOD activity, MSI and chlorophyll content was more in IC530491 and IC519330, T44 as compared to Uttara. Lipid peroxidation was high in Uttara. Though chlorophyll fluorescence reduced in all the genotypes under waterlogging, genotypic differences were non-significant. More efficient antioxidative scavenging to maintain membrane stability and chlorophyll content in black gram was found to be associated with tolerance to waterlogging.