Table 1_Waterlogging tolerance in pigeonpea: current understanding of physiological responses, genetic resources, and genomic prospects.xlsx

Waterlogging in pigeonpea has historically been associated with substantial production losses in affected areas; however, the magnitude of these losses depends on stress duration, developmental stage, genotype, environmental conditions, and post-stress recovery.

Oxygen deprivation disrupts root respiration, energy metabolism, and symbiotic nitrogen fixation, yet the mechanistic basis of tolerance remains poorly resolved. This review distinguishes experimentally supported physiological and anatomical responses from transcriptome-derived molecular hypotheses through a five-tier evidence-classification framework (Categories I–V). Experimental studies provide Category I evidence for traits associated with waterlogging tolerance, including cortical aerenchyma formation, hypertrophied lenticels, adventitious rooting, enhanced fermentative metabolism, and antioxidant enzyme activity in tolerant genotypes.