Manifestation of physiological and biochemical traits associated with waterlogging stress in sugarcane (Saccharum spp. hybrid)

Waterlogging is a major abiotic constraint on sugarcane ( Saccharum spp. hybrid) productivity in poorly drained, monsoon affected parts of north-western India. In this study, thirteen sugarcane clones were evaluated under waterlogged and control conditions in a randomized complete block design to assess how eight physiological and biochemical parameters, namely chlorophyll content, total soluble sugars, total reducing sugars, total soluble protein, proline content, total phenol content, catalase (CAT) activity, and superoxide dismutase (SOD) activity, responded to sixty days of continuous waterlogging. Genotype, treatment, and their interaction significantly affected all studied parameters ( P < 0.0001). Waterlogging reduced chlorophyll content, total soluble sugars, and total soluble protein by 22.6, 25.0, and 16.0%, respectively, while increasing total reducing sugars, proline, total phenol content, catalase activity, and SOD activity by 39.6, 64.0, 32.0, 97.0, and 87.0%, respectively. CoPb 18,213 showed comparatively high values for chlorophyll, total soluble sugars, proline, and total phenol content, whereas CoLk 19,017 showed comparatively low values for several pigment and metabolic parameters and CoPb 19,212 recorded comparatively low CAT and SOD activities. Correlation and principal component analyses showed that CAT and SOD activity ( r = 0.906, P < 0.001) were strong positively correlated with each other but only weak and non-significantly correlated with the other measured traits, indicating that these associations reflect patterns within the present dataset rather than confirmed physiological independence, coordinated regulation, or waterlogging tolerance mechanisms. When compared using each genotype’s percentage change from its own control, CoPb 18,213’s CoPb 18,213’s- Do not put commas in all the varieties/clones names. Write them as CoPb 18213 (without using comma) strongest relative responses were enzymatic antioxidant induction (CAT, SOD) and reducing-sugar accumulation rather than proline or chlorophyll retention. CoLk 19,017’s comparatively low pooled means, in turn, were concentrated mainly in chlorophyll retention rather than a uniformly weak response across traits. These findings indicate that sugarcane clones rely on distinct combinations of pigment, metabolic and antioxidant-enzyme responses to cope with waterlogging, a distinction relevant to future screening and breeding for waterlogging resilience.